[PATCH] D95455: [InstCombine] Preserve FMF for powi simplifications.

[Valeriy Dmitriev via Phabricator via llvm-commits]

vdmitrie created this revision.
vdmitrie added a reviewer: spatel.
Herald added a subscriber: hiraditya.
vdmitrie requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D95455

Files:
  llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
  llvm/test/Transforms/InstCombine/intrinsics.ll


Index: llvm/test/Transforms/InstCombine/intrinsics.ll
===================================================================
--- llvm/test/Transforms/InstCombine/intrinsics.ll
+++ llvm/test/Transforms/InstCombine/intrinsics.ll
@@ -28,9 +28,9 @@
   store volatile double %D, double* %P
   ret void
 ; CHECK-LABEL: @powi(
-; CHECK: %A = fdiv double 1.0{{.*}}, %V
+; CHECK: %A = fdiv fast double 1.0{{.*}}, %V
 ; CHECK: store volatile double %A,
-; CHECK: %D = fmul double %V, %V
+; CHECK: %D = fmul fast double %V, %V
 ; CHECK: store volatile double %D
 }
 
Index: llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
===================================================================
--- llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -886,15 +886,14 @@
   case Intrinsic::powi:
     if (ConstantInt *Power = dyn_cast<ConstantInt>(II->getArgOperand(1))) {
       // 0 and 1 are handled in instsimplify
-
       // powi(x, -1) -> 1/x
       if (Power->isMinusOne())
-        return BinaryOperator::CreateFDiv(ConstantFP::get(CI.getType(), 1.0),
-                                          II->getArgOperand(0));
+        return BinaryOperator::CreateFDivFMF(ConstantFP::get(CI.getType(), 1.0),
+                                             II->getArgOperand(0), II);
       // powi(x, 2) -> x*x
       if (Power->equalsInt(2))
-        return BinaryOperator::CreateFMul(II->getArgOperand(0),
-                                          II->getArgOperand(0));
+        return BinaryOperator::CreateFMulFMF(II->getArgOperand(0),
+                                             II->getArgOperand(0), II);
     }
     break;
 


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