commit 0db50189dcde3408134e9011052ed8b731ec303a
author Benjamin Kramer <benny.kra@googlemail.com> Thu Mar 31 10:12:15 2011 +0000
committer Benjamin Kramer <benny.kra@googlemail.com> Thu Mar 31 10:12:15 2011 +0000
tree 3b0ab5bfc16905ec88b7b548951e7578c3ca40d0
parent b194bdc03b6aa932ba4f719a8aa02db8d498f364

InstCombine: fold fcmp pred (fneg x), C -> fcmp swap(pred) x, -C

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128626 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/InstCombine/InstCombineCompares.cpp

diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 48ce7cf..6743885 100644
--- a/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -2834,6 +2834,14 @@
           return SelectInst::Create(LHSI->getOperand(0), Op1, Op2);
         break;
       }
+      case Instruction::FSub: {
+        // fcmp pred (fneg x), C -> fcmp swap(pred) x, -C
+        Value *Op;
+        if (match(LHSI, m_FNeg(m_Value(Op))))
+          return new FCmpInst(I.getSwappedPredicate(), Op,
+                              ConstantExpr::getFNeg(RHSC));
+        break;
+      }
       case Instruction::Load:
         if (GetElementPtrInst *GEP =
             dyn_cast<GetElementPtrInst>(LHSI->getOperand(0))) {