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|
{-# LANGUAGE TypeFamilies, ViewPatterns, OverloadedStrings #-}
-- -----------------------------------------------------------------------------
-- | This is the top-level module in the LLVM code generator.
--
module GHC.CmmToLlvm
( LlvmVersion
, llvmVersionList
, llvmCodeGen
, llvmFixupAsm
)
where
import GHC.Prelude hiding ( head )
import GHC.Llvm
import GHC.CmmToLlvm.Base
import GHC.CmmToLlvm.CodeGen
import GHC.CmmToLlvm.Config
import GHC.CmmToLlvm.Data
import GHC.CmmToLlvm.Ppr
import GHC.CmmToLlvm.Regs
import GHC.CmmToLlvm.Mangler
import GHC.StgToCmm.CgUtils ( fixStgRegisters )
import GHC.Cmm
import GHC.Cmm.Dataflow.Collections
import GHC.Utils.BufHandle
import GHC.Driver.Session
import GHC.Platform ( platformArch, Arch(..) )
import GHC.Utils.Error
import GHC.Data.FastString
import GHC.Utils.Outputable
import GHC.Utils.Panic
import GHC.Utils.Logger
import qualified GHC.Data.Stream as Stream
import Control.Monad ( when, forM_ )
import Data.List.NonEmpty ( head )
import Data.Maybe ( fromMaybe, catMaybes )
import System.IO
-- -----------------------------------------------------------------------------
-- | Top-level of the LLVM Code generator
--
llvmCodeGen :: Logger -> LlvmCgConfig -> Handle
-> Stream.Stream IO RawCmmGroup a
-> IO a
llvmCodeGen logger cfg h cmm_stream
= withTiming logger (text "LLVM CodeGen") (const ()) $ do
bufh <- newBufHandle h
-- Pass header
showPass logger "LLVM CodeGen"
-- get llvm version, cache for later use
let mb_ver = llvmCgLlvmVersion cfg
-- warn if unsupported
forM_ mb_ver $ \ver -> do
debugTraceMsg logger 2
(text "Using LLVM version:" <+> text (llvmVersionStr ver))
let doWarn = llvmCgDoWarn cfg
when (not (llvmVersionSupported ver) && doWarn) $ putMsg logger $
"You are using an unsupported version of LLVM!" $$
"Currently only" <+> text (llvmVersionStr supportedLlvmVersionLowerBound) <+>
"up to" <+> text (llvmVersionStr supportedLlvmVersionUpperBound) <+> "(non inclusive) is supported." <+>
"System LLVM version: " <> text (llvmVersionStr ver) $$
"We will try though..."
let isS390X = platformArch (llvmCgPlatform cfg) == ArchS390X
let major_ver = head . llvmVersionNE $ ver
when (isS390X && major_ver < 10 && doWarn) $ putMsg logger $
"Warning: For s390x the GHC calling convention is only supported since LLVM version 10." <+>
"You are using LLVM version: " <> text (llvmVersionStr ver)
-- HACK: the Nothing case here is potentially wrong here but we
-- currently don't use the LLVM version to guide code generation
-- so this is okay.
let llvm_ver :: LlvmVersion
llvm_ver = fromMaybe supportedLlvmVersionLowerBound mb_ver
-- run code generation
a <- runLlvm logger cfg llvm_ver bufh $
llvmCodeGen' cfg cmm_stream
bFlush bufh
return a
llvmCodeGen' :: LlvmCgConfig -> Stream.Stream IO RawCmmGroup a -> LlvmM a
llvmCodeGen' cfg cmm_stream
= do -- Preamble
renderLlvm header
ghcInternalFunctions
cmmMetaLlvmPrelude
-- Procedures
a <- Stream.consume cmm_stream liftIO llvmGroupLlvmGens
-- Declare aliases for forward references
renderLlvm . pprLlvmData cfg =<< generateExternDecls
-- Postamble
cmmUsedLlvmGens
return a
where
header :: SDoc
header =
let target = llvmCgLlvmTarget cfg
llvmCfg = llvmCgLlvmConfig cfg
in (text "target datalayout = \"" <> text (getDataLayout llvmCfg target) <> text "\"")
$+$ (text "target triple = \"" <> text target <> text "\"")
getDataLayout :: LlvmConfig -> String -> String
getDataLayout config target =
case lookup target (llvmTargets config) of
Just (LlvmTarget {lDataLayout=dl}) -> dl
Nothing -> pprPanic "Failed to lookup LLVM data layout" $
text "Target:" <+> text target $$
hang (text "Available targets:") 4
(vcat $ map (text . fst) $ llvmTargets config)
llvmGroupLlvmGens :: RawCmmGroup -> LlvmM ()
llvmGroupLlvmGens cmm = do
-- Insert functions into map, collect data
let split (CmmData s d' ) = return $ Just (s, d')
split (CmmProc h l live g) = do
-- Set function type
let l' = case mapLookup (g_entry g) h :: Maybe RawCmmStatics of
Nothing -> l
Just (CmmStaticsRaw info_lbl _) -> info_lbl
lml <- strCLabel_llvm l'
funInsert lml =<< llvmFunTy live
return Nothing
cdata <- fmap catMaybes $ mapM split cmm
{-# SCC "llvm_datas_gen" #-}
cmmDataLlvmGens cdata
{-# SCC "llvm_procs_gen" #-}
mapM_ cmmLlvmGen cmm
-- -----------------------------------------------------------------------------
-- | Do LLVM code generation on all these Cmms data sections.
--
cmmDataLlvmGens :: [(Section,RawCmmStatics)] -> LlvmM ()
cmmDataLlvmGens statics
= do lmdatas <- mapM genLlvmData statics
let (concat -> gs, tss) = unzip lmdatas
let regGlobal (LMGlobal (LMGlobalVar l ty _ _ _ _) _)
= funInsert l ty
regGlobal _ = pure ()
mapM_ regGlobal gs
gss' <- mapM aliasify $ gs
cfg <- getConfig
renderLlvm $ pprLlvmData cfg (concat gss', concat tss)
-- | Complete LLVM code generation phase for a single top-level chunk of Cmm.
cmmLlvmGen ::RawCmmDecl -> LlvmM ()
cmmLlvmGen cmm@CmmProc{} = do
-- rewrite assignments to global regs
platform <- getPlatform
let fixed_cmm = {-# SCC "llvm_fix_regs" #-} fixStgRegisters platform cmm
dumpIfSetLlvm Opt_D_dump_opt_cmm "Optimised Cmm"
FormatCMM (pprCmmGroup platform [fixed_cmm])
-- generate llvm code from cmm
llvmBC <- withClearVars $ genLlvmProc fixed_cmm
-- pretty print
(docs, ivars) <- fmap unzip $ mapM pprLlvmCmmDecl llvmBC
-- Output, note down used variables
renderLlvm (vcat docs)
mapM_ markUsedVar $ concat ivars
cmmLlvmGen _ = return ()
-- -----------------------------------------------------------------------------
-- | Generate meta data nodes
--
cmmMetaLlvmPrelude :: LlvmM ()
cmmMetaLlvmPrelude = do
metas <- flip mapM stgTBAA $ \(uniq, name, parent) -> do
-- Generate / lookup meta data IDs
tbaaId <- getMetaUniqueId
setUniqMeta uniq tbaaId
parentId <- maybe (return Nothing) getUniqMeta parent
-- Build definition
return $ MetaUnnamed tbaaId $ MetaStruct $
case parentId of
Just p -> [ MetaStr name, MetaNode p ]
-- As of LLVM 4.0, a node without parents should be rendered as
-- just a name on its own. Previously `null` was accepted as the
-- name.
Nothing -> [ MetaStr name ]
cfg <- getConfig
renderLlvm $ ppLlvmMetas cfg metas
-- -----------------------------------------------------------------------------
-- | Marks variables as used where necessary
--
cmmUsedLlvmGens :: LlvmM ()
cmmUsedLlvmGens = do
-- LLVM would discard variables that are internal and not obviously
-- used if we didn't provide these hints. This will generate a
-- definition of the form
--
-- @llvm.used = appending global [42 x i8*] [i8* bitcast <var> to i8*, ...]
--
-- Which is the LLVM way of protecting them against getting removed.
ivars <- getUsedVars
let cast x = LMBitc (LMStaticPointer (pVarLift x)) i8Ptr
ty = LMArray (length ivars) i8Ptr
usedArray = LMStaticArray (map cast ivars) ty
sectName = Just $ fsLit "llvm.metadata"
lmUsedVar = LMGlobalVar (fsLit "llvm.used") ty Appending sectName Nothing Constant
lmUsed = LMGlobal lmUsedVar (Just usedArray)
if null ivars
then return ()
else getConfig >>= renderLlvm . flip pprLlvmData ([lmUsed], [])
|
