llvm/test/Transforms/MemCpyOpt/callslot_throw.ll
David Majnemer 4b3bb8d03e [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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@270892 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-26 19:24:24 +00:00

35 lines
1.1 KiB
LLVM

; 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
}