From 893c630fbe393916d9b7e07a5ac58046ea5db30e Mon Sep 17 00:00:00 2001
From: Nikita Popov <nikita.ppv@gmail.com>
Date: Sun, 16 Feb 2020 10:15:53 +0100
Subject: [PATCH] [InstCombine] Create new log2 intrinsic; NFCI

Rather than mixing creation of new instructions and in-place
modification here, create a new log2 intrinsic. This should be
NFC apart from worklist order changes.
---
 llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
index 5b825581a32f..bf3e025697a3 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
@@ -563,8 +563,7 @@ Instruction *InstCombiner::visitFMul(BinaryOperator &I) {
       Y = Op0;
     }
     if (Log2) {
-      Log2->setArgOperand(0, X);
-      Log2->copyFastMathFlags(&I);
+      Value *Log2 = Builder.CreateUnaryIntrinsic(Intrinsic::log2, X, &I);
       Value *LogXTimesY = Builder.CreateFMulFMF(Log2, Y, &I);
       return BinaryOperator::CreateFSubFMF(LogXTimesY, Y, &I);
     }