diff options
| -rw-r--r-- | compiler/main/DynFlags.hs | 7 | ||||
| -rw-r--r-- | compiler/nativeGen/X86/Ppr.hs | 7 | ||||
| -rw-r--r-- | docs/users_guide/debugging.rst | 11 |
3 files changed, 25 insertions, 0 deletions
diff --git a/compiler/main/DynFlags.hs b/compiler/main/DynFlags.hs index b9141f9e87..b2c82fa2ee 100644 --- a/compiler/main/DynFlags.hs +++ b/compiler/main/DynFlags.hs @@ -876,6 +876,8 @@ data DynFlags = DynFlags { floatLamArgs :: Maybe Int, -- ^ Arg count for lambda floating -- See CoreMonad.FloatOutSwitches + cmmProcAlignment :: Maybe Int, -- ^ Align Cmm functions at this boundry or use default. + historySize :: Int, -- ^ Simplification history size importPaths :: [FilePath], @@ -1758,6 +1760,7 @@ defaultDynFlags mySettings (myLlvmTargets, myLlvmPasses) = specConstrRecursive = 3, liberateCaseThreshold = Just 2000, floatLamArgs = Just 0, -- Default: float only if no fvs + cmmProcAlignment = Nothing, historySize = 20, strictnessBefore = [], @@ -3397,6 +3400,10 @@ dynamic_flags_deps = [ (intSuffix (\n d -> d { floatLamArgs = Just n })) , make_ord_flag defFlag "ffloat-all-lams" (noArg (\d -> d { floatLamArgs = Nothing })) + , make_ord_flag defFlag "fproc-alignment" + (intSuffix (\n d -> d { cmmProcAlignment = Just n })) + + , make_ord_flag defFlag "fhistory-size" (intSuffix (\n d -> d { historySize = n })) , make_ord_flag defFlag "funfolding-creation-threshold" diff --git a/compiler/nativeGen/X86/Ppr.hs b/compiler/nativeGen/X86/Ppr.hs index c03bf4f14c..c5fbeb544e 100644 --- a/compiler/nativeGen/X86/Ppr.hs +++ b/compiler/nativeGen/X86/Ppr.hs @@ -73,12 +73,17 @@ import Data.Bits -- .subsections_via_symbols and -dead_strip can be found at -- <https://developer.apple.com/library/mac/documentation/DeveloperTools/Reference/Assembler/040-Assembler_Directives/asm_directives.html#//apple_ref/doc/uid/TP30000823-TPXREF101> +pprProcAlignment :: SDoc +pprProcAlignment = sdocWithDynFlags $ \dflags -> + (maybe empty pprAlign . cmmProcAlignment $ dflags) + pprNatCmmDecl :: NatCmmDecl (Alignment, CmmStatics) Instr -> SDoc pprNatCmmDecl (CmmData section dats) = pprSectionAlign section $$ pprDatas dats pprNatCmmDecl proc@(CmmProc top_info lbl _ (ListGraph blocks)) = sdocWithDynFlags $ \dflags -> + pprProcAlignment $$ case topInfoTable proc of Nothing -> case blocks of @@ -86,6 +91,7 @@ pprNatCmmDecl proc@(CmmProc top_info lbl _ (ListGraph blocks)) = pprLabel lbl blocks -> -- special case for code without info table: pprSectionAlign (Section Text lbl) $$ + pprProcAlignment $$ pprLabel lbl $$ -- blocks guaranteed not null, so label needed vcat (map (pprBasicBlock top_info) blocks) $$ (if debugLevel dflags > 0 @@ -95,6 +101,7 @@ pprNatCmmDecl proc@(CmmProc top_info lbl _ (ListGraph blocks)) = Just (Statics info_lbl _) -> sdocWithPlatform $ \platform -> pprSectionAlign (Section Text info_lbl) $$ + pprProcAlignment $$ (if platformHasSubsectionsViaSymbols platform then ppr (mkDeadStripPreventer info_lbl) <> char ':' else empty) $$ diff --git a/docs/users_guide/debugging.rst b/docs/users_guide/debugging.rst index 4e0be937f4..7adcc84f13 100644 --- a/docs/users_guide/debugging.rst +++ b/docs/users_guide/debugging.rst @@ -758,6 +758,17 @@ Checking for consistency Compile with alignment checks for all info table dereferences. This can be useful when finding pointer tagging issues. +.. ghc-flag:: -fproc-alignment + :shortdesc: Align functions at given boundry. + :type: dynamic + + Align functions to multiples of the given value. Only valid values are powers + of two. + + ``-fproc-alignment=64`` can be used to limit alignment impact on performance + as each function will start at a cache line. + However forcing larger alignments in general reduces performance. + .. ghc-flag:: -fcatch-bottoms :shortdesc: Insert ``error`` expressions after bottoming expressions; useful when debugging the compiler. |