From c368563bd679fd74dd19723f78352b4f5b5c4164 Mon Sep 17 00:00:00 2001
From: Arnold Schwaighofer <aschwaighofer@apple.com>
Date: Tue, 31 Jan 2017 17:53:49 +0000
Subject: [PATCH] Don't combine stores to a swifterror pointer operand to a
 different type

llvm-svn: 293658
---
 .../InstCombineLoadStoreAlloca.cpp            |  3 ++-
 llvm/test/Transforms/InstCombine/load.ll      | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
index 5fe9e5c645a4..6ceca78d4551 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
@@ -502,7 +502,8 @@ static Instruction *combineLoadToOperationType(InstCombiner &IC, LoadInst &LI) {
       !DL.isNonIntegralPointerType(Ty)) {
     if (all_of(LI.users(), [&LI](User *U) {
           auto *SI = dyn_cast<StoreInst>(U);
-          return SI && SI->getPointerOperand() != &LI;
+          return SI && SI->getPointerOperand() != &LI &&
+                 !SI->getPointerOperand()->isSwiftError();
         })) {
       LoadInst *NewLoad = combineLoadToNewType(
           IC, LI,
diff --git a/llvm/test/Transforms/InstCombine/load.ll b/llvm/test/Transforms/InstCombine/load.ll
index cad2899ea35d..49ed897fd2ea 100644
--- a/llvm/test/Transforms/InstCombine/load.ll
+++ b/llvm/test/Transforms/InstCombine/load.ll
@@ -219,3 +219,22 @@ entry:
   store %swift.error* %err.res, %swift.error** %err, align 8
   ret void
 }
+
+; Make sure we preseve the type of the store to a swifterror pointer.
+; CHECK-LABEL: @test19(
+; CHECK: [[A:%.*]] = alloca
+; CHECK: call
+; CHECK: [[BC:%.*]] = bitcast i8** [[A]] to
+; CHECK: [[ERRVAL:%.*]] =  load {{.*}}[[BC]]
+; CHECK: store {{.*}}[[ERRVAL]]
+; CHECK: ret
+declare void @initi8(i8**)
+define void @test19(%swift.error** swifterror %err) {
+entry:
+  %tmp = alloca i8*, align 8
+  call void @initi8(i8** %tmp)
+  %swifterror = bitcast i8** %tmp to %swift.error**
+  %err.res = load %swift.error*, %swift.error** %swifterror, align 8
+  store %swift.error* %err.res, %swift.error** %err, align 8
+  ret void
+}