[MemCpyOpt] Don't perform callslot optimization across may-throw calls
An exception could prevent a store from occurring but MemCpyOpt's
callslot optimization would fire anyway, causing the store to occur.
This fixes PR27849.
llvm-svn: 270892
diff --git a/llvm/test/Transforms/MemCpyOpt/callslot_throw.ll b/llvm/test/Transforms/MemCpyOpt/callslot_throw.ll
new file mode 100644
index 0000000..1aa4c92
--- /dev/null
+++ b/llvm/test/Transforms/MemCpyOpt/callslot_throw.ll
@@ -0,0 +1,34 @@
+; RUN: opt -S -memcpyopt < %s | FileCheck %s
+declare void @may_throw(i32* nocapture %x)
+
+; CHECK-LABEL: define void @test1(
+define void @test1(i32* nocapture noalias dereferenceable(4) %x) {
+entry:
+ %t = alloca i32, align 4
+ call void @may_throw(i32* nonnull %t)
+ %load = load i32, i32* %t, align 4
+ store i32 %load, i32* %x, align 4
+; CHECK: %[[t:.*]] = alloca i32, align 4
+; CHECK-NEXT: call void @may_throw(i32* {{.*}} %[[t]])
+; CHECK-NEXT: %[[load:.*]] = load i32, i32* %[[t]], align 4
+; CHECK-NEXT: store i32 %[[load]], i32* %x, align 4
+ ret void
+}
+
+declare void @always_throws()
+
+; CHECK-LABEL: define void @test2(
+define void @test2(i32* nocapture noalias dereferenceable(4) %x) {
+entry:
+ %t = alloca i32, align 4
+ call void @may_throw(i32* nonnull %t) nounwind
+ %load = load i32, i32* %t, align 4
+ call void @always_throws()
+ store i32 %load, i32* %x, align 4
+; CHECK: %[[t:.*]] = alloca i32, align 4
+; CHECK-NEXT: call void @may_throw(i32* {{.*}} %[[t]])
+; CHECK-NEXT: %[[load:.*]] = load i32, i32* %[[t]], align 4
+; CHECK-NEXT: call void @always_throws()
+; CHECK-NEXT: store i32 %[[load]], i32* %x, align 4
+ ret void
+}
diff --git a/llvm/test/Transforms/MemCpyOpt/loadstore-sret.ll b/llvm/test/Transforms/MemCpyOpt/loadstore-sret.ll
index 55cbe59..4c6136c 100644
--- a/llvm/test/Transforms/MemCpyOpt/loadstore-sret.ll
+++ b/llvm/test/Transforms/MemCpyOpt/loadstore-sret.ll
@@ -22,4 +22,4 @@
ret void
}
-declare void @_Z3barv(%"class.std::auto_ptr"* nocapture sret)
+declare void @_Z3barv(%"class.std::auto_ptr"* nocapture sret) nounwind