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authorBen Gamari <ben@smart-cactus.org>2018-11-07 08:06:18 -0500
committerBen Gamari <ben@smart-cactus.org>2018-11-07 08:09:40 -0500
commit39cd12b8d73b9d931ce1acaa7d9e74271c51086f (patch)
treead699c69d96bda2e5ffb3426e8b83a7ed34c711b
parent802ce6eb090838d4e7573d96cf056afd2d898b78 (diff)
downloadhaskell-39cd12b8d73b9d931ce1acaa7d9e74271c51086f.tar.gz
Revert "Multiple fixes / improvements for LLVM backend"
This reverts commit adcb5fb47c0942671d409b940d8884daa9359ca4.
-rw-r--r--compiler/llvmGen/Llvm/Types.hs2
-rw-r--r--compiler/llvmGen/LlvmCodeGen/Base.hs62
-rw-r--r--compiler/llvmGen/LlvmCodeGen/CodeGen.hs60
-rw-r--r--llvm-passes2
-rw-r--r--testsuite/tests/codeGen/should_run/all.T3
5 files changed, 62 insertions, 67 deletions
diff --git a/compiler/llvmGen/Llvm/Types.hs b/compiler/llvmGen/Llvm/Types.hs
index a45004d3a8..bc7bbaab1b 100644
--- a/compiler/llvmGen/Llvm/Types.hs
+++ b/compiler/llvmGen/Llvm/Types.hs
@@ -564,7 +564,7 @@ instance Outputable LlvmFuncAttr where
ppr OptSize = text "optsize"
ppr NoReturn = text "noreturn"
ppr NoUnwind = text "nounwind"
- ppr ReadNone = text "readnone"
+ ppr ReadNone = text "readnon"
ppr ReadOnly = text "readonly"
ppr Ssp = text "ssp"
ppr SspReq = text "ssqreq"
diff --git a/compiler/llvmGen/LlvmCodeGen/Base.hs b/compiler/llvmGen/LlvmCodeGen/Base.hs
index ec91bacc4c..6e20da48c1 100644
--- a/compiler/llvmGen/LlvmCodeGen/Base.hs
+++ b/compiler/llvmGen/LlvmCodeGen/Base.hs
@@ -26,7 +26,7 @@ module LlvmCodeGen.Base (
cmmToLlvmType, widthToLlvmFloat, widthToLlvmInt, llvmFunTy,
llvmFunSig, llvmFunArgs, llvmStdFunAttrs, llvmFunAlign, llvmInfAlign,
- llvmPtrBits, tysToParams, llvmFunSection, padLiveArgs, isSSE,
+ llvmPtrBits, tysToParams, llvmFunSection,
strCLabel_llvm, strDisplayName_llvm, strProcedureName_llvm,
getGlobalPtr, generateExternDecls,
@@ -58,8 +58,6 @@ import ErrUtils
import qualified Stream
import Control.Monad (ap)
-import Data.List (sort)
-import Data.Maybe (mapMaybe)
-- ----------------------------------------------------------------------------
-- * Some Data Types
@@ -149,58 +147,16 @@ llvmFunSection dflags lbl
-- | A Function's arguments
llvmFunArgs :: DynFlags -> LiveGlobalRegs -> [LlvmVar]
llvmFunArgs dflags live =
- map (lmGlobalRegArg dflags) (filter isPassed allRegs)
+ map (lmGlobalRegArg dflags) (filter isPassed (activeStgRegs platform))
where platform = targetPlatform dflags
- allRegs = activeStgRegs platform
- paddedLive = map (\(_,r) -> r) $ padLiveArgs live
- isLive r = r `elem` alwaysLive || r `elem` paddedLive
+ isLive r = not (isSSE r) || r `elem` alwaysLive || r `elem` live
isPassed r = not (isSSE r) || isLive r
-
-
-isSSE :: GlobalReg -> Bool
-isSSE (FloatReg _) = True
-isSSE (DoubleReg _) = True
-isSSE (XmmReg _) = True
-isSSE (YmmReg _) = True
-isSSE (ZmmReg _) = True
-isSSE _ = False
-
-sseRegNum :: GlobalReg -> Maybe Int
-sseRegNum (FloatReg i) = Just i
-sseRegNum (DoubleReg i) = Just i
-sseRegNum (XmmReg i) = Just i
-sseRegNum (YmmReg i) = Just i
-sseRegNum (ZmmReg i) = Just i
-sseRegNum _ = Nothing
-
--- the bool indicates whether the global reg was added as padding.
--- the returned list is not sorted in any particular order,
--- but does indicate the set of live registers needed, with SSE padding.
-padLiveArgs :: LiveGlobalRegs -> [(Bool, GlobalReg)]
-padLiveArgs live = allRegs
- where
- sseRegNums = sort $ mapMaybe sseRegNum live
- (_, padding) = foldl assignSlots (1, []) $ sseRegNums
- allRegs = padding ++ map (\r -> (False, r)) live
-
- assignSlots (i, acc) regNum
- | i == regNum = -- don't need padding here
- (i+1, acc)
- | i < regNum = let -- add padding for slots i .. regNum-1
- numNeeded = regNum-i
- acc' = genPad i numNeeded ++ acc
- in
- (regNum+1, acc')
- | otherwise = error "padLiveArgs -- i > regNum ??"
-
- genPad start n =
- take n $ flip map (iterate (+1) start) (\i ->
- (True, FloatReg i))
- -- NOTE: Picking float should be fine for the following reasons:
- -- (1) Float aliases with all the other SSE register types on
- -- the given platform.
- -- (2) The argument is not live anyways.
-
+ isSSE (FloatReg _) = True
+ isSSE (DoubleReg _) = True
+ isSSE (XmmReg _) = True
+ isSSE (YmmReg _) = True
+ isSSE (ZmmReg _) = True
+ isSSE _ = False
-- | Llvm standard fun attributes
llvmStdFunAttrs :: [LlvmFuncAttr]
diff --git a/compiler/llvmGen/LlvmCodeGen/CodeGen.hs b/compiler/llvmGen/LlvmCodeGen/CodeGen.hs
index de839fbdeb..bb82049dda 100644
--- a/compiler/llvmGen/LlvmCodeGen/CodeGen.hs
+++ b/compiler/llvmGen/LlvmCodeGen/CodeGen.hs
@@ -14,7 +14,7 @@ import LlvmCodeGen.Base
import LlvmCodeGen.Regs
import BlockId
-import CodeGen.Platform ( activeStgRegs )
+import CodeGen.Platform ( activeStgRegs, callerSaves )
import CLabel
import Cmm
import PprCmm
@@ -211,6 +211,7 @@ genCall t@(PrimTarget (MO_Prefetch_Data localityInt)) [] args
fptr <- liftExprData $ getFunPtr funTy t
argVars' <- castVarsW Signed $ zip argVars argTy
+ doTrashStmts
let argSuffix = [mkIntLit i32 0, mkIntLit i32 localityInt, mkIntLit i32 1]
statement $ Expr $ Call StdCall fptr (argVars' ++ argSuffix) []
| otherwise = panic $ "prefetch locality level integer must be between 0 and 3, given: " ++ (show localityInt)
@@ -293,6 +294,7 @@ genCall t@(PrimTarget op) [] args
fptr <- getFunPtrW funTy t
argVars' <- castVarsW Signed $ zip argVars argTy
+ doTrashStmts
let alignVal = mkIntLit i32 align
arguments = argVars' ++ (alignVal:isVolVal)
statement $ Expr $ Call StdCall fptr arguments []
@@ -447,6 +449,7 @@ genCall target res args = runStmtsDecls $ do
| never_returns = statement $ Unreachable
| otherwise = return ()
+ doTrashStmts
-- make the actual call
case retTy of
@@ -1787,9 +1790,12 @@ genLit _ CmmHighStackMark
funPrologue :: LiveGlobalRegs -> [CmmBlock] -> LlvmM StmtData
funPrologue live cmmBlocks = do
+ trash <- getTrashRegs
let getAssignedRegs :: CmmNode O O -> [CmmReg]
getAssignedRegs (CmmAssign reg _) = [reg]
- getAssignedRegs (CmmUnsafeForeignCall _ rs _) = map CmmLocal rs
+ -- Calls will trash all registers. Unfortunately, this needs them to
+ -- be stack-allocated in the first place.
+ getAssignedRegs (CmmUnsafeForeignCall _ rs _) = map CmmGlobal trash ++ map CmmLocal rs
getAssignedRegs _ = []
getRegsBlock (_, body, _) = concatMap getAssignedRegs $ blockToList body
assignedRegs = nub $ concatMap (getRegsBlock . blockSplit) cmmBlocks
@@ -1819,9 +1825,14 @@ funPrologue live cmmBlocks = do
funEpilogue :: LiveGlobalRegs -> LlvmM ([LlvmVar], LlvmStatements)
funEpilogue live = do
- -- the bool indicates whether the register is padding.
- let alwaysNeeded = map (\r -> (False, r)) alwaysLive
- livePadded = alwaysNeeded ++ padLiveArgs live
+ -- Have information and liveness optimisation is enabled?
+ let liveRegs = alwaysLive ++ live
+ isSSE (FloatReg _) = True
+ isSSE (DoubleReg _) = True
+ isSSE (XmmReg _) = True
+ isSSE (YmmReg _) = True
+ isSSE (ZmmReg _) = True
+ isSSE _ = False
-- Set to value or "undef" depending on whether the register is
-- actually live
@@ -1833,17 +1844,39 @@ funEpilogue live = do
let ty = (pLower . getVarType $ lmGlobalRegVar dflags r)
return (Just $ LMLitVar $ LMUndefLit ty, nilOL)
platform <- getDynFlag targetPlatform
- let allRegs = activeStgRegs platform
- loads <- flip mapM allRegs $ \r -> case () of
- _ | (False, r) `elem` livePadded
- -> loadExpr r -- if r is not padding, load it
- | not (isSSE r) || (True, r) `elem` livePadded
- -> loadUndef r
+ loads <- flip mapM (activeStgRegs platform) $ \r -> case () of
+ _ | r `elem` liveRegs -> loadExpr r
+ | not (isSSE r) -> loadUndef r
| otherwise -> return (Nothing, nilOL)
let (vars, stmts) = unzip loads
return (catMaybes vars, concatOL stmts)
+
+-- | A series of statements to trash all the STG registers.
+--
+-- In LLVM we pass the STG registers around everywhere in function calls.
+-- So this means LLVM considers them live across the entire function, when
+-- in reality they usually aren't. For Caller save registers across C calls
+-- the saving and restoring of them is done by the Cmm code generator,
+-- using Cmm local vars. So to stop LLVM saving them as well (and saving
+-- all of them since it thinks they're always live, we trash them just
+-- before the call by assigning the 'undef' value to them. The ones we
+-- need are restored from the Cmm local var and the ones we don't need
+-- are fine to be trashed.
+getTrashStmts :: LlvmM LlvmStatements
+getTrashStmts = do
+ regs <- getTrashRegs
+ stmts <- flip mapM regs $ \ r -> do
+ reg <- getCmmReg (CmmGlobal r)
+ let ty = (pLower . getVarType) reg
+ return $ Store (LMLitVar $ LMUndefLit ty) reg
+ return $ toOL stmts
+
+getTrashRegs :: LlvmM [GlobalReg]
+getTrashRegs = do plat <- getLlvmPlatform
+ return $ filter (callerSaves plat) (activeStgRegs plat)
+
-- | Get a function pointer to the CLabel specified.
--
-- This is for Haskell functions, function type is assumed, so doesn't work
@@ -1965,6 +1998,11 @@ getCmmRegW = lift . getCmmReg
genLoadW :: Atomic -> CmmExpr -> CmmType -> WriterT LlvmAccum LlvmM LlvmVar
genLoadW atomic e ty = liftExprData $ genLoad atomic e ty
+doTrashStmts :: WriterT LlvmAccum LlvmM ()
+doTrashStmts = do
+ stmts <- lift getTrashStmts
+ tell $ LlvmAccum stmts mempty
+
-- | Return element of single-element list; 'panic' if list is not a single-element list
singletonPanic :: String -> [a] -> a
singletonPanic _ [x] = x
diff --git a/llvm-passes b/llvm-passes
index 14eb62d87c..5183c9f2ab 100644
--- a/llvm-passes
+++ b/llvm-passes
@@ -1,5 +1,5 @@
[
-(0, "-mem2reg -globalopt -lower-expect"),
+(0, "-mem2reg -globalopt"),
(1, "-O1 -globalopt"),
(2, "-O2")
]
diff --git a/testsuite/tests/codeGen/should_run/all.T b/testsuite/tests/codeGen/should_run/all.T
index f7ec405b16..3935574549 100644
--- a/testsuite/tests/codeGen/should_run/all.T
+++ b/testsuite/tests/codeGen/should_run/all.T
@@ -172,7 +172,8 @@ test('T13825-unit',
test('T14619', normal, compile_and_run, [''])
test('T14754', normal, compile_and_run, [''])
test('T14346', only_ways(['threaded1','threaded2']), compile_and_run, ['-O -threaded'])
-test('T14251', normal, compile_and_run, [''])
+test('T14251', [expect_broken_for(14251, ['optllvm'])],
+ compile_and_run, [''])
# These actually used to fail with all optimisation settings, but adding -O just
# to make sure