--
-- Code generator utilities; mostly monadic
--
--- (c) The University of Glasgow 2004
+-- (c) The University of Glasgow 2004-2006
--
-----------------------------------------------------------------------------
cgLit,
emitDataLits, emitRODataLits, emitIf, emitIfThenElse,
emitRtsCall, emitRtsCallWithVols, emitRtsCallWithResult,
- assignTemp, newTemp,
+ assignNonPtrTemp, newNonPtrTemp,
+ assignPtrTemp, newPtrTemp,
emitSimultaneously,
emitSwitch, emitLitSwitch,
tagToClosure,
addToMem, addToMemE,
mkWordCLit,
- mkStringCLit,
+ mkStringCLit, mkByteStringCLit,
packHalfWordsCLit,
blankWord
) where
#include "HsVersions.h"
import CgMonad
-import TyCon ( TyCon, tyConName )
-import Id ( Id )
-import Constants ( wORD_SIZE )
-import SMRep ( CgRep, StgWord, hALF_WORD_SIZE_IN_BITS, ByteOff,
- WordOff, idCgRep )
+import TyCon
+import Id
+import Constants
+import SMRep
import PprCmm ( {- instances -} )
import Cmm
import CLabel
import CmmUtils
-import MachOp ( MachRep(..), wordRep, MachOp(..), MachHint(..),
- mo_wordOr, mo_wordAnd, mo_wordNe, mo_wordEq,
- mo_wordULt, mo_wordUGt, mo_wordUGe, machRepByteWidth )
-import ForeignCall ( CCallConv(..) )
-import Literal ( Literal(..) )
-import Digraph ( SCC(..), stronglyConnComp )
-import ListSetOps ( assocDefault )
-import Util ( filterOut, sortLe )
-import DynFlags ( DynFlags(..), HscTarget(..) )
-import FastString ( LitString, bytesFS )
-import PackageConfig ( PackageId )
+import MachOp
+import ForeignCall
+import Literal
+import Digraph
+import ListSetOps
+import Util
+import DynFlags
+import FastString
+import PackageConfig
import Outputable
-import Char ( ord )
-import DATA_BITS
-import DATA_WORD ( Word8 )
-import Maybe ( isNothing )
+import MachRegs (callerSaveVolatileRegs)
+ -- HACK: this is part of the NCG so we shouldn't use this, but we need
+ -- it for now to eliminate the need for saved regs to be in CmmCall.
+ -- The long term solution is to factor callerSaveVolatileRegs
+ -- from nativeGen into codeGen
+
+import Data.Char
+import Data.Bits
+import Data.Word
+import Data.Maybe
-------------------------------------------------------------------------
--
emitRtsCallWithVols fun args vols
= emitRtsCall' [] fun args (Just vols)
-emitRtsCallWithResult :: CmmReg -> MachHint -> LitString
+emitRtsCallWithResult :: LocalReg -> MachHint -> LitString
-> [(CmmExpr,MachHint)] -> Code
emitRtsCallWithResult res hint fun args
= emitRtsCall' [(res,hint)] fun args Nothing
-- Make a call to an RTS C procedure
emitRtsCall'
- :: [(CmmReg,MachHint)]
+ :: CmmHintFormals
-> LitString
-> [(CmmExpr,MachHint)]
-> Maybe [GlobalReg]
-> Code
-emitRtsCall' res fun args vols = stmtC (CmmCall target res args vols)
+emitRtsCall' res fun args vols = do
+ stmtsC caller_save
+ stmtC (CmmCall target res args)
+ stmtsC caller_load
where
+ (caller_save, caller_load) = callerSaveVolatileRegs vols
target = CmmForeignCall fun_expr CCallConv
fun_expr = mkLblExpr (mkRtsCodeLabel fun)
--
-------------------------------------------------------------------------
-assignTemp :: CmmExpr -> FCode CmmExpr
+assignNonPtrTemp :: CmmExpr -> FCode CmmExpr
+-- For a non-trivial expression, e, create a local
+-- variable and assign the expression to it
+assignNonPtrTemp e
+ | isTrivialCmmExpr e = return e
+ | otherwise = do { reg <- newNonPtrTemp (cmmExprRep e)
+ ; stmtC (CmmAssign (CmmLocal reg) e)
+ ; return (CmmReg (CmmLocal reg)) }
+
+assignPtrTemp :: CmmExpr -> FCode CmmExpr
-- For a non-trivial expression, e, create a local
-- variable and assign the expression to it
-assignTemp e
+assignPtrTemp e
| isTrivialCmmExpr e = return e
- | otherwise = do { reg <- newTemp (cmmExprRep e)
- ; stmtC (CmmAssign reg e)
- ; return (CmmReg reg) }
+ | otherwise = do { reg <- newPtrTemp (cmmExprRep e)
+ ; stmtC (CmmAssign (CmmLocal reg) e)
+ ; return (CmmReg (CmmLocal reg)) }
+newNonPtrTemp :: MachRep -> FCode LocalReg
+newNonPtrTemp rep = do { uniq <- newUnique; return (LocalReg uniq rep KindNonPtr) }
-newTemp :: MachRep -> FCode CmmReg
-newTemp rep = do { uniq <- newUnique; return (CmmLocal (LocalReg uniq rep)) }
+newPtrTemp :: MachRep -> FCode LocalReg
+newPtrTemp rep = do { uniq <- newUnique; return (LocalReg uniq rep KindPtr) }
-------------------------------------------------------------------------
-- if we can knock off a bunch of default cases with one if, then do so
| Just deflt <- mb_deflt, (lowest_branch - lo_tag) >= n_branches
- = do { (assign_tag, tag_expr') <- assignTemp' tag_expr
+ = do { (assign_tag, tag_expr') <- assignNonPtrTemp' tag_expr
; let cond = cmmULtWord tag_expr' (CmmLit (mkIntCLit lowest_branch))
branch = CmmCondBranch cond deflt
; stmts <- mk_switch tag_expr' branches mb_deflt
}
| Just deflt <- mb_deflt, (hi_tag - highest_branch) >= n_branches
- = do { (assign_tag, tag_expr') <- assignTemp' tag_expr
+ = do { (assign_tag, tag_expr') <- assignNonPtrTemp' tag_expr
; let cond = cmmUGtWord tag_expr' (CmmLit (mkIntCLit highest_branch))
branch = CmmCondBranch cond deflt
; stmts <- mk_switch tag_expr' branches mb_deflt
}
| otherwise -- Use an if-tree
- = do { (assign_tag, tag_expr') <- assignTemp' tag_expr
+ = do { (assign_tag, tag_expr') <- assignNonPtrTemp' tag_expr
-- To avoid duplication
; lo_stmts <- mk_switch tag_expr' lo_branches mb_deflt
lo_tag (mid_tag-1) via_C
where
use_switch = {- pprTrace "mk_switch" (
ppr tag_expr <+> text "n_tags:" <+> int n_tags <+>
+ text "branches:" <+> ppr (map fst branches) <+>
text "n_branches:" <+> int n_branches <+>
- text "lo_tag: " <+> int lo_tag <+>
- text "hi_tag: " <+> int hi_tag <+>
- text "real_lo_tag: " <+> int real_lo_tag <+>
- text "real_hi_tag: " <+> int real_hi_tag) $ -}
+ text "lo_tag:" <+> int lo_tag <+>
+ text "hi_tag:" <+> int hi_tag <+>
+ text "real_lo_tag:" <+> int real_lo_tag <+>
+ text "real_hi_tag:" <+> int real_hi_tag) $ -}
ASSERT( n_branches > 1 && n_tags > 1 )
- n_tags > 2 && (small || dense || via_C)
- -- a 2-branch switch always turns into an if.
- small = n_tags <= 4
+ n_tags > 2 && (via_C || (dense && big_enough))
+ -- up to 4 branches we use a decision tree, otherwise
+ -- a switch (== jump table in the NCG). This seems to be
+ -- optimal, and corresponds with what gcc does.
+ big_enough = n_branches > 4
dense = n_branches > (n_tags `div` 2)
n_branches = length branches
is_lo (t,_) = t < mid_tag
-assignTemp' e
+assignNonPtrTemp' e
| isTrivialCmmExpr e = return (CmmNop, e)
- | otherwise = do { reg <- newTemp (cmmExprRep e)
- ; return (CmmAssign reg e, CmmReg reg) }
-
+ | otherwise = do { reg <- newNonPtrTemp (cmmExprRep e)
+ ; return (CmmAssign (CmmLocal reg) e, CmmReg (CmmLocal reg)) }
emitLitSwitch :: CmmExpr -- Tag to switch on
-> [(Literal, CgStmts)] -- Tagged branches
emitLitSwitch scrut [] deflt
= emitCgStmts deflt
emitLitSwitch scrut branches deflt_blk
- = do { scrut' <- assignTemp scrut
+ = do { scrut' <- assignNonPtrTemp scrut
; deflt_blk_id <- forkCgStmts deflt_blk
; blk <- mk_lit_switch scrut' deflt_blk_id (sortLe le branches)
; emitCgStmts blk }
; stmtC from_temp }
go_via_temp (CmmAssign dest src)
- = do { tmp <- newTemp (cmmRegRep dest)
- ; stmtC (CmmAssign tmp src)
- ; return (CmmAssign dest (CmmReg tmp)) }
+ = do { tmp <- newNonPtrTemp (cmmRegRep dest) -- TODO FIXME NOW if the pair of assignments move across a call this will be wrong
+ ; stmtC (CmmAssign (CmmLocal tmp) src)
+ ; return (CmmAssign dest (CmmReg (CmmLocal tmp))) }
go_via_temp (CmmStore dest src)
- = do { tmp <- newTemp (cmmExprRep src)
- ; stmtC (CmmAssign tmp src)
- ; return (CmmStore dest (CmmReg tmp)) }
+ = do { tmp <- newNonPtrTemp (cmmExprRep src) -- TODO FIXME NOW if the pair of assignemnts move across a call this will be wrong
+ ; stmtC (CmmAssign (CmmLocal tmp) src)
+ ; return (CmmStore dest (CmmReg (CmmLocal tmp))) }
in
mapCs do_component components
projects / ghc-hetmet.git / blobdiff