From ff985d421880a5d39077f25db9117c7301f3f79d Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault@amd.com>
Date: Mon, 14 Jul 2014 22:39:26 +0000
Subject: [PATCH] Look through addrspacecast in IsConstantOffsetFromGlobal

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213000 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Analysis/ConstantFolding.cpp   |  3 ++-
 test/Transforms/ConstProp/loads.ll | 13 +++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index eb3e2c63690..8dc94219027 100644
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -240,7 +240,8 @@ static bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV,
 
   // Look through ptr->int and ptr->ptr casts.
   if (CE->getOpcode() == Instruction::PtrToInt ||
-      CE->getOpcode() == Instruction::BitCast)
+      CE->getOpcode() == Instruction::BitCast ||
+      CE->getOpcode() == Instruction::AddrSpaceCast)
     return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD);
 
   // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5)
diff --git a/test/Transforms/ConstProp/loads.ll b/test/Transforms/ConstProp/loads.ll
index 0ea9c47d448..5a23dad87f3 100644
--- a/test/Transforms/ConstProp/loads.ll
+++ b/test/Transforms/ConstProp/loads.ll
@@ -36,6 +36,19 @@ define i16 @test2() {
 ; BE: ret i16 -8531
 }
 
+define i16 @test2_addrspacecast() {
+  %r = load i16 addrspace(1)* addrspacecast(i32* getelementptr ({{i32,i8},i32}* @g1, i32 0, i32 0, i32 0) to i16 addrspace(1)*)
+  ret i16 %r
+
+; 0xBEEF
+; LE-LABEL: @test2_addrspacecast(
+; LE: ret i16 -16657
+
+; 0xDEAD
+; BE-LABEL: @test2_addrspacecast(
+; BE: ret i16 -8531
+}
+
 ; Load of second 16 bits of 32-bit value.
 define i16 @test3() {
   %r = load i16* getelementptr(i16* bitcast(i32* getelementptr ({{i32,i8},i32}* @g1, i32 0, i32 0, i32 0) to i16*), i32 1)