1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py 2; Test to make sure llvm.invariant.start calls are not treated as clobbers. 3; RUN: opt < %s -passes=dse -S | FileCheck %s 4 5declare ptr @llvm.invariant.start.p0(i64, ptr nocapture) nounwind readonly 6 7; We could remove either store here. The first store is dead in the 8; conventional sense, because there is a later killing store. The second store 9; is undefined behavior by the semantics of invariant.start, and as such 10; unreachable. 11define void @test(ptr %p) { 12; CHECK-LABEL: @test( 13; CHECK-NEXT: store i8 3, ptr [[P:%.*]], align 4 14; CHECK-NEXT: ret void 15; 16 store i8 1, ptr %p, align 4 17 %i = call ptr @llvm.invariant.start.p0(i64 1, ptr %p) 18 store i8 3, ptr %p, align 4 19 ret void 20} 21 22; FIXME: We should be able to remove the first store to p, even though p and q 23; may alias. 24define void @test2(ptr %p, ptr %q) { 25; CHECK-LABEL: @test2( 26; CHECK-NEXT: store i8 1, ptr [[P:%.*]], align 4 27; CHECK-NEXT: store i8 2, ptr [[Q:%.*]], align 4 28; CHECK-NEXT: [[I:%.*]] = call ptr @llvm.invariant.start.p0(i64 1, ptr [[Q]]) 29; CHECK-NEXT: store i8 3, ptr [[P]], align 4 30; CHECK-NEXT: ret void 31; 32 store i8 1, ptr %p, align 4 33 store i8 2, ptr %q, align 4 34 %i = call ptr @llvm.invariant.start.p0(i64 1, ptr %q) 35 store i8 3, ptr %p, align 4 36 ret void 37} 38