diff options
| author | Peter Collingbourne <peter@pcc.me.uk> | 2013-04-17 02:01:10 +0000 |
|---|---|---|
| committer | Peter Collingbourne <peter@pcc.me.uk> | 2013-04-17 02:01:10 +0000 |
| commit | c7ab4f99beceef00525f9a7df9ef58e63225cc7f (patch) | |
| tree | 78225ec0f6ccf7432281fd6dfa3f3609f30ee2dd | |
| parent | 8afc8b7e63d5ce2d027e92934d16b19e5ba2db59 (diff) | |
Do not optimise fprintf() calls if its return value is used.
Differential Revision: http://llvm-reviews.chandlerc.com/D620
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179661 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Transforms/Utils/SimplifyLibCalls.cpp | 21 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/fprintf-1.ll | 9 |
2 files changed, 21 insertions, 9 deletions
diff --git a/lib/Transforms/Utils/SimplifyLibCalls.cpp b/lib/Transforms/Utils/SimplifyLibCalls.cpp index c231704414..6bea2ddd20 100644 --- a/lib/Transforms/Utils/SimplifyLibCalls.cpp +++ b/lib/Transforms/Utils/SimplifyLibCalls.cpp @@ -1518,6 +1518,12 @@ struct FPrintFOpt : public LibCallOptimization { if (!getConstantStringInfo(CI->getArgOperand(1), FormatStr)) return 0; + // Do not do any of the following transformations if the fprintf return + // value is used, in general the fprintf return value is not compatible + // with fwrite(), fputc() or fputs(). + if (!CI->use_empty()) + return 0; + // fprintf(F, "foo") --> fwrite("foo", 3, 1, F) if (CI->getNumArgOperands() == 2) { for (unsigned i = 0, e = FormatStr.size(); i != e; ++i) @@ -1527,11 +1533,10 @@ struct FPrintFOpt : public LibCallOptimization { // These optimizations require DataLayout. if (!TD) return 0; - Value *NewCI = EmitFWrite(CI->getArgOperand(1), - ConstantInt::get(TD->getIntPtrType(*Context), - FormatStr.size()), - CI->getArgOperand(0), B, TD, TLI); - return NewCI ? ConstantInt::get(CI->getType(), FormatStr.size()) : 0; + return EmitFWrite(CI->getArgOperand(1), + ConstantInt::get(TD->getIntPtrType(*Context), + FormatStr.size()), + CI->getArgOperand(0), B, TD, TLI); } // The remaining optimizations require the format string to be "%s" or "%c" @@ -1544,14 +1549,12 @@ struct FPrintFOpt : public LibCallOptimization { if (FormatStr[1] == 'c') { // fprintf(F, "%c", chr) --> fputc(chr, F) if (!CI->getArgOperand(2)->getType()->isIntegerTy()) return 0; - Value *NewCI = EmitFPutC(CI->getArgOperand(2), CI->getArgOperand(0), B, - TD, TLI); - return NewCI ? ConstantInt::get(CI->getType(), 1) : 0; + return EmitFPutC(CI->getArgOperand(2), CI->getArgOperand(0), B, TD, TLI); } if (FormatStr[1] == 's') { // fprintf(F, "%s", str) --> fputs(str, F) - if (!CI->getArgOperand(2)->getType()->isPointerTy() || !CI->use_empty()) + if (!CI->getArgOperand(2)->getType()->isPointerTy()) return 0; return EmitFPutS(CI->getArgOperand(2), CI->getArgOperand(0), B, TD, TLI); } diff --git a/test/Transforms/InstCombine/fprintf-1.ll b/test/Transforms/InstCombine/fprintf-1.ll index 39d86b4588..e1dc191bd7 100644 --- a/test/Transforms/InstCombine/fprintf-1.ll +++ b/test/Transforms/InstCombine/fprintf-1.ll @@ -78,3 +78,12 @@ define void @test_no_simplify2(%FILE* %fp, double %d) { ret void ; CHECK-NEXT: ret void } + +define i32 @test_no_simplify3(%FILE* %fp) { +; CHECK: @test_no_simplify3 + %fmt = getelementptr [13 x i8]* @hello_world, i32 0, i32 0 + %1 = call i32 (%FILE*, i8*, ...)* @fprintf(%FILE* %fp, i8* %fmt) +; CHECK-NEXT: call i32 (%FILE*, i8*, ...)* @fprintf(%FILE* %fp, i8* getelementptr inbounds ([13 x i8]* @hello_world, i32 0, i32 0)) + ret i32 %1 +; CHECK-NEXT: ret i32 %1 +} |