{-# LANGUAGE CPP #-}

-----------------------------------------------------------------------------
--
-- Machine-specific parts of the register allocator
--
-- (c) The University of Glasgow 1996-2004
--
-----------------------------------------------------------------------------
module GHC.CmmToAsm.PPC.RegInfo (
        JumpDest( DestBlockId ), getJumpDestBlockId,
        canShortcut,
        shortcutJump,

        shortcutStatics
)

where

#include "HsVersions.h"

import GHC.Prelude

import GHC.CmmToAsm.PPC.Instr

import GHC.Cmm.BlockId
import GHC.Cmm
import GHC.Cmm.CLabel

import GHC.Types.Unique
import GHC.Utils.Outputable (ppr, text, Outputable, (<>))

data JumpDest = DestBlockId BlockId

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

getJumpDestBlockId :: JumpDest -> Maybe BlockId
getJumpDestBlockId :: JumpDest -> Maybe BlockId
getJumpDestBlockId (DestBlockId BlockId
bid) = BlockId -> Maybe BlockId
forall a. a -> Maybe a
Just BlockId
bid

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


-- Here because it knows about JumpDest
shortcutStatics :: (BlockId -> Maybe JumpDest) -> RawCmmStatics -> RawCmmStatics
shortcutStatics :: (BlockId -> Maybe JumpDest) -> RawCmmStatics -> RawCmmStatics
shortcutStatics BlockId -> Maybe JumpDest
fn (CmmStaticsRaw CLabel
lbl [CmmStatic]
statics)
  = CLabel -> [CmmStatic] -> RawCmmStatics
forall (a :: Bool). CLabel -> [CmmStatic] -> GenCmmStatics a
CmmStaticsRaw CLabel
lbl ([CmmStatic] -> RawCmmStatics) -> [CmmStatic] -> RawCmmStatics
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 -> Unique -> CLabel
mkLocalBlockLabel Unique
uq
      Just (DestBlockId BlockId
blockid')  -> (BlockId -> Maybe JumpDest) -> BlockId -> CLabel
shortBlockId BlockId -> Maybe JumpDest
fn BlockId
blockid'
   where uq :: Unique
uq = BlockId -> Unique
forall a. Uniquable a => a -> Unique
getUnique BlockId
blockid