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{-# LANGUAGE CPP, GADTs #-}
{-# OPTIONS_GHC -fno-warn-type-defaults #-}
-- ----------------------------------------------------------------------------
-- | Handle conversion of CmmProc to LLVM code.
--
module LlvmCodeGen.CodeGen ( genLlvmProc ) where
#include "HsVersions.h"
import GhcPrelude
import Llvm
import LlvmCodeGen.Base
import LlvmCodeGen.Regs
import BlockId
import CodeGen.Platform ( activeStgRegs, callerSaves )
import CLabel
import Cmm
import PprCmm
import CmmUtils
import CmmSwitch
import Hoopl.Block
import Hoopl.Graph
import Hoopl.Collections
import DynFlags
import FastString
import ForeignCall
import Outputable hiding (panic, pprPanic)
import qualified Outputable
import GHC.Platform
import OrdList
import UniqSupply
import Unique
import Util
import Control.Monad.Trans.Class
import Control.Monad.Trans.Writer
import qualified Data.Semigroup as Semigroup
import Data.List ( nub )
import Data.Maybe ( catMaybes )
type Atomic = Bool
type LlvmStatements = OrdList LlvmStatement
data Signage = Signed | Unsigned deriving (Eq, Show)
-- -----------------------------------------------------------------------------
-- | Top-level of the LLVM proc Code generator
--
genLlvmProc :: RawCmmDecl -> LlvmM [LlvmCmmDecl]
genLlvmProc (CmmProc infos lbl live graph) = do
let blocks = toBlockListEntryFirstFalseFallthrough graph
(lmblocks, lmdata) <- basicBlocksCodeGen live blocks
let info = mapLookup (g_entry graph) infos
proc = CmmProc info lbl live (ListGraph lmblocks)
return (proc:lmdata)
genLlvmProc _ = panic "genLlvmProc: case that shouldn't reach here!"
-- -----------------------------------------------------------------------------
-- * Block code generation
--
-- | Generate code for a list of blocks that make up a complete
-- procedure. The first block in the list is expected to be the entry
-- point and will get the prologue.
basicBlocksCodeGen :: LiveGlobalRegs -> [CmmBlock]
-> LlvmM ([LlvmBasicBlock], [LlvmCmmDecl])
basicBlocksCodeGen _ [] = panic "no entry block!"
basicBlocksCodeGen live (entryBlock:cmmBlocks)
= do (prologue, prologueTops) <- funPrologue live (entryBlock:cmmBlocks)
-- Generate code
(BasicBlock bid entry, entryTops) <- basicBlockCodeGen entryBlock
(blocks, topss) <- fmap unzip $ mapM basicBlockCodeGen cmmBlocks
-- Compose
let entryBlock = BasicBlock bid (fromOL prologue ++ entry)
return (entryBlock : blocks, prologueTops ++ entryTops ++ concat topss)
-- | Generate code for one block
basicBlockCodeGen :: CmmBlock -> LlvmM ( LlvmBasicBlock, [LlvmCmmDecl] )
basicBlockCodeGen block
= do let (_, nodes, tail) = blockSplit block
id = entryLabel block
(mid_instrs, top) <- stmtsToInstrs $ blockToList nodes
(tail_instrs, top') <- stmtToInstrs tail
let instrs = fromOL (mid_instrs `appOL` tail_instrs)
return (BasicBlock id instrs, top' ++ top)
-- -----------------------------------------------------------------------------
-- * CmmNode code generation
--
-- A statement conversion return data.
-- * LlvmStatements: The compiled LLVM statements.
-- * LlvmCmmDecl: Any global data needed.
type StmtData = (LlvmStatements, [LlvmCmmDecl])
-- | Convert a list of CmmNode's to LlvmStatement's
stmtsToInstrs :: [CmmNode e x] -> LlvmM StmtData
stmtsToInstrs stmts
= do (instrss, topss) <- fmap unzip $ mapM stmtToInstrs stmts
return (concatOL instrss, concat topss)
-- | Convert a CmmStmt to a list of LlvmStatement's
stmtToInstrs :: CmmNode e x -> LlvmM StmtData
stmtToInstrs stmt = case stmt of
CmmComment _ -> return (nilOL, []) -- nuke comments
CmmTick _ -> return (nilOL, [])
CmmUnwind {} -> return (nilOL, [])
CmmAssign reg src -> genAssign reg src
CmmStore addr src -> genStore addr src
CmmBranch id -> genBranch id
CmmCondBranch arg true false likely
-> genCondBranch arg true false likely
CmmSwitch arg ids -> genSwitch arg ids
-- Foreign Call
CmmUnsafeForeignCall target res args
-> genCall target res args
-- Tail call
CmmCall { cml_target = arg,
cml_args_regs = live } -> genJump arg live
_ -> panic "Llvm.CodeGen.stmtToInstrs"
-- | Wrapper function to declare an instrinct function by function type
getInstrinct2 :: LMString -> LlvmType -> LlvmM ExprData
getInstrinct2 fname fty@(LMFunction funSig) = do
let fv = LMGlobalVar fname fty (funcLinkage funSig) Nothing Nothing Constant
fn <- funLookup fname
tops <- case fn of
Just _ ->
return []
Nothing -> do
funInsert fname fty
un <- getUniqueM
let lbl = mkAsmTempLabel un
return [CmmData (Section Data lbl) [([],[fty])]]
return (fv, nilOL, tops)
getInstrinct2 _ _ = error "getInstrinct2: Non-function type!"
-- | Declares an instrinct function by return and parameter types
getInstrinct :: LMString -> LlvmType -> [LlvmType] -> LlvmM ExprData
getInstrinct fname retTy parTys =
let funSig = LlvmFunctionDecl fname ExternallyVisible CC_Ccc retTy
FixedArgs (tysToParams parTys) Nothing
fty = LMFunction funSig
in getInstrinct2 fname fty
-- | Memory barrier instruction for LLVM >= 3.0
barrier :: LlvmM StmtData
barrier = do
let s = Fence False SyncSeqCst
return (unitOL s, [])
-- | Insert a 'barrier', unless the target platform is in the provided list of
-- exceptions (where no code will be emitted instead).
barrierUnless :: [Arch] -> LlvmM StmtData
barrierUnless exs = do
platform <- getLlvmPlatform
if platformArch platform `elem` exs
then return (nilOL, [])
else barrier
-- | Foreign Calls
genCall :: ForeignTarget -> [CmmFormal] -> [CmmActual]
-> LlvmM StmtData
-- Barriers need to be handled specially as they are implemented as LLVM
-- intrinsic functions.
genCall (PrimTarget MO_ReadBarrier) _ _ =
barrierUnless [ArchX86, ArchX86_64, ArchSPARC]
genCall (PrimTarget MO_WriteBarrier) _ _ = do
barrierUnless [ArchX86, ArchX86_64, ArchSPARC]
genCall (PrimTarget MO_Touch) _ _
= return (nilOL, [])
genCall (PrimTarget (MO_UF_Conv w)) [dst] [e] = runStmtsDecls $ do
dstV <- getCmmRegW (CmmLocal dst)
let ty = cmmToLlvmType $ localRegType dst
width = widthToLlvmFloat w
castV <- lift $ mkLocalVar ty
ve <- exprToVarW e
statement $ Assignment castV $ Cast LM_Uitofp ve width
statement $ Store castV dstV
genCall (PrimTarget (MO_UF_Conv _)) [_] args =
panic $ "genCall: Too many arguments to MO_UF_Conv. " ++
"Can only handle 1, given" ++ show (length args) ++ "."
-- Handle prefetching data
genCall t@(PrimTarget (MO_Prefetch_Data localityInt)) [] args
| 0 <= localityInt && localityInt <= 3 = runStmtsDecls $ do
let argTy = [i8Ptr, i32, i32, i32]
funTy = \name -> LMFunction $ LlvmFunctionDecl name ExternallyVisible
CC_Ccc LMVoid FixedArgs (tysToParams argTy) Nothing
let (_, arg_hints) = foreignTargetHints t
let args_hints' = zip args arg_hints
argVars <- arg_varsW args_hints' ([], nilOL, [])
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)
-- Handle PopCnt, Clz, Ctz, and BSwap that need to only convert arg
-- and return types
genCall t@(PrimTarget (MO_PopCnt w)) dsts args =
genCallSimpleCast w t dsts args
genCall t@(PrimTarget (MO_Pdep w)) dsts args =
genCallSimpleCast2 w t dsts args
genCall t@(PrimTarget (MO_Pext w)) dsts args =
genCallSimpleCast2 w t dsts args
genCall t@(PrimTarget (MO_Clz w)) dsts args =
genCallSimpleCast w t dsts args
genCall t@(PrimTarget (MO_Ctz w)) dsts args =
genCallSimpleCast w t dsts args
genCall t@(PrimTarget (MO_BSwap w)) dsts args =
genCallSimpleCast w t dsts args
genCall t@(PrimTarget (MO_BRev w)) dsts args =
genCallSimpleCast w t dsts args
genCall (PrimTarget (MO_AtomicRMW width amop)) [dst] [addr, n] = runStmtsDecls $ do
addrVar <- exprToVarW addr
nVar <- exprToVarW n
let targetTy = widthToLlvmInt width
ptrExpr = Cast LM_Inttoptr addrVar (pLift targetTy)
ptrVar <- doExprW (pLift targetTy) ptrExpr
dstVar <- getCmmRegW (CmmLocal dst)
let op = case amop of
AMO_Add -> LAO_Add
AMO_Sub -> LAO_Sub
AMO_And -> LAO_And
AMO_Nand -> LAO_Nand
AMO_Or -> LAO_Or
AMO_Xor -> LAO_Xor
retVar <- doExprW targetTy $ AtomicRMW op ptrVar nVar SyncSeqCst
statement $ Store retVar dstVar
genCall (PrimTarget (MO_AtomicRead _)) [dst] [addr] = runStmtsDecls $ do
dstV <- getCmmRegW (CmmLocal dst)
v1 <- genLoadW True addr (localRegType dst)
statement $ Store v1 dstV
genCall (PrimTarget (MO_Cmpxchg _width))
[dst] [addr, old, new] = runStmtsDecls $ do
addrVar <- exprToVarW addr
oldVar <- exprToVarW old
newVar <- exprToVarW new
let targetTy = getVarType oldVar
ptrExpr = Cast LM_Inttoptr addrVar (pLift targetTy)
ptrVar <- doExprW (pLift targetTy) ptrExpr
dstVar <- getCmmRegW (CmmLocal dst)
retVar <- doExprW (LMStructU [targetTy,i1])
$ CmpXChg ptrVar oldVar newVar SyncSeqCst SyncSeqCst
retVar' <- doExprW targetTy $ ExtractV retVar 0
statement $ Store retVar' dstVar
genCall (PrimTarget (MO_AtomicWrite _width)) [] [addr, val] = runStmtsDecls $ do
addrVar <- exprToVarW addr
valVar <- exprToVarW val
let ptrTy = pLift $ getVarType valVar
ptrExpr = Cast LM_Inttoptr addrVar ptrTy
ptrVar <- doExprW ptrTy ptrExpr
statement $ Expr $ AtomicRMW LAO_Xchg ptrVar valVar SyncSeqCst
-- Handle memcpy function specifically since llvm's intrinsic version takes
-- some extra parameters.
genCall t@(PrimTarget op) [] args
| Just align <- machOpMemcpyishAlign op = runStmtsDecls $ do
dflags <- getDynFlags
let isVolTy = [i1]
isVolVal = [mkIntLit i1 0]
argTy | MO_Memset _ <- op = [i8Ptr, i8, llvmWord dflags, i32] ++ isVolTy
| otherwise = [i8Ptr, i8Ptr, llvmWord dflags, i32] ++ isVolTy
funTy = \name -> LMFunction $ LlvmFunctionDecl name ExternallyVisible
CC_Ccc LMVoid FixedArgs (tysToParams argTy) Nothing
let (_, arg_hints) = foreignTargetHints t
let args_hints = zip args arg_hints
argVars <- arg_varsW args_hints ([], nilOL, [])
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 []
-- We handle MO_U_Mul2 by simply using a 'mul' instruction, but with operands
-- twice the width (we first zero-extend them), e.g., on 64-bit arch we will
-- generate 'mul' on 128-bit operands. Then we only need some plumbing to
-- extract the two 64-bit values out of 128-bit result.
genCall (PrimTarget (MO_U_Mul2 w)) [dstH, dstL] [lhs, rhs] = runStmtsDecls $ do
let width = widthToLlvmInt w
bitWidth = widthInBits w
width2x = LMInt (bitWidth * 2)
-- First zero-extend the operands ('mul' instruction requires the operands
-- and the result to be of the same type). Note that we don't use 'castVars'
-- because it tries to do LM_Sext.
lhsVar <- exprToVarW lhs
rhsVar <- exprToVarW rhs
lhsExt <- doExprW width2x $ Cast LM_Zext lhsVar width2x
rhsExt <- doExprW width2x $ Cast LM_Zext rhsVar width2x
-- Do the actual multiplication (note that the result is also 2x width).
retV <- doExprW width2x $ LlvmOp LM_MO_Mul lhsExt rhsExt
-- Extract the lower bits of the result into retL.
retL <- doExprW width $ Cast LM_Trunc retV width
-- Now we right-shift the higher bits by width.
let widthLlvmLit = LMLitVar $ LMIntLit (fromIntegral bitWidth) width
retShifted <- doExprW width2x $ LlvmOp LM_MO_LShr retV widthLlvmLit
-- And extract them into retH.
retH <- doExprW width $ Cast LM_Trunc retShifted width
dstRegL <- getCmmRegW (CmmLocal dstL)
dstRegH <- getCmmRegW (CmmLocal dstH)
statement $ Store retL dstRegL
statement $ Store retH dstRegH
-- MO_U_QuotRem2 is another case we handle by widening the registers to double
-- the width and use normal LLVM instructions (similarly to the MO_U_Mul2). The
-- main difference here is that we need to combine two words into one register
-- and then use both 'udiv' and 'urem' instructions to compute the result.
genCall (PrimTarget (MO_U_QuotRem2 w))
[dstQ, dstR] [lhsH, lhsL, rhs] = runStmtsDecls $ do
let width = widthToLlvmInt w
bitWidth = widthInBits w
width2x = LMInt (bitWidth * 2)
-- First zero-extend all parameters to double width.
let zeroExtend expr = do
var <- exprToVarW expr
doExprW width2x $ Cast LM_Zext var width2x
lhsExtH <- zeroExtend lhsH
lhsExtL <- zeroExtend lhsL
rhsExt <- zeroExtend rhs
-- Now we combine the first two parameters (that represent the high and low
-- bits of the value). So first left-shift the high bits to their position
-- and then bit-or them with the low bits.
let widthLlvmLit = LMLitVar $ LMIntLit (fromIntegral bitWidth) width
lhsExtHShifted <- doExprW width2x $ LlvmOp LM_MO_Shl lhsExtH widthLlvmLit
lhsExt <- doExprW width2x $ LlvmOp LM_MO_Or lhsExtHShifted lhsExtL
-- Finally, we can call 'udiv' and 'urem' to compute the results.
retExtDiv <- doExprW width2x $ LlvmOp LM_MO_UDiv lhsExt rhsExt
retExtRem <- doExprW width2x $ LlvmOp LM_MO_URem lhsExt rhsExt
-- And since everything is in 2x width, we need to truncate the results and
-- then return them.
let narrow var = doExprW width $ Cast LM_Trunc var width
retDiv <- narrow retExtDiv
retRem <- narrow retExtRem
dstRegQ <- lift $ getCmmReg (CmmLocal dstQ)
dstRegR <- lift $ getCmmReg (CmmLocal dstR)
statement $ Store retDiv dstRegQ
statement $ Store retRem dstRegR
-- Handle the MO_{Add,Sub}IntC separately. LLVM versions return a record from
-- which we need to extract the actual values.
genCall t@(PrimTarget (MO_AddIntC w)) [dstV, dstO] [lhs, rhs] =
genCallWithOverflow t w [dstV, dstO] [lhs, rhs]
genCall t@(PrimTarget (MO_SubIntC w)) [dstV, dstO] [lhs, rhs] =
genCallWithOverflow t w [dstV, dstO] [lhs, rhs]
-- Similar to MO_{Add,Sub}IntC, but MO_Add2 expects the first element of the
-- return tuple to be the overflow bit and the second element to contain the
-- actual result of the addition. So we still use genCallWithOverflow but swap
-- the return registers.
genCall t@(PrimTarget (MO_Add2 w)) [dstO, dstV] [lhs, rhs] =
genCallWithOverflow t w [dstV, dstO] [lhs, rhs]
genCall t@(PrimTarget (MO_AddWordC w)) [dstV, dstO] [lhs, rhs] =
genCallWithOverflow t w [dstV, dstO] [lhs, rhs]
genCall t@(PrimTarget (MO_SubWordC w)) [dstV, dstO] [lhs, rhs] =
genCallWithOverflow t w [dstV, dstO] [lhs, rhs]
-- Handle all other foreign calls and prim ops.
genCall target res args = runStmtsDecls $ do
dflags <- getDynFlags
-- parameter types
let arg_type (_, AddrHint) = i8Ptr
-- cast pointers to i8*. Llvm equivalent of void*
arg_type (expr, _) = cmmToLlvmType $ cmmExprType dflags expr
-- ret type
let ret_type [] = LMVoid
ret_type [(_, AddrHint)] = i8Ptr
ret_type [(reg, _)] = cmmToLlvmType $ localRegType reg
ret_type t = panic $ "genCall: Too many return values! Can only handle"
++ " 0 or 1, given " ++ show (length t) ++ "."
-- extract Cmm call convention, and translate to LLVM call convention
platform <- lift $ getLlvmPlatform
let lmconv = case target of
ForeignTarget _ (ForeignConvention conv _ _ _) ->
case conv of
StdCallConv -> case platformArch platform of
ArchX86 -> CC_X86_Stdcc
ArchX86_64 -> CC_X86_Stdcc
_ -> CC_Ccc
CCallConv -> CC_Ccc
CApiConv -> CC_Ccc
PrimCallConv -> panic "LlvmCodeGen.CodeGen.genCall: PrimCallConv"
JavaScriptCallConv -> panic "LlvmCodeGen.CodeGen.genCall: JavaScriptCallConv"
PrimTarget _ -> CC_Ccc
{-
CC_Ccc of the possibilities here are a worry with the use of a custom
calling convention for passing STG args. In practice the more
dangerous combinations (e.g StdCall + llvmGhcCC) don't occur.
The native code generator only handles StdCall and CCallConv.
-}
-- call attributes
let fnAttrs | never_returns = NoReturn : llvmStdFunAttrs
| otherwise = llvmStdFunAttrs
never_returns = case target of
ForeignTarget _ (ForeignConvention _ _ _ CmmNeverReturns) -> True
_ -> False
-- fun type
let (res_hints, arg_hints) = foreignTargetHints target
let args_hints = zip args arg_hints
let ress_hints = zip res res_hints
let ccTy = StdCall -- tail calls should be done through CmmJump
let retTy = ret_type ress_hints
let argTy = tysToParams $ map arg_type args_hints
let funTy = \name -> LMFunction $ LlvmFunctionDecl name ExternallyVisible
lmconv retTy FixedArgs argTy (llvmFunAlign dflags)
argVars <- arg_varsW args_hints ([], nilOL, [])
fptr <- getFunPtrW funTy target
let doReturn | ccTy == TailCall = statement $ Return Nothing
| never_returns = statement $ Unreachable
| otherwise = return ()
doTrashStmts
-- make the actual call
case retTy of
LMVoid -> do
statement $ Expr $ Call ccTy fptr argVars fnAttrs
_ -> do
v1 <- doExprW retTy $ Call ccTy fptr argVars fnAttrs
-- get the return register
let ret_reg [reg] = reg
ret_reg t = panic $ "genCall: Bad number of registers! Can only handle"
++ " 1, given " ++ show (length t) ++ "."
let creg = ret_reg res
vreg <- getCmmRegW (CmmLocal creg)
if retTy == pLower (getVarType vreg)
then do
statement $ Store v1 vreg
doReturn
else do
let ty = pLower $ getVarType vreg
let op = case ty of
vt | isPointer vt -> LM_Bitcast
| isInt vt -> LM_Ptrtoint
| otherwise ->
panic $ "genCall: CmmReg bad match for"
++ " returned type!"
v2 <- doExprW ty $ Cast op v1 ty
statement $ Store v2 vreg
doReturn
-- | Generate a call to an LLVM intrinsic that performs arithmetic operation
-- with overflow bit (i.e., returns a struct containing the actual result of the
-- operation and an overflow bit). This function will also extract the overflow
-- bit and zero-extend it (all the corresponding Cmm PrimOps represent the
-- overflow "bit" as a usual Int# or Word#).
genCallWithOverflow
:: ForeignTarget -> Width -> [CmmFormal] -> [CmmActual] -> LlvmM StmtData
genCallWithOverflow t@(PrimTarget op) w [dstV, dstO] [lhs, rhs] = do
-- So far this was only tested for the following four CallishMachOps.
let valid = op `elem` [ MO_Add2 w
, MO_AddIntC w
, MO_SubIntC w
, MO_AddWordC w
, MO_SubWordC w
]
MASSERT(valid)
let width = widthToLlvmInt w
-- This will do most of the work of generating the call to the intrinsic and
-- extracting the values from the struct.
(value, overflowBit, (stmts, top)) <-
genCallExtract t w (lhs, rhs) (width, i1)
-- value is i<width>, but overflowBit is i1, so we need to cast (Cmm expects
-- both to be i<width>)
(overflow, zext) <- doExpr width $ Cast LM_Zext overflowBit width
dstRegV <- getCmmReg (CmmLocal dstV)
dstRegO <- getCmmReg (CmmLocal dstO)
let storeV = Store value dstRegV
storeO = Store overflow dstRegO
return (stmts `snocOL` zext `snocOL` storeV `snocOL` storeO, top)
genCallWithOverflow _ _ _ _ =
panic "genCallExtract: wrong ForeignTarget or number of arguments"
-- | A helper function for genCallWithOverflow that handles generating the call
-- to the LLVM intrinsic and extracting the result from the struct to LlvmVars.
genCallExtract
:: ForeignTarget -- ^ PrimOp
-> Width -- ^ Width of the operands.
-> (CmmActual, CmmActual) -- ^ Actual arguments.
-> (LlvmType, LlvmType) -- ^ LLVM types of the returned struct.
-> LlvmM (LlvmVar, LlvmVar, StmtData)
genCallExtract target@(PrimTarget op) w (argA, argB) (llvmTypeA, llvmTypeB) = do
let width = widthToLlvmInt w
argTy = [width, width]
retTy = LMStructU [llvmTypeA, llvmTypeB]
-- Process the arguments.
let args_hints = zip [argA, argB] (snd $ foreignTargetHints target)
(argsV1, args1, top1) <- arg_vars args_hints ([], nilOL, [])
(argsV2, args2) <- castVars Signed $ zip argsV1 argTy
-- Get the function and make the call.
fname <- cmmPrimOpFunctions op
(fptr, _, top2) <- getInstrinct fname retTy argTy
-- We use StdCall for primops. See also the last case of genCall.
(retV, call) <- doExpr retTy $ Call StdCall fptr argsV2 []
-- This will result in a two element struct, we need to use "extractvalue"
-- to get them out of it.
(res1, ext1) <- doExpr llvmTypeA (ExtractV retV 0)
(res2, ext2) <- doExpr llvmTypeB (ExtractV retV 1)
let stmts = args1 `appOL` args2 `snocOL` call `snocOL` ext1 `snocOL` ext2
tops = top1 ++ top2
return (res1, res2, (stmts, tops))
genCallExtract _ _ _ _ =
panic "genCallExtract: unsupported ForeignTarget"
-- Handle simple function call that only need simple type casting, of the form:
-- truncate arg >>= \a -> call(a) >>= zext
--
-- since GHC only really has i32 and i64 types and things like Word8 are backed
-- by an i32 and just present a logical i8 range. So we must handle conversions
-- from i32 to i8 explicitly as LLVM is strict about types.
genCallSimpleCast :: Width -> ForeignTarget -> [CmmFormal] -> [CmmActual]
-> LlvmM StmtData
genCallSimpleCast w t@(PrimTarget op) [dst] args = do
let width = widthToLlvmInt w
dstTy = cmmToLlvmType $ localRegType dst
fname <- cmmPrimOpFunctions op
(fptr, _, top3) <- getInstrinct fname width [width]
dstV <- getCmmReg (CmmLocal dst)
let (_, arg_hints) = foreignTargetHints t
let args_hints = zip args arg_hints
(argsV, stmts2, top2) <- arg_vars args_hints ([], nilOL, [])
(argsV', stmts4) <- castVars Signed $ zip argsV [width]
(retV, s1) <- doExpr width $ Call StdCall fptr argsV' []
(retVs', stmts5) <- castVars (cmmPrimOpRetValSignage op) [(retV,dstTy)]
let retV' = singletonPanic "genCallSimpleCast" retVs'
let s2 = Store retV' dstV
let stmts = stmts2 `appOL` stmts4 `snocOL`
s1 `appOL` stmts5 `snocOL` s2
return (stmts, top2 ++ top3)
genCallSimpleCast _ _ dsts _ =
panic ("genCallSimpleCast: " ++ show (length dsts) ++ " dsts")
-- Handle simple function call that only need simple type casting, of the form:
-- truncate arg >>= \a -> call(a) >>= zext
--
-- since GHC only really has i32 and i64 types and things like Word8 are backed
-- by an i32 and just present a logical i8 range. So we must handle conversions
-- from i32 to i8 explicitly as LLVM is strict about types.
genCallSimpleCast2 :: Width -> ForeignTarget -> [CmmFormal] -> [CmmActual]
-> LlvmM StmtData
genCallSimpleCast2 w t@(PrimTarget op) [dst] args = do
let width = widthToLlvmInt w
dstTy = cmmToLlvmType $ localRegType dst
fname <- cmmPrimOpFunctions op
(fptr, _, top3) <- getInstrinct fname width (const width <$> args)
dstV <- getCmmReg (CmmLocal dst)
let (_, arg_hints) = foreignTargetHints t
let args_hints = zip args arg_hints
(argsV, stmts2, top2) <- arg_vars args_hints ([], nilOL, [])
(argsV', stmts4) <- castVars Signed $ zip argsV (const width <$> argsV)
(retV, s1) <- doExpr width $ Call StdCall fptr argsV' []
(retVs', stmts5) <- castVars (cmmPrimOpRetValSignage op) [(retV,dstTy)]
let retV' = singletonPanic "genCallSimpleCast2" retVs'
let s2 = Store retV' dstV
let stmts = stmts2 `appOL` stmts4 `snocOL`
s1 `appOL` stmts5 `snocOL` s2
return (stmts, top2 ++ top3)
genCallSimpleCast2 _ _ dsts _ =
panic ("genCallSimpleCast2: " ++ show (length dsts) ++ " dsts")
-- | Create a function pointer from a target.
getFunPtrW :: (LMString -> LlvmType) -> ForeignTarget
-> WriterT LlvmAccum LlvmM LlvmVar
getFunPtrW funTy targ = liftExprData $ getFunPtr funTy targ
-- | Create a function pointer from a target.
getFunPtr :: (LMString -> LlvmType) -> ForeignTarget
-> LlvmM ExprData
getFunPtr funTy targ = case targ of
ForeignTarget (CmmLit (CmmLabel lbl)) _ -> do
name <- strCLabel_llvm lbl
getHsFunc' name (funTy name)
ForeignTarget expr _ -> do
(v1, stmts, top) <- exprToVar expr
dflags <- getDynFlags
let fty = funTy $ fsLit "dynamic"
cast = case getVarType v1 of
ty | isPointer ty -> LM_Bitcast
ty | isInt ty -> LM_Inttoptr
ty -> panic $ "genCall: Expr is of bad type for function"
++ " call! (" ++ showSDoc dflags (ppr ty) ++ ")"
(v2,s1) <- doExpr (pLift fty) $ Cast cast v1 (pLift fty)
return (v2, stmts `snocOL` s1, top)
PrimTarget mop -> do
name <- cmmPrimOpFunctions mop
let fty = funTy name
getInstrinct2 name fty
-- | Conversion of call arguments.
arg_varsW :: [(CmmActual, ForeignHint)]
-> ([LlvmVar], LlvmStatements, [LlvmCmmDecl])
-> WriterT LlvmAccum LlvmM [LlvmVar]
arg_varsW xs ys = do
(vars, stmts, decls) <- lift $ arg_vars xs ys
tell $ LlvmAccum stmts decls
return vars
-- | Conversion of call arguments.
arg_vars :: [(CmmActual, ForeignHint)]
-> ([LlvmVar], LlvmStatements, [LlvmCmmDecl])
-> LlvmM ([LlvmVar], LlvmStatements, [LlvmCmmDecl])
arg_vars [] (vars, stmts, tops)
= return (vars, stmts, tops)
arg_vars ((e, AddrHint):rest) (vars, stmts, tops)
= do (v1, stmts', top') <- exprToVar e
dflags <- getDynFlags
let op = case getVarType v1 of
ty | isPointer ty -> LM_Bitcast
ty | isInt ty -> LM_Inttoptr
a -> panic $ "genCall: Can't cast llvmType to i8*! ("
++ showSDoc dflags (ppr a) ++ ")"
(v2, s1) <- doExpr i8Ptr $ Cast op v1 i8Ptr
arg_vars rest (vars ++ [v2], stmts `appOL` stmts' `snocOL` s1,
tops ++ top')
arg_vars ((e, _):rest) (vars, stmts, tops)
= do (v1, stmts', top') <- exprToVar e
arg_vars rest (vars ++ [v1], stmts `appOL` stmts', tops ++ top')
-- | Cast a collection of LLVM variables to specific types.
castVarsW :: Signage
-> [(LlvmVar, LlvmType)]
-> WriterT LlvmAccum LlvmM [LlvmVar]
castVarsW signage vars = do
(vars, stmts) <- lift $ castVars signage vars
tell $ LlvmAccum stmts mempty
return vars
-- | Cast a collection of LLVM variables to specific types.
castVars :: Signage -> [(LlvmVar, LlvmType)]
-> LlvmM ([LlvmVar], LlvmStatements)
castVars signage vars = do
done <- mapM (uncurry (castVar signage)) vars
let (vars', stmts) = unzip done
return (vars', toOL stmts)
-- | Cast an LLVM variable to a specific type, panicing if it can't be done.
castVar :: Signage -> LlvmVar -> LlvmType -> LlvmM (LlvmVar, LlvmStatement)
castVar signage v t | getVarType v == t
= return (v, Nop)
| otherwise
= do dflags <- getDynFlags
let op = case (getVarType v, t) of
(LMInt n, LMInt m)
-> if n < m then extend else LM_Trunc
(vt, _) | isFloat vt && isFloat t
-> if llvmWidthInBits dflags vt < llvmWidthInBits dflags t
then LM_Fpext else LM_Fptrunc
(vt, _) | isInt vt && isFloat t -> LM_Sitofp
(vt, _) | isFloat vt && isInt t -> LM_Fptosi
(vt, _) | isInt vt && isPointer t -> LM_Inttoptr
(vt, _) | isPointer vt && isInt t -> LM_Ptrtoint
(vt, _) | isPointer vt && isPointer t -> LM_Bitcast
(vt, _) | isVector vt && isVector t -> LM_Bitcast
(vt, _) -> panic $ "castVars: Can't cast this type ("
++ showSDoc dflags (ppr vt) ++ ") to (" ++ showSDoc dflags (ppr t) ++ ")"
doExpr t $ Cast op v t
where extend = case signage of
Signed -> LM_Sext
Unsigned -> LM_Zext
cmmPrimOpRetValSignage :: CallishMachOp -> Signage
cmmPrimOpRetValSignage mop = case mop of
MO_Pdep _ -> Unsigned
MO_Pext _ -> Unsigned
_ -> Signed
-- | Decide what C function to use to implement a CallishMachOp
cmmPrimOpFunctions :: CallishMachOp -> LlvmM LMString
cmmPrimOpFunctions mop = do
dflags <- getDynFlags
let intrinTy1 = "p0i8.p0i8." ++ showSDoc dflags (ppr $ llvmWord dflags)
intrinTy2 = "p0i8." ++ showSDoc dflags (ppr $ llvmWord dflags)
unsupported = panic ("cmmPrimOpFunctions: " ++ show mop
++ " not supported here")
return $ case mop of
MO_F32_Exp -> fsLit "expf"
MO_F32_ExpM1 -> fsLit "expm1f"
MO_F32_Log -> fsLit "logf"
MO_F32_Log1P -> fsLit "log1pf"
MO_F32_Sqrt -> fsLit "llvm.sqrt.f32"
MO_F32_Fabs -> fsLit "llvm.fabs.f32"
MO_F32_Pwr -> fsLit "llvm.pow.f32"
MO_F32_Sin -> fsLit "llvm.sin.f32"
MO_F32_Cos -> fsLit "llvm.cos.f32"
MO_F32_Tan -> fsLit "tanf"
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_Asinh -> fsLit "asinhf"
MO_F32_Acosh -> fsLit "acoshf"
MO_F32_Atanh -> fsLit "atanhf"
MO_F64_Exp -> fsLit "exp"
MO_F64_ExpM1 -> fsLit "expm1"
MO_F64_Log -> fsLit "log"
MO_F64_Log1P -> fsLit "log1p"
MO_F64_Sqrt -> fsLit "llvm.sqrt.f64"
MO_F64_Fabs -> fsLit "llvm.fabs.f64"
MO_F64_Pwr -> fsLit "llvm.pow.f64"
MO_F64_Sin -> fsLit "llvm.sin.f64"
MO_F64_Cos -> fsLit "llvm.cos.f64"
MO_F64_Tan -> fsLit "tan"
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_Asinh -> fsLit "asinh"
MO_F64_Acosh -> fsLit "acosh"
MO_F64_Atanh -> fsLit "atanh"
MO_Memcpy _ -> fsLit $ "llvm.memcpy." ++ intrinTy1
MO_Memmove _ -> fsLit $ "llvm.memmove." ++ intrinTy1
MO_Memset _ -> fsLit $ "llvm.memset." ++ intrinTy2
MO_Memcmp _ -> fsLit $ "memcmp"
(MO_PopCnt w) -> fsLit $ "llvm.ctpop." ++ showSDoc dflags (ppr $ widthToLlvmInt w)
(MO_BSwap w) -> fsLit $ "llvm.bswap." ++ showSDoc dflags (ppr $ widthToLlvmInt w)
(MO_BRev w) -> fsLit $ "llvm.bitreverse." ++ showSDoc dflags (ppr $ widthToLlvmInt w)
(MO_Clz w) -> fsLit $ "llvm.ctlz." ++ showSDoc dflags (ppr $ widthToLlvmInt w)
(MO_Ctz w) -> fsLit $ "llvm.cttz." ++ showSDoc dflags (ppr $ widthToLlvmInt w)
(MO_Pdep w) -> let w' = showSDoc dflags (ppr $ widthInBits w)
in if isBmi2Enabled dflags
then fsLit $ "llvm.x86.bmi.pdep." ++ w'
else fsLit $ "hs_pdep" ++ w'
(MO_Pext w) -> let w' = showSDoc dflags (ppr $ widthInBits w)
in if isBmi2Enabled dflags
then fsLit $ "llvm.x86.bmi.pext." ++ w'
else fsLit $ "hs_pext" ++ w'
(MO_Prefetch_Data _ )-> fsLit "llvm.prefetch"
MO_AddIntC w -> fsLit $ "llvm.sadd.with.overflow."
++ showSDoc dflags (ppr $ widthToLlvmInt w)
MO_SubIntC w -> fsLit $ "llvm.ssub.with.overflow."
++ showSDoc dflags (ppr $ widthToLlvmInt w)
MO_Add2 w -> fsLit $ "llvm.uadd.with.overflow."
++ showSDoc dflags (ppr $ widthToLlvmInt w)
MO_AddWordC w -> fsLit $ "llvm.uadd.with.overflow."
++ showSDoc dflags (ppr $ widthToLlvmInt w)
MO_SubWordC w -> fsLit $ "llvm.usub.with.overflow."
++ showSDoc dflags (ppr $ widthToLlvmInt w)
MO_S_QuotRem {} -> unsupported
MO_U_QuotRem {} -> unsupported
MO_U_QuotRem2 {} -> unsupported
-- We support MO_U_Mul2 through ordinary LLVM mul instruction, see the
-- appropriate case of genCall.
MO_U_Mul2 {} -> unsupported
MO_ReadBarrier -> unsupported
MO_WriteBarrier -> unsupported
MO_Touch -> unsupported
MO_UF_Conv _ -> unsupported
MO_AtomicRead _ -> unsupported
MO_AtomicRMW _ _ -> unsupported
MO_AtomicWrite _ -> unsupported
MO_Cmpxchg _ -> unsupported
-- | Tail function calls
genJump :: CmmExpr -> [GlobalReg] -> LlvmM StmtData
-- Call to known function
genJump (CmmLit (CmmLabel lbl)) live = do
(vf, stmts, top) <- getHsFunc live lbl
(stgRegs, stgStmts) <- funEpilogue live
let s1 = Expr $ Call TailCall vf stgRegs llvmStdFunAttrs
let s2 = Return Nothing
return (stmts `appOL` stgStmts `snocOL` s1 `snocOL` s2, top)
-- Call to unknown function / address
genJump expr live = do
fty <- llvmFunTy live
(vf, stmts, top) <- exprToVar expr
dflags <- getDynFlags
let cast = case getVarType vf of
ty | isPointer ty -> LM_Bitcast
ty | isInt ty -> LM_Inttoptr
ty -> panic $ "genJump: Expr is of bad type for function call! ("
++ showSDoc dflags (ppr ty) ++ ")"
(v1, s1) <- doExpr (pLift fty) $ Cast cast vf (pLift fty)
(stgRegs, stgStmts) <- funEpilogue live
let s2 = Expr $ Call TailCall v1 stgRegs llvmStdFunAttrs
let s3 = Return Nothing
return (stmts `snocOL` s1 `appOL` stgStmts `snocOL` s2 `snocOL` s3,
top)
-- | CmmAssign operation
--
-- We use stack allocated variables for CmmReg. The optimiser will replace
-- these with registers when possible.
genAssign :: CmmReg -> CmmExpr -> LlvmM StmtData
genAssign reg val = do
vreg <- getCmmReg reg
(vval, stmts2, top2) <- exprToVar val
let stmts = stmts2
let ty = (pLower . getVarType) vreg
dflags <- getDynFlags
case ty of
-- Some registers are pointer types, so need to cast value to pointer
LMPointer _ | getVarType vval == llvmWord dflags -> do
(v, s1) <- doExpr ty $ Cast LM_Inttoptr vval ty
let s2 = Store v vreg
return (stmts `snocOL` s1 `snocOL` s2, top2)
LMVector _ _ -> do
(v, s1) <- doExpr ty $ Cast LM_Bitcast vval ty
let s2 = Store v vreg
return (stmts `snocOL` s1 `snocOL` s2, top2)
_ -> do
let s1 = Store vval vreg
return (stmts `snocOL` s1, top2)
-- | CmmStore operation
genStore :: CmmExpr -> CmmExpr -> LlvmM StmtData
-- First we try to detect a few common cases and produce better code for
-- these then the default case. We are mostly trying to detect Cmm code
-- like I32[Sp + n] and use 'getelementptr' operations instead of the
-- generic case that uses casts and pointer arithmetic
genStore addr@(CmmReg (CmmGlobal r)) val
= genStore_fast addr r 0 val
genStore addr@(CmmRegOff (CmmGlobal r) n) val
= genStore_fast addr r n val
genStore addr@(CmmMachOp (MO_Add _) [
(CmmReg (CmmGlobal r)),
(CmmLit (CmmInt n _))])
val
= genStore_fast addr r (fromInteger n) val
genStore addr@(CmmMachOp (MO_Sub _) [
(CmmReg (CmmGlobal r)),
(CmmLit (CmmInt n _))])
val
= genStore_fast addr r (negate $ fromInteger n) val
-- generic case
genStore addr val
= getTBAAMeta topN >>= genStore_slow addr val
-- | CmmStore operation
-- This is a special case for storing to a global register pointer
-- offset such as I32[Sp+8].
genStore_fast :: CmmExpr -> GlobalReg -> Int -> CmmExpr
-> LlvmM StmtData
genStore_fast addr r n val
= do dflags <- getDynFlags
(gv, grt, s1) <- getCmmRegVal (CmmGlobal r)
meta <- getTBAARegMeta r
let (ix,rem) = n `divMod` ((llvmWidthInBits dflags . pLower) grt `div` 8)
case isPointer grt && rem == 0 of
True -> do
(vval, stmts, top) <- exprToVar val
(ptr, s2) <- doExpr grt $ GetElemPtr True gv [toI32 ix]
-- We might need a different pointer type, so check
case pLower grt == getVarType vval of
-- were fine
True -> do
let s3 = MetaStmt meta $ Store vval ptr
return (stmts `appOL` s1 `snocOL` s2
`snocOL` s3, top)
-- cast to pointer type needed
False -> do
let ty = (pLift . getVarType) vval
(ptr', s3) <- doExpr ty $ Cast LM_Bitcast ptr ty
let s4 = MetaStmt meta $ Store vval ptr'
return (stmts `appOL` s1 `snocOL` s2
`snocOL` s3 `snocOL` s4, top)
-- If its a bit type then we use the slow method since
-- we can't avoid casting anyway.
False -> genStore_slow addr val meta
-- | CmmStore operation
-- Generic case. Uses casts and pointer arithmetic if needed.
genStore_slow :: CmmExpr -> CmmExpr -> [MetaAnnot] -> LlvmM StmtData
genStore_slow addr val meta = do
(vaddr, stmts1, top1) <- exprToVar addr
(vval, stmts2, top2) <- exprToVar val
let stmts = stmts1 `appOL` stmts2
dflags <- getDynFlags
case getVarType vaddr of
-- sometimes we need to cast an int to a pointer before storing
LMPointer ty@(LMPointer _) | getVarType vval == llvmWord dflags -> do
(v, s1) <- doExpr ty $ Cast LM_Inttoptr vval ty
let s2 = MetaStmt meta $ Store v vaddr
return (stmts `snocOL` s1 `snocOL` s2, top1 ++ top2)
LMPointer _ -> do
let s1 = MetaStmt meta $ Store vval vaddr
return (stmts `snocOL` s1, top1 ++ top2)
i@(LMInt _) | i == llvmWord dflags -> do
let vty = pLift $ getVarType vval
(vptr, s1) <- doExpr vty $ Cast LM_Inttoptr vaddr vty
let s2 = MetaStmt meta $ Store vval vptr
return (stmts `snocOL` s1 `snocOL` s2, top1 ++ top2)
other ->
pprPanic "genStore: ptr not right type!"
(PprCmm.pprExpr addr <+> text (
"Size of Ptr: " ++ show (llvmPtrBits dflags) ++
", Size of var: " ++ show (llvmWidthInBits dflags other) ++
", Var: " ++ showSDoc dflags (ppr vaddr)))
-- | Unconditional branch
genBranch :: BlockId -> LlvmM StmtData
genBranch id =
let label = blockIdToLlvm id
in return (unitOL $ Branch label, [])
-- | Conditional branch
genCondBranch :: CmmExpr -> BlockId -> BlockId -> Maybe Bool -> LlvmM StmtData
genCondBranch cond idT idF likely = do
let labelT = blockIdToLlvm idT
let labelF = blockIdToLlvm idF
-- See Note [Literals and branch conditions].
(vc, stmts1, top1) <- exprToVarOpt i1Option cond
if getVarType vc == i1
then do
(vc', (stmts2, top2)) <- case likely of
Just b -> genExpectLit (if b then 1 else 0) i1 vc
_ -> pure (vc, (nilOL, []))
let s1 = BranchIf vc' labelT labelF
return (stmts1 `appOL` stmts2 `snocOL` s1, top1 ++ top2)
else do
dflags <- getDynFlags
panic $ "genCondBranch: Cond expr not bool! (" ++ showSDoc dflags (ppr vc) ++ ")"
-- | Generate call to llvm.expect.x intrinsic. Assigning result to a new var.
genExpectLit :: Integer -> LlvmType -> LlvmVar -> LlvmM (LlvmVar, StmtData)
genExpectLit expLit expTy var = do
dflags <- getDynFlags
let
lit = LMLitVar $ LMIntLit expLit expTy
llvmExpectName
| isInt expTy = fsLit $ "llvm.expect." ++ showSDoc dflags (ppr expTy)
| otherwise = panic $ "genExpectedLit: Type not an int!"
(llvmExpect, stmts, top) <-
getInstrinct llvmExpectName expTy [expTy, expTy]
(var', call) <- doExpr expTy $ Call StdCall llvmExpect [var, lit] []
return (var', (stmts `snocOL` call, top))
{- Note [Literals and branch conditions]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
It is important that whenever we generate branch conditions for
literals like '1', they are properly narrowed to an LLVM expression of
type 'i1' (for bools.) Otherwise, nobody is happy. So when we convert
a CmmExpr to an LLVM expression for a branch conditional, exprToVarOpt
must be certain to return a properly narrowed type. genLit is
responsible for this, in the case of literal integers.
Often, we won't see direct statements like:
if(1) {
...
} else {
...
}
at this point in the pipeline, because the Glorious Code Generator
will do trivial branch elimination in the sinking pass (among others,)
which will eliminate the expression entirely.
However, it's certainly possible and reasonable for this to occur in
hand-written C-- code. Consider something like:
#if !defined(SOME_CONDITIONAL)
#define CHECK_THING(x) 1
#else
#define CHECK_THING(x) some_operation((x))
#endif
f() {
if (CHECK_THING(xyz)) {
...
} else {
...
}
}
In such an instance, CHECK_THING might result in an *expression* in
one case, and a *literal* in the other, depending on what in
particular was #define'd. So we must be sure to properly narrow the
literal in this case to i1 as it won't be eliminated beforehand.
For a real example of this, see ./rts/StgStdThunks.cmm
-}
-- | Switch branch
genSwitch :: CmmExpr -> SwitchTargets -> LlvmM StmtData
genSwitch cond ids = do
(vc, stmts, top) <- exprToVar cond
let ty = getVarType vc
let labels = [ (mkIntLit ty ix, blockIdToLlvm b)
| (ix, b) <- switchTargetsCases ids ]
-- out of range is undefined, so let's just branch to first label
let defLbl | Just l <- switchTargetsDefault ids = blockIdToLlvm l
| otherwise = snd (head labels)
let s1 = Switch vc defLbl labels
return $ (stmts `snocOL` s1, top)
-- -----------------------------------------------------------------------------
-- * CmmExpr code generation
--
-- | An expression conversion return data:
-- * LlvmVar: The var holding the result of the expression
-- * LlvmStatements: Any statements needed to evaluate the expression
-- * LlvmCmmDecl: Any global data needed for this expression
type ExprData = (LlvmVar, LlvmStatements, [LlvmCmmDecl])
-- | Values which can be passed to 'exprToVar' to configure its
-- behaviour in certain circumstances.
--
-- Currently just used for determining if a comparison should return
-- a boolean (i1) or a word. See Note [Literals and branch conditions].
newtype EOption = EOption { i1Expected :: Bool }
-- XXX: EOption is an ugly and inefficient solution to this problem.
-- | i1 type expected (condition scrutinee).
i1Option :: EOption
i1Option = EOption True
-- | Word type expected (usual).
wordOption :: EOption
wordOption = EOption False
-- | Convert a CmmExpr to a list of LlvmStatements with the result of the
-- expression being stored in the returned LlvmVar.
exprToVar :: CmmExpr -> LlvmM ExprData
exprToVar = exprToVarOpt wordOption
exprToVarOpt :: EOption -> CmmExpr -> LlvmM ExprData
exprToVarOpt opt e = case e of
CmmLit lit
-> genLit opt lit
CmmLoad e' ty
-> genLoad False e' ty
-- Cmmreg in expression is the value, so must load. If you want actual
-- reg pointer, call getCmmReg directly.
CmmReg r -> do
(v1, ty, s1) <- getCmmRegVal r
case isPointer ty of
True -> do
-- Cmm wants the value, so pointer types must be cast to ints
dflags <- getDynFlags
(v2, s2) <- doExpr (llvmWord dflags) $ Cast LM_Ptrtoint v1 (llvmWord dflags)
return (v2, s1 `snocOL` s2, [])
False -> return (v1, s1, [])
CmmMachOp op exprs
-> genMachOp opt op exprs
CmmRegOff r i
-> do dflags <- getDynFlags
exprToVar $ expandCmmReg dflags (r, i)
CmmStackSlot _ _
-> panic "exprToVar: CmmStackSlot not supported!"
-- | Handle CmmMachOp expressions
genMachOp :: EOption -> MachOp -> [CmmExpr] -> LlvmM ExprData
-- Unary Machop
genMachOp _ op [x] = case op of
MO_Not w ->
let all1 = mkIntLit (widthToLlvmInt w) (-1)
in negate (widthToLlvmInt w) all1 LM_MO_Xor
MO_S_Neg w ->
let all0 = mkIntLit (widthToLlvmInt w) 0
in negate (widthToLlvmInt w) all0 LM_MO_Sub
MO_F_Neg w ->
let all0 = LMLitVar $ LMFloatLit (-0) (widthToLlvmFloat w)
in negate (widthToLlvmFloat w) all0 LM_MO_FSub
MO_SF_Conv _ w -> fiConv (widthToLlvmFloat w) LM_Sitofp
MO_FS_Conv _ w -> fiConv (widthToLlvmInt w) LM_Fptosi
MO_SS_Conv from to
-> sameConv from (widthToLlvmInt to) LM_Trunc LM_Sext
MO_UU_Conv from to
-> sameConv from (widthToLlvmInt to) LM_Trunc LM_Zext
MO_XX_Conv from to
-> sameConv from (widthToLlvmInt to) LM_Trunc LM_Zext
MO_FF_Conv from to
-> sameConv from (widthToLlvmFloat to) LM_Fptrunc LM_Fpext
MO_VS_Neg len w ->
let ty = widthToLlvmInt w
vecty = LMVector len ty
all0 = LMIntLit (-0) ty
all0s = LMLitVar $ LMVectorLit (replicate len all0)
in negateVec vecty all0s LM_MO_Sub
MO_VF_Neg len w ->
let ty = widthToLlvmFloat w
vecty = LMVector len ty
all0 = LMFloatLit (-0) ty
all0s = LMLitVar $ LMVectorLit (replicate len all0)
in negateVec vecty all0s LM_MO_FSub
MO_AlignmentCheck _ _ -> panic "-falignment-sanitisation is not supported by -fllvm"
-- Handle unsupported cases explicitly so we get a warning
-- of missing case when new MachOps added
MO_Add _ -> panicOp
MO_Mul _ -> panicOp
MO_Sub _ -> panicOp
MO_S_MulMayOflo _ -> panicOp
MO_S_Quot _ -> panicOp
MO_S_Rem _ -> panicOp
MO_U_MulMayOflo _ -> panicOp
MO_U_Quot _ -> panicOp
MO_U_Rem _ -> panicOp
MO_Eq _ -> panicOp
MO_Ne _ -> panicOp
MO_S_Ge _ -> panicOp
MO_S_Gt _ -> panicOp
MO_S_Le _ -> panicOp
MO_S_Lt _ -> panicOp
MO_U_Ge _ -> panicOp
MO_U_Gt _ -> panicOp
MO_U_Le _ -> panicOp
MO_U_Lt _ -> panicOp
MO_F_Add _ -> panicOp
MO_F_Sub _ -> panicOp
MO_F_Mul _ -> panicOp
MO_F_Quot _ -> panicOp
MO_F_Eq _ -> panicOp
MO_F_Ne _ -> panicOp
MO_F_Ge _ -> panicOp
MO_F_Gt _ -> panicOp
MO_F_Le _ -> panicOp
MO_F_Lt _ -> panicOp
MO_And _ -> panicOp
MO_Or _ -> panicOp
MO_Xor _ -> panicOp
MO_Shl _ -> panicOp
MO_U_Shr _ -> panicOp
MO_S_Shr _ -> panicOp
MO_V_Insert _ _ -> panicOp
MO_V_Extract _ _ -> panicOp
MO_V_Add _ _ -> panicOp
MO_V_Sub _ _ -> panicOp
MO_V_Mul _ _ -> panicOp
MO_VS_Quot _ _ -> panicOp
MO_VS_Rem _ _ -> panicOp
MO_VU_Quot _ _ -> panicOp
MO_VU_Rem _ _ -> panicOp
MO_VF_Insert _ _ -> panicOp
MO_VF_Extract _ _ -> panicOp
MO_VF_Add _ _ -> panicOp
MO_VF_Sub _ _ -> panicOp
MO_VF_Mul _ _ -> panicOp
MO_VF_Quot _ _ -> panicOp
where
negate ty v2 negOp = do
(vx, stmts, top) <- exprToVar x
(v1, s1) <- doExpr ty $ LlvmOp negOp v2 vx
return (v1, stmts `snocOL` s1, top)
negateVec ty v2 negOp = do
(vx, stmts1, top) <- exprToVar x
(vxs', stmts2) <- castVars Signed [(vx, ty)]
let vx' = singletonPanic "genMachOp: negateVec" vxs'
(v1, s1) <- doExpr ty $ LlvmOp negOp v2 vx'
return (v1, stmts1 `appOL` stmts2 `snocOL` s1, top)
fiConv ty convOp = do
(vx, stmts, top) <- exprToVar x
(v1, s1) <- doExpr ty $ Cast convOp vx ty
return (v1, stmts `snocOL` s1, top)
sameConv from ty reduce expand = do
x'@(vx, stmts, top) <- exprToVar x
let sameConv' op = do
(v1, s1) <- doExpr ty $ Cast op vx ty
return (v1, stmts `snocOL` s1, top)
dflags <- getDynFlags
let toWidth = llvmWidthInBits dflags ty
-- LLVM doesn't like trying to convert to same width, so
-- need to check for that as we do get Cmm code doing it.
case widthInBits from of
w | w < toWidth -> sameConv' expand
w | w > toWidth -> sameConv' reduce
_w -> return x'
panicOp = panic $ "LLVM.CodeGen.genMachOp: non unary op encountered"
++ "with one argument! (" ++ show op ++ ")"
-- Handle GlobalRegs pointers
genMachOp opt o@(MO_Add _) e@[(CmmReg (CmmGlobal r)), (CmmLit (CmmInt n _))]
= genMachOp_fast opt o r (fromInteger n) e
genMachOp opt o@(MO_Sub _) e@[(CmmReg (CmmGlobal r)), (CmmLit (CmmInt n _))]
= genMachOp_fast opt o r (negate . fromInteger $ n) e
-- Generic case
genMachOp opt op e = genMachOp_slow opt op e
-- | Handle CmmMachOp expressions
-- This is a specialised method that handles Global register manipulations like
-- 'Sp - 16', using the getelementptr instruction.
genMachOp_fast :: EOption -> MachOp -> GlobalReg -> Int -> [CmmExpr]
-> LlvmM ExprData
genMachOp_fast opt op r n e
= do (gv, grt, s1) <- getCmmRegVal (CmmGlobal r)
dflags <- getDynFlags
let (ix,rem) = n `divMod` ((llvmWidthInBits dflags . pLower) grt `div` 8)
case isPointer grt && rem == 0 of
True -> do
(ptr, s2) <- doExpr grt $ GetElemPtr True gv [toI32 ix]
(var, s3) <- doExpr (llvmWord dflags) $ Cast LM_Ptrtoint ptr (llvmWord dflags)
return (var, s1 `snocOL` s2 `snocOL` s3, [])
False -> genMachOp_slow opt op e
-- | Handle CmmMachOp expressions
-- This handles all the cases not handle by the specialised genMachOp_fast.
genMachOp_slow :: EOption -> MachOp -> [CmmExpr] -> LlvmM ExprData
-- Element extraction
genMachOp_slow _ (MO_V_Extract l w) [val, idx] = runExprData $ do
vval <- exprToVarW val
vidx <- exprToVarW idx
vval' <- singletonPanic "genMachOp_slow" <$>
castVarsW Signed [(vval, LMVector l ty)]
doExprW ty $ Extract vval' vidx
where
ty = widthToLlvmInt w
genMachOp_slow _ (MO_VF_Extract l w) [val, idx] = runExprData $ do
vval <- exprToVarW val
vidx <- exprToVarW idx
vval' <- singletonPanic "genMachOp_slow" <$>
castVarsW Signed [(vval, LMVector l ty)]
doExprW ty $ Extract vval' vidx
where
ty = widthToLlvmFloat w
-- Element insertion
genMachOp_slow _ (MO_V_Insert l w) [val, elt, idx] = runExprData $ do
vval <- exprToVarW val
velt <- exprToVarW elt
vidx <- exprToVarW idx
vval' <- singletonPanic "genMachOp_slow" <$>
castVarsW Signed [(vval, ty)]
doExprW ty $ Insert vval' velt vidx
where
ty = LMVector l (widthToLlvmInt w)
genMachOp_slow _ (MO_VF_Insert l w) [val, elt, idx] = runExprData $ do
vval <- exprToVarW val
velt <- exprToVarW elt
vidx <- exprToVarW idx
vval' <- singletonPanic "genMachOp_slow" <$>
castVarsW Signed [(vval, ty)]
doExprW ty $ Insert vval' velt vidx
where
ty = LMVector l (widthToLlvmFloat w)
-- Binary MachOp
genMachOp_slow opt op [x, y] = case op of
MO_Eq _ -> genBinComp opt LM_CMP_Eq
MO_Ne _ -> genBinComp opt LM_CMP_Ne
MO_S_Gt _ -> genBinComp opt LM_CMP_Sgt
MO_S_Ge _ -> genBinComp opt LM_CMP_Sge
MO_S_Lt _ -> genBinComp opt LM_CMP_Slt
MO_S_Le _ -> genBinComp opt LM_CMP_Sle
MO_U_Gt _ -> genBinComp opt LM_CMP_Ugt
MO_U_Ge _ -> genBinComp opt LM_CMP_Uge
MO_U_Lt _ -> genBinComp opt LM_CMP_Ult
MO_U_Le _ -> genBinComp opt LM_CMP_Ule
MO_Add _ -> genBinMach LM_MO_Add
MO_Sub _ -> genBinMach LM_MO_Sub
MO_Mul _ -> genBinMach LM_MO_Mul
MO_U_MulMayOflo _ -> panic "genMachOp: MO_U_MulMayOflo unsupported!"
MO_S_MulMayOflo w -> isSMulOK w x y
MO_S_Quot _ -> genBinMach LM_MO_SDiv
MO_S_Rem _ -> genBinMach LM_MO_SRem
MO_U_Quot _ -> genBinMach LM_MO_UDiv
MO_U_Rem _ -> genBinMach LM_MO_URem
MO_F_Eq _ -> genBinComp opt LM_CMP_Feq
MO_F_Ne _ -> genBinComp opt LM_CMP_Fne
MO_F_Gt _ -> genBinComp opt LM_CMP_Fgt
MO_F_Ge _ -> genBinComp opt LM_CMP_Fge
MO_F_Lt _ -> genBinComp opt LM_CMP_Flt
MO_F_Le _ -> genBinComp opt LM_CMP_Fle
MO_F_Add _ -> genBinMach LM_MO_FAdd
MO_F_Sub _ -> genBinMach LM_MO_FSub
MO_F_Mul _ -> genBinMach LM_MO_FMul
MO_F_Quot _ -> genBinMach LM_MO_FDiv
MO_And _ -> genBinMach LM_MO_And
MO_Or _ -> genBinMach LM_MO_Or
MO_Xor _ -> genBinMach LM_MO_Xor
MO_Shl _ -> genBinMach LM_MO_Shl
MO_U_Shr _ -> genBinMach LM_MO_LShr
MO_S_Shr _ -> genBinMach LM_MO_AShr
MO_V_Add l w -> genCastBinMach (LMVector l (widthToLlvmInt w)) LM_MO_Add
MO_V_Sub l w -> genCastBinMach (LMVector l (widthToLlvmInt w)) LM_MO_Sub
MO_V_Mul l w -> genCastBinMach (LMVector l (widthToLlvmInt w)) LM_MO_Mul
MO_VS_Quot l w -> genCastBinMach (LMVector l (widthToLlvmInt w)) LM_MO_SDiv
MO_VS_Rem l w -> genCastBinMach (LMVector l (widthToLlvmInt w)) LM_MO_SRem
MO_VU_Quot l w -> genCastBinMach (LMVector l (widthToLlvmInt w)) LM_MO_UDiv
MO_VU_Rem l w -> genCastBinMach (LMVector l (widthToLlvmInt w)) LM_MO_URem
MO_VF_Add l w -> genCastBinMach (LMVector l (widthToLlvmFloat w)) LM_MO_FAdd
MO_VF_Sub l w -> genCastBinMach (LMVector l (widthToLlvmFloat w)) LM_MO_FSub
MO_VF_Mul l w -> genCastBinMach (LMVector l (widthToLlvmFloat w)) LM_MO_FMul
MO_VF_Quot l w -> genCastBinMach (LMVector l (widthToLlvmFloat w)) LM_MO_FDiv
MO_Not _ -> panicOp
MO_S_Neg _ -> panicOp
MO_F_Neg _ -> panicOp
MO_SF_Conv _ _ -> panicOp
MO_FS_Conv _ _ -> panicOp
MO_SS_Conv _ _ -> panicOp
MO_UU_Conv _ _ -> panicOp
MO_XX_Conv _ _ -> panicOp
MO_FF_Conv _ _ -> panicOp
MO_V_Insert {} -> panicOp
MO_V_Extract {} -> panicOp
MO_VS_Neg {} -> panicOp
MO_VF_Insert {} -> panicOp
MO_VF_Extract {} -> panicOp
MO_VF_Neg {} -> panicOp
MO_AlignmentCheck {} -> panicOp
where
binLlvmOp ty binOp = runExprData $ do
vx <- exprToVarW x
vy <- exprToVarW y
if getVarType vx == getVarType vy
then do
doExprW (ty vx) $ binOp vx vy
else do
-- Error. Continue anyway so we can debug the generated ll file.
dflags <- getDynFlags
let style = mkCodeStyle CStyle
toString doc = renderWithStyle dflags doc style
cmmToStr = (lines . toString . PprCmm.pprExpr)
statement $ Comment $ map fsLit $ cmmToStr x
statement $ Comment $ map fsLit $ cmmToStr y
doExprW (ty vx) $ binOp vx vy
binCastLlvmOp ty binOp = runExprData $ do
vx <- exprToVarW x
vy <- exprToVarW y
vxy' <- castVarsW Signed [(vx, ty), (vy, ty)]
case vxy' of
[vx',vy'] -> doExprW ty $ binOp vx' vy'
_ -> panic "genMachOp_slow: binCastLlvmOp"
-- | Need to use EOption here as Cmm expects word size results from
-- comparisons while LLVM return i1. Need to extend to llvmWord type
-- if expected. See Note [Literals and branch conditions].
genBinComp opt cmp = do
ed@(v1, stmts, top) <- binLlvmOp (\_ -> i1) (Compare cmp)
dflags <- getDynFlags
if getVarType v1 == i1
then case i1Expected opt of
True -> return ed
False -> do
let w_ = llvmWord dflags
(v2, s1) <- doExpr w_ $ Cast LM_Zext v1 w_
return (v2, stmts `snocOL` s1, top)
else
panic $ "genBinComp: Compare returned type other then i1! "
++ (showSDoc dflags $ ppr $ getVarType v1)
genBinMach op = binLlvmOp getVarType (LlvmOp op)
genCastBinMach ty op = binCastLlvmOp ty (LlvmOp op)
-- | Detect if overflow will occur in signed multiply of the two
-- CmmExpr's. This is the LLVM assembly equivalent of the NCG
-- implementation. Its much longer due to type information/safety.
-- This should actually compile to only about 3 asm instructions.
isSMulOK :: Width -> CmmExpr -> CmmExpr -> LlvmM ExprData
isSMulOK _ x y = runExprData $ do
vx <- exprToVarW x
vy <- exprToVarW y
dflags <- getDynFlags
let word = getVarType vx
let word2 = LMInt $ 2 * (llvmWidthInBits dflags $ getVarType vx)
let shift = llvmWidthInBits dflags word
let shift1 = toIWord dflags (shift - 1)
let shift2 = toIWord dflags shift
if isInt word
then do
x1 <- doExprW word2 $ Cast LM_Sext vx word2
y1 <- doExprW word2 $ Cast LM_Sext vy word2
r1 <- doExprW word2 $ LlvmOp LM_MO_Mul x1 y1
rlow1 <- doExprW word $ Cast LM_Trunc r1 word
rlow2 <- doExprW word $ LlvmOp LM_MO_AShr rlow1 shift1
rhigh1 <- doExprW word2 $ LlvmOp LM_MO_AShr r1 shift2
rhigh2 <- doExprW word $ Cast LM_Trunc rhigh1 word
doExprW word $ LlvmOp LM_MO_Sub rlow2 rhigh2
else
panic $ "isSMulOK: Not bit type! (" ++ showSDoc dflags (ppr word) ++ ")"
panicOp = panic $ "LLVM.CodeGen.genMachOp_slow: unary op encountered"
++ "with two arguments! (" ++ show op ++ ")"
-- More than two expression, invalid!
genMachOp_slow _ _ _ = panic "genMachOp: More than 2 expressions in MachOp!"
-- | Handle CmmLoad expression.
genLoad :: Atomic -> CmmExpr -> CmmType -> LlvmM ExprData
-- First we try to detect a few common cases and produce better code for
-- these then the default case. We are mostly trying to detect Cmm code
-- like I32[Sp + n] and use 'getelementptr' operations instead of the
-- generic case that uses casts and pointer arithmetic
genLoad atomic e@(CmmReg (CmmGlobal r)) ty
= genLoad_fast atomic e r 0 ty
genLoad atomic e@(CmmRegOff (CmmGlobal r) n) ty
= genLoad_fast atomic e r n ty
genLoad atomic e@(CmmMachOp (MO_Add _) [
(CmmReg (CmmGlobal r)),
(CmmLit (CmmInt n _))])
ty
= genLoad_fast atomic e r (fromInteger n) ty
genLoad atomic e@(CmmMachOp (MO_Sub _) [
(CmmReg (CmmGlobal r)),
(CmmLit (CmmInt n _))])
ty
= genLoad_fast atomic e r (negate $ fromInteger n) ty
-- generic case
genLoad atomic e ty
= getTBAAMeta topN >>= genLoad_slow atomic e ty
-- | Handle CmmLoad expression.
-- This is a special case for loading from a global register pointer
-- offset such as I32[Sp+8].
genLoad_fast :: Atomic -> CmmExpr -> GlobalReg -> Int -> CmmType
-> LlvmM ExprData
genLoad_fast atomic e r n ty = do
dflags <- getDynFlags
(gv, grt, s1) <- getCmmRegVal (CmmGlobal r)
meta <- getTBAARegMeta r
let ty' = cmmToLlvmType ty
(ix,rem) = n `divMod` ((llvmWidthInBits dflags . pLower) grt `div` 8)
case isPointer grt && rem == 0 of
True -> do
(ptr, s2) <- doExpr grt $ GetElemPtr True gv [toI32 ix]
-- We might need a different pointer type, so check
case grt == ty' of
-- were fine
True -> do
(var, s3) <- doExpr ty' (MExpr meta $ loadInstr ptr)
return (var, s1 `snocOL` s2 `snocOL` s3,
[])
-- cast to pointer type needed
False -> do
let pty = pLift ty'
(ptr', s3) <- doExpr pty $ Cast LM_Bitcast ptr pty
(var, s4) <- doExpr ty' (MExpr meta $ loadInstr ptr')
return (var, s1 `snocOL` s2 `snocOL` s3
`snocOL` s4, [])
-- If its a bit type then we use the slow method since
-- we can't avoid casting anyway.
False -> genLoad_slow atomic e ty meta
where
loadInstr ptr | atomic = ALoad SyncSeqCst False ptr
| otherwise = Load ptr
-- | Handle Cmm load expression.
-- Generic case. Uses casts and pointer arithmetic if needed.
genLoad_slow :: Atomic -> CmmExpr -> CmmType -> [MetaAnnot] -> LlvmM ExprData
genLoad_slow atomic e ty meta = runExprData $ do
iptr <- exprToVarW e
dflags <- getDynFlags
case getVarType iptr of
LMPointer _ -> do
doExprW (cmmToLlvmType ty) (MExpr meta $ loadInstr iptr)
i@(LMInt _) | i == llvmWord dflags -> do
let pty = LMPointer $ cmmToLlvmType ty
ptr <- doExprW pty $ Cast LM_Inttoptr iptr pty
doExprW (cmmToLlvmType ty) (MExpr meta $ loadInstr ptr)
other -> do pprPanic "exprToVar: CmmLoad expression is not right type!"
(PprCmm.pprExpr e <+> text (
"Size of Ptr: " ++ show (llvmPtrBits dflags) ++
", Size of var: " ++ show (llvmWidthInBits dflags other) ++
", Var: " ++ showSDoc dflags (ppr iptr)))
where
loadInstr ptr | atomic = ALoad SyncSeqCst False ptr
| otherwise = Load ptr
-- | Handle CmmReg expression. This will return a pointer to the stack
-- location of the register. Throws an error if it isn't allocated on
-- the stack.
getCmmReg :: CmmReg -> LlvmM LlvmVar
getCmmReg (CmmLocal (LocalReg un _))
= do exists <- varLookup un
dflags <- getDynFlags
case exists of
Just ety -> return (LMLocalVar un $ pLift ety)
Nothing -> panic $ "getCmmReg: Cmm register " ++ showSDoc dflags (ppr un) ++ " was not allocated!"
-- This should never happen, as every local variable should
-- have been assigned a value at some point, triggering
-- "funPrologue" to allocate it on the stack.
getCmmReg (CmmGlobal g)
= do onStack <- checkStackReg g
dflags <- getDynFlags
if onStack
then return (lmGlobalRegVar dflags g)
else panic $ "getCmmReg: Cmm register " ++ showSDoc dflags (ppr g) ++ " not stack-allocated!"
-- | Return the value of a given register, as well as its type. Might
-- need to be load from stack.
getCmmRegVal :: CmmReg -> LlvmM (LlvmVar, LlvmType, LlvmStatements)
getCmmRegVal reg =
case reg of
CmmGlobal g -> do
onStack <- checkStackReg g
dflags <- getDynFlags
if onStack then loadFromStack else do
let r = lmGlobalRegArg dflags g
return (r, getVarType r, nilOL)
_ -> loadFromStack
where loadFromStack = do
ptr <- getCmmReg reg
let ty = pLower $ getVarType ptr
(v, s) <- doExpr ty (Load ptr)
return (v, ty, unitOL s)
-- | Allocate a local CmmReg on the stack
allocReg :: CmmReg -> (LlvmVar, LlvmStatements)
allocReg (CmmLocal (LocalReg un ty))
= let ty' = cmmToLlvmType ty
var = LMLocalVar un (LMPointer ty')
alc = Alloca ty' 1
in (var, unitOL $ Assignment var alc)
allocReg _ = panic $ "allocReg: Global reg encountered! Global registers should"
++ " have been handled elsewhere!"
-- | Generate code for a literal
genLit :: EOption -> CmmLit -> LlvmM ExprData
genLit opt (CmmInt i w)
-- See Note [Literals and branch conditions].
= let width | i1Expected opt = i1
| otherwise = LMInt (widthInBits w)
-- comm = Comment [ fsLit $ "EOption: " ++ show opt
-- , fsLit $ "Width : " ++ show w
-- , fsLit $ "Width' : " ++ show (widthInBits w)
-- ]
in return (mkIntLit width i, nilOL, [])
genLit _ (CmmFloat r w)
= return (LMLitVar $ LMFloatLit (fromRational r) (widthToLlvmFloat w),
nilOL, [])
genLit opt (CmmVec ls)
= do llvmLits <- mapM toLlvmLit ls
return (LMLitVar $ LMVectorLit llvmLits, nilOL, [])
where
toLlvmLit :: CmmLit -> LlvmM LlvmLit
toLlvmLit lit = do
(llvmLitVar, _, _) <- genLit opt lit
case llvmLitVar of
LMLitVar llvmLit -> return llvmLit
_ -> panic "genLit"
genLit _ cmm@(CmmLabel l)
= do var <- getGlobalPtr =<< strCLabel_llvm l
dflags <- getDynFlags
let lmty = cmmToLlvmType $ cmmLitType dflags cmm
(v1, s1) <- doExpr lmty $ Cast LM_Ptrtoint var (llvmWord dflags)
return (v1, unitOL s1, [])
genLit opt (CmmLabelOff label off) = do
dflags <- getDynFlags
(vlbl, stmts, stat) <- genLit opt (CmmLabel label)
let voff = toIWord dflags off
(v1, s1) <- doExpr (getVarType vlbl) $ LlvmOp LM_MO_Add vlbl voff
return (v1, stmts `snocOL` s1, stat)
genLit opt (CmmLabelDiffOff l1 l2 off w) = do
dflags <- getDynFlags
(vl1, stmts1, stat1) <- genLit opt (CmmLabel l1)
(vl2, stmts2, stat2) <- genLit opt (CmmLabel l2)
let voff = toIWord dflags off
let ty1 = getVarType vl1
let ty2 = getVarType vl2
if (isInt ty1) && (isInt ty2)
&& (llvmWidthInBits dflags ty1 == llvmWidthInBits dflags ty2)
then do
(v1, s1) <- doExpr (getVarType vl1) $ LlvmOp LM_MO_Sub vl1 vl2
(v2, s2) <- doExpr (getVarType v1 ) $ LlvmOp LM_MO_Add v1 voff
let ty = widthToLlvmInt w
let stmts = stmts1 `appOL` stmts2 `snocOL` s1 `snocOL` s2
if w /= wordWidth dflags
then do
(v3, s3) <- doExpr ty $ Cast LM_Trunc v2 ty
return (v3, stmts `snocOL` s3, stat1 ++ stat2)
else
return (v2, stmts, stat1 ++ stat2)
else
panic "genLit: CmmLabelDiffOff encountered with different label ty!"
genLit opt (CmmBlock b)
= genLit opt (CmmLabel $ infoTblLbl b)
genLit _ CmmHighStackMark
= panic "genStaticLit - CmmHighStackMark unsupported!"
-- -----------------------------------------------------------------------------
-- * Misc
--
-- | Find CmmRegs that get assigned and allocate them on the stack
--
-- Any register that gets written needs to be allcoated on the
-- stack. This avoids having to map a CmmReg to an equivalent SSA form
-- and avoids having to deal with Phi node insertion. This is also
-- the approach recommended by LLVM developers.
--
-- On the other hand, this is unnecessarily verbose if the register in
-- question is never written. Therefore we skip it where we can to
-- save a few lines in the output and hopefully speed compilation up a
-- bit.
funPrologue :: LiveGlobalRegs -> [CmmBlock] -> LlvmM StmtData
funPrologue live cmmBlocks = do
trash <- getTrashRegs
let getAssignedRegs :: CmmNode O O -> [CmmReg]
getAssignedRegs (CmmAssign reg _) = [reg]
-- 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
isLive r = r `elem` alwaysLive || r `elem` live
dflags <- getDynFlags
stmtss <- flip mapM assignedRegs $ \reg ->
case reg of
CmmLocal (LocalReg un _) -> do
let (newv, stmts) = allocReg reg
varInsert un (pLower $ getVarType newv)
return stmts
CmmGlobal r -> do
let reg = lmGlobalRegVar dflags r
arg = lmGlobalRegArg dflags r
ty = (pLower . getVarType) reg
trash = LMLitVar $ LMUndefLit ty
rval = if isLive r then arg else trash
alloc = Assignment reg $ Alloca (pLower $ getVarType reg) 1
markStackReg r
return $ toOL [alloc, Store rval reg]
return (concatOL stmtss, [])
-- | Function epilogue. Load STG variables to use as argument for call.
-- STG Liveness optimisation done here.
funEpilogue :: LiveGlobalRegs -> LlvmM ([LlvmVar], LlvmStatements)
funEpilogue live = do
-- 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
dflags <- getDynFlags
let loadExpr r = do
(v, _, s) <- getCmmRegVal (CmmGlobal r)
return (Just $ v, s)
loadUndef r = do
let ty = (pLower . getVarType $ lmGlobalRegVar dflags r)
return (Just $ LMLitVar $ LMUndefLit ty, nilOL)
platform <- getDynFlag targetPlatform
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
-- with foreign functions.
getHsFunc :: LiveGlobalRegs -> CLabel -> LlvmM ExprData
getHsFunc live lbl
= do fty <- llvmFunTy live
name <- strCLabel_llvm lbl
getHsFunc' name fty
getHsFunc' :: LMString -> LlvmType -> LlvmM ExprData
getHsFunc' name fty
= do fun <- getGlobalPtr name
if getVarType fun == fty
then return (fun, nilOL, [])
else do (v1, s1) <- doExpr (pLift fty)
$ Cast LM_Bitcast fun (pLift fty)
return (v1, unitOL s1, [])
-- | Create a new local var
mkLocalVar :: LlvmType -> LlvmM LlvmVar
mkLocalVar ty = do
un <- getUniqueM
return $ LMLocalVar un ty
-- | Execute an expression, assigning result to a var
doExpr :: LlvmType -> LlvmExpression -> LlvmM (LlvmVar, LlvmStatement)
doExpr ty expr = do
v <- mkLocalVar ty
return (v, Assignment v expr)
-- | Expand CmmRegOff
expandCmmReg :: DynFlags -> (CmmReg, Int) -> CmmExpr
expandCmmReg dflags (reg, off)
= let width = typeWidth (cmmRegType dflags reg)
voff = CmmLit $ CmmInt (fromIntegral off) width
in CmmMachOp (MO_Add width) [CmmReg reg, voff]
-- | Convert a block id into a appropriate Llvm label
blockIdToLlvm :: BlockId -> LlvmVar
blockIdToLlvm bid = LMLocalVar (getUnique bid) LMLabel
-- | Create Llvm int Literal
mkIntLit :: Integral a => LlvmType -> a -> LlvmVar
mkIntLit ty i = LMLitVar $ LMIntLit (toInteger i) ty
-- | Convert int type to a LLvmVar of word or i32 size
toI32 :: Integral a => a -> LlvmVar
toI32 = mkIntLit i32
toIWord :: Integral a => DynFlags -> a -> LlvmVar
toIWord dflags = mkIntLit (llvmWord dflags)
-- | Error functions
panic :: String -> a
panic s = Outputable.panic $ "LlvmCodeGen.CodeGen." ++ s
pprPanic :: String -> SDoc -> a
pprPanic s d = Outputable.pprPanic ("LlvmCodeGen.CodeGen." ++ s) d
-- | Returns TBAA meta data by unique
getTBAAMeta :: Unique -> LlvmM [MetaAnnot]
getTBAAMeta u = do
mi <- getUniqMeta u
return [MetaAnnot tbaa (MetaNode i) | let Just i = mi]
-- | Returns TBAA meta data for given register
getTBAARegMeta :: GlobalReg -> LlvmM [MetaAnnot]
getTBAARegMeta = getTBAAMeta . getTBAA
-- | A more convenient way of accumulating LLVM statements and declarations.
data LlvmAccum = LlvmAccum LlvmStatements [LlvmCmmDecl]
instance Semigroup LlvmAccum where
LlvmAccum stmtsA declsA <> LlvmAccum stmtsB declsB =
LlvmAccum (stmtsA Semigroup.<> stmtsB) (declsA Semigroup.<> declsB)
instance Monoid LlvmAccum where
mempty = LlvmAccum nilOL []
mappend = (Semigroup.<>)
liftExprData :: LlvmM ExprData -> WriterT LlvmAccum LlvmM LlvmVar
liftExprData action = do
(var, stmts, decls) <- lift action
tell $ LlvmAccum stmts decls
return var
statement :: LlvmStatement -> WriterT LlvmAccum LlvmM ()
statement stmt = tell $ LlvmAccum (unitOL stmt) []
doExprW :: LlvmType -> LlvmExpression -> WriterT LlvmAccum LlvmM LlvmVar
doExprW a b = do
(var, stmt) <- lift $ doExpr a b
statement stmt
return var
exprToVarW :: CmmExpr -> WriterT LlvmAccum LlvmM LlvmVar
exprToVarW = liftExprData . exprToVar
runExprData :: WriterT LlvmAccum LlvmM LlvmVar -> LlvmM ExprData
runExprData action = do
(var, LlvmAccum stmts decls) <- runWriterT action
return (var, stmts, decls)
runStmtsDecls :: WriterT LlvmAccum LlvmM () -> LlvmM (LlvmStatements, [LlvmCmmDecl])
runStmtsDecls action = do
LlvmAccum stmts decls <- execWriterT action
return (stmts, decls)
getCmmRegW :: CmmReg -> WriterT LlvmAccum LlvmM LlvmVar
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
singletonPanic s _ = panic s
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