From: Chris Lattner <sabre@nondot.org>
Date: Wed, 15 Oct 2008 05:18:04 +0000 (+0000)
Subject: fold compare of null pointer into compare with 0.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=d53886bb488fbef11b8083d7e99bcf53a51861a0;p=oota-llvm.git

fold compare of null pointer into compare with 0.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57553 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp
index 954a3a0640e..e04e91a7acd 100644
--- a/lib/Target/X86/X86FastISel.cpp
+++ b/lib/Target/X86/X86FastISel.cpp
@@ -549,6 +549,10 @@ bool X86FastISel::X86FastEmitCompare(Value *Op0, Value *Op1, MVT VT) {
   unsigned Op0Reg = getRegForValue(Op0);
   if (Op0Reg == 0) return false;
   
+  // Handle 'null' like i32/i64 0.
+  if (isa<ConstantPointerNull>(Op1))
+    Op1 = Constant::getNullValue(TD.getIntPtrType());
+  
   // We have two options: compare with register or immediate.  If the RHS of
   // the compare is an immediate that we can fold into this compare, use
   // CMPri, otherwise use CMPrr.