From: Dan Gohman <gohman@apple.com>
Date: Fri, 17 Jul 2009 19:23:21 +0000 (+0000)
Subject: GetElementPtr instructions default to having no overflow.
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=1bd9f58d6dd26ad8085e90a753d0a9aa76fb15e3;p=oota-llvm.git

GetElementPtr instructions default to having no overflow.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76222 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/VMCore/Instructions.cpp b/lib/VMCore/Instructions.cpp
index 6a259fb9251..a5e082c2377 100644
--- a/lib/VMCore/Instructions.cpp
+++ b/lib/VMCore/Instructions.cpp
@@ -1022,6 +1022,9 @@ void GetElementPtrInst::init(Value *Ptr, Value* const *Idx, unsigned NumIdx,
     OL[i+1] = Idx[i];
 
   setName(Name);
+
+  // GetElementPtr instructions have undefined results on overflow by default.
+  setHasNoPointerOverflow(true);
 }
 
 void GetElementPtrInst::init(Value *Ptr, Value *Idx, const std::string &Name) {
@@ -1031,6 +1034,9 @@ void GetElementPtrInst::init(Value *Ptr, Value *Idx, const std::string &Name) {
   OL[1] = Idx;
 
   setName(Name);
+
+  // GetElementPtr instructions have undefined results on overflow by default.
+  setHasNoPointerOverflow(true);
 }
 
 GetElementPtrInst::GetElementPtrInst(const GetElementPtrInst &GEPI)
@@ -1042,6 +1048,9 @@ GetElementPtrInst::GetElementPtrInst(const GetElementPtrInst &GEPI)
   Use *GEPIOL = GEPI.OperandList;
   for (unsigned i = 0, E = NumOperands; i != E; ++i)
     OL[i] = GEPIOL[i];
+
+  // Transfor the hasNoPointerOverflow() value from the original GEPI.
+  setHasNoPointerOverflow(GEPI.hasNoPointerOverflow());
 }
 
 GetElementPtrInst::GetElementPtrInst(Value *Ptr, Value *Idx,