module SPARC.ShortcutJump (
        JumpDest(..), getJumpDestBlockId,
        canShortcut,
        shortcutJump,
        shortcutStatics,
        shortBlockId
)

where

import GhcPrelude

import SPARC.Instr
import SPARC.Imm

import CLabel
import BlockId
import Cmm

import Panic
import Outputable

data JumpDest
        = DestBlockId BlockId
        | DestImm Imm

-- Debug Instance
instance Outputable JumpDest where
  ppr :: JumpDest -> SDoc
ppr (DestBlockId BlockId
bid) = String -> SDoc
text String
"blk:" SDoc -> SDoc -> SDoc
<> BlockId -> SDoc
forall a. Outputable a => a -> SDoc
ppr BlockId
bid
  ppr (DestImm Imm
_bid)    = String -> SDoc
text String
"imm:?"

getJumpDestBlockId :: JumpDest -> Maybe BlockId
getJumpDestBlockId :: JumpDest -> Maybe BlockId
getJumpDestBlockId (DestBlockId BlockId
bid) = BlockId -> Maybe BlockId
forall a. a -> Maybe a
Just BlockId
bid
getJumpDestBlockId JumpDest
_                 = Maybe BlockId
forall a. Maybe a
Nothing


canShortcut :: Instr -> Maybe JumpDest
canShortcut :: Instr -> Maybe JumpDest
canShortcut Instr
_ = Maybe JumpDest
forall a. Maybe a
Nothing


shortcutJump :: (BlockId -> Maybe JumpDest) -> Instr -> Instr
shortcutJump :: (BlockId -> Maybe JumpDest) -> Instr -> Instr
shortcutJump BlockId -> Maybe JumpDest
_ Instr
other = Instr
other



shortcutStatics :: (BlockId -> Maybe JumpDest) -> CmmStatics -> CmmStatics
shortcutStatics :: (BlockId -> Maybe JumpDest) -> CmmStatics -> CmmStatics
shortcutStatics BlockId -> Maybe JumpDest
fn (Statics CLabel
lbl [CmmStatic]
statics)
  = CLabel -> [CmmStatic] -> CmmStatics
Statics CLabel
lbl ([CmmStatic] -> CmmStatics) -> [CmmStatic] -> CmmStatics
forall a b. (a -> b) -> a -> b
$ (CmmStatic -> CmmStatic) -> [CmmStatic] -> [CmmStatic]
forall a b. (a -> b) -> [a] -> [b]
map ((BlockId -> Maybe JumpDest) -> CmmStatic -> CmmStatic
shortcutStatic BlockId -> Maybe JumpDest
fn) [CmmStatic]
statics
  -- we need to get the jump tables, so apply the mapping to the entries
  -- of a CmmData too.

shortcutLabel :: (BlockId -> Maybe JumpDest) -> CLabel -> CLabel
shortcutLabel :: (BlockId -> Maybe JumpDest) -> CLabel -> CLabel
shortcutLabel BlockId -> Maybe JumpDest
fn CLabel
lab
  | Just BlockId
blkId <- CLabel -> Maybe BlockId
maybeLocalBlockLabel CLabel
lab = (BlockId -> Maybe JumpDest) -> BlockId -> CLabel
shortBlockId BlockId -> Maybe JumpDest
fn BlockId
blkId
  | Bool
otherwise                              = CLabel
lab

shortcutStatic :: (BlockId -> Maybe JumpDest) -> CmmStatic -> CmmStatic
shortcutStatic :: (BlockId -> Maybe JumpDest) -> CmmStatic -> CmmStatic
shortcutStatic BlockId -> Maybe JumpDest
fn (CmmStaticLit (CmmLabel CLabel
lab))
        = CmmLit -> CmmStatic
CmmStaticLit (CLabel -> CmmLit
CmmLabel ((BlockId -> Maybe JumpDest) -> CLabel -> CLabel
shortcutLabel BlockId -> Maybe JumpDest
fn CLabel
lab))
shortcutStatic BlockId -> Maybe JumpDest
fn (CmmStaticLit (CmmLabelDiffOff CLabel
lbl1 CLabel
lbl2 Int
off Width
w))
        = CmmLit -> CmmStatic
CmmStaticLit (CLabel -> CLabel -> Int -> Width -> CmmLit
CmmLabelDiffOff ((BlockId -> Maybe JumpDest) -> CLabel -> CLabel
shortcutLabel BlockId -> Maybe JumpDest
fn CLabel
lbl1) CLabel
lbl2 Int
off Width
w)
-- slightly dodgy, we're ignoring the second label, but this
-- works with the way we use CmmLabelDiffOff for jump tables now.
shortcutStatic BlockId -> Maybe JumpDest
_ CmmStatic
other_static
        = CmmStatic
other_static


shortBlockId :: (BlockId -> Maybe JumpDest) -> BlockId -> CLabel
shortBlockId :: (BlockId -> Maybe JumpDest) -> BlockId -> CLabel
shortBlockId BlockId -> Maybe JumpDest
fn BlockId
blockid =
   case BlockId -> Maybe JumpDest
fn BlockId
blockid of
      Maybe JumpDest
Nothing -> BlockId -> CLabel
blockLbl BlockId
blockid
      Just (DestBlockId BlockId
blockid')  -> (BlockId -> Maybe JumpDest) -> BlockId -> CLabel
shortBlockId BlockId -> Maybe JumpDest
fn BlockId
blockid'
      Just (DestImm (ImmCLbl CLabel
lbl)) -> CLabel
lbl
      Maybe JumpDest
_other -> String -> CLabel
forall a. String -> a
panic String
"shortBlockId"