From 95365ca482c338634fdbc0a6c8176c52ad8bc7c6 Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault@amd.com>
Date: Mon, 27 Jul 2015 18:31:03 +0000
Subject: [PATCH] Fix assert when inlining a constantexpr addrspacecast

The pointer size of the addrspacecasted pointer might not have matched,
so this would have hit an assert in accumulateConstantOffset.

I think this was here to allow constant folding of a load of an
addrspacecasted constant. Accumulating the offset through the
addrspacecast doesn't make much sense, so something else is necessary
to allow folding the load through this cast.

llvm-svn: 243300
---
 llvm/lib/Analysis/ConstantFolding.cpp         |  3 +-
 llvm/test/Transforms/ConstProp/loads.ll       |  7 +++--
 ...inline-constexpr-addrspacecast-argument.ll | 30 +++++++++++++++++++
 3 files changed, 36 insertions(+), 4 deletions(-)
 create mode 100644 llvm/test/Transforms/Inline/inline-constexpr-addrspacecast-argument.ll

diff --git a/llvm/lib/Analysis/ConstantFolding.cpp b/llvm/lib/Analysis/ConstantFolding.cpp
index 70c929b53a3f..07f53bedc776 100644
--- a/llvm/lib/Analysis/ConstantFolding.cpp
+++ b/llvm/lib/Analysis/ConstantFolding.cpp
@@ -248,8 +248,7 @@ 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::AddrSpaceCast)
+      CE->getOpcode() == Instruction::BitCast)
     return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, DL);
 
   // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5)
diff --git a/llvm/test/Transforms/ConstProp/loads.ll b/llvm/test/Transforms/ConstProp/loads.ll
index 5426ad0f8adb..89387ad06ba8 100644
--- a/llvm/test/Transforms/ConstProp/loads.ll
+++ b/llvm/test/Transforms/ConstProp/loads.ll
@@ -40,13 +40,16 @@ define i16 @test2_addrspacecast() {
   %r = load i16, i16 addrspace(1)* addrspacecast(i32* getelementptr ({{i32,i8},i32}, {{i32,i8},i32}* @g1, i32 0, i32 0, i32 0) to i16 addrspace(1)*)
   ret i16 %r
 
+; FIXME: Should be able to load through a constant addrspacecast.
 ; 0xBEEF
 ; LE-LABEL: @test2_addrspacecast(
-; LE: ret i16 -16657
+; XLE: ret i16 -16657
+; LE: load i16, i16 addrspace(1)* addrspacecast
 
 ; 0xDEAD
 ; BE-LABEL: @test2_addrspacecast(
-; BE: ret i16 -8531
+; XBE: ret i16 -8531
+; BE: load i16, i16 addrspace(1)* addrspacecast
 }
 
 ; Load of second 16 bits of 32-bit value.
diff --git a/llvm/test/Transforms/Inline/inline-constexpr-addrspacecast-argument.ll b/llvm/test/Transforms/Inline/inline-constexpr-addrspacecast-argument.ll
new file mode 100644
index 000000000000..498a995ecd45
--- /dev/null
+++ b/llvm/test/Transforms/Inline/inline-constexpr-addrspacecast-argument.ll
@@ -0,0 +1,30 @@
+; RUN: opt -S -inline < %s | FileCheck %s
+
+target datalayout = "e-p3:32:32-p4:64:64-n32"
+
+@lds = internal addrspace(3) global [64 x i64] zeroinitializer
+
+; CHECK-LABEL: @constexpr_addrspacecast_ptr_size_change(
+; CHECK: load i64, i64 addrspace(4)* getelementptr (i64, i64 addrspace(4)* addrspacecast (i64 addrspace(3)* getelementptr inbounds ([64 x i64], [64 x i64] addrspace(3)* @lds, i32 0, i32 0) to i64 addrspace(4)*), i64 undef)
+; CHECK-NEXT: br
+define void @constexpr_addrspacecast_ptr_size_change() #0 {
+  %tmp0 = call i32 @foo(i64 addrspace(4)* addrspacecast (i64 addrspace(3)* getelementptr inbounds ([64 x i64], [64 x i64] addrspace(3)* @lds, i32 0, i32 0) to i64 addrspace(4)*)) #1
+  ret void
+}
+
+define i32 @foo(i64 addrspace(4)* %arg) #1 {
+bb:
+  %tmp = getelementptr i64, i64 addrspace(4)* %arg, i64 undef
+  %tmp1 = load i64, i64 addrspace(4)* %tmp
+  br i1 undef, label %bb2, label %bb3
+
+bb2:
+  store i64 0, i64 addrspace(4)* %tmp
+  br label %bb3
+
+bb3:
+  unreachable
+}
+
+attributes #0 = { nounwind }
+attributes #1 = { alwaysinline nounwind }