diff options
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineCompares.cpp | 39 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/fcmp.ll | 82 |
2 files changed, 121 insertions, 0 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp index bdd310e..3fc1357 100644 --- a/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -17,6 +17,7 @@ #include "llvm/Analysis/InstructionSimplify.h" #include "llvm/Analysis/MemoryBuiltins.h" #include "llvm/Target/TargetData.h" +#include "llvm/Target/TargetLibraryInfo.h" #include "llvm/Support/ConstantRange.h" #include "llvm/Support/GetElementPtrTypeIterator.h" #include "llvm/Support/PatternMatch.h" @@ -2985,6 +2986,44 @@ Instruction *InstCombiner::visitFCmpInst(FCmpInst &I) { return Res; } break; + case Instruction::Call: { + CallInst *CI = cast<CallInst>(LHSI); + LibFunc::Func Func; + // Various optimization for fabs compared with zero. + if (RHSC->isNullValue() && CI->hasOneUse() && + TLI->getLibFunc(CI->getCalledFunction()->getName(), Func) && + TLI->has(Func)) { + if (Func == LibFunc::fabs || Func == LibFunc::fabsf || + Func == LibFunc::fabsl) { + switch (I.getPredicate()) { + default: break; + // fabs(x) < 0 --> false + case FCmpInst::FCMP_OLT: + return ReplaceInstUsesWith(I, Builder->getFalse()); + // fabs(x) > 0 --> x != 0 + case FCmpInst::FCMP_OGT: + return new FCmpInst(FCmpInst::FCMP_ONE, CI->getArgOperand(0), + RHSC); + // fabs(x) <= 0 --> x == 0 + case FCmpInst::FCMP_OLE: + return new FCmpInst(FCmpInst::FCMP_OEQ, CI->getArgOperand(0), + RHSC); + // fabs(x) >= 0 --> !isnan(x) + case FCmpInst::FCMP_OGE: + return new FCmpInst(FCmpInst::FCMP_ORD, CI->getArgOperand(0), + RHSC); + // fabs(x) == 0 --> x == 0 + // fabs(x) != 0 --> x != 0 + case FCmpInst::FCMP_OEQ: + case FCmpInst::FCMP_UEQ: + case FCmpInst::FCMP_ONE: + case FCmpInst::FCMP_UNE: + return new FCmpInst(I.getPredicate(), CI->getArgOperand(0), + RHSC); + } + } + } + } } } diff --git a/test/Transforms/InstCombine/fcmp.ll b/test/Transforms/InstCombine/fcmp.ll index d08cbf5..82fef48 100644 --- a/test/Transforms/InstCombine/fcmp.ll +++ b/test/Transforms/InstCombine/fcmp.ll @@ -69,3 +69,85 @@ define float @test8(float %x) nounwind readnone optsize ssp { ; CHECK: @test8 ; CHECK-NEXT: fcmp olt float %x, 0.000000e+00 } + +declare double @fabs(double) nounwind readnone + +define i32 @test9(double %a) nounwind { + %call = tail call double @fabs(double %a) nounwind + %cmp = fcmp olt double %call, 0.000000e+00 + %conv = zext i1 %cmp to i32 + ret i32 %conv +; CHECK: @test9 +; CHECK-NOT: fabs +; CHECK: ret i32 0 +} + +define i32 @test10(double %a) nounwind { + %call = tail call double @fabs(double %a) nounwind + %cmp = fcmp ole double %call, 0.000000e+00 + %conv = zext i1 %cmp to i32 + ret i32 %conv +; CHECK: @test10 +; CHECK-NOT: fabs +; CHECK: fcmp oeq double %a, 0.000000e+00 +} + +define i32 @test11(double %a) nounwind { + %call = tail call double @fabs(double %a) nounwind + %cmp = fcmp ogt double %call, 0.000000e+00 + %conv = zext i1 %cmp to i32 + ret i32 %conv +; CHECK: @test11 +; CHECK-NOT: fabs +; CHECK: fcmp one double %a, 0.000000e+00 +} + +define i32 @test12(double %a) nounwind { + %call = tail call double @fabs(double %a) nounwind + %cmp = fcmp oge double %call, 0.000000e+00 + %conv = zext i1 %cmp to i32 + ret i32 %conv +; CHECK: @test12 +; CHECK-NOT: fabs +; CHECK: fcmp ord double %a, 0.000000e+00 +} + +define i32 @test13(double %a) nounwind { + %call = tail call double @fabs(double %a) nounwind + %cmp = fcmp une double %call, 0.000000e+00 + %conv = zext i1 %cmp to i32 + ret i32 %conv +; CHECK: @test13 +; CHECK-NOT: fabs +; CHECK: fcmp une double %a, 0.000000e+00 +} + +define i32 @test14(double %a) nounwind { + %call = tail call double @fabs(double %a) nounwind + %cmp = fcmp oeq double %call, 0.000000e+00 + %conv = zext i1 %cmp to i32 + ret i32 %conv +; CHECK: @test14 +; CHECK-NOT: fabs +; CHECK: fcmp oeq double %a, 0.000000e+00 +} + +define i32 @test15(double %a) nounwind { + %call = tail call double @fabs(double %a) nounwind + %cmp = fcmp one double %call, 0.000000e+00 + %conv = zext i1 %cmp to i32 + ret i32 %conv +; CHECK: @test15 +; CHECK-NOT: fabs +; CHECK: fcmp one double %a, 0.000000e+00 +} + +define i32 @test16(double %a) nounwind { + %call = tail call double @fabs(double %a) nounwind + %cmp = fcmp ueq double %call, 0.000000e+00 + %conv = zext i1 %cmp to i32 + ret i32 %conv +; CHECK: @test16 +; CHECK-NOT: fabs +; CHECK: fcmp ueq double %a, 0.000000e+00 +} |