From 8532cf6258b6f62de2787f1b22b6325d64924b6d Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Mon, 17 Oct 2005 20:18:38 +0000
Subject: [PATCH] Make this work for FP constantexprs

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23773 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Scalar/InstructionCombining.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index d92e126b080..f4d44a17755 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -697,8 +697,9 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) {
     if (!I.getType()->isFloatingPoint()) { // NOTE: -0 + +0 = +0.
       if (RHSC->isNullValue())
         return ReplaceInstUsesWith(I, LHS);
-    } else if (cast<ConstantFP>(RHSC)->isExactlyValue(-0.0)) {
-      return ReplaceInstUsesWith(I, LHS);
+    } else if (ConstantFP *CFP = dyn_cast<ConstantFP>(RHSC)) {
+      if (CFP->isExactlyValue(-0.0))
+        return ReplaceInstUsesWith(I, LHS);
     }
 
     // X + (signbit) --> X ^ signbit