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

[oota-llvm.git] / lib / Transforms / Utils / SimplifyLibCalls.cpp

diff --git a/lib/Transforms/Utils/SimplifyLibCalls.cpp b/lib/Transforms/Utils/SimplifyLibCalls.cpp
index dc5fee523d4cd11c096e143416e533a309756156..563b65ce5d32baba56b61f7da9c4c445bd8028e0 100644 (file)
--- a/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -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