From 2c9cc9c7311a9dfaf0aec24db5a6ffcb783bac82 Mon Sep 17 00:00:00 2001 From: David Bolvansky Date: Thu, 26 Apr 2018 22:31:43 +0000 Subject: [SimplifyLibcalls] Replace locked IO with unlocked IO Summary: If file stream arg is not captured and source is fopen, we could replace IO calls by unlocked IO ("_unlocked" function variants) to gain better speed, Reviewers: efriedma, RKSimon, spatel, sanjoy, hfinkel, majnemer Subscribers: lebedev.ri, llvm-commits Differential Revision: https://reviews.llvm.org/D45736 llvm-svn: 331002 --- llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp | 111 ++++++++++++++++++++----- 1 file changed, 92 insertions(+), 19 deletions(-) (limited to 'llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp') diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp index ce804aef7da..85b6de3c064 100644 --- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp @@ -21,6 +21,7 @@ #include "llvm/Analysis/TargetLibraryInfo.h" #include "llvm/Analysis/Utils/Local.h" #include "llvm/Analysis/ValueTracking.h" +#include "llvm/Analysis/CaptureTracking.h" #include "llvm/IR/DataLayout.h" #include "llvm/IR/Function.h" #include "llvm/IR/IRBuilder.h" @@ -127,6 +128,28 @@ static Value *convertStrToNumber(CallInst *CI, StringRef &Str, int64_t Base) { return ConstantInt::get(CI->getType(), Result); } +static bool isLocallyOpenedFile(Value *File, CallInst *CI, IRBuilder<> &B, + const TargetLibraryInfo *TLI) { + CallInst *FOpen = dyn_cast(File); + if (!FOpen) + return false; + + Function *InnerCallee = FOpen->getCalledFunction(); + if (!InnerCallee) + return false; + + LibFunc Func; + if (!TLI->getLibFunc(*InnerCallee, Func) || !TLI->has(Func) || + Func != LibFunc_fopen) + return false; + + inferLibFuncAttributes(*CI->getCalledFunction(), *TLI); + if (PointerMayBeCaptured(File, true, true)) + return false; + + return true; +} + //===----------------------------------------------------------------------===// // String and Memory Library Call Optimizations //===----------------------------------------------------------------------===// @@ -1988,22 +2011,27 @@ Value *LibCallSimplifier::optimizeFWrite(CallInst *CI, IRBuilder<> &B) { // Get the element size and count. ConstantInt *SizeC = dyn_cast(CI->getArgOperand(1)); ConstantInt *CountC = dyn_cast(CI->getArgOperand(2)); - if (!SizeC || !CountC) - return nullptr; - uint64_t Bytes = SizeC->getZExtValue() * CountC->getZExtValue(); - - // If this is writing zero records, remove the call (it's a noop). - if (Bytes == 0) - return ConstantInt::get(CI->getType(), 0); - - // If this is writing one byte, turn it into fputc. - // This optimisation is only valid, if the return value is unused. - if (Bytes == 1 && CI->use_empty()) { // fwrite(S,1,1,F) -> fputc(S[0],F) - Value *Char = B.CreateLoad(castToCStr(CI->getArgOperand(0), B), "char"); - Value *NewCI = emitFPutC(Char, CI->getArgOperand(3), B, TLI); - return NewCI ? ConstantInt::get(CI->getType(), 1) : nullptr; + if (SizeC && CountC) { + uint64_t Bytes = SizeC->getZExtValue() * CountC->getZExtValue(); + + // If this is writing zero records, remove the call (it's a noop). + if (Bytes == 0) + return ConstantInt::get(CI->getType(), 0); + + // If this is writing one byte, turn it into fputc. + // This optimisation is only valid, if the return value is unused. + if (Bytes == 1 && CI->use_empty()) { // fwrite(S,1,1,F) -> fputc(S[0],F) + Value *Char = B.CreateLoad(castToCStr(CI->getArgOperand(0), B), "char"); + Value *NewCI = emitFPutC(Char, CI->getArgOperand(3), B, TLI); + return NewCI ? ConstantInt::get(CI->getType(), 1) : nullptr; + } } + if (isLocallyOpenedFile(CI->getArgOperand(3), CI, B, TLI)) + return emitFWriteUnlocked(CI->getArgOperand(0), CI->getArgOperand(1), + CI->getArgOperand(2), CI->getArgOperand(3), B, DL, + TLI); + return nullptr; } @@ -2015,9 +2043,14 @@ Value *LibCallSimplifier::optimizeFPuts(CallInst *CI, IRBuilder<> &B) { if (CI->getParent()->getParent()->optForSize()) return nullptr; - // We can't optimize if return value is used. - if (!CI->use_empty()) - return nullptr; + if (CI->use_empty()) { + if (isLocallyOpenedFile(CI->getArgOperand(1), CI, B, TLI)) + return emitFPutSUnlocked(CI->getArgOperand(0), CI->getArgOperand(1), B, + TLI); + else + // We can't optimize if return value is used. + return nullptr; + } // fputs(s,F) --> fwrite(s,1,strlen(s),F) uint64_t Len = GetStringLength(CI->getArgOperand(0)); @@ -2031,6 +2064,40 @@ Value *LibCallSimplifier::optimizeFPuts(CallInst *CI, IRBuilder<> &B) { CI->getArgOperand(1), B, DL, TLI); } +Value *LibCallSimplifier::optimizeFPutc(CallInst *CI, IRBuilder<> &B) { + optimizeErrorReporting(CI, B, 1); + + if (isLocallyOpenedFile(CI->getArgOperand(1), CI, B, TLI)) + return emitFPutCUnlocked(CI->getArgOperand(0), CI->getArgOperand(1), B, + TLI); + + return nullptr; +} + +Value *LibCallSimplifier::optimizeFGetc(CallInst *CI, IRBuilder<> &B) { + if (isLocallyOpenedFile(CI->getArgOperand(0), CI, B, TLI)) + return emitFGetCUnlocked(CI->getArgOperand(0), B, TLI); + + return nullptr; +} + +Value *LibCallSimplifier::optimizeFGets(CallInst *CI, IRBuilder<> &B) { + if (isLocallyOpenedFile(CI->getArgOperand(2), CI, B, TLI)) + return emitFGetSUnlocked(CI->getArgOperand(0), CI->getArgOperand(1), + CI->getArgOperand(2), B, TLI); + + return nullptr; +} + +Value *LibCallSimplifier::optimizeFRead(CallInst *CI, IRBuilder<> &B) { + if (isLocallyOpenedFile(CI->getArgOperand(3), CI, B, TLI)) + return emitFReadUnlocked(CI->getArgOperand(0), CI->getArgOperand(1), + CI->getArgOperand(2), CI->getArgOperand(3), B, DL, + TLI); + + return nullptr; +} + Value *LibCallSimplifier::optimizePuts(CallInst *CI, IRBuilder<> &B) { // Check for a constant string. StringRef Str; @@ -2322,8 +2389,16 @@ Value *LibCallSimplifier::optimizeCall(CallInst *CI) { return optimizeFPrintF(CI, Builder); case LibFunc_fwrite: return optimizeFWrite(CI, Builder); + case LibFunc_fread: + return optimizeFRead(CI, Builder); case LibFunc_fputs: return optimizeFPuts(CI, Builder); + case LibFunc_fgets: + return optimizeFGets(CI, Builder); + case LibFunc_fputc: + return optimizeFPutc(CI, Builder); + case LibFunc_fgetc: + return optimizeFGetc(CI, Builder); case LibFunc_puts: return optimizePuts(CI, Builder); case LibFunc_perror: @@ -2331,8 +2406,6 @@ Value *LibCallSimplifier::optimizeCall(CallInst *CI) { case LibFunc_vfprintf: case LibFunc_fiprintf: return optimizeErrorReporting(CI, Builder, 0); - case LibFunc_fputc: - return optimizeErrorReporting(CI, Builder, 1); default: return nullptr; } -- cgit v1.2.3