{-# LANGUAGE CPP, GADTs, NondecreasingIndentation #-} {-# LANGUAGE TupleSections #-} {-# LANGUAGE BangPatterns #-} #if __GLASGOW_HASKELL__ <= 808 -- GHC 8.10 deprecates this flag, but GHC 8.8 needs it -- The default iteration limit is a bit too low for the definitions -- in this module. {-# OPTIONS_GHC -fmax-pmcheck-iterations=10000000 #-} #endif ----------------------------------------------------------------------------- -- -- Generating machine code (instruction selection) -- -- (c) The University of Glasgow 1996-2004 -- ----------------------------------------------------------------------------- -- This is a big module, but, if you pay attention to -- (a) the sectioning, and (b) the type signatures, the -- structure should not be too overwhelming. module X86.CodeGen ( cmmTopCodeGen, generateJumpTableForInstr, extractUnwindPoints, invertCondBranches, InstrBlock ) where #include "HsVersions.h" -- NCG stuff: import GhcPrelude import X86.Instr import X86.Cond import X86.Regs import X86.Ppr ( ) import X86.RegInfo import GHC.Platform.Regs import CPrim import Debug ( DebugBlock(..), UnwindPoint(..), UnwindTable , UnwindExpr(UwReg), toUnwindExpr ) import Instruction import PIC import NCGMonad ( NatM, getNewRegNat, getNewLabelNat, setDeltaNat , getDeltaNat, getBlockIdNat, getPicBaseNat, getNewRegPairNat , getPicBaseMaybeNat, getDebugBlock, getFileId , addImmediateSuccessorNat, updateCfgNat) import CFG import Format import Reg import GHC.Platform -- Our intermediate code: import BasicTypes import BlockId import Module ( primUnitId ) import CmmUtils import CmmSwitch import Cmm import Hoopl.Block import Hoopl.Collections import Hoopl.Graph import Hoopl.Label import CLabel import CoreSyn ( Tickish(..) ) import SrcLoc ( srcSpanFile, srcSpanStartLine, srcSpanStartCol ) -- The rest: import ForeignCall ( CCallConv(..) ) import OrdList import Outputable import FastString import DynFlags import Util import UniqSupply ( getUniqueM ) import Control.Monad import Data.Bits import Data.Foldable (fold) import Data.Int import Data.Maybe import Data.Word import qualified Data.Map as M is32BitPlatform :: NatM Bool is32BitPlatform = do dflags <- getDynFlags return $ target32Bit (targetPlatform dflags) sse2Enabled :: NatM Bool sse2Enabled = do dflags <- getDynFlags case platformArch (targetPlatform dflags) of -- We Assume SSE1 and SSE2 operations are available on both -- x86 and x86_64. Historically we didn't default to SSE2 and -- SSE1 on x86, which results in defacto nondeterminism for how -- rounding behaves in the associated x87 floating point instructions -- because variations in the spill/fpu stack placement of arguments for -- operations would change the precision and final result of what -- would otherwise be the same expressions with respect to single or -- double precision IEEE floating point computations. ArchX86_64 -> return True ArchX86 -> return True _ -> panic "trying to generate x86/x86_64 on the wrong platform" sse4_2Enabled :: NatM Bool sse4_2Enabled = do dflags <- getDynFlags return (isSse4_2Enabled dflags) cmmTopCodeGen :: RawCmmDecl -> NatM [NatCmmDecl (Alignment, CmmStatics) Instr] cmmTopCodeGen (CmmProc info lab live graph) = do let blocks = toBlockListEntryFirst graph (nat_blocks,statics) <- mapAndUnzipM basicBlockCodeGen blocks picBaseMb <- getPicBaseMaybeNat dflags <- getDynFlags let proc = CmmProc info lab live (ListGraph $ concat nat_blocks) tops = proc : concat statics os = platformOS $ targetPlatform dflags case picBaseMb of Just picBase -> initializePicBase_x86 ArchX86 os picBase tops Nothing -> return tops cmmTopCodeGen (CmmData sec dat) = do return [CmmData sec (mkAlignment 1, dat)] -- no translation, we just use CmmStatic {- Note [Verifying basic blocks] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ We want to guarantee a few things about the results of instruction selection. Namely that each basic blocks consists of: * A (potentially empty) sequence of straight line instructions followed by * A (potentially empty) sequence of jump like instructions. We can verify this by going through the instructions and making sure that any non-jumpish instruction can't appear after a jumpish instruction. There are gotchas however: * CALLs are strictly speaking control flow but here we care not about them. Hence we treat them as regular instructions. It's safe for them to appear inside a basic block as (ignoring side effects inside the call) they will result in straight line code. * NEWBLOCK marks the start of a new basic block so can be followed by any instructions. -} -- Verifying basic blocks is cheap, but not cheap enough to enable it unconditionally. verifyBasicBlock :: [Instr] -> () verifyBasicBlock instrs | debugIsOn = go False instrs | otherwise = () where go _ [] = () go atEnd (i:instr) = case i of -- Start a new basic block NEWBLOCK {} -> go False instr -- Calls are not viable block terminators CALL {} | atEnd -> faultyBlockWith i | not atEnd -> go atEnd instr -- All instructions ok, check if we reached the end and continue. _ | not atEnd -> go (isJumpishInstr i) instr -- Only jumps allowed at the end of basic blocks. | otherwise -> if isJumpishInstr i then go True instr else faultyBlockWith i faultyBlockWith i = pprPanic "Non control flow instructions after end of basic block." (ppr i <+> text "in:" $$ vcat (map ppr instrs)) basicBlockCodeGen :: CmmBlock -> NatM ( [NatBasicBlock Instr] , [NatCmmDecl (Alignment, CmmStatics) Instr]) basicBlockCodeGen block = do let (_, nodes, tail) = blockSplit block id = entryLabel block stmts = blockToList nodes -- Generate location directive dbg <- getDebugBlock (entryLabel block) loc_instrs <- case dblSourceTick =<< dbg of Just (SourceNote span name) -> do fileId <- getFileId (srcSpanFile span) let line = srcSpanStartLine span; col = srcSpanStartCol span return $ unitOL $ LOCATION fileId line col name _ -> return nilOL (mid_instrs,mid_bid) <- stmtsToInstrs id stmts (!tail_instrs,_) <- stmtToInstrs mid_bid tail let instrs = loc_instrs `appOL` mid_instrs `appOL` tail_instrs return $! verifyBasicBlock (fromOL instrs) instrs' <- fold <$> traverse addSpUnwindings instrs -- code generation may introduce new basic block boundaries, which -- are indicated by the NEWBLOCK instruction. We must split up the -- instruction stream into basic blocks again. Also, we extract -- LDATAs here too. let (top,other_blocks,statics) = foldrOL mkBlocks ([],[],[]) instrs' mkBlocks (NEWBLOCK id) (instrs,blocks,statics) = ([], BasicBlock id instrs : blocks, statics) mkBlocks (LDATA sec dat) (instrs,blocks,statics) = (instrs, blocks, CmmData sec dat:statics) mkBlocks instr (instrs,blocks,statics) = (instr:instrs, blocks, statics) return (BasicBlock id top : other_blocks, statics) -- | Convert 'DELTA' instructions into 'UNWIND' instructions to capture changes -- in the @sp@ register. See Note [What is this unwinding business?] in Debug -- for details. addSpUnwindings :: Instr -> NatM (OrdList Instr) addSpUnwindings instr@(DELTA d) = do dflags <- getDynFlags if debugLevel dflags >= 1 then do lbl <- mkAsmTempLabel <$> getUniqueM let unwind = M.singleton MachSp (Just $ UwReg MachSp $ negate d) return $ toOL [ instr, UNWIND lbl unwind ] else return (unitOL instr) addSpUnwindings instr = return $ unitOL instr {- Note [Keeping track of the current block] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ When generating instructions for Cmm we sometimes require the current block for things like retry loops. We also sometimes change the current block, if a MachOP results in branching control flow. Issues arise if we have two statements in the same block, which both depend on the current block id *and* change the basic block after them. This happens for atomic primops in the X86 backend where we want to update the CFG data structure when introducing new basic blocks. For example in #17334 we got this Cmm code: c3Bf: // global (_s3t1::I64) = call MO_AtomicRMW W64 AMO_And(_s3sQ::P64 + 88, 18); (_s3t4::I64) = call MO_AtomicRMW W64 AMO_Or(_s3sQ::P64 + 88, 0); _s3sT::I64 = _s3sV::I64; goto c3B1; This resulted in two new basic blocks being inserted: c3Bf: movl $18,%vI_n3Bo movq 88(%vI_s3sQ),%rax jmp _n3Bp n3Bp: ... cmpxchgq %vI_n3Bq,88(%vI_s3sQ) jne _n3Bp ... jmp _n3Bs n3Bs: ... cmpxchgq %vI_n3Bt,88(%vI_s3sQ) jne _n3Bs ... jmp _c3B1 ... Based on the Cmm we called stmtToInstrs we translated both atomic operations under the assumption they would be placed into their Cmm basic block `c3Bf`. However for the retry loop we introduce new labels, so this is not the case for the second statement. This resulted in a desync between the explicit control flow graph we construct as a separate data type and the actual control flow graph in the code. Instead we now return the new basic block if a statement causes a change in the current block and use the block for all following statements. For this reason genCCall is also split into two parts. One for calls which *won't* change the basic blocks in which successive instructions will be placed (since they only evaluate CmmExpr, which can only contain MachOps, which cannot introduce basic blocks in their lowerings). A different one for calls which *are* known to change the basic block. -} -- See Note [Keeping track of the current block] for why -- we pass the BlockId. stmtsToInstrs :: BlockId -- ^ Basic block these statement will start to be placed in. -> [CmmNode O O] -- ^ Cmm Statement -> NatM (InstrBlock, BlockId) -- ^ Resulting instruction stmtsToInstrs bid stmts = go bid stmts nilOL where go bid [] instrs = return (instrs,bid) go bid (s:stmts) instrs = do (instrs',bid') <- stmtToInstrs bid s -- If the statement introduced a new block, we use that one let !newBid = fromMaybe bid bid' go newBid stmts (instrs `appOL` instrs') -- | `bid` refers to the current block and is used to update the CFG -- if new blocks are inserted in the control flow. -- See Note [Keeping track of the current block] for more details. stmtToInstrs :: BlockId -- ^ Basic block this statement will start to be placed in. -> CmmNode e x -> NatM (InstrBlock, Maybe BlockId) -- ^ Instructions, and bid of new block if successive -- statements are placed in a different basic block. stmtToInstrs bid stmt = do dflags <- getDynFlags is32Bit <- is32BitPlatform case stmt of CmmUnsafeForeignCall target result_regs args -> genCCall dflags is32Bit target result_regs args bid _ -> (,Nothing) <$> case stmt of CmmComment s -> return (unitOL (COMMENT s)) CmmTick {} -> return nilOL CmmUnwind regs -> do let to_unwind_entry :: (GlobalReg, Maybe CmmExpr) -> UnwindTable to_unwind_entry (reg, expr) = M.singleton reg (fmap toUnwindExpr expr) case foldMap to_unwind_entry regs of tbl | M.null tbl -> return nilOL | otherwise -> do lbl <- mkAsmTempLabel <$> getUniqueM return $ unitOL $ UNWIND lbl tbl CmmAssign reg src | isFloatType ty -> assignReg_FltCode format reg src | is32Bit && isWord64 ty -> assignReg_I64Code reg src | otherwise -> assignReg_IntCode format reg src where ty = cmmRegType dflags reg format = cmmTypeFormat ty CmmStore addr src | isFloatType ty -> assignMem_FltCode format addr src | is32Bit && isWord64 ty -> assignMem_I64Code addr src | otherwise -> assignMem_IntCode format addr src where ty = cmmExprType dflags src format = cmmTypeFormat ty CmmBranch id -> return $ genBranch id --We try to arrange blocks such that the likely branch is the fallthrough --in CmmContFlowOpt. So we can assume the condition is likely false here. CmmCondBranch arg true false _ -> genCondBranch bid true false arg CmmSwitch arg ids -> do dflags <- getDynFlags genSwitch dflags arg ids CmmCall { cml_target = arg , cml_args_regs = gregs } -> do dflags <- getDynFlags genJump arg (jumpRegs dflags gregs) _ -> panic "stmtToInstrs: statement should have been cps'd away" jumpRegs :: DynFlags -> [GlobalReg] -> [Reg] jumpRegs dflags gregs = [ RegReal r | Just r <- map (globalRegMaybe platform) gregs ] where platform = targetPlatform dflags -------------------------------------------------------------------------------- -- | 'InstrBlock's are the insn sequences generated by the insn selectors. -- They are really trees of insns to facilitate fast appending, where a -- left-to-right traversal yields the insns in the correct order. -- type InstrBlock = OrdList Instr -- | Condition codes passed up the tree. -- data CondCode = CondCode Bool Cond InstrBlock -- | a.k.a "Register64" -- Reg is the lower 32-bit temporary which contains the result. -- Use getHiVRegFromLo to find the other VRegUnique. -- -- Rules of this simplified insn selection game are therefore that -- the returned Reg may be modified -- data ChildCode64 = ChildCode64 InstrBlock Reg -- | Register's passed up the tree. If the stix code forces the register -- to live in a pre-decided machine register, it comes out as @Fixed@; -- otherwise, it comes out as @Any@, and the parent can decide which -- register to put it in. -- data Register = Fixed Format Reg InstrBlock | Any Format (Reg -> InstrBlock) swizzleRegisterRep :: Register -> Format -> Register swizzleRegisterRep (Fixed _ reg code) format = Fixed format reg code swizzleRegisterRep (Any _ codefn) format = Any format codefn -- | Grab the Reg for a CmmReg getRegisterReg :: Platform -> CmmReg -> Reg getRegisterReg _ (CmmLocal (LocalReg u pk)) = -- by Assuming SSE2, Int,Word,Float,Double all can be register allocated let fmt = cmmTypeFormat pk in RegVirtual (mkVirtualReg u fmt) getRegisterReg platform (CmmGlobal mid) = case globalRegMaybe platform mid of Just reg -> RegReal $ reg Nothing -> pprPanic "getRegisterReg-memory" (ppr $ CmmGlobal mid) -- By this stage, the only MagicIds remaining should be the -- ones which map to a real machine register on this -- platform. Hence ... -- | Memory addressing modes passed up the tree. data Amode = Amode AddrMode InstrBlock {- Now, given a tree (the argument to a CmmLoad) that references memory, produce a suitable addressing mode. A Rule of the Game (tm) for Amodes: use of the addr bit must immediately follow use of the code part, since the code part puts values in registers which the addr then refers to. So you can't put anything in between, lest it overwrite some of those registers. If you need to do some other computation between the code part and use of the addr bit, first store the effective address from the amode in a temporary, then do the other computation, and then use the temporary: code LEA amode, tmp ... other computation ... ... (tmp) ... -} -- | Check whether an integer will fit in 32 bits. -- A CmmInt is intended to be truncated to the appropriate -- number of bits, so here we truncate it to Int64. This is -- important because e.g. -1 as a CmmInt might be either -- -1 or 18446744073709551615. -- is32BitInteger :: Integer -> Bool is32BitInteger i = i64 <= 0x7fffffff && i64 >= -0x80000000 where i64 = fromIntegral i :: Int64 -- | Convert a BlockId to some CmmStatic data jumpTableEntry :: DynFlags -> Maybe BlockId -> CmmStatic jumpTableEntry dflags Nothing = CmmStaticLit (CmmInt 0 (wordWidth dflags)) jumpTableEntry _ (Just blockid) = CmmStaticLit (CmmLabel blockLabel) where blockLabel = blockLbl blockid -- ----------------------------------------------------------------------------- -- General things for putting together code sequences -- Expand CmmRegOff. ToDo: should we do it this way around, or convert -- CmmExprs into CmmRegOff? mangleIndexTree :: DynFlags -> CmmReg -> Int -> CmmExpr mangleIndexTree dflags reg off = CmmMachOp (MO_Add width) [CmmReg reg, CmmLit (CmmInt (fromIntegral off) width)] where width = typeWidth (cmmRegType dflags reg) -- | The dual to getAnyReg: compute an expression into a register, but -- we don't mind which one it is. getSomeReg :: CmmExpr -> NatM (Reg, InstrBlock) getSomeReg expr = do r <- getRegister expr case r of Any rep code -> do tmp <- getNewRegNat rep return (tmp, code tmp) Fixed _ reg code -> return (reg, code) assignMem_I64Code :: CmmExpr -> CmmExpr -> NatM InstrBlock assignMem_I64Code addrTree valueTree = do Amode addr addr_code <- getAmode addrTree ChildCode64 vcode rlo <- iselExpr64 valueTree let rhi = getHiVRegFromLo rlo -- Little-endian store mov_lo = MOV II32 (OpReg rlo) (OpAddr addr) mov_hi = MOV II32 (OpReg rhi) (OpAddr (fromJust (addrOffset addr 4))) return (vcode `appOL` addr_code `snocOL` mov_lo `snocOL` mov_hi) assignReg_I64Code :: CmmReg -> CmmExpr -> NatM InstrBlock assignReg_I64Code (CmmLocal (LocalReg u_dst _)) valueTree = do ChildCode64 vcode r_src_lo <- iselExpr64 valueTree let r_dst_lo = RegVirtual $ mkVirtualReg u_dst II32 r_dst_hi = getHiVRegFromLo r_dst_lo r_src_hi = getHiVRegFromLo r_src_lo mov_lo = MOV II32 (OpReg r_src_lo) (OpReg r_dst_lo) mov_hi = MOV II32 (OpReg r_src_hi) (OpReg r_dst_hi) return ( vcode `snocOL` mov_lo `snocOL` mov_hi ) assignReg_I64Code _ _ = panic "assignReg_I64Code(i386): invalid lvalue" iselExpr64 :: CmmExpr -> NatM ChildCode64 iselExpr64 (CmmLit (CmmInt i _)) = do (rlo,rhi) <- getNewRegPairNat II32 let r = fromIntegral (fromIntegral i :: Word32) q = fromIntegral (fromIntegral (i `shiftR` 32) :: Word32) code = toOL [ MOV II32 (OpImm (ImmInteger r)) (OpReg rlo), MOV II32 (OpImm (ImmInteger q)) (OpReg rhi) ] return (ChildCode64 code rlo) iselExpr64 (CmmLoad addrTree ty) | isWord64 ty = do Amode addr addr_code <- getAmode addrTree (rlo,rhi) <- getNewRegPairNat II32 let mov_lo = MOV II32 (OpAddr addr) (OpReg rlo) mov_hi = MOV II32 (OpAddr (fromJust (addrOffset addr 4))) (OpReg rhi) return ( ChildCode64 (addr_code `snocOL` mov_lo `snocOL` mov_hi) rlo ) iselExpr64 (CmmReg (CmmLocal (LocalReg vu ty))) | isWord64 ty = return (ChildCode64 nilOL (RegVirtual $ mkVirtualReg vu II32)) -- we handle addition, but rather badly iselExpr64 (CmmMachOp (MO_Add _) [e1, CmmLit (CmmInt i _)]) = do ChildCode64 code1 r1lo <- iselExpr64 e1 (rlo,rhi) <- getNewRegPairNat II32 let r = fromIntegral (fromIntegral i :: Word32) q = fromIntegral (fromIntegral (i `shiftR` 32) :: Word32) r1hi = getHiVRegFromLo r1lo code = code1 `appOL` toOL [ MOV II32 (OpReg r1lo) (OpReg rlo), ADD II32 (OpImm (ImmInteger r)) (OpReg rlo), MOV II32 (OpReg r1hi) (OpReg rhi), ADC II32 (OpImm (ImmInteger q)) (OpReg rhi) ] return (ChildCode64 code rlo) iselExpr64 (CmmMachOp (MO_Add _) [e1,e2]) = do ChildCode64 code1 r1lo <- iselExpr64 e1 ChildCode64 code2 r2lo <- iselExpr64 e2 (rlo,rhi) <- getNewRegPairNat II32 let r1hi = getHiVRegFromLo r1lo r2hi = getHiVRegFromLo r2lo code = code1 `appOL` code2 `appOL` toOL [ MOV II32 (OpReg r1lo) (OpReg rlo), ADD II32 (OpReg r2lo) (OpReg rlo), MOV II32 (OpReg r1hi) (OpReg rhi), ADC II32 (OpReg r2hi) (OpReg rhi) ] return (ChildCode64 code rlo) iselExpr64 (CmmMachOp (MO_Sub _) [e1,e2]) = do ChildCode64 code1 r1lo <- iselExpr64 e1 ChildCode64 code2 r2lo <- iselExpr64 e2 (rlo,rhi) <- getNewRegPairNat II32 let r1hi = getHiVRegFromLo r1lo r2hi = getHiVRegFromLo r2lo code = code1 `appOL` code2 `appOL` toOL [ MOV II32 (OpReg r1lo) (OpReg rlo), SUB II32 (OpReg r2lo) (OpReg rlo), MOV II32 (OpReg r1hi) (OpReg rhi), SBB II32 (OpReg r2hi) (OpReg rhi) ] return (ChildCode64 code rlo) iselExpr64 (CmmMachOp (MO_UU_Conv _ W64) [expr]) = do fn <- getAnyReg expr r_dst_lo <- getNewRegNat II32 let r_dst_hi = getHiVRegFromLo r_dst_lo code = fn r_dst_lo return ( ChildCode64 (code `snocOL` MOV II32 (OpImm (ImmInt 0)) (OpReg r_dst_hi)) r_dst_lo ) iselExpr64 (CmmMachOp (MO_SS_Conv W32 W64) [expr]) = do fn <- getAnyReg expr r_dst_lo <- getNewRegNat II32 let r_dst_hi = getHiVRegFromLo r_dst_lo code = fn r_dst_lo return ( ChildCode64 (code `snocOL` MOV II32 (OpReg r_dst_lo) (OpReg eax) `snocOL` CLTD II32 `snocOL` MOV II32 (OpReg eax) (OpReg r_dst_lo) `snocOL` MOV II32 (OpReg edx) (OpReg r_dst_hi)) r_dst_lo ) iselExpr64 expr = pprPanic "iselExpr64(i386)" (ppr expr) -------------------------------------------------------------------------------- getRegister :: CmmExpr -> NatM Register getRegister e = do dflags <- getDynFlags is32Bit <- is32BitPlatform getRegister' dflags is32Bit e getRegister' :: DynFlags -> Bool -> CmmExpr -> NatM Register getRegister' dflags is32Bit (CmmReg reg) = case reg of CmmGlobal PicBaseReg | is32Bit -> -- on x86_64, we have %rip for PicBaseReg, but it's not -- a full-featured register, it can only be used for -- rip-relative addressing. do reg' <- getPicBaseNat (archWordFormat is32Bit) return (Fixed (archWordFormat is32Bit) reg' nilOL) _ -> do let fmt = cmmTypeFormat (cmmRegType dflags reg) format = fmt -- let platform = targetPlatform dflags return (Fixed format (getRegisterReg platform reg) nilOL) getRegister' dflags is32Bit (CmmRegOff r n) = getRegister' dflags is32Bit $ mangleIndexTree dflags r n getRegister' dflags is32Bit (CmmMachOp (MO_AlignmentCheck align _) [e]) = addAlignmentCheck align <$> getRegister' dflags is32Bit e -- for 32-bit architectures, support some 64 -> 32 bit conversions: -- TO_W_(x), TO_W_(x >> 32) getRegister' _ is32Bit (CmmMachOp (MO_UU_Conv W64 W32) [CmmMachOp (MO_U_Shr W64) [x,CmmLit (CmmInt 32 _)]]) | is32Bit = do ChildCode64 code rlo <- iselExpr64 x return $ Fixed II32 (getHiVRegFromLo rlo) code getRegister' _ is32Bit (CmmMachOp (MO_SS_Conv W64 W32) [CmmMachOp (MO_U_Shr W64) [x,CmmLit (CmmInt 32 _)]]) | is32Bit = do ChildCode64 code rlo <- iselExpr64 x return $ Fixed II32 (getHiVRegFromLo rlo) code getRegister' _ is32Bit (CmmMachOp (MO_UU_Conv W64 W32) [x]) | is32Bit = do ChildCode64 code rlo <- iselExpr64 x return $ Fixed II32 rlo code getRegister' _ is32Bit (CmmMachOp (MO_SS_Conv W64 W32) [x]) | is32Bit = do ChildCode64 code rlo <- iselExpr64 x return $ Fixed II32 rlo code getRegister' _ _ (CmmLit lit@(CmmFloat f w)) = float_const_sse2 where float_const_sse2 | f == 0.0 = do let format = floatFormat w code dst = unitOL (XOR format (OpReg dst) (OpReg dst)) -- I don't know why there are xorpd, xorps, and pxor instructions. -- They all appear to do the same thing --SDM return (Any format code) | otherwise = do Amode addr code <- memConstant (mkAlignment $ widthInBytes w) lit loadFloatAmode w addr code -- catch simple cases of zero- or sign-extended load getRegister' _ _ (CmmMachOp (MO_UU_Conv W8 W32) [CmmLoad addr _]) = do code <- intLoadCode (MOVZxL II8) addr return (Any II32 code) getRegister' _ _ (CmmMachOp (MO_SS_Conv W8 W32) [CmmLoad addr _]) = do code <- intLoadCode (MOVSxL II8) addr return (Any II32 code) getRegister' _ _ (CmmMachOp (MO_UU_Conv W16 W32) [CmmLoad addr _]) = do code <- intLoadCode (MOVZxL II16) addr return (Any II32 code) getRegister' _ _ (CmmMachOp (MO_SS_Conv W16 W32) [CmmLoad addr _]) = do code <- intLoadCode (MOVSxL II16) addr return (Any II32 code) -- catch simple cases of zero- or sign-extended load getRegister' _ is32Bit (CmmMachOp (MO_UU_Conv W8 W64) [CmmLoad addr _]) | not is32Bit = do code <- intLoadCode (MOVZxL II8) addr return (Any II64 code) getRegister' _ is32Bit (CmmMachOp (MO_SS_Conv W8 W64) [CmmLoad addr _]) | not is32Bit = do code <- intLoadCode (MOVSxL II8) addr return (Any II64 code) getRegister' _ is32Bit (CmmMachOp (MO_UU_Conv W16 W64) [CmmLoad addr _]) | not is32Bit = do code <- intLoadCode (MOVZxL II16) addr return (Any II64 code) getRegister' _ is32Bit (CmmMachOp (MO_SS_Conv W16 W64) [CmmLoad addr _]) | not is32Bit = do code <- intLoadCode (MOVSxL II16) addr return (Any II64 code) getRegister' _ is32Bit (CmmMachOp (MO_UU_Conv W32 W64) [CmmLoad addr _]) | not is32Bit = do code <- intLoadCode (MOV II32) addr -- 32-bit loads zero-extend return (Any II64 code) getRegister' _ is32Bit (CmmMachOp (MO_SS_Conv W32 W64) [CmmLoad addr _]) | not is32Bit = do code <- intLoadCode (MOVSxL II32) addr return (Any II64 code) getRegister' _ is32Bit (CmmMachOp (MO_Add W64) [CmmReg (CmmGlobal PicBaseReg), CmmLit displacement]) | not is32Bit = do return $ Any II64 (\dst -> unitOL $ LEA II64 (OpAddr (ripRel (litToImm displacement))) (OpReg dst)) getRegister' dflags is32Bit (CmmMachOp mop [x]) = do -- unary MachOps case mop of MO_F_Neg w -> sse2NegCode w x MO_S_Neg w -> triv_ucode NEGI (intFormat w) MO_Not w -> triv_ucode NOT (intFormat w) -- Nop conversions MO_UU_Conv W32 W8 -> toI8Reg W32 x MO_SS_Conv W32 W8 -> toI8Reg W32 x MO_XX_Conv W32 W8 -> toI8Reg W32 x MO_UU_Conv W16 W8 -> toI8Reg W16 x MO_SS_Conv W16 W8 -> toI8Reg W16 x MO_XX_Conv W16 W8 -> toI8Reg W16 x MO_UU_Conv W32 W16 -> toI16Reg W32 x MO_SS_Conv W32 W16 -> toI16Reg W32 x MO_XX_Conv W32 W16 -> toI16Reg W32 x MO_UU_Conv W64 W32 | not is32Bit -> conversionNop II64 x MO_SS_Conv W64 W32 | not is32Bit -> conversionNop II64 x MO_XX_Conv W64 W32 | not is32Bit -> conversionNop II64 x MO_UU_Conv W64 W16 | not is32Bit -> toI16Reg W64 x MO_SS_Conv W64 W16 | not is32Bit -> toI16Reg W64 x MO_XX_Conv W64 W16 | not is32Bit -> toI16Reg W64 x MO_UU_Conv W64 W8 | not is32Bit -> toI8Reg W64 x MO_SS_Conv W64 W8 | not is32Bit -> toI8Reg W64 x MO_XX_Conv W64 W8 | not is32Bit -> toI8Reg W64 x MO_UU_Conv rep1 rep2 | rep1 == rep2 -> conversionNop (intFormat rep1) x MO_SS_Conv rep1 rep2 | rep1 == rep2 -> conversionNop (intFormat rep1) x MO_XX_Conv rep1 rep2 | rep1 == rep2 -> conversionNop (intFormat rep1) x -- widenings MO_UU_Conv W8 W32 -> integerExtend W8 W32 MOVZxL x MO_UU_Conv W16 W32 -> integerExtend W16 W32 MOVZxL x MO_UU_Conv W8 W16 -> integerExtend W8 W16 MOVZxL x MO_SS_Conv W8 W32 -> integerExtend W8 W32 MOVSxL x MO_SS_Conv W16 W32 -> integerExtend W16 W32 MOVSxL x MO_SS_Conv W8 W16 -> integerExtend W8 W16 MOVSxL x -- We don't care about the upper bits for MO_XX_Conv, so MOV is enough. However, on 32-bit we -- have 8-bit registers only for a few registers (as opposed to x86-64 where every register -- has 8-bit version). So for 32-bit code, we'll just zero-extend. MO_XX_Conv W8 W32 | is32Bit -> integerExtend W8 W32 MOVZxL x | otherwise -> integerExtend W8 W32 MOV x MO_XX_Conv W8 W16 | is32Bit -> integerExtend W8 W16 MOVZxL x | otherwise -> integerExtend W8 W16 MOV x MO_XX_Conv W16 W32 -> integerExtend W16 W32 MOV x MO_UU_Conv W8 W64 | not is32Bit -> integerExtend W8 W64 MOVZxL x MO_UU_Conv W16 W64 | not is32Bit -> integerExtend W16 W64 MOVZxL x MO_UU_Conv W32 W64 | not is32Bit -> integerExtend W32 W64 MOVZxL x MO_SS_Conv W8 W64 | not is32Bit -> integerExtend W8 W64 MOVSxL x MO_SS_Conv W16 W64 | not is32Bit -> integerExtend W16 W64 MOVSxL x MO_SS_Conv W32 W64 | not is32Bit -> integerExtend W32 W64 MOVSxL x -- For 32-to-64 bit zero extension, amd64 uses an ordinary movl. -- However, we don't want the register allocator to throw it -- away as an unnecessary reg-to-reg move, so we keep it in -- the form of a movzl and print it as a movl later. -- This doesn't apply to MO_XX_Conv since in this case we don't care about -- the upper bits. So we can just use MOV. MO_XX_Conv W8 W64 | not is32Bit -> integerExtend W8 W64 MOV x MO_XX_Conv W16 W64 | not is32Bit -> integerExtend W16 W64 MOV x MO_XX_Conv W32 W64 | not is32Bit -> integerExtend W32 W64 MOV x MO_FF_Conv W32 W64 -> coerceFP2FP W64 x MO_FF_Conv W64 W32 -> coerceFP2FP W32 x MO_FS_Conv from to -> coerceFP2Int from to x MO_SF_Conv from to -> coerceInt2FP from to x MO_V_Insert {} -> needLlvm MO_V_Extract {} -> needLlvm MO_V_Add {} -> needLlvm MO_V_Sub {} -> needLlvm MO_V_Mul {} -> needLlvm MO_VS_Quot {} -> needLlvm MO_VS_Rem {} -> needLlvm MO_VS_Neg {} -> needLlvm MO_VU_Quot {} -> needLlvm MO_VU_Rem {} -> needLlvm MO_VF_Insert {} -> needLlvm MO_VF_Extract {} -> needLlvm MO_VF_Add {} -> needLlvm MO_VF_Sub {} -> needLlvm MO_VF_Mul {} -> needLlvm MO_VF_Quot {} -> needLlvm MO_VF_Neg {} -> needLlvm _other -> pprPanic "getRegister" (pprMachOp mop) where triv_ucode :: (Format -> Operand -> Instr) -> Format -> NatM Register triv_ucode instr format = trivialUCode format (instr format) x -- signed or unsigned extension. integerExtend :: Width -> Width -> (Format -> Operand -> Operand -> Instr) -> CmmExpr -> NatM Register integerExtend from to instr expr = do (reg,e_code) <- if from == W8 then getByteReg expr else getSomeReg expr let code dst = e_code `snocOL` instr (intFormat from) (OpReg reg) (OpReg dst) return (Any (intFormat to) code) toI8Reg :: Width -> CmmExpr -> NatM Register toI8Reg new_rep expr = do codefn <- getAnyReg expr return (Any (intFormat new_rep) codefn) -- HACK: use getAnyReg to get a byte-addressable register. -- If the source was a Fixed register, this will add the -- mov instruction to put it into the desired destination. -- We're assuming that the destination won't be a fixed -- non-byte-addressable register; it won't be, because all -- fixed registers are word-sized. toI16Reg = toI8Reg -- for now conversionNop :: Format -> CmmExpr -> NatM Register conversionNop new_format expr = do e_code <- getRegister' dflags is32Bit expr return (swizzleRegisterRep e_code new_format) getRegister' _ is32Bit (CmmMachOp mop [x, y]) = do -- dyadic MachOps case mop of MO_F_Eq _ -> condFltReg is32Bit EQQ x y MO_F_Ne _ -> condFltReg is32Bit NE x y MO_F_Gt _ -> condFltReg is32Bit GTT x y MO_F_Ge _ -> condFltReg is32Bit GE x y -- Invert comparison condition and swap operands -- See Note [SSE Parity Checks] MO_F_Lt _ -> condFltReg is32Bit GTT y x MO_F_Le _ -> condFltReg is32Bit GE y x MO_Eq _ -> condIntReg EQQ x y MO_Ne _ -> condIntReg NE x y MO_S_Gt _ -> condIntReg GTT x y MO_S_Ge _ -> condIntReg GE x y MO_S_Lt _ -> condIntReg LTT x y MO_S_Le _ -> condIntReg LE x y MO_U_Gt _ -> condIntReg GU x y MO_U_Ge _ -> condIntReg GEU x y MO_U_Lt _ -> condIntReg LU x y MO_U_Le _ -> condIntReg LEU x y MO_F_Add w -> trivialFCode_sse2 w ADD x y MO_F_Sub w -> trivialFCode_sse2 w SUB x y MO_F_Quot w -> trivialFCode_sse2 w FDIV x y MO_F_Mul w -> trivialFCode_sse2 w MUL x y MO_Add rep -> add_code rep x y MO_Sub rep -> sub_code rep x y MO_S_Quot rep -> div_code rep True True x y MO_S_Rem rep -> div_code rep True False x y MO_U_Quot rep -> div_code rep False True x y MO_U_Rem rep -> div_code rep False False x y MO_S_MulMayOflo rep -> imulMayOflo rep x y MO_Mul W8 -> imulW8 x y MO_Mul rep -> triv_op rep IMUL MO_And rep -> triv_op rep AND MO_Or rep -> triv_op rep OR MO_Xor rep -> triv_op rep XOR {- Shift ops on x86s have constraints on their source, it either has to be Imm, CL or 1 => trivialCode is not restrictive enough (sigh.) -} MO_Shl rep -> shift_code rep SHL x y {-False-} MO_U_Shr rep -> shift_code rep SHR x y {-False-} MO_S_Shr rep -> shift_code rep SAR x y {-False-} MO_V_Insert {} -> needLlvm MO_V_Extract {} -> needLlvm MO_V_Add {} -> needLlvm MO_V_Sub {} -> needLlvm MO_V_Mul {} -> needLlvm MO_VS_Quot {} -> needLlvm MO_VS_Rem {} -> needLlvm MO_VS_Neg {} -> needLlvm MO_VF_Insert {} -> needLlvm MO_VF_Extract {} -> needLlvm MO_VF_Add {} -> needLlvm MO_VF_Sub {} -> needLlvm MO_VF_Mul {} -> needLlvm MO_VF_Quot {} -> needLlvm MO_VF_Neg {} -> needLlvm _other -> pprPanic "getRegister(x86) - binary CmmMachOp (1)" (pprMachOp mop) where -------------------- triv_op width instr = trivialCode width op (Just op) x y where op = instr (intFormat width) -- Special case for IMUL for bytes, since the result of IMULB will be in -- %ax, the split to %dx/%edx/%rdx and %ax/%eax/%rax happens only for wider -- values. imulW8 :: CmmExpr -> CmmExpr -> NatM Register imulW8 arg_a arg_b = do (a_reg, a_code) <- getNonClobberedReg arg_a b_code <- getAnyReg arg_b let code = a_code `appOL` b_code eax `appOL` toOL [ IMUL2 format (OpReg a_reg) ] format = intFormat W8 return (Fixed format eax code) imulMayOflo :: Width -> CmmExpr -> CmmExpr -> NatM Register imulMayOflo rep a b = do (a_reg, a_code) <- getNonClobberedReg a b_code <- getAnyReg b let shift_amt = case rep of W32 -> 31 W64 -> 63 _ -> panic "shift_amt" format = intFormat rep code = a_code `appOL` b_code eax `appOL` toOL [ IMUL2 format (OpReg a_reg), -- result in %edx:%eax SAR format (OpImm (ImmInt shift_amt)) (OpReg eax), -- sign extend lower part SUB format (OpReg edx) (OpReg eax) -- compare against upper -- eax==0 if high part == sign extended low part ] return (Fixed format eax code) -------------------- shift_code :: Width -> (Format -> Operand -> Operand -> Instr) -> CmmExpr -> CmmExpr -> NatM Register {- Case1: shift length as immediate -} shift_code width instr x (CmmLit lit) = do x_code <- getAnyReg x let format = intFormat width code dst = x_code dst `snocOL` instr format (OpImm (litToImm lit)) (OpReg dst) return (Any format code) {- Case2: shift length is complex (non-immediate) * y must go in %ecx. * we cannot do y first *and* put its result in %ecx, because %ecx might be clobbered by x. * if we do y second, then x cannot be in a clobbered reg. Also, we cannot clobber x's reg with the instruction itself. * so we can either: - do y first, put its result in a fresh tmp, then copy it to %ecx later - do y second and put its result into %ecx. x gets placed in a fresh tmp. This is likely to be better, because the reg alloc can eliminate this reg->reg move here (it won't eliminate the other one, because the move is into the fixed %ecx). * in the case of C calls the use of ecx here can interfere with arguments. We avoid this with the hack described in Note [Evaluate C-call arguments before placing in destination registers] -} shift_code width instr x y{-amount-} = do x_code <- getAnyReg x let format = intFormat width tmp <- getNewRegNat format y_code <- getAnyReg y let code = x_code tmp `appOL` y_code ecx `snocOL` instr format (OpReg ecx) (OpReg tmp) return (Fixed format tmp code) -------------------- add_code :: Width -> CmmExpr -> CmmExpr -> NatM Register add_code rep x (CmmLit (CmmInt y _)) | is32BitInteger y = add_int rep x y add_code rep x y = trivialCode rep (ADD format) (Just (ADD format)) x y where format = intFormat rep -- TODO: There are other interesting patterns we want to replace -- with a LEA, e.g. `(x + offset) + (y << shift)`. -------------------- sub_code :: Width -> CmmExpr -> CmmExpr -> NatM Register sub_code rep x (CmmLit (CmmInt y _)) | is32BitInteger (-y) = add_int rep x (-y) sub_code rep x y = trivialCode rep (SUB (intFormat rep)) Nothing x y -- our three-operand add instruction: add_int width x y = do (x_reg, x_code) <- getSomeReg x let format = intFormat width imm = ImmInt (fromInteger y) code dst = x_code `snocOL` LEA format (OpAddr (AddrBaseIndex (EABaseReg x_reg) EAIndexNone imm)) (OpReg dst) -- return (Any format code) ---------------------- -- See Note [DIV/IDIV for bytes] div_code W8 signed quotient x y = do let widen | signed = MO_SS_Conv W8 W16 | otherwise = MO_UU_Conv W8 W16 div_code W16 signed quotient (CmmMachOp widen [x]) (CmmMachOp widen [y]) div_code width signed quotient x y = do (y_op, y_code) <- getRegOrMem y -- cannot be clobbered x_code <- getAnyReg x let format = intFormat width widen | signed = CLTD format | otherwise = XOR format (OpReg edx) (OpReg edx) instr | signed = IDIV | otherwise = DIV code = y_code `appOL` x_code eax `appOL` toOL [widen, instr format y_op] result | quotient = eax | otherwise = edx return (Fixed format result code) getRegister' _ _ (CmmLoad mem pk) | isFloatType pk = do Amode addr mem_code <- getAmode mem loadFloatAmode (typeWidth pk) addr mem_code getRegister' _ is32Bit (CmmLoad mem pk) | is32Bit && not (isWord64 pk) = do code <- intLoadCode instr mem return (Any format code) where width = typeWidth pk format = intFormat width instr = case width of W8 -> MOVZxL II8 _other -> MOV format -- We always zero-extend 8-bit loads, if we -- can't think of anything better. This is because -- we can't guarantee access to an 8-bit variant of every register -- (esi and edi don't have 8-bit variants), so to make things -- simpler we do our 8-bit arithmetic with full 32-bit registers. -- Simpler memory load code on x86_64 getRegister' _ is32Bit (CmmLoad mem pk) | not is32Bit = do code <- intLoadCode (MOV format) mem return (Any format code) where format = intFormat $ typeWidth pk getRegister' _ is32Bit (CmmLit (CmmInt 0 width)) = let format = intFormat width -- x86_64: 32-bit xor is one byte shorter, and zero-extends to 64 bits format1 = if is32Bit then format else case format of II64 -> II32 _ -> format code dst = unitOL (XOR format1 (OpReg dst) (OpReg dst)) in return (Any format code) -- optimisation for loading small literals on x86_64: take advantage -- of the automatic zero-extension from 32 to 64 bits, because the 32-bit -- instruction forms are shorter. getRegister' dflags is32Bit (CmmLit lit) | not is32Bit, isWord64 (cmmLitType dflags lit), not (isBigLit lit) = let imm = litToImm lit code dst = unitOL (MOV II32 (OpImm imm) (OpReg dst)) in return (Any II64 code) where isBigLit (CmmInt i _) = i < 0 || i > 0xffffffff isBigLit _ = False -- note1: not the same as (not.is32BitLit), because that checks for -- signed literals that fit in 32 bits, but we want unsigned -- literals here. -- note2: all labels are small, because we're assuming the -- small memory model (see gcc docs, -mcmodel=small). getRegister' dflags _ (CmmLit lit) = do let format = cmmTypeFormat (cmmLitType dflags lit) imm = litToImm lit code dst = unitOL (MOV format (OpImm imm) (OpReg dst)) return (Any format code) getRegister' _ _ other | isVecExpr other = needLlvm | otherwise = pprPanic "getRegister(x86)" (ppr other) intLoadCode :: (Operand -> Operand -> Instr) -> CmmExpr -> NatM (Reg -> InstrBlock) intLoadCode instr mem = do Amode src mem_code <- getAmode mem return (\dst -> mem_code `snocOL` instr (OpAddr src) (OpReg dst)) -- Compute an expression into *any* register, adding the appropriate -- move instruction if necessary. getAnyReg :: CmmExpr -> NatM (Reg -> InstrBlock) getAnyReg expr = do r <- getRegister expr anyReg r anyReg :: Register -> NatM (Reg -> InstrBlock) anyReg (Any _ code) = return code anyReg (Fixed rep reg fcode) = return (\dst -> fcode `snocOL` reg2reg rep reg dst) -- A bit like getSomeReg, but we want a reg that can be byte-addressed. -- Fixed registers might not be byte-addressable, so we make sure we've -- got a temporary, inserting an extra reg copy if necessary. getByteReg :: CmmExpr -> NatM (Reg, InstrBlock) getByteReg expr = do is32Bit <- is32BitPlatform if is32Bit then do r <- getRegister expr case r of Any rep code -> do tmp <- getNewRegNat rep return (tmp, code tmp) Fixed rep reg code | isVirtualReg reg -> return (reg,code) | otherwise -> do tmp <- getNewRegNat rep return (tmp, code `snocOL` reg2reg rep reg tmp) -- ToDo: could optimise slightly by checking for -- byte-addressable real registers, but that will -- happen very rarely if at all. else getSomeReg expr -- all regs are byte-addressable on x86_64 -- Another variant: this time we want the result in a register that cannot -- be modified by code to evaluate an arbitrary expression. getNonClobberedReg :: CmmExpr -> NatM (Reg, InstrBlock) getNonClobberedReg expr = do dflags <- getDynFlags r <- getRegister expr case r of Any rep code -> do tmp <- getNewRegNat rep return (tmp, code tmp) Fixed rep reg code -- only certain regs can be clobbered | reg `elem` instrClobberedRegs (targetPlatform dflags) -> do tmp <- getNewRegNat rep return (tmp, code `snocOL` reg2reg rep reg tmp) | otherwise -> return (reg, code) reg2reg :: Format -> Reg -> Reg -> Instr reg2reg format src dst = MOV format (OpReg src) (OpReg dst) -------------------------------------------------------------------------------- getAmode :: CmmExpr -> NatM Amode getAmode e = do is32Bit <- is32BitPlatform getAmode' is32Bit e getAmode' :: Bool -> CmmExpr -> NatM Amode getAmode' _ (CmmRegOff r n) = do dflags <- getDynFlags getAmode $ mangleIndexTree dflags r n getAmode' is32Bit (CmmMachOp (MO_Add W64) [CmmReg (CmmGlobal PicBaseReg), CmmLit displacement]) | not is32Bit = return $ Amode (ripRel (litToImm displacement)) nilOL -- This is all just ridiculous, since it carefully undoes -- what mangleIndexTree has just done. getAmode' is32Bit (CmmMachOp (MO_Sub _rep) [x, CmmLit lit@(CmmInt i _)]) | is32BitLit is32Bit lit -- ASSERT(rep == II32)??? = do (x_reg, x_code) <- getSomeReg x let off = ImmInt (-(fromInteger i)) return (Amode (AddrBaseIndex (EABaseReg x_reg) EAIndexNone off) x_code) getAmode' is32Bit (CmmMachOp (MO_Add _rep) [x, CmmLit lit]) | is32BitLit is32Bit lit -- ASSERT(rep == II32)??? = do (x_reg, x_code) <- getSomeReg x let off = litToImm lit return (Amode (AddrBaseIndex (EABaseReg x_reg) EAIndexNone off) x_code) -- Turn (lit1 << n + lit2) into (lit2 + lit1 << n) so it will be -- recognised by the next rule. getAmode' is32Bit (CmmMachOp (MO_Add rep) [a@(CmmMachOp (MO_Shl _) _), b@(CmmLit _)]) = getAmode' is32Bit (CmmMachOp (MO_Add rep) [b,a]) -- Matches: (x + offset) + (y << shift) getAmode' _ (CmmMachOp (MO_Add _) [CmmRegOff x offset, CmmMachOp (MO_Shl _) [y, CmmLit (CmmInt shift _)]]) | shift == 0 || shift == 1 || shift == 2 || shift == 3 = x86_complex_amode (CmmReg x) y shift (fromIntegral offset) getAmode' _ (CmmMachOp (MO_Add _) [x, CmmMachOp (MO_Shl _) [y, CmmLit (CmmInt shift _)]]) | shift == 0 || shift == 1 || shift == 2 || shift == 3 = x86_complex_amode x y shift 0 getAmode' _ (CmmMachOp (MO_Add _) [x, CmmMachOp (MO_Add _) [CmmMachOp (MO_Shl _) [y, CmmLit (CmmInt shift _)], CmmLit (CmmInt offset _)]]) | shift == 0 || shift == 1 || shift == 2 || shift == 3 && is32BitInteger offset = x86_complex_amode x y shift offset getAmode' _ (CmmMachOp (MO_Add _) [x,y]) = x86_complex_amode x y 0 0 getAmode' is32Bit (CmmLit lit) | is32BitLit is32Bit lit = return (Amode (ImmAddr (litToImm lit) 0) nilOL) getAmode' _ expr = do (reg,code) <- getSomeReg expr return (Amode (AddrBaseIndex (EABaseReg reg) EAIndexNone (ImmInt 0)) code) -- | Like 'getAmode', but on 32-bit use simple register addressing -- (i.e. no index register). This stops us from running out of -- registers on x86 when using instructions such as cmpxchg, which can -- use up to three virtual registers and one fixed register. getSimpleAmode :: DynFlags -> Bool -> CmmExpr -> NatM Amode getSimpleAmode dflags is32Bit addr | is32Bit = do addr_code <- getAnyReg addr addr_r <- getNewRegNat (intFormat (wordWidth dflags)) let amode = AddrBaseIndex (EABaseReg addr_r) EAIndexNone (ImmInt 0) return $! Amode amode (addr_code addr_r) | otherwise = getAmode addr x86_complex_amode :: CmmExpr -> CmmExpr -> Integer -> Integer -> NatM Amode x86_complex_amode base index shift offset = do (x_reg, x_code) <- getNonClobberedReg base -- x must be in a temp, because it has to stay live over y_code -- we could compre x_reg and y_reg and do something better here... (y_reg, y_code) <- getSomeReg index let code = x_code `appOL` y_code base = case shift of 0 -> 1; 1 -> 2; 2 -> 4; 3 -> 8; n -> panic $ "x86_complex_amode: unhandled shift! (" ++ show n ++ ")" return (Amode (AddrBaseIndex (EABaseReg x_reg) (EAIndex y_reg base) (ImmInt (fromIntegral offset))) code) -- ----------------------------------------------------------------------------- -- getOperand: sometimes any operand will do. -- getNonClobberedOperand: the value of the operand will remain valid across -- the computation of an arbitrary expression, unless the expression -- is computed directly into a register which the operand refers to -- (see trivialCode where this function is used for an example). getNonClobberedOperand :: CmmExpr -> NatM (Operand, InstrBlock) getNonClobberedOperand (CmmLit lit) = do if isSuitableFloatingPointLit lit then do let CmmFloat _ w = lit Amode addr code <- memConstant (mkAlignment $ widthInBytes w) lit return (OpAddr addr, code) else do is32Bit <- is32BitPlatform dflags <- getDynFlags if is32BitLit is32Bit lit && not (isFloatType (cmmLitType dflags lit)) then return (OpImm (litToImm lit), nilOL) else getNonClobberedOperand_generic (CmmLit lit) getNonClobberedOperand (CmmLoad mem pk) = do is32Bit <- is32BitPlatform -- this logic could be simplified -- TODO FIXME if (if is32Bit then not (isWord64 pk) else True) -- if 32bit and pk is at float/double/simd value -- or if 64bit -- this could use some eyeballs or i'll need to stare at it more later then do dflags <- getDynFlags let platform = targetPlatform dflags Amode src mem_code <- getAmode mem (src',save_code) <- if (amodeCouldBeClobbered platform src) then do tmp <- getNewRegNat (archWordFormat is32Bit) return (AddrBaseIndex (EABaseReg tmp) EAIndexNone (ImmInt 0), unitOL (LEA (archWordFormat is32Bit) (OpAddr src) (OpReg tmp))) else return (src, nilOL) return (OpAddr src', mem_code `appOL` save_code) else do -- if its a word or gcptr on 32bit? getNonClobberedOperand_generic (CmmLoad mem pk) getNonClobberedOperand e = getNonClobberedOperand_generic e getNonClobberedOperand_generic :: CmmExpr -> NatM (Operand, InstrBlock) getNonClobberedOperand_generic e = do (reg, code) <- getNonClobberedReg e return (OpReg reg, code) amodeCouldBeClobbered :: Platform -> AddrMode -> Bool amodeCouldBeClobbered platform amode = any (regClobbered platform) (addrModeRegs amode) regClobbered :: Platform -> Reg -> Bool regClobbered platform (RegReal (RealRegSingle rr)) = freeReg platform rr regClobbered _ _ = False -- getOperand: the operand is not required to remain valid across the -- computation of an arbitrary expression. getOperand :: CmmExpr -> NatM (Operand, InstrBlock) getOperand (CmmLit lit) = do use_sse2 <- sse2Enabled if (use_sse2 && isSuitableFloatingPointLit lit) then do let CmmFloat _ w = lit Amode addr code <- memConstant (mkAlignment $ widthInBytes w) lit return (OpAddr addr, code) else do is32Bit <- is32BitPlatform dflags <- getDynFlags if is32BitLit is32Bit lit && not (isFloatType (cmmLitType dflags lit)) then return (OpImm (litToImm lit), nilOL) else getOperand_generic (CmmLit lit) getOperand (CmmLoad mem pk) = do is32Bit <- is32BitPlatform use_sse2 <- sse2Enabled if (not (isFloatType pk) || use_sse2) && (if is32Bit then not (isWord64 pk) else True) then do Amode src mem_code <- getAmode mem return (OpAddr src, mem_code) else getOperand_generic (CmmLoad mem pk) getOperand e = getOperand_generic e getOperand_generic :: CmmExpr -> NatM (Operand, InstrBlock) getOperand_generic e = do (reg, code) <- getSomeReg e return (OpReg reg, code) isOperand :: Bool -> CmmExpr -> Bool isOperand _ (CmmLoad _ _) = True isOperand is32Bit (CmmLit lit) = is32BitLit is32Bit lit || isSuitableFloatingPointLit lit isOperand _ _ = False -- | Given a 'Register', produce a new 'Register' with an instruction block -- which will check the value for alignment. Used for @-falignment-sanitisation@. addAlignmentCheck :: Int -> Register -> Register addAlignmentCheck align reg = case reg of Fixed fmt reg code -> Fixed fmt reg (code `appOL` check fmt reg) Any fmt f -> Any fmt (\reg -> f reg `appOL` check fmt reg) where check :: Format -> Reg -> InstrBlock check fmt reg = ASSERT(not $ isFloatFormat fmt) toOL [ TEST fmt (OpImm $ ImmInt $ align-1) (OpReg reg) , JXX_GBL NE $ ImmCLbl mkBadAlignmentLabel ] memConstant :: Alignment -> CmmLit -> NatM Amode memConstant align lit = do lbl <- getNewLabelNat let rosection = Section ReadOnlyData lbl dflags <- getDynFlags (addr, addr_code) <- if target32Bit (targetPlatform dflags) then do dynRef <- cmmMakeDynamicReference dflags DataReference lbl Amode addr addr_code <- getAmode dynRef return (addr, addr_code) else return (ripRel (ImmCLbl lbl), nilOL) let code = LDATA rosection (align, Statics lbl [CmmStaticLit lit]) `consOL` addr_code return (Amode addr code) loadFloatAmode :: Width -> AddrMode -> InstrBlock -> NatM Register loadFloatAmode w addr addr_code = do let format = floatFormat w code dst = addr_code `snocOL` MOV format (OpAddr addr) (OpReg dst) return (Any format code) -- if we want a floating-point literal as an operand, we can -- use it directly from memory. However, if the literal is -- zero, we're better off generating it into a register using -- xor. isSuitableFloatingPointLit :: CmmLit -> Bool isSuitableFloatingPointLit (CmmFloat f _) = f /= 0.0 isSuitableFloatingPointLit _ = False getRegOrMem :: CmmExpr -> NatM (Operand, InstrBlock) getRegOrMem e@(CmmLoad mem pk) = do is32Bit <- is32BitPlatform use_sse2 <- sse2Enabled if (not (isFloatType pk) || use_sse2) && (if is32Bit then not (isWord64 pk) else True) then do Amode src mem_code <- getAmode mem return (OpAddr src, mem_code) else do (reg, code) <- getNonClobberedReg e return (OpReg reg, code) getRegOrMem e = do (reg, code) <- getNonClobberedReg e return (OpReg reg, code) is32BitLit :: Bool -> CmmLit -> Bool is32BitLit is32Bit (CmmInt i W64) | not is32Bit = -- assume that labels are in the range 0-2^31-1: this assumes the -- small memory model (see gcc docs, -mcmodel=small). is32BitInteger i is32BitLit _ _ = True -- Set up a condition code for a conditional branch. getCondCode :: CmmExpr -> NatM CondCode -- yes, they really do seem to want exactly the same! getCondCode (CmmMachOp mop [x, y]) = case mop of MO_F_Eq W32 -> condFltCode EQQ x y MO_F_Ne W32 -> condFltCode NE x y MO_F_Gt W32 -> condFltCode GTT x y MO_F_Ge W32 -> condFltCode GE x y -- Invert comparison condition and swap operands -- See Note [SSE Parity Checks] MO_F_Lt W32 -> condFltCode GTT y x MO_F_Le W32 -> condFltCode GE y x MO_F_Eq W64 -> condFltCode EQQ x y MO_F_Ne W64 -> condFltCode NE x y MO_F_Gt W64 -> condFltCode GTT x y MO_F_Ge W64 -> condFltCode GE x y MO_F_Lt W64 -> condFltCode GTT y x MO_F_Le W64 -> condFltCode GE y x _ -> condIntCode (machOpToCond mop) x y getCondCode other = pprPanic "getCondCode(2)(x86,x86_64)" (ppr other) machOpToCond :: MachOp -> Cond machOpToCond mo = case mo of MO_Eq _ -> EQQ MO_Ne _ -> NE MO_S_Gt _ -> GTT MO_S_Ge _ -> GE MO_S_Lt _ -> LTT MO_S_Le _ -> LE MO_U_Gt _ -> GU MO_U_Ge _ -> GEU MO_U_Lt _ -> LU MO_U_Le _ -> LEU _other -> pprPanic "machOpToCond" (pprMachOp mo) -- @cond(Int|Flt)Code@: Turn a boolean expression into a condition, to be -- passed back up the tree. condIntCode :: Cond -> CmmExpr -> CmmExpr -> NatM CondCode condIntCode cond x y = do is32Bit <- is32BitPlatform condIntCode' is32Bit cond x y condIntCode' :: Bool -> Cond -> CmmExpr -> CmmExpr -> NatM CondCode -- memory vs immediate condIntCode' is32Bit cond (CmmLoad x pk) (CmmLit lit) | is32BitLit is32Bit lit = do Amode x_addr x_code <- getAmode x let imm = litToImm lit code = x_code `snocOL` CMP (cmmTypeFormat pk) (OpImm imm) (OpAddr x_addr) -- return (CondCode False cond code) -- anything vs zero, using a mask -- TODO: Add some sanity checking!!!! condIntCode' is32Bit cond (CmmMachOp (MO_And _) [x,o2]) (CmmLit (CmmInt 0 pk)) | (CmmLit lit@(CmmInt mask _)) <- o2, is32BitLit is32Bit lit = do (x_reg, x_code) <- getSomeReg x let code = x_code `snocOL` TEST (intFormat pk) (OpImm (ImmInteger mask)) (OpReg x_reg) -- return (CondCode False cond code) -- anything vs zero condIntCode' _ cond x (CmmLit (CmmInt 0 pk)) = do (x_reg, x_code) <- getSomeReg x let code = x_code `snocOL` TEST (intFormat pk) (OpReg x_reg) (OpReg x_reg) -- return (CondCode False cond code) -- anything vs operand condIntCode' is32Bit cond x y | isOperand is32Bit y = do dflags <- getDynFlags (x_reg, x_code) <- getNonClobberedReg x (y_op, y_code) <- getOperand y let code = x_code `appOL` y_code `snocOL` CMP (cmmTypeFormat (cmmExprType dflags x)) y_op (OpReg x_reg) return (CondCode False cond code) -- operand vs. anything: invert the comparison so that we can use a -- single comparison instruction. | isOperand is32Bit x , Just revcond <- maybeFlipCond cond = do dflags <- getDynFlags (y_reg, y_code) <- getNonClobberedReg y (x_op, x_code) <- getOperand x let code = y_code `appOL` x_code `snocOL` CMP (cmmTypeFormat (cmmExprType dflags x)) x_op (OpReg y_reg) return (CondCode False revcond code) -- anything vs anything condIntCode' _ cond x y = do dflags <- getDynFlags (y_reg, y_code) <- getNonClobberedReg y (x_op, x_code) <- getRegOrMem x let code = y_code `appOL` x_code `snocOL` CMP (cmmTypeFormat (cmmExprType dflags x)) (OpReg y_reg) x_op return (CondCode False cond code) -------------------------------------------------------------------------------- condFltCode :: Cond -> CmmExpr -> CmmExpr -> NatM CondCode condFltCode cond x y = condFltCode_sse2 where -- in the SSE2 comparison ops (ucomiss, ucomisd) the left arg may be -- an operand, but the right must be a reg. We can probably do better -- than this general case... condFltCode_sse2 = do dflags <- getDynFlags (x_reg, x_code) <- getNonClobberedReg x (y_op, y_code) <- getOperand y let code = x_code `appOL` y_code `snocOL` CMP (floatFormat $ cmmExprWidth dflags x) y_op (OpReg x_reg) -- NB(1): we need to use the unsigned comparison operators on the -- result of this comparison. return (CondCode True (condToUnsigned cond) code) -- ----------------------------------------------------------------------------- -- Generating assignments -- Assignments are really at the heart of the whole code generation -- business. Almost all top-level nodes of any real importance are -- assignments, which correspond to loads, stores, or register -- transfers. If we're really lucky, some of the register transfers -- will go away, because we can use the destination register to -- complete the code generation for the right hand side. This only -- fails when the right hand side is forced into a fixed register -- (e.g. the result of a call). assignMem_IntCode :: Format -> CmmExpr -> CmmExpr -> NatM InstrBlock assignReg_IntCode :: Format -> CmmReg -> CmmExpr -> NatM InstrBlock assignMem_FltCode :: Format -> CmmExpr -> CmmExpr -> NatM InstrBlock assignReg_FltCode :: Format -> CmmReg -> CmmExpr -> NatM InstrBlock -- integer assignment to memory -- specific case of adding/subtracting an integer to a particular address. -- ToDo: catch other cases where we can use an operation directly on a memory -- address. assignMem_IntCode pk addr (CmmMachOp op [CmmLoad addr2 _, CmmLit (CmmInt i _)]) | addr == addr2, pk /= II64 || is32BitInteger i, Just instr <- check op = do Amode amode code_addr <- getAmode addr let code = code_addr `snocOL` instr pk (OpImm (ImmInt (fromIntegral i))) (OpAddr amode) return code where check (MO_Add _) = Just ADD check (MO_Sub _) = Just SUB check _ = Nothing -- ToDo: more? -- general case assignMem_IntCode pk addr src = do is32Bit <- is32BitPlatform Amode addr code_addr <- getAmode addr (code_src, op_src) <- get_op_RI is32Bit src let code = code_src `appOL` code_addr `snocOL` MOV pk op_src (OpAddr addr) -- NOTE: op_src is stable, so it will still be valid -- after code_addr. This may involve the introduction -- of an extra MOV to a temporary register, but we hope -- the register allocator will get rid of it. -- return code where get_op_RI :: Bool -> CmmExpr -> NatM (InstrBlock,Operand) -- code, operator get_op_RI is32Bit (CmmLit lit) | is32BitLit is32Bit lit = return (nilOL, OpImm (litToImm lit)) get_op_RI _ op = do (reg,code) <- getNonClobberedReg op return (code, OpReg reg) -- Assign; dst is a reg, rhs is mem assignReg_IntCode pk reg (CmmLoad src _) = do load_code <- intLoadCode (MOV pk) src dflags <- getDynFlags let platform = targetPlatform dflags return (load_code (getRegisterReg platform reg)) -- dst is a reg, but src could be anything assignReg_IntCode _ reg src = do dflags <- getDynFlags let platform = targetPlatform dflags code <- getAnyReg src return (code (getRegisterReg platform reg)) -- Floating point assignment to memory assignMem_FltCode pk addr src = do (src_reg, src_code) <- getNonClobberedReg src Amode addr addr_code <- getAmode addr let code = src_code `appOL` addr_code `snocOL` MOV pk (OpReg src_reg) (OpAddr addr) return code -- Floating point assignment to a register/temporary assignReg_FltCode _ reg src = do src_code <- getAnyReg src dflags <- getDynFlags let platform = targetPlatform dflags return (src_code (getRegisterReg platform reg)) genJump :: CmmExpr{-the branch target-} -> [Reg] -> NatM InstrBlock genJump (CmmLoad mem _) regs = do Amode target code <- getAmode mem return (code `snocOL` JMP (OpAddr target) regs) genJump (CmmLit lit) regs = do return (unitOL (JMP (OpImm (litToImm lit)) regs)) genJump expr regs = do (reg,code) <- getSomeReg expr return (code `snocOL` JMP (OpReg reg) regs) -- ----------------------------------------------------------------------------- -- Unconditional branches genBranch :: BlockId -> InstrBlock genBranch = toOL . mkJumpInstr -- ----------------------------------------------------------------------------- -- Conditional jumps/branches {- Conditional jumps are always to local labels, so we can use branch instructions. We peek at the arguments to decide what kind of comparison to do. I386: First, we have to ensure that the condition codes are set according to the supplied comparison operation. -} genCondBranch :: BlockId -- the source of the jump -> BlockId -- the true branch target -> BlockId -- the false branch target -> CmmExpr -- the condition on which to branch -> NatM InstrBlock -- Instructions genCondBranch bid id false expr = do is32Bit <- is32BitPlatform genCondBranch' is32Bit bid id false expr -- | We return the instructions generated. genCondBranch' :: Bool -> BlockId -> BlockId -> BlockId -> CmmExpr -> NatM InstrBlock -- 64-bit integer comparisons on 32-bit genCondBranch' is32Bit _bid true false (CmmMachOp mop [e1,e2]) | is32Bit, Just W64 <- maybeIntComparison mop = do ChildCode64 code1 r1_lo <- iselExpr64 e1 ChildCode64 code2 r2_lo <- iselExpr64 e2 let r1_hi = getHiVRegFromLo r1_lo r2_hi = getHiVRegFromLo r2_lo cond = machOpToCond mop Just cond' = maybeFlipCond cond --TODO: Update CFG for x86 let code = code1 `appOL` code2 `appOL` toOL [ CMP II32 (OpReg r2_hi) (OpReg r1_hi), JXX cond true, JXX cond' false, CMP II32 (OpReg r2_lo) (OpReg r1_lo), JXX cond true] `appOL` genBranch false return code genCondBranch' _ bid id false bool = do CondCode is_float cond cond_code <- getCondCode bool use_sse2 <- sse2Enabled if not is_float || not use_sse2 then return (cond_code `snocOL` JXX cond id `appOL` genBranch false) else do -- See Note [SSE Parity Checks] let jmpFalse = genBranch false code = case cond of NE -> or_unordered GU -> plain_test GEU -> plain_test -- Use ASSERT so we don't break releases if -- LTT/LE creep in somehow. LTT -> ASSERT2(False, ppr "Should have been turned into >") and_ordered LE -> ASSERT2(False, ppr "Should have been turned into >=") and_ordered _ -> and_ordered plain_test = unitOL ( JXX cond id ) `appOL` jmpFalse or_unordered = toOL [ JXX cond id, JXX PARITY id ] `appOL` jmpFalse and_ordered = toOL [ JXX PARITY false, JXX cond id, JXX ALWAYS false ] updateCfgNat (\cfg -> adjustEdgeWeight cfg (+3) bid false) return (cond_code `appOL` code) {- Note [Introducing cfg edges inside basic blocks] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ During instruction selection a statement `s` in a block B with control of the sort: B -> C will sometimes result in control flow of the sort: ┌ < ┐ v ^ B -> B1 ┴ -> C as is the case for some atomic operations. Now to keep the CFG in sync when introducing B1 we clearly want to insert it between B and C. However there is a catch when we have to deal with self loops. We might start with code and a CFG of these forms: loop: stmt1 ┌ < ┐ .... v ^ stmtX loop ┘ stmtY .... goto loop: Now we introduce B1: ┌ ─ ─ ─ ─ ─┐ loop: │ ┌ < ┐ │ instrs v │ │ ^ .... loop ┴ B1 ┴ ┘ instrsFromX stmtY goto loop: This is simple, all outgoing edges from loop now simply start from B1 instead and the code generator knows which new edges it introduced for the self loop of B1. Disaster strikes if the statement Y follows the same pattern. If we apply the same rule that all outgoing edges change then we end up with: loop ─> B1 ─> B2 ┬─┐ │ │ └─<┤ │ │ └───<───┘ │ └───────<────────┘ This is problematic. The edge B1->B1 is modified as expected. However the modification is wrong! The assembly in this case looked like this: _loop: _B1: ... cmpxchgq ... jne _B1 _B2: ... cmpxchgq ... jne _B2 jmp loop There is no edge _B2 -> _B1 here. It's still a self loop onto _B1. The problem here is that really B1 should be two basic blocks. Otherwise we have control flow in the *middle* of a basic block. A contradiction! So to account for this we add yet another basic block marker: _B: _B1: ... cmpxchgq ... jne _B1 jmp _B1' _B1': _B2: ... Now when inserting B2 we will only look at the outgoing edges of B1' and everything will work out nicely. You might also wonder why we don't insert jumps at the end of _B1'. There is no way another block ends up jumping to the labels _B1 or _B2 since they are essentially invisible to other blocks. View them as control flow labels local to the basic block if you'd like. Not doing this ultimately caused (part 2 of) #17334. -} -- ----------------------------------------------------------------------------- -- Generating C calls -- Now the biggest nightmare---calls. Most of the nastiness is buried in -- @get_arg@, which moves the arguments to the correct registers/stack -- locations. Apart from that, the code is easy. -- -- (If applicable) Do not fill the delay slots here; you will confuse the -- register allocator. -- -- See Note [Keeping track of the current block] for information why we need -- to take/return a block id. genCCall :: DynFlags -> Bool -- 32 bit platform? -> ForeignTarget -- function to call -> [CmmFormal] -- where to put the result -> [CmmActual] -- arguments (of mixed type) -> BlockId -- The block we are in -> NatM (InstrBlock, Maybe BlockId) -- First we deal with cases which might introduce new blocks in the stream. genCCall dflags is32Bit (PrimTarget (MO_AtomicRMW width amop)) [dst] [addr, n] bid = do Amode amode addr_code <- if amop `elem` [AMO_Add, AMO_Sub] then getAmode addr else getSimpleAmode dflags is32Bit addr -- See genCCall for MO_Cmpxchg arg <- getNewRegNat format arg_code <- getAnyReg n let platform = targetPlatform dflags dst_r = getRegisterReg platform (CmmLocal dst) (code, lbl) <- op_code dst_r arg amode return (addr_code `appOL` arg_code arg `appOL` code, Just lbl) where -- Code for the operation op_code :: Reg -- Destination reg -> Reg -- Register containing argument -> AddrMode -- Address of location to mutate -> NatM (OrdList Instr,BlockId) -- TODO: Return Maybe BlockId op_code dst_r arg amode = case amop of -- In the common case where dst_r is a virtual register the -- final move should go away, because it's the last use of arg -- and the first use of dst_r. AMO_Add -> return $ (toOL [ LOCK (XADD format (OpReg arg) (OpAddr amode)) , MOV format (OpReg arg) (OpReg dst_r) ], bid) AMO_Sub -> return $ (toOL [ NEGI format (OpReg arg) , LOCK (XADD format (OpReg arg) (OpAddr amode)) , MOV format (OpReg arg) (OpReg dst_r) ], bid) -- In these cases we need a new block id, and have to return it so -- that later instruction selection can reference it. AMO_And -> cmpxchg_code (\ src dst -> unitOL $ AND format src dst) AMO_Nand -> cmpxchg_code (\ src dst -> toOL [ AND format src dst , NOT format dst ]) AMO_Or -> cmpxchg_code (\ src dst -> unitOL $ OR format src dst) AMO_Xor -> cmpxchg_code (\ src dst -> unitOL $ XOR format src dst) where -- Simulate operation that lacks a dedicated instruction using -- cmpxchg. cmpxchg_code :: (Operand -> Operand -> OrdList Instr) -> NatM (OrdList Instr, BlockId) cmpxchg_code instrs = do lbl1 <- getBlockIdNat lbl2 <- getBlockIdNat tmp <- getNewRegNat format --Record inserted blocks -- We turn A -> B into A -> A' -> A'' -> B -- with a self loop on A'. addImmediateSuccessorNat bid lbl1 addImmediateSuccessorNat lbl1 lbl2 updateCfgNat (addWeightEdge lbl1 lbl1 0) return $ (toOL [ MOV format (OpAddr amode) (OpReg eax) , JXX ALWAYS lbl1 , NEWBLOCK lbl1 -- Keep old value so we can return it: , MOV format (OpReg eax) (OpReg dst_r) , MOV format (OpReg eax) (OpReg tmp) ] `appOL` instrs (OpReg arg) (OpReg tmp) `appOL` toOL [ LOCK (CMPXCHG format (OpReg tmp) (OpAddr amode)) , JXX NE lbl1 -- See Note [Introducing cfg edges inside basic blocks] -- why this basic block is required. , JXX ALWAYS lbl2 , NEWBLOCK lbl2 ], lbl2) format = intFormat width genCCall dflags is32Bit (PrimTarget (MO_Ctz width)) [dst] [src] bid | is32Bit, width == W64 = do ChildCode64 vcode rlo <- iselExpr64 src let rhi = getHiVRegFromLo rlo dst_r = getRegisterReg platform (CmmLocal dst) lbl1 <- getBlockIdNat lbl2 <- getBlockIdNat let format = if width == W8 then II16 else intFormat width tmp_r <- getNewRegNat format -- New CFG Edges: -- bid -> lbl2 -- bid -> lbl1 -> lbl2 -- We also changes edges originating at bid to start at lbl2 instead. updateCfgNat (addWeightEdge bid lbl1 110 . addWeightEdge lbl1 lbl2 110 . addImmediateSuccessor bid lbl2) -- The following instruction sequence corresponds to the pseudo-code -- -- if (src) { -- dst = src.lo32 ? BSF(src.lo32) : (BSF(src.hi32) + 32); -- } else { -- dst = 64; -- } let !instrs = vcode `appOL` toOL ([ MOV II32 (OpReg rhi) (OpReg tmp_r) , OR II32 (OpReg rlo) (OpReg tmp_r) , MOV II32 (OpImm (ImmInt 64)) (OpReg dst_r) , JXX EQQ lbl2 , JXX ALWAYS lbl1 , NEWBLOCK lbl1 , BSF II32 (OpReg rhi) dst_r , ADD II32 (OpImm (ImmInt 32)) (OpReg dst_r) , BSF II32 (OpReg rlo) tmp_r , CMOV NE II32 (OpReg tmp_r) dst_r , JXX ALWAYS lbl2 , NEWBLOCK lbl2 ]) return (instrs, Just lbl2) | otherwise = do code_src <- getAnyReg src let dst_r = getRegisterReg platform (CmmLocal dst) if isBmi2Enabled dflags then do src_r <- getNewRegNat (intFormat width) let instrs = appOL (code_src src_r) $ case width of W8 -> toOL [ OR II32 (OpImm (ImmInteger 0xFFFFFF00)) (OpReg src_r) , TZCNT II32 (OpReg src_r) dst_r ] W16 -> toOL [ TZCNT II16 (OpReg src_r) dst_r , MOVZxL II16 (OpReg dst_r) (OpReg dst_r) ] _ -> unitOL $ TZCNT (intFormat width) (OpReg src_r) dst_r return (instrs, Nothing) else do -- The following insn sequence makes sure 'ctz 0' has a defined value. -- starting with Haswell, one could use the TZCNT insn instead. let format = if width == W8 then II16 else intFormat width src_r <- getNewRegNat format tmp_r <- getNewRegNat format let !instrs = code_src src_r `appOL` toOL ([ MOVZxL II8 (OpReg src_r) (OpReg src_r) | width == W8 ] ++ [ BSF format (OpReg src_r) tmp_r , MOV II32 (OpImm (ImmInt bw)) (OpReg dst_r) , CMOV NE format (OpReg tmp_r) dst_r ]) -- NB: We don't need to zero-extend the result for the -- W8/W16 cases because the 'MOV' insn already -- took care of implicitly clearing the upper bits return (instrs, Nothing) where bw = widthInBits width platform = targetPlatform dflags genCCall dflags bits mop dst args bid = do instr <- genCCall' dflags bits mop dst args bid return (instr, Nothing) -- genCCall' handles cases not introducing new code blocks. genCCall' :: DynFlags -> Bool -- 32 bit platform? -> ForeignTarget -- function to call -> [CmmFormal] -- where to put the result -> [CmmActual] -- arguments (of mixed type) -> BlockId -- The block we are in -> NatM InstrBlock -- Unroll memcpy calls if the number of bytes to copy isn't too -- large. Otherwise, call C's memcpy. genCCall' dflags _ (PrimTarget (MO_Memcpy align)) _ [dst, src, CmmLit (CmmInt n _)] _ | fromInteger insns <= maxInlineMemcpyInsns dflags = do code_dst <- getAnyReg dst dst_r <- getNewRegNat format code_src <- getAnyReg src src_r <- getNewRegNat format tmp_r <- getNewRegNat format return $ code_dst dst_r `appOL` code_src src_r `appOL` go dst_r src_r tmp_r (fromInteger n) where -- The number of instructions we will generate (approx). We need 2 -- instructions per move. insns = 2 * ((n + sizeBytes - 1) `div` sizeBytes) maxAlignment = wordAlignment dflags -- only machine word wide MOVs are supported effectiveAlignment = min (alignmentOf align) maxAlignment format = intFormat . widthFromBytes $ alignmentBytes effectiveAlignment -- The size of each move, in bytes. sizeBytes :: Integer sizeBytes = fromIntegral (formatInBytes format) go :: Reg -> Reg -> Reg -> Integer -> OrdList Instr go dst src tmp i | i >= sizeBytes = unitOL (MOV format (OpAddr src_addr) (OpReg tmp)) `appOL` unitOL (MOV format (OpReg tmp) (OpAddr dst_addr)) `appOL` go dst src tmp (i - sizeBytes) -- Deal with remaining bytes. | i >= 4 = -- Will never happen on 32-bit unitOL (MOV II32 (OpAddr src_addr) (OpReg tmp)) `appOL` unitOL (MOV II32 (OpReg tmp) (OpAddr dst_addr)) `appOL` go dst src tmp (i - 4) | i >= 2 = unitOL (MOVZxL II16 (OpAddr src_addr) (OpReg tmp)) `appOL` unitOL (MOV II16 (OpReg tmp) (OpAddr dst_addr)) `appOL` go dst src tmp (i - 2) | i >= 1 = unitOL (MOVZxL II8 (OpAddr src_addr) (OpReg tmp)) `appOL` unitOL (MOV II8 (OpReg tmp) (OpAddr dst_addr)) `appOL` go dst src tmp (i - 1) | otherwise = nilOL where src_addr = AddrBaseIndex (EABaseReg src) EAIndexNone (ImmInteger (n - i)) dst_addr = AddrBaseIndex (EABaseReg dst) EAIndexNone (ImmInteger (n - i)) genCCall' dflags _ (PrimTarget (MO_Memset align)) _ [dst, CmmLit (CmmInt c _), CmmLit (CmmInt n _)] _ | fromInteger insns <= maxInlineMemsetInsns dflags = do code_dst <- getAnyReg dst dst_r <- getNewRegNat format if format == II64 && n >= 8 then do code_imm8byte <- getAnyReg (CmmLit (CmmInt c8 W64)) imm8byte_r <- getNewRegNat II64 return $ code_dst dst_r `appOL` code_imm8byte imm8byte_r `appOL` go8 dst_r imm8byte_r (fromInteger n) else return $ code_dst dst_r `appOL` go4 dst_r (fromInteger n) where maxAlignment = wordAlignment dflags -- only machine word wide MOVs are supported effectiveAlignment = min (alignmentOf align) maxAlignment format = intFormat . widthFromBytes $ alignmentBytes effectiveAlignment c2 = c `shiftL` 8 .|. c c4 = c2 `shiftL` 16 .|. c2 c8 = c4 `shiftL` 32 .|. c4 -- The number of instructions we will generate (approx). We need 1 -- instructions per move. insns = (n + sizeBytes - 1) `div` sizeBytes -- The size of each move, in bytes. sizeBytes :: Integer sizeBytes = fromIntegral (formatInBytes format) -- Depending on size returns the widest MOV instruction and its -- width. gen4 :: AddrMode -> Integer -> (InstrBlock, Integer) gen4 addr size | size >= 4 = (unitOL (MOV II32 (OpImm (ImmInteger c4)) (OpAddr addr)), 4) | size >= 2 = (unitOL (MOV II16 (OpImm (ImmInteger c2)) (OpAddr addr)), 2) | size >= 1 = (unitOL (MOV II8 (OpImm (ImmInteger c)) (OpAddr addr)), 1) | otherwise = (nilOL, 0) -- Generates a 64-bit wide MOV instruction from REG to MEM. gen8 :: AddrMode -> Reg -> InstrBlock gen8 addr reg8byte = unitOL (MOV format (OpReg reg8byte) (OpAddr addr)) -- Unrolls memset when the widest MOV is <= 4 bytes. go4 :: Reg -> Integer -> InstrBlock go4 dst left = if left <= 0 then nilOL else curMov `appOL` go4 dst (left - curWidth) where possibleWidth = minimum [left, sizeBytes] dst_addr = AddrBaseIndex (EABaseReg dst) EAIndexNone (ImmInteger (n - left)) (curMov, curWidth) = gen4 dst_addr possibleWidth -- Unrolls memset when the widest MOV is 8 bytes (thus another Reg -- argument). Falls back to go4 when all 8 byte moves are -- exhausted. go8 :: Reg -> Reg -> Integer -> InstrBlock go8 dst reg8byte left = if possibleWidth >= 8 then let curMov = gen8 dst_addr reg8byte in curMov `appOL` go8 dst reg8byte (left - 8) else go4 dst left where possibleWidth = minimum [left, sizeBytes] dst_addr = AddrBaseIndex (EABaseReg dst) EAIndexNone (ImmInteger (n - left)) genCCall' _ _ (PrimTarget MO_ReadBarrier) _ _ _ = return nilOL genCCall' _ _ (PrimTarget MO_WriteBarrier) _ _ _ = return nilOL -- barriers compile to no code on x86/x86-64; -- we keep it this long in order to prevent earlier optimisations. genCCall' _ _ (PrimTarget MO_Touch) _ _ _ = return nilOL genCCall' _ is32bit (PrimTarget (MO_Prefetch_Data n )) _ [src] _ = case n of 0 -> genPrefetch src $ PREFETCH NTA format 1 -> genPrefetch src $ PREFETCH Lvl2 format 2 -> genPrefetch src $ PREFETCH Lvl1 format 3 -> genPrefetch src $ PREFETCH Lvl0 format l -> panic $ "unexpected prefetch level in genCCall MO_Prefetch_Data: " ++ (show l) -- the c / llvm prefetch convention is 0, 1, 2, and 3 -- the x86 corresponding names are : NTA, 2 , 1, and 0 where format = archWordFormat is32bit -- need to know what register width for pointers! genPrefetch inRegSrc prefetchCTor = do code_src <- getAnyReg inRegSrc src_r <- getNewRegNat format return $ code_src src_r `appOL` (unitOL (prefetchCTor (OpAddr ((AddrBaseIndex (EABaseReg src_r ) EAIndexNone (ImmInt 0)))) )) -- prefetch always takes an address genCCall' dflags is32Bit (PrimTarget (MO_BSwap width)) [dst] [src] _ = do let platform = targetPlatform dflags let dst_r = getRegisterReg platform (CmmLocal dst) case width of W64 | is32Bit -> do ChildCode64 vcode rlo <- iselExpr64 src let dst_rhi = getHiVRegFromLo dst_r rhi = getHiVRegFromLo rlo return $ vcode `appOL` toOL [ MOV II32 (OpReg rlo) (OpReg dst_rhi), MOV II32 (OpReg rhi) (OpReg dst_r), BSWAP II32 dst_rhi, BSWAP II32 dst_r ] W16 -> do code_src <- getAnyReg src return $ code_src dst_r `appOL` unitOL (BSWAP II32 dst_r) `appOL` unitOL (SHR II32 (OpImm $ ImmInt 16) (OpReg dst_r)) _ -> do code_src <- getAnyReg src return $ code_src dst_r `appOL` unitOL (BSWAP format dst_r) where format = intFormat width genCCall' dflags is32Bit (PrimTarget (MO_PopCnt width)) dest_regs@[dst] args@[src] bid = do sse4_2 <- sse4_2Enabled let platform = targetPlatform dflags if sse4_2 then do code_src <- getAnyReg src src_r <- getNewRegNat format let dst_r = getRegisterReg platform (CmmLocal dst) return $ code_src src_r `appOL` (if width == W8 then -- The POPCNT instruction doesn't take a r/m8 unitOL (MOVZxL II8 (OpReg src_r) (OpReg src_r)) `appOL` unitOL (POPCNT II16 (OpReg src_r) dst_r) else unitOL (POPCNT format (OpReg src_r) dst_r)) `appOL` (if width == W8 || width == W16 then -- We used a 16-bit destination register above, -- so zero-extend unitOL (MOVZxL II16 (OpReg dst_r) (OpReg dst_r)) else nilOL) else do targetExpr <- cmmMakeDynamicReference dflags CallReference lbl let target = ForeignTarget targetExpr (ForeignConvention CCallConv [NoHint] [NoHint] CmmMayReturn) genCCall' dflags is32Bit target dest_regs args bid where format = intFormat width lbl = mkCmmCodeLabel primUnitId (fsLit (popCntLabel width)) genCCall' dflags is32Bit (PrimTarget (MO_Pdep width)) dest_regs@[dst] args@[src, mask] bid = do let platform = targetPlatform dflags if isBmi2Enabled dflags then do code_src <- getAnyReg src code_mask <- getAnyReg mask src_r <- getNewRegNat format mask_r <- getNewRegNat format let dst_r = getRegisterReg platform (CmmLocal dst) return $ code_src src_r `appOL` code_mask mask_r `appOL` (if width == W8 then -- The PDEP instruction doesn't take a r/m8 unitOL (MOVZxL II8 (OpReg src_r ) (OpReg src_r )) `appOL` unitOL (MOVZxL II8 (OpReg mask_r) (OpReg mask_r)) `appOL` unitOL (PDEP II16 (OpReg mask_r) (OpReg src_r ) dst_r) else unitOL (PDEP format (OpReg mask_r) (OpReg src_r) dst_r)) `appOL` (if width == W8 || width == W16 then -- We used a 16-bit destination register above, -- so zero-extend unitOL (MOVZxL II16 (OpReg dst_r) (OpReg dst_r)) else nilOL) else do targetExpr <- cmmMakeDynamicReference dflags CallReference lbl let target = ForeignTarget targetExpr (ForeignConvention CCallConv [NoHint] [NoHint] CmmMayReturn) genCCall' dflags is32Bit target dest_regs args bid where format = intFormat width lbl = mkCmmCodeLabel primUnitId (fsLit (pdepLabel width)) genCCall' dflags is32Bit (PrimTarget (MO_Pext width)) dest_regs@[dst] args@[src, mask] bid = do let platform = targetPlatform dflags if isBmi2Enabled dflags then do code_src <- getAnyReg src code_mask <- getAnyReg mask src_r <- getNewRegNat format mask_r <- getNewRegNat format let dst_r = getRegisterReg platform (CmmLocal dst) return $ code_src src_r `appOL` code_mask mask_r `appOL` (if width == W8 then -- The PEXT instruction doesn't take a r/m8 unitOL (MOVZxL II8 (OpReg src_r ) (OpReg src_r )) `appOL` unitOL (MOVZxL II8 (OpReg mask_r) (OpReg mask_r)) `appOL` unitOL (PEXT II16 (OpReg mask_r) (OpReg src_r) dst_r) else unitOL (PEXT format (OpReg mask_r) (OpReg src_r) dst_r)) `appOL` (if width == W8 || width == W16 then -- We used a 16-bit destination register above, -- so zero-extend unitOL (MOVZxL II16 (OpReg dst_r) (OpReg dst_r)) else nilOL) else do targetExpr <- cmmMakeDynamicReference dflags CallReference lbl let target = ForeignTarget targetExpr (ForeignConvention CCallConv [NoHint] [NoHint] CmmMayReturn) genCCall' dflags is32Bit target dest_regs args bid where format = intFormat width lbl = mkCmmCodeLabel primUnitId (fsLit (pextLabel width)) genCCall' dflags is32Bit (PrimTarget (MO_Clz width)) dest_regs@[dst] args@[src] bid | is32Bit && width == W64 = do -- Fallback to `hs_clz64` on i386 targetExpr <- cmmMakeDynamicReference dflags CallReference lbl let target = ForeignTarget targetExpr (ForeignConvention CCallConv [NoHint] [NoHint] CmmMayReturn) genCCall' dflags is32Bit target dest_regs args bid | otherwise = do code_src <- getAnyReg src let dst_r = getRegisterReg platform (CmmLocal dst) if isBmi2Enabled dflags then do src_r <- getNewRegNat (intFormat width) return $ appOL (code_src src_r) $ case width of W8 -> toOL [ MOVZxL II8 (OpReg src_r) (OpReg src_r) -- zero-extend to 32 bit , LZCNT II32 (OpReg src_r) dst_r -- lzcnt with extra 24 zeros , SUB II32 (OpImm (ImmInt 24)) (OpReg dst_r) -- compensate for extra zeros ] W16 -> toOL [ LZCNT II16 (OpReg src_r) dst_r , MOVZxL II16 (OpReg dst_r) (OpReg dst_r) -- zero-extend from 16 bit ] _ -> unitOL (LZCNT (intFormat width) (OpReg src_r) dst_r) else do let format = if width == W8 then II16 else intFormat width src_r <- getNewRegNat format tmp_r <- getNewRegNat format return $ code_src src_r `appOL` toOL ([ MOVZxL II8 (OpReg src_r) (OpReg src_r) | width == W8 ] ++ [ BSR format (OpReg src_r) tmp_r , MOV II32 (OpImm (ImmInt (2*bw-1))) (OpReg dst_r) , CMOV NE format (OpReg tmp_r) dst_r , XOR format (OpImm (ImmInt (bw-1))) (OpReg dst_r) ]) -- NB: We don't need to zero-extend the result for the -- W8/W16 cases because the 'MOV' insn already -- took care of implicitly clearing the upper bits where bw = widthInBits width platform = targetPlatform dflags lbl = mkCmmCodeLabel primUnitId (fsLit (clzLabel width)) genCCall' dflags is32Bit (PrimTarget (MO_UF_Conv width)) dest_regs args bid = do targetExpr <- cmmMakeDynamicReference dflags CallReference lbl let target = ForeignTarget targetExpr (ForeignConvention CCallConv [NoHint] [NoHint] CmmMayReturn) genCCall' dflags is32Bit target dest_regs args bid where lbl = mkCmmCodeLabel primUnitId (fsLit (word2FloatLabel width)) genCCall' dflags _ (PrimTarget (MO_AtomicRead width)) [dst] [addr] _ = do load_code <- intLoadCode (MOV (intFormat width)) addr let platform = targetPlatform dflags return (load_code (getRegisterReg platform (CmmLocal dst))) genCCall' _ _ (PrimTarget (MO_AtomicWrite width)) [] [addr, val] _ = do code <- assignMem_IntCode (intFormat width) addr val return $ code `snocOL` MFENCE genCCall' dflags is32Bit (PrimTarget (MO_Cmpxchg width)) [dst] [addr, old, new] _ = do -- On x86 we don't have enough registers to use cmpxchg with a -- complicated addressing mode, so on that architecture we -- pre-compute the address first. Amode amode addr_code <- getSimpleAmode dflags is32Bit addr newval <- getNewRegNat format newval_code <- getAnyReg new oldval <- getNewRegNat format oldval_code <- getAnyReg old let platform = targetPlatform dflags dst_r = getRegisterReg platform (CmmLocal dst) code = toOL [ MOV format (OpReg oldval) (OpReg eax) , LOCK (CMPXCHG format (OpReg newval) (OpAddr amode)) , MOV format (OpReg eax) (OpReg dst_r) ] return $ addr_code `appOL` newval_code newval `appOL` oldval_code oldval `appOL` code where format = intFormat width genCCall' _ is32Bit target dest_regs args bid = do dflags <- getDynFlags let platform = targetPlatform dflags case (target, dest_regs) of -- void return type prim op (PrimTarget op, []) -> outOfLineCmmOp bid op Nothing args -- we only cope with a single result for foreign calls (PrimTarget op, [r]) -> case op of MO_F32_Fabs -> case args of [x] -> sse2FabsCode W32 x _ -> panic "genCCall: Wrong number of arguments for fabs" MO_F64_Fabs -> case args of [x] -> sse2FabsCode W64 x _ -> panic "genCCall: Wrong number of arguments for fabs" MO_F32_Sqrt -> actuallyInlineSSE2Op (\fmt r -> SQRT fmt (OpReg r)) FF32 args MO_F64_Sqrt -> actuallyInlineSSE2Op (\fmt r -> SQRT fmt (OpReg r)) FF64 args _other_op -> outOfLineCmmOp bid op (Just r) args where actuallyInlineSSE2Op = actuallyInlineFloatOp' actuallyInlineFloatOp' instr format [x] = do res <- trivialUFCode format (instr format) x any <- anyReg res return (any (getRegisterReg platform (CmmLocal r))) actuallyInlineFloatOp' _ _ args = panic $ "genCCall.actuallyInlineFloatOp': bad number of arguments! (" ++ show (length args) ++ ")" sse2FabsCode :: Width -> CmmExpr -> NatM InstrBlock sse2FabsCode w x = do let fmt = floatFormat w x_code <- getAnyReg x let const | FF32 <- fmt = CmmInt 0x7fffffff W32 | otherwise = CmmInt 0x7fffffffffffffff W64 Amode amode amode_code <- memConstant (mkAlignment $ widthInBytes w) const tmp <- getNewRegNat fmt let code dst = x_code dst `appOL` amode_code `appOL` toOL [ MOV fmt (OpAddr amode) (OpReg tmp), AND fmt (OpReg tmp) (OpReg dst) ] return $ code (getRegisterReg platform (CmmLocal r)) (PrimTarget (MO_S_QuotRem width), _) -> divOp1 platform True width dest_regs args (PrimTarget (MO_U_QuotRem width), _) -> divOp1 platform False width dest_regs args (PrimTarget (MO_U_QuotRem2 width), _) -> divOp2 platform False width dest_regs args (PrimTarget (MO_Add2 width), [res_h, res_l]) -> case args of [arg_x, arg_y] -> do hCode <- getAnyReg (CmmLit (CmmInt 0 width)) let format = intFormat width lCode <- anyReg =<< trivialCode width (ADD_CC format) (Just (ADD_CC format)) arg_x arg_y let reg_l = getRegisterReg platform (CmmLocal res_l) reg_h = getRegisterReg platform (CmmLocal res_h) code = hCode reg_h `appOL` lCode reg_l `snocOL` ADC format (OpImm (ImmInteger 0)) (OpReg reg_h) return code _ -> panic "genCCall: Wrong number of arguments/results for add2" (PrimTarget (MO_AddWordC width), [res_r, res_c]) -> addSubIntC platform ADD_CC (const Nothing) CARRY width res_r res_c args (PrimTarget (MO_SubWordC width), [res_r, res_c]) -> addSubIntC platform SUB_CC (const Nothing) CARRY width res_r res_c args (PrimTarget (MO_AddIntC width), [res_r, res_c]) -> addSubIntC platform ADD_CC (Just . ADD_CC) OFLO width res_r res_c args (PrimTarget (MO_SubIntC width), [res_r, res_c]) -> addSubIntC platform SUB_CC (const Nothing) OFLO width res_r res_c args (PrimTarget (MO_U_Mul2 width), [res_h, res_l]) -> case args of [arg_x, arg_y] -> do (y_reg, y_code) <- getRegOrMem arg_y x_code <- getAnyReg arg_x let format = intFormat width reg_h = getRegisterReg platform (CmmLocal res_h) reg_l = getRegisterReg platform (CmmLocal res_l) code = y_code `appOL` x_code rax `appOL` toOL [MUL2 format y_reg, MOV format (OpReg rdx) (OpReg reg_h), MOV format (OpReg rax) (OpReg reg_l)] return code _ -> panic "genCCall: Wrong number of arguments/results for mul2" _ -> do (instrs0, args') <- evalArgs bid args instrs1 <- if is32Bit then genCCall32' dflags target dest_regs args' else genCCall64' dflags target dest_regs args' return (instrs0 `appOL` instrs1) where divOp1 platform signed width results [arg_x, arg_y] = divOp platform signed width results Nothing arg_x arg_y divOp1 _ _ _ _ _ = panic "genCCall: Wrong number of arguments for divOp1" divOp2 platform signed width results [arg_x_high, arg_x_low, arg_y] = divOp platform signed width results (Just arg_x_high) arg_x_low arg_y divOp2 _ _ _ _ _ = panic "genCCall: Wrong number of arguments for divOp2" -- See Note [DIV/IDIV for bytes] divOp platform signed W8 [res_q, res_r] m_arg_x_high arg_x_low arg_y = let widen | signed = MO_SS_Conv W8 W16 | otherwise = MO_UU_Conv W8 W16 arg_x_low_16 = CmmMachOp widen [arg_x_low] arg_y_16 = CmmMachOp widen [arg_y] m_arg_x_high_16 = (\p -> CmmMachOp widen [p]) <$> m_arg_x_high in divOp platform signed W16 [res_q, res_r] m_arg_x_high_16 arg_x_low_16 arg_y_16 divOp platform signed width [res_q, res_r] m_arg_x_high arg_x_low arg_y = do let format = intFormat width reg_q = getRegisterReg platform (CmmLocal res_q) reg_r = getRegisterReg platform (CmmLocal res_r) widen | signed = CLTD format | otherwise = XOR format (OpReg rdx) (OpReg rdx) instr | signed = IDIV | otherwise = DIV (y_reg, y_code) <- getRegOrMem arg_y x_low_code <- getAnyReg arg_x_low x_high_code <- case m_arg_x_high of Just arg_x_high -> getAnyReg arg_x_high Nothing -> return $ const $ unitOL widen return $ y_code `appOL` x_low_code rax `appOL` x_high_code rdx `appOL` toOL [instr format y_reg, MOV format (OpReg rax) (OpReg reg_q), MOV format (OpReg rdx) (OpReg reg_r)] divOp _ _ _ _ _ _ _ = panic "genCCall: Wrong number of results for divOp" addSubIntC platform instr mrevinstr cond width res_r res_c [arg_x, arg_y] = do let format = intFormat width rCode <- anyReg =<< trivialCode width (instr format) (mrevinstr format) arg_x arg_y reg_tmp <- getNewRegNat II8 let reg_c = getRegisterReg platform (CmmLocal res_c) reg_r = getRegisterReg platform (CmmLocal res_r) code = rCode reg_r `snocOL` SETCC cond (OpReg reg_tmp) `snocOL` MOVZxL II8 (OpReg reg_tmp) (OpReg reg_c) return code addSubIntC _ _ _ _ _ _ _ _ = panic "genCCall: Wrong number of arguments/results for addSubIntC" {- Note [Evaluate C-call arguments before placing in destination registers] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ When producing code for C calls we must take care when placing arguments in their final registers. Specifically, we must ensure that temporary register usage due to evaluation of one argument does not clobber a register in which we already placed a previous argument (e.g. as the code generation logic for MO_Shl can clobber %rcx due to x86 instruction limitations). This is precisely what happened in #18527. Consider this C--: (result::I64) = call "ccall" doSomething(_s2hp::I64, 2244, _s2hq::I64, _s2hw::I64 | (1 << _s2hz::I64)); Here we are calling the C function `doSomething` with three arguments, the last involving a non-trivial expression involving MO_Shl. In this case the NCG could naively generate the following assembly (where $tmp denotes some temporary register and $argN denotes the register for argument N, as dictated by the platform's calling convention): mov _s2hp, $arg1 # place first argument mov _s2hq, $arg2 # place second argument # Compute 1 << _s2hz mov _s2hz, %rcx shl %cl, $tmp # Compute (_s2hw | (1 << _s2hz)) mov _s2hw, $arg3 or $tmp, $arg3 # Perform the call call func This code is outright broken on Windows which assigns $arg1 to %rcx. This means that the evaluation of the last argument clobbers the first argument. To avoid this we use a rather awful hack: when producing code for a C call with at least one non-trivial argument, we first evaluate all of the arguments into local registers before moving them into their final calling-convention-defined homes. This is performed by 'evalArgs'. Here we define "non-trivial" to be an expression which might contain a MachOp since these are the only cases which might clobber registers. Furthermore, we use a conservative approximation of this condition (only looking at the top-level of CmmExprs) to avoid spending too much effort trying to decide whether we want to take the fast path. Note that this hack *also* applies to calls to out-of-line PrimTargets (which are lowered via a C call) since outOfLineCmmOp produces the call via (stmtToInstrs (CmmUnsafeForeignCall ...)), which will ultimately end up back in genCCall{32,64}. -} -- | See Note [Evaluate C-call arguments before placing in destination registers] evalArgs :: BlockId -> [CmmActual] -> NatM (InstrBlock, [CmmActual]) evalArgs bid actuals | any mightContainMachOp actuals = do regs_blks <- mapM evalArg actuals return (concatOL $ map fst regs_blks, map snd regs_blks) | otherwise = return (nilOL, actuals) where mightContainMachOp (CmmReg _) = False mightContainMachOp (CmmRegOff _ _) = False mightContainMachOp (CmmLit _) = False mightContainMachOp _ = True evalArg :: CmmActual -> NatM (InstrBlock, CmmExpr) evalArg actual = do dflags <- getDynFlags lreg <- newLocalReg $ cmmExprType dflags actual (instrs, bid1) <- stmtToInstrs bid $ CmmAssign (CmmLocal lreg) actual -- The above assignment shouldn't change the current block MASSERT(isNothing bid1) return (instrs, CmmReg $ CmmLocal lreg) newLocalReg :: CmmType -> NatM LocalReg newLocalReg ty = LocalReg <$> getUniqueM <*> pure ty -- Note [DIV/IDIV for bytes] -- -- IDIV reminder: -- Size Dividend Divisor Quotient Remainder -- byte %ax r/m8 %al %ah -- word %dx:%ax r/m16 %ax %dx -- dword %edx:%eax r/m32 %eax %edx -- qword %rdx:%rax r/m64 %rax %rdx -- -- We do a special case for the byte division because the current -- codegen doesn't deal well with accessing %ah register (also, -- accessing %ah in 64-bit mode is complicated because it cannot be an -- operand of many instructions). So we just widen operands to 16 bits -- and get the results from %al, %dl. This is not optimal, but a few -- register moves are probably not a huge deal when doing division. genCCall32' :: DynFlags -> ForeignTarget -- function to call -> [CmmFormal] -- where to put the result -> [CmmActual] -- arguments (of mixed type) -> NatM InstrBlock genCCall32' dflags target dest_regs args = do let prom_args = map (maybePromoteCArg dflags W32) args -- Align stack to 16n for calls, assuming a starting stack -- alignment of 16n - word_size on procedure entry. Which we -- maintiain. See Note [rts/StgCRun.c : Stack Alignment on X86] sizes = map (arg_size_bytes . cmmExprType dflags) (reverse args) raw_arg_size = sum sizes + wORD_SIZE dflags arg_pad_size = (roundTo 16 $ raw_arg_size) - raw_arg_size tot_arg_size = raw_arg_size + arg_pad_size - wORD_SIZE dflags delta0 <- getDeltaNat setDeltaNat (delta0 - arg_pad_size) push_codes <- mapM push_arg (reverse prom_args) delta <- getDeltaNat MASSERT(delta == delta0 - tot_arg_size) -- deal with static vs dynamic call targets (callinsns,cconv) <- case target of ForeignTarget (CmmLit (CmmLabel lbl)) conv -> -- ToDo: stdcall arg sizes return (unitOL (CALL (Left fn_imm) []), conv) where fn_imm = ImmCLbl lbl ForeignTarget expr conv -> do { (dyn_r, dyn_c) <- getSomeReg expr ; ASSERT( isWord32 (cmmExprType dflags expr) ) return (dyn_c `snocOL` CALL (Right dyn_r) [], conv) } PrimTarget _ -> panic $ "genCCall: Can't handle PrimTarget call type here, error " ++ "probably because too many return values." let push_code | arg_pad_size /= 0 = toOL [SUB II32 (OpImm (ImmInt arg_pad_size)) (OpReg esp), DELTA (delta0 - arg_pad_size)] `appOL` concatOL push_codes | otherwise = concatOL push_codes -- Deallocate parameters after call for ccall; -- but not for stdcall (callee does it) -- -- We have to pop any stack padding we added -- even if we are doing stdcall, though (#5052) pop_size | ForeignConvention StdCallConv _ _ _ <- cconv = arg_pad_size | otherwise = tot_arg_size call = callinsns `appOL` toOL ( (if pop_size==0 then [] else [ADD II32 (OpImm (ImmInt pop_size)) (OpReg esp)]) ++ [DELTA delta0] ) setDeltaNat delta0 dflags <- getDynFlags let platform = targetPlatform dflags let -- assign the results, if necessary assign_code [] = nilOL assign_code [dest] | isFloatType ty = -- we assume SSE2 let tmp_amode = AddrBaseIndex (EABaseReg esp) EAIndexNone (ImmInt 0) fmt = floatFormat w in toOL [ SUB II32 (OpImm (ImmInt b)) (OpReg esp), DELTA (delta0 - b), X87Store fmt tmp_amode, -- X87Store only supported for the CDECL ABI -- NB: This code will need to be -- revisted once GHC does more work around -- SIGFPE f MOV fmt (OpAddr tmp_amode) (OpReg r_dest), ADD II32 (OpImm (ImmInt b)) (OpReg esp), DELTA delta0] | isWord64 ty = toOL [MOV II32 (OpReg eax) (OpReg r_dest), MOV II32 (OpReg edx) (OpReg r_dest_hi)] | otherwise = unitOL (MOV (intFormat w) (OpReg eax) (OpReg r_dest)) where ty = localRegType dest w = typeWidth ty b = widthInBytes w r_dest_hi = getHiVRegFromLo r_dest r_dest = getRegisterReg platform (CmmLocal dest) assign_code many = pprPanic "genCCall.assign_code - too many return values:" (ppr many) return (push_code `appOL` call `appOL` assign_code dest_regs) where -- If the size is smaller than the word, we widen things (see maybePromoteCArg) arg_size_bytes :: CmmType -> Int arg_size_bytes ty = max (widthInBytes (typeWidth ty)) (widthInBytes (wordWidth dflags)) roundTo a x | x `mod` a == 0 = x | otherwise = x + a - (x `mod` a) push_arg :: CmmActual {-current argument-} -> NatM InstrBlock -- code push_arg arg -- we don't need the hints on x86 | isWord64 arg_ty = do ChildCode64 code r_lo <- iselExpr64 arg delta <- getDeltaNat setDeltaNat (delta - 8) let r_hi = getHiVRegFromLo r_lo return ( code `appOL` toOL [PUSH II32 (OpReg r_hi), DELTA (delta - 4), PUSH II32 (OpReg r_lo), DELTA (delta - 8), DELTA (delta-8)] ) | isFloatType arg_ty = do (reg, code) <- getSomeReg arg delta <- getDeltaNat setDeltaNat (delta-size) return (code `appOL` toOL [SUB II32 (OpImm (ImmInt size)) (OpReg esp), DELTA (delta-size), let addr = AddrBaseIndex (EABaseReg esp) EAIndexNone (ImmInt 0) format = floatFormat (typeWidth arg_ty) in -- assume SSE2 MOV format (OpReg reg) (OpAddr addr) ] ) | otherwise = do -- Arguments can be smaller than 32-bit, but we still use @PUSH -- II32@ - the usual calling conventions expect integers to be -- 4-byte aligned. ASSERT((typeWidth arg_ty) <= W32) return () (operand, code) <- getOperand arg delta <- getDeltaNat setDeltaNat (delta-size) return (code `snocOL` PUSH II32 operand `snocOL` DELTA (delta-size)) where arg_ty = cmmExprType dflags arg size = arg_size_bytes arg_ty -- Byte size genCCall64' :: DynFlags -> ForeignTarget -- function to call -> [CmmFormal] -- where to put the result -> [CmmActual] -- arguments (of mixed type) -> NatM InstrBlock genCCall64' dflags target dest_regs args = do -- load up the register arguments let prom_args = map (maybePromoteCArg dflags W32) args (stack_args, int_regs_used, fp_regs_used, load_args_code, assign_args_code) <- if platformOS platform == OSMinGW32 then load_args_win prom_args [] [] (allArgRegs platform) nilOL else do (stack_args, aregs, fregs, load_args_code, assign_args_code) <- load_args prom_args (allIntArgRegs platform) (allFPArgRegs platform) nilOL nilOL let used_regs rs as = reverse (drop (length rs) (reverse as)) fregs_used = used_regs fregs (allFPArgRegs platform) aregs_used = used_regs aregs (allIntArgRegs platform) return (stack_args, aregs_used, fregs_used, load_args_code , assign_args_code) let arg_regs_used = int_regs_used ++ fp_regs_used arg_regs = [eax] ++ arg_regs_used -- for annotating the call instruction with sse_regs = length fp_regs_used arg_stack_slots = if platformOS platform == OSMinGW32 then length stack_args + length (allArgRegs platform) else length stack_args tot_arg_size = arg_size * arg_stack_slots -- Align stack to 16n for calls, assuming a starting stack -- alignment of 16n - word_size on procedure entry. Which we -- maintain. See Note [rts/StgCRun.c : Stack Alignment on X86] (real_size, adjust_rsp) <- if (tot_arg_size + wORD_SIZE dflags) `rem` 16 == 0 then return (tot_arg_size, nilOL) else do -- we need to adjust... delta <- getDeltaNat setDeltaNat (delta - wORD_SIZE dflags) return (tot_arg_size + wORD_SIZE dflags, toOL [ SUB II64 (OpImm (ImmInt (wORD_SIZE dflags))) (OpReg rsp), DELTA (delta - wORD_SIZE dflags) ]) -- push the stack args, right to left push_code <- push_args (reverse stack_args) nilOL -- On Win64, we also have to leave stack space for the arguments -- that we are passing in registers lss_code <- if platformOS platform == OSMinGW32 then leaveStackSpace (length (allArgRegs platform)) else return nilOL delta <- getDeltaNat -- deal with static vs dynamic call targets (callinsns,_cconv) <- case target of ForeignTarget (CmmLit (CmmLabel lbl)) conv -> -- ToDo: stdcall arg sizes return (unitOL (CALL (Left fn_imm) arg_regs), conv) where fn_imm = ImmCLbl lbl ForeignTarget expr conv -> do (dyn_r, dyn_c) <- getSomeReg expr return (dyn_c `snocOL` CALL (Right dyn_r) arg_regs, conv) PrimTarget _ -> panic $ "genCCall: Can't handle PrimTarget call type here, error " ++ "probably because too many return values." let -- The x86_64 ABI requires us to set %al to the number of SSE2 -- registers that contain arguments, if the called routine -- is a varargs function. We don't know whether it's a -- varargs function or not, so we have to assume it is. -- -- It's not safe to omit this assignment, even if the number -- of SSE2 regs in use is zero. If %al is larger than 8 -- on entry to a varargs function, seg faults ensue. assign_eax n = unitOL (MOV II32 (OpImm (ImmInt n)) (OpReg eax)) let call = callinsns `appOL` toOL ( -- Deallocate parameters after call for ccall; -- stdcall has callee do it, but is not supported on -- x86_64 target (see #3336) (if real_size==0 then [] else [ADD (intFormat (wordWidth dflags)) (OpImm (ImmInt real_size)) (OpReg esp)]) ++ [DELTA (delta + real_size)] ) setDeltaNat (delta + real_size) let -- assign the results, if necessary assign_code [] = nilOL assign_code [dest] = case typeWidth rep of W32 | isFloatType rep -> unitOL (MOV (floatFormat W32) (OpReg xmm0) (OpReg r_dest)) W64 | isFloatType rep -> unitOL (MOV (floatFormat W64) (OpReg xmm0) (OpReg r_dest)) _ -> unitOL (MOV (cmmTypeFormat rep) (OpReg rax) (OpReg r_dest)) where rep = localRegType dest r_dest = getRegisterReg platform (CmmLocal dest) assign_code _many = panic "genCCall.assign_code many" return (adjust_rsp `appOL` push_code `appOL` load_args_code `appOL` assign_args_code `appOL` lss_code `appOL` assign_eax sse_regs `appOL` call `appOL` assign_code dest_regs) where platform = targetPlatform dflags arg_size = 8 -- always, at the mo load_args :: [CmmExpr] -> [Reg] -- int regs avail for args -> [Reg] -- FP regs avail for args -> InstrBlock -- code computing args -> InstrBlock -- code assigning args to ABI regs -> NatM ([CmmExpr],[Reg],[Reg],InstrBlock,InstrBlock) -- no more regs to use load_args args [] [] code acode = return (args, [], [], code, acode) -- no more args to push load_args [] aregs fregs code acode = return ([], aregs, fregs, code, acode) load_args (arg : rest) aregs fregs code acode | isFloatType arg_rep = case fregs of [] -> push_this_arg (r:rs) -> do (code',acode') <- reg_this_arg r load_args rest aregs rs code' acode' | otherwise = case aregs of [] -> push_this_arg (r:rs) -> do (code',acode') <- reg_this_arg r load_args rest rs fregs code' acode' where -- put arg into the list of stack pushed args push_this_arg = do (args',ars,frs,code',acode') <- load_args rest aregs fregs code acode return (arg:args', ars, frs, code', acode') -- pass the arg into the given register reg_this_arg r -- "operand" args can be directly assigned into r | isOperand False arg = do arg_code <- getAnyReg arg return (code, (acode `appOL` arg_code r)) -- The last non-operand arg can be directly assigned after its -- computation without going into a temporary register | all (isOperand False) rest = do arg_code <- getAnyReg arg return (code `appOL` arg_code r,acode) -- other args need to be computed beforehand to avoid clobbering -- previously assigned registers used to pass parameters (see -- #11792, #12614). They are assigned into temporary registers -- and get assigned to proper call ABI registers after they all -- have been computed. | otherwise = do arg_code <- getAnyReg arg tmp <- getNewRegNat arg_fmt let code' = code `appOL` arg_code tmp acode' = acode `snocOL` reg2reg arg_fmt tmp r return (code',acode') arg_rep = cmmExprType dflags arg arg_fmt = cmmTypeFormat arg_rep load_args_win :: [CmmExpr] -> [Reg] -- used int regs -> [Reg] -- used FP regs -> [(Reg, Reg)] -- (int, FP) regs avail for args -> InstrBlock -> NatM ([CmmExpr],[Reg],[Reg],InstrBlock,InstrBlock) load_args_win args usedInt usedFP [] code = return (args, usedInt, usedFP, code, nilOL) -- no more regs to use load_args_win [] usedInt usedFP _ code = return ([], usedInt, usedFP, code, nilOL) -- no more args to push load_args_win (arg : rest) usedInt usedFP ((ireg, freg) : regs) code | isFloatType arg_rep = do arg_code <- getAnyReg arg load_args_win rest (ireg : usedInt) (freg : usedFP) regs (code `appOL` arg_code freg `snocOL` -- If we are calling a varargs function -- then we need to define ireg as well -- as freg MOV II64 (OpReg freg) (OpReg ireg)) | otherwise = do arg_code <- getAnyReg arg load_args_win rest (ireg : usedInt) usedFP regs (code `appOL` arg_code ireg) where arg_rep = cmmExprType dflags arg push_args [] code = return code push_args (arg:rest) code | isFloatType arg_rep = do (arg_reg, arg_code) <- getSomeReg arg delta <- getDeltaNat setDeltaNat (delta-arg_size) let code' = code `appOL` arg_code `appOL` toOL [ SUB (intFormat (wordWidth dflags)) (OpImm (ImmInt arg_size)) (OpReg rsp), DELTA (delta-arg_size), MOV (floatFormat width) (OpReg arg_reg) (OpAddr (spRel dflags 0))] push_args rest code' | otherwise = do -- Arguments can be smaller than 64-bit, but we still use @PUSH -- II64@ - the usual calling conventions expect integers to be -- 8-byte aligned. ASSERT(width <= W64) return () (arg_op, arg_code) <- getOperand arg delta <- getDeltaNat setDeltaNat (delta-arg_size) let code' = code `appOL` arg_code `appOL` toOL [ PUSH II64 arg_op, DELTA (delta-arg_size)] push_args rest code' where arg_rep = cmmExprType dflags arg width = typeWidth arg_rep leaveStackSpace n = do delta <- getDeltaNat setDeltaNat (delta - n * arg_size) return $ toOL [ SUB II64 (OpImm (ImmInt (n * wORD_SIZE dflags))) (OpReg rsp), DELTA (delta - n * arg_size)] maybePromoteCArg :: DynFlags -> Width -> CmmExpr -> CmmExpr maybePromoteCArg dflags wto arg | wfrom < wto = CmmMachOp (MO_UU_Conv wfrom wto) [arg] | otherwise = arg where wfrom = cmmExprWidth dflags arg outOfLineCmmOp :: BlockId -> CallishMachOp -> Maybe CmmFormal -> [CmmActual] -> NatM InstrBlock outOfLineCmmOp bid mop res args = do dflags <- getDynFlags targetExpr <- cmmMakeDynamicReference dflags CallReference lbl let target = ForeignTarget targetExpr (ForeignConvention CCallConv [] [] CmmMayReturn) -- We know foreign calls results in no new basic blocks, so we can ignore -- the returned block id. (instrs, _) <- stmtToInstrs bid (CmmUnsafeForeignCall target (catMaybes [res]) args) return instrs where -- Assume we can call these functions directly, and that they're not in a dynamic library. -- TODO: Why is this ok? Under linux this code will be in libm.so -- Is it because they're really implemented as a primitive instruction by the assembler?? -- BL 2009/12/31 lbl = mkForeignLabel fn Nothing ForeignLabelInThisPackage IsFunction fn = case mop of MO_F32_Sqrt -> fsLit "sqrtf" MO_F32_Fabs -> fsLit "fabsf" MO_F32_Sin -> fsLit "sinf" MO_F32_Cos -> fsLit "cosf" MO_F32_Tan -> fsLit "tanf" MO_F32_Exp -> fsLit "expf" MO_F32_ExpM1 -> fsLit "expm1f" MO_F32_Log -> fsLit "logf" MO_F32_Log1P -> fsLit "log1pf" MO_F32_Asin -> fsLit "asinf" MO_F32_Acos -> fsLit "acosf" MO_F32_Atan -> fsLit "atanf" MO_F32_Sinh -> fsLit "sinhf" MO_F32_Cosh -> fsLit "coshf" MO_F32_Tanh -> fsLit "tanhf" MO_F32_Pwr -> fsLit "powf" MO_F32_Asinh -> fsLit "asinhf" MO_F32_Acosh -> fsLit "acoshf" MO_F32_Atanh -> fsLit "atanhf" MO_F64_Sqrt -> fsLit "sqrt" MO_F64_Fabs -> fsLit "fabs" MO_F64_Sin -> fsLit "sin" MO_F64_Cos -> fsLit "cos" MO_F64_Tan -> fsLit "tan" MO_F64_Exp -> fsLit "exp" MO_F64_ExpM1 -> fsLit "expm1" MO_F64_Log -> fsLit "log" MO_F64_Log1P -> fsLit "log1p" MO_F64_Asin -> fsLit "asin" MO_F64_Acos -> fsLit "acos" MO_F64_Atan -> fsLit "atan" MO_F64_Sinh -> fsLit "sinh" MO_F64_Cosh -> fsLit "cosh" MO_F64_Tanh -> fsLit "tanh" MO_F64_Pwr -> fsLit "pow" MO_F64_Asinh -> fsLit "asinh" MO_F64_Acosh -> fsLit "acosh" MO_F64_Atanh -> fsLit "atanh" MO_Memcpy _ -> fsLit "memcpy" MO_Memset _ -> fsLit "memset" MO_Memmove _ -> fsLit "memmove" MO_Memcmp _ -> fsLit "memcmp" MO_PopCnt _ -> fsLit "popcnt" MO_BSwap _ -> fsLit "bswap" {- Here the C implementation is used as there is no x86 instruction to reverse a word's bit order. -} MO_BRev w -> fsLit $ bRevLabel w MO_Clz w -> fsLit $ clzLabel w MO_Ctz _ -> unsupported MO_Pdep w -> fsLit $ pdepLabel w MO_Pext w -> fsLit $ pextLabel w MO_AtomicRMW _ _ -> fsLit "atomicrmw" MO_AtomicRead _ -> fsLit "atomicread" MO_AtomicWrite _ -> fsLit "atomicwrite" MO_Cmpxchg _ -> fsLit "cmpxchg" MO_UF_Conv _ -> unsupported MO_S_QuotRem {} -> unsupported MO_U_QuotRem {} -> unsupported MO_U_QuotRem2 {} -> unsupported MO_Add2 {} -> unsupported MO_AddIntC {} -> unsupported MO_SubIntC {} -> unsupported MO_AddWordC {} -> unsupported MO_SubWordC {} -> unsupported MO_U_Mul2 {} -> unsupported MO_ReadBarrier -> unsupported MO_WriteBarrier -> unsupported MO_Touch -> unsupported (MO_Prefetch_Data _ ) -> unsupported unsupported = panic ("outOfLineCmmOp: " ++ show mop ++ " not supported here") -- ----------------------------------------------------------------------------- -- Generating a table-branch genSwitch :: DynFlags -> CmmExpr -> SwitchTargets -> NatM InstrBlock genSwitch dflags expr targets | positionIndependent dflags = do (reg,e_code) <- getNonClobberedReg (cmmOffset dflags expr offset) -- getNonClobberedReg because it needs to survive across t_code lbl <- getNewLabelNat dflags <- getDynFlags let is32bit = target32Bit (targetPlatform dflags) os = platformOS (targetPlatform dflags) -- Might want to use .rodata. instead, but as -- long as it's something unique it'll work out since the -- references to the jump table are in the appropriate section. rosection = case os of -- on Mac OS X/x86_64, put the jump table in the text section to -- work around a limitation of the linker. -- ld64 is unable to handle the relocations for -- .quad L1 - L0 -- if L0 is not preceded by a non-anonymous label in its section. OSDarwin | not is32bit -> Section Text lbl _ -> Section ReadOnlyData lbl dynRef <- cmmMakeDynamicReference dflags DataReference lbl (tableReg,t_code) <- getSomeReg $ dynRef let op = OpAddr (AddrBaseIndex (EABaseReg tableReg) (EAIndex reg (wORD_SIZE dflags)) (ImmInt 0)) offsetReg <- getNewRegNat (intFormat (wordWidth dflags)) return $ if is32bit || os == OSDarwin then e_code `appOL` t_code `appOL` toOL [ ADD (intFormat (wordWidth dflags)) op (OpReg tableReg), JMP_TBL (OpReg tableReg) ids rosection lbl ] else -- HACK: On x86_64 binutils<2.17 is only able to generate -- PC32 relocations, hence we only get 32-bit offsets in -- the jump table. As these offsets are always negative -- we need to properly sign extend them to 64-bit. This -- hack should be removed in conjunction with the hack in -- PprMach.hs/pprDataItem once binutils 2.17 is standard. e_code `appOL` t_code `appOL` toOL [ MOVSxL II32 op (OpReg offsetReg), ADD (intFormat (wordWidth dflags)) (OpReg offsetReg) (OpReg tableReg), JMP_TBL (OpReg tableReg) ids rosection lbl ] | otherwise = do (reg,e_code) <- getSomeReg (cmmOffset dflags expr offset) lbl <- getNewLabelNat let op = OpAddr (AddrBaseIndex EABaseNone (EAIndex reg (wORD_SIZE dflags)) (ImmCLbl lbl)) code = e_code `appOL` toOL [ JMP_TBL op ids (Section ReadOnlyData lbl) lbl ] return code where (offset, blockIds) = switchTargetsToTable targets ids = map (fmap DestBlockId) blockIds generateJumpTableForInstr :: DynFlags -> Instr -> Maybe (NatCmmDecl (Alignment, CmmStatics) Instr) generateJumpTableForInstr dflags (JMP_TBL _ ids section lbl) = let getBlockId (DestBlockId id) = id getBlockId _ = panic "Non-Label target in Jump Table" blockIds = map (fmap getBlockId) ids in Just (createJumpTable dflags blockIds section lbl) generateJumpTableForInstr _ _ = Nothing createJumpTable :: DynFlags -> [Maybe BlockId] -> Section -> CLabel -> GenCmmDecl (Alignment, CmmStatics) h g createJumpTable dflags ids section lbl = let jumpTable | positionIndependent dflags = let ww = wordWidth dflags jumpTableEntryRel Nothing = CmmStaticLit (CmmInt 0 ww) jumpTableEntryRel (Just blockid) = CmmStaticLit (CmmLabelDiffOff blockLabel lbl 0 ww) where blockLabel = blockLbl blockid in map jumpTableEntryRel ids | otherwise = map (jumpTableEntry dflags) ids in CmmData section (mkAlignment 1, Statics lbl jumpTable) extractUnwindPoints :: [Instr] -> [UnwindPoint] extractUnwindPoints instrs = [ UnwindPoint lbl unwinds | UNWIND lbl unwinds <- instrs] -- ----------------------------------------------------------------------------- -- 'condIntReg' and 'condFltReg': condition codes into registers -- Turn those condition codes into integers now (when they appear on -- the right hand side of an assignment). -- -- (If applicable) Do not fill the delay slots here; you will confuse the -- register allocator. condIntReg :: Cond -> CmmExpr -> CmmExpr -> NatM Register condIntReg cond x y = do CondCode _ cond cond_code <- condIntCode cond x y tmp <- getNewRegNat II8 let code dst = cond_code `appOL` toOL [ SETCC cond (OpReg tmp), MOVZxL II8 (OpReg tmp) (OpReg dst) ] return (Any II32 code) ----------------------------------------------------------- --- Note [SSE Parity Checks] --- ----------------------------------------------------------- -- We have to worry about unordered operands (eg. comparisons -- against NaN). If the operands are unordered, the comparison -- sets the parity flag, carry flag and zero flag. -- All comparisons are supposed to return false for unordered -- operands except for !=, which returns true. -- -- Optimisation: we don't have to test the parity flag if we -- know the test has already excluded the unordered case: eg > -- and >= test for a zero carry flag, which can only occur for -- ordered operands. -- -- By reversing comparisons we can avoid testing the parity -- for < and <= as well. If any of the arguments is an NaN we -- return false either way. If both arguments are valid then -- x <= y <-> y >= x holds. So it's safe to swap these. -- -- We invert the condition inside getRegister'and getCondCode -- which should cover all invertable cases. -- All other functions translating FP comparisons to assembly -- use these to two generate the comparison code. -- -- As an example consider a simple check: -- -- func :: Float -> Float -> Int -- func x y = if x < y then 1 else 0 -- -- Which in Cmm gives the floating point comparison. -- -- if (%MO_F_Lt_W32(F1, F2)) goto c2gg; else goto c2gf; -- -- We used to compile this to an assembly code block like this: -- _c2gh: -- ucomiss %xmm2,%xmm1 -- jp _c2gf -- jb _c2gg -- jmp _c2gf -- -- Where we have to introduce an explicit -- check for unordered results (using jmp parity): -- -- We can avoid this by exchanging the arguments and inverting the direction -- of the comparison. This results in the sequence of: -- -- ucomiss %xmm1,%xmm2 -- ja _c2g2 -- jmp _c2g1 -- -- Removing the jump reduces the pressure on the branch predidiction system -- and plays better with the uOP cache. condFltReg :: Bool -> Cond -> CmmExpr -> CmmExpr -> NatM Register condFltReg is32Bit cond x y = condFltReg_sse2 where condFltReg_sse2 = do CondCode _ cond cond_code <- condFltCode cond x y tmp1 <- getNewRegNat (archWordFormat is32Bit) tmp2 <- getNewRegNat (archWordFormat is32Bit) let -- See Note [SSE Parity Checks] code dst = cond_code `appOL` (case cond of NE -> or_unordered dst GU -> plain_test dst GEU -> plain_test dst -- Use ASSERT so we don't break releases if these creep in. LTT -> ASSERT2(False, ppr "Should have been turned into >") and_ordered dst LE -> ASSERT2(False, ppr "Should have been turned into >=") and_ordered dst _ -> and_ordered dst) plain_test dst = toOL [ SETCC cond (OpReg tmp1), MOVZxL II8 (OpReg tmp1) (OpReg dst) ] or_unordered dst = toOL [ SETCC cond (OpReg tmp1), SETCC PARITY (OpReg tmp2), OR II8 (OpReg tmp1) (OpReg tmp2), MOVZxL II8 (OpReg tmp2) (OpReg dst) ] and_ordered dst = toOL [ SETCC cond (OpReg tmp1), SETCC NOTPARITY (OpReg tmp2), AND II8 (OpReg tmp1) (OpReg tmp2), MOVZxL II8 (OpReg tmp2) (OpReg dst) ] return (Any II32 code) -- ----------------------------------------------------------------------------- -- 'trivial*Code': deal with trivial instructions -- Trivial (dyadic: 'trivialCode', floating-point: 'trivialFCode', -- unary: 'trivialUCode', unary fl-pt:'trivialUFCode') instructions. -- Only look for constants on the right hand side, because that's -- where the generic optimizer will have put them. -- Similarly, for unary instructions, we don't have to worry about -- matching an StInt as the argument, because genericOpt will already -- have handled the constant-folding. {- The Rules of the Game are: * You cannot assume anything about the destination register dst; it may be anything, including a fixed reg. * You may compute an operand into a fixed reg, but you may not subsequently change the contents of that fixed reg. If you want to do so, first copy the value either to a temporary or into dst. You are free to modify dst even if it happens to be a fixed reg -- that's not your problem. * You cannot assume that a fixed reg will stay live over an arbitrary computation. The same applies to the dst reg. * Temporary regs obtained from getNewRegNat are distinct from each other and from all other regs, and stay live over arbitrary computations. -------------------- SDM's version of The Rules: * If getRegister returns Any, that means it can generate correct code which places the result in any register, period. Even if that register happens to be read during the computation. Corollary #1: this means that if you are generating code for an operation with two arbitrary operands, you cannot assign the result of the first operand into the destination register before computing the second operand. The second operand might require the old value of the destination register. Corollary #2: A function might be able to generate more efficient code if it knows the destination register is a new temporary (and therefore not read by any of the sub-computations). * If getRegister returns Any, then the code it generates may modify only: (a) fresh temporaries (b) the destination register (c) known registers (eg. %ecx is used by shifts) In particular, it may *not* modify global registers, unless the global register happens to be the destination register. -} trivialCode :: Width -> (Operand -> Operand -> Instr) -> Maybe (Operand -> Operand -> Instr) -> CmmExpr -> CmmExpr -> NatM Register trivialCode width instr m a b = do is32Bit <- is32BitPlatform trivialCode' is32Bit width instr m a b trivialCode' :: Bool -> Width -> (Operand -> Operand -> Instr) -> Maybe (Operand -> Operand -> Instr) -> CmmExpr -> CmmExpr -> NatM Register trivialCode' is32Bit width _ (Just revinstr) (CmmLit lit_a) b | is32BitLit is32Bit lit_a = do b_code <- getAnyReg b let code dst = b_code dst `snocOL` revinstr (OpImm (litToImm lit_a)) (OpReg dst) return (Any (intFormat width) code) trivialCode' _ width instr _ a b = genTrivialCode (intFormat width) instr a b -- This is re-used for floating pt instructions too. genTrivialCode :: Format -> (Operand -> Operand -> Instr) -> CmmExpr -> CmmExpr -> NatM Register genTrivialCode rep instr a b = do (b_op, b_code) <- getNonClobberedOperand b a_code <- getAnyReg a tmp <- getNewRegNat rep let -- We want the value of b to stay alive across the computation of a. -- But, we want to calculate a straight into the destination register, -- because the instruction only has two operands (dst := dst `op` src). -- The troublesome case is when the result of b is in the same register -- as the destination reg. In this case, we have to save b in a -- new temporary across the computation of a. code dst | dst `regClashesWithOp` b_op = b_code `appOL` unitOL (MOV rep b_op (OpReg tmp)) `appOL` a_code dst `snocOL` instr (OpReg tmp) (OpReg dst) | otherwise = b_code `appOL` a_code dst `snocOL` instr b_op (OpReg dst) return (Any rep code) regClashesWithOp :: Reg -> Operand -> Bool reg `regClashesWithOp` OpReg reg2 = reg == reg2 reg `regClashesWithOp` OpAddr amode = any (==reg) (addrModeRegs amode) _ `regClashesWithOp` _ = False ----------- trivialUCode :: Format -> (Operand -> Instr) -> CmmExpr -> NatM Register trivialUCode rep instr x = do x_code <- getAnyReg x let code dst = x_code dst `snocOL` instr (OpReg dst) return (Any rep code) ----------- trivialFCode_sse2 :: Width -> (Format -> Operand -> Operand -> Instr) -> CmmExpr -> CmmExpr -> NatM Register trivialFCode_sse2 pk instr x y = genTrivialCode format (instr format) x y where format = floatFormat pk trivialUFCode :: Format -> (Reg -> Reg -> Instr) -> CmmExpr -> NatM Register trivialUFCode format instr x = do (x_reg, x_code) <- getSomeReg x let code dst = x_code `snocOL` instr x_reg dst return (Any format code) -------------------------------------------------------------------------------- coerceInt2FP :: Width -> Width -> CmmExpr -> NatM Register coerceInt2FP from to x = coerce_sse2 where coerce_sse2 = do (x_op, x_code) <- getOperand x -- ToDo: could be a safe operand let opc = case to of W32 -> CVTSI2SS; W64 -> CVTSI2SD n -> panic $ "coerceInt2FP.sse: unhandled width (" ++ show n ++ ")" code dst = x_code `snocOL` opc (intFormat from) x_op dst return (Any (floatFormat to) code) -- works even if the destination rep is Width -> CmmExpr -> NatM Register coerceFP2Int from to x = coerceFP2Int_sse2 where coerceFP2Int_sse2 = do (x_op, x_code) <- getOperand x -- ToDo: could be a safe operand let opc = case from of W32 -> CVTTSS2SIQ; W64 -> CVTTSD2SIQ; n -> panic $ "coerceFP2Init.sse: unhandled width (" ++ show n ++ ")" code dst = x_code `snocOL` opc (intFormat to) x_op dst return (Any (intFormat to) code) -- works even if the destination rep is CmmExpr -> NatM Register coerceFP2FP to x = do (x_reg, x_code) <- getSomeReg x let opc = case to of W32 -> CVTSD2SS; W64 -> CVTSS2SD; n -> panic $ "coerceFP2FP: unhandled width (" ++ show n ++ ")" code dst = x_code `snocOL` opc x_reg dst return (Any ( floatFormat to) code) -------------------------------------------------------------------------------- sse2NegCode :: Width -> CmmExpr -> NatM Register sse2NegCode w x = do let fmt = floatFormat w x_code <- getAnyReg x -- This is how gcc does it, so it can't be that bad: let const = case fmt of FF32 -> CmmInt 0x80000000 W32 FF64 -> CmmInt 0x8000000000000000 W64 x@II8 -> wrongFmt x x@II16 -> wrongFmt x x@II32 -> wrongFmt x x@II64 -> wrongFmt x where wrongFmt x = panic $ "sse2NegCode: " ++ show x Amode amode amode_code <- memConstant (mkAlignment $ widthInBytes w) const tmp <- getNewRegNat fmt let code dst = x_code dst `appOL` amode_code `appOL` toOL [ MOV fmt (OpAddr amode) (OpReg tmp), XOR fmt (OpReg tmp) (OpReg dst) ] -- return (Any fmt code) isVecExpr :: CmmExpr -> Bool isVecExpr (CmmMachOp (MO_V_Insert {}) _) = True isVecExpr (CmmMachOp (MO_V_Extract {}) _) = True isVecExpr (CmmMachOp (MO_V_Add {}) _) = True isVecExpr (CmmMachOp (MO_V_Sub {}) _) = True isVecExpr (CmmMachOp (MO_V_Mul {}) _) = True isVecExpr (CmmMachOp (MO_VS_Quot {}) _) = True isVecExpr (CmmMachOp (MO_VS_Rem {}) _) = True isVecExpr (CmmMachOp (MO_VS_Neg {}) _) = True isVecExpr (CmmMachOp (MO_VF_Insert {}) _) = True isVecExpr (CmmMachOp (MO_VF_Extract {}) _) = True isVecExpr (CmmMachOp (MO_VF_Add {}) _) = True isVecExpr (CmmMachOp (MO_VF_Sub {}) _) = True isVecExpr (CmmMachOp (MO_VF_Mul {}) _) = True isVecExpr (CmmMachOp (MO_VF_Quot {}) _) = True isVecExpr (CmmMachOp (MO_VF_Neg {}) _) = True isVecExpr (CmmMachOp _ [e]) = isVecExpr e isVecExpr _ = False needLlvm :: NatM a needLlvm = sorry $ unlines ["The native code generator does not support vector" ,"instructions. Please use -fllvm."] -- | This works on the invariant that all jumps in the given blocks are required. -- Starting from there we try to make a few more jumps redundant by reordering -- them. -- We depend on the information in the CFG to do so so without a given CFG -- we do nothing. invertCondBranches :: Maybe CFG -- ^ CFG if present -> LabelMap a -- ^ Blocks with info tables -> [NatBasicBlock Instr] -- ^ List of basic blocks -> [NatBasicBlock Instr] invertCondBranches Nothing _ bs = bs invertCondBranches (Just cfg) keep bs = invert bs where invert :: [NatBasicBlock Instr] -> [NatBasicBlock Instr] invert ((BasicBlock lbl1 ins@(_:_:_xs)):b2@(BasicBlock lbl2 _):bs) | --pprTrace "Block" (ppr lbl1) True, (jmp1,jmp2) <- last2 ins , JXX cond1 target1 <- jmp1 , target1 == lbl2 --, pprTrace "CutChance" (ppr b1) True , JXX ALWAYS target2 <- jmp2 -- We have enough information to check if we can perform the inversion -- TODO: We could also check for the last asm instruction which sets -- status flags instead. Which I suspect is worse in terms of compiler -- performance, but might be applicable to more cases , Just edgeInfo1 <- getEdgeInfo lbl1 target1 cfg , Just edgeInfo2 <- getEdgeInfo lbl1 target2 cfg -- Both jumps come from the same cmm statement , transitionSource edgeInfo1 == transitionSource edgeInfo2 , CmmSource {trans_cmmNode = cmmCondBranch} <- transitionSource edgeInfo1 --Int comparisons are invertable , CmmCondBranch (CmmMachOp op _args) _ _ _ <- cmmCondBranch , Just _ <- maybeIntComparison op , Just invCond <- maybeInvertCond cond1 --Swap the last two jumps, invert the conditional jumps condition. = let jumps = case () of -- We are free the eliminate the jmp. So we do so. _ | not (mapMember target1 keep) -> [JXX invCond target2] -- If the conditional target is unlikely we put the other -- target at the front. | edgeWeight edgeInfo2 > edgeWeight edgeInfo1 -> [JXX invCond target2, JXX ALWAYS target1] -- Keep things as-is otherwise | otherwise -> [jmp1, jmp2] in --pprTrace "Cutable" (ppr [jmp1,jmp2] <+> text "=>" <+> ppr jumps) $ (BasicBlock lbl1 (dropTail 2 ins ++ jumps)) : invert (b2:bs) invert (b:bs) = b : invert bs invert [] = []