From: Chris Lattner <sabre@nondot.org>
Date: Sun, 23 Jan 2011 21:15:29 +0000 (+0000)
Subject: teach Value::isDereferenceablePointer that byval arguments are always
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=3928af6ac47f9abef7dff32823a5fd41743c8fbc;p=oota-llvm.git

teach Value::isDereferenceablePointer that byval arguments are always
dereferencable, noticed by inspection.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124085 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/VMCore/Value.cpp b/lib/VMCore/Value.cpp
index 38438265dd6..29f6a8094f0 100644
--- a/lib/VMCore/Value.cpp
+++ b/lib/VMCore/Value.cpp
@@ -363,6 +363,10 @@ bool Value::isDereferenceablePointer() const {
   if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(this))
     return !GV->hasExternalWeakLinkage();
 
+  // byval arguments are ok.
+  if (const Argument *A = dyn_cast<Argument>(this))
+    return A->hasByValAttr();
+  
   // For GEPs, determine if the indexing lands within the allocated object.
   if (const GEPOperator *GEP = dyn_cast<GEPOperator>(this)) {
     // Conservatively require that the base pointer be fully dereferenceable.