[LibCallSimplifier] use instruction-level fast-math-flags for tan/atan transform

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256964 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Sanjay Patel 2016-01-06 19:23:35 +00:00
parent 4377f132ae
commit 78a42b0707
2 changed files with 14 additions and 12 deletions

View File

@ -1457,6 +1457,7 @@ Value *LibCallSimplifier::optimizeSqrt(CallInst *CI, IRBuilder<> &B) {
return Ret;
}
// TODO: Generalize to handle any trig function and its inverse.
Value *LibCallSimplifier::optimizeTan(CallInst *CI, IRBuilder<> &B) {
Function *Callee = CI->getCalledFunction();
Value *Ret = nullptr;
@ -1471,13 +1472,15 @@ Value *LibCallSimplifier::optimizeTan(CallInst *CI, IRBuilder<> &B) {
!FT->getParamType(0)->isFloatingPointTy())
return Ret;
if (!canUseUnsafeFPMath(CI->getParent()->getParent()))
return Ret;
Value *Op1 = CI->getArgOperand(0);
auto *OpC = dyn_cast<CallInst>(Op1);
if (!OpC)
return Ret;
// Both calls must allow unsafe optimizations in order to remove them.
if (!CI->hasUnsafeAlgebra() || !OpC->hasUnsafeAlgebra())
return Ret;
// tan(atan(x)) -> x
// tanf(atanf(x)) -> x
// tanl(atanl(x)) -> x

View File

@ -1,24 +1,23 @@
; RUN: opt < %s -instcombine -S | FileCheck %s
define float @mytan(float %x) #0 {
entry:
%call = call float @atanf(float %x)
%call1 = call float @tanf(float %call)
define float @mytan(float %x) {
%call = call fast float @atanf(float %x)
%call1 = call fast float @tanf(float %call)
ret float %call1
}
; CHECK-LABEL: define float @mytan(
; CHECK: ret float %x
define float @test2(float ()* %fptr) #0 {
%call1 = call float %fptr()
%tan = call float @tanf(float %call1)
define float @test2(float ()* %fptr) {
%call1 = call fast float %fptr()
%tan = call fast float @tanf(float %call1)
ret float %tan
}
; CHECK-LABEL: @test2
; CHECK: tanf
declare float @tanf(float) #0
declare float @atanf(float) #0
attributes #0 = { "unsafe-fp-math"="true" }
declare float @tanf(float)
declare float @atanf(float)