From 4c77b290822d5c2d54beb15ce099f9c10ffbda7f Mon Sep 17 00:00:00 2001
From: Louis Gerbarg <lgg@apple.com>
Date: Thu, 30 Oct 2014 22:21:03 +0000
Subject: [PATCH] Fix incorrect invariant check in DAG Combine

Earlier this summer I fixed an issue where we were incorrectly combining
multiple loads that had different constraints such alignment, invariance,
temporality, etc. Apparently in one case I made copt paste error and swapped
alignment and invariance.

Tests included.

rdar://18816719

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220933 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/SelectionDAG/DAGCombiner.cpp      |  2 +-
 .../CodeGen/AArch64/dag-combine-invaraints.ll | 36 +++++++++++++++++++
 2 files changed, 37 insertions(+), 1 deletion(-)
 create mode 100644 test/CodeGen/AArch64/dag-combine-invaraints.ll

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index acea763f5ba..0d5cabaaf27 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -11542,7 +11542,7 @@ bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDValue LHS,
     // It is safe to replace the two loads if they have different alignments,
     // but the new load must be the minimum (most restrictive) alignment of the
     // inputs.
-    bool isInvariant = LLD->getAlignment() & RLD->getAlignment();
+    bool isInvariant = LLD->isInvariant() & RLD->isInvariant();
     unsigned Alignment = std::min(LLD->getAlignment(), RLD->getAlignment());
     if (LLD->getExtensionType() == ISD::NON_EXTLOAD) {
       Load = DAG.getLoad(TheSelect->getValueType(0),
diff --git a/test/CodeGen/AArch64/dag-combine-invaraints.ll b/test/CodeGen/AArch64/dag-combine-invaraints.ll
new file mode 100644
index 00000000000..115fc64174c
--- /dev/null
+++ b/test/CodeGen/AArch64/dag-combine-invaraints.ll
@@ -0,0 +1,36 @@
+; RUN: llc -mtriple=arm64-apple-darwin8.0 -relocation-model=pic -O1 < %s | FileCheck %s
+
+@.str2 = private unnamed_addr constant [9 x i8] c"_%d____\0A\00", align 1
+
+; Function Attrs: nounwind ssp
+define i32 @main(i32 %argc, i8** %argv) #0 {
+main_:
+  %tmp = alloca i32, align 4
+  %i32T = alloca i32, align 4
+  %i32F = alloca i32, align 4
+  %i32X = alloca i32, align 4
+  store i32 0, i32* %tmp
+  store i32 15, i32* %i32T, align 4
+  store i32 5, i32* %i32F, align 4
+  %tmp6 = load i32* %tmp, align 4
+  %tmp7 = icmp ne i32 %tmp6, 0
+  %tmp8 = xor i1 %tmp7, true
+  %tmp9 = load i32* %i32T, align 4
+  %tmp10 = load i32* %i32F, align 4
+  %DHSelect = select i1 %tmp8, i32 %tmp9, i32 %tmp10
+  store i32 %DHSelect, i32* %i32X, align 4
+  %tmp15 = load i32* %i32X, align 4
+  %tmp17 = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([9 x i8]* @.str2, i32 0, i32 0), i32 %tmp15)
+  ret i32 0
+
+; CHECK: main:
+; CHECK-DAG: movz
+; CHECK-DAG: orr
+; CHECK: csel
+}
+
+
+declare i32 @printf(i8*, ...) #1
+
+attributes #0 = { nounwind ssp "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
-- 
2.34.1