; Test to make sure llvm.invariant.start calls are not treated as clobbers. ; RUN: opt < %s -basic-aa -dse -enable-dse-memoryssa=false -S | FileCheck %s declare {}* @llvm.invariant.start.p0i8(i64, i8* nocapture) nounwind readonly ; We cannot remove the store 1 to %p. ; FIXME: By the semantics of invariant.start, the store 3 to p is unreachable. define void @test(i8 *%p) { store i8 1, i8* %p, align 4 %i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %p) store i8 3, i8* %p, align 4 ret void ; CHECK-LABEL: @test( ; CHECK-NEXT: store i8 1, i8* %p, align 4 ; CHECK-NEXT: %i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %p) ; CHECK-NEXT: store i8 3, i8* %p, align 4 ; CHECK-NEXT: ret void } ; FIXME: We should be able to remove the first store to p, even though p and q ; may alias. define void @test2(i8* %p, i8* %q) { store i8 1, i8* %p, align 4 store i8 2, i8* %q, align 4 %i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %q) store i8 3, i8* %p, align 4 ret void ; CHECK-LABEL: @test2( ; CHECK-NEXT: store i8 1, i8* %p, align 4 ; CHECK-NEXT: store i8 2, i8* %q, align 4 ; CHECK-NEXT: %i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %q) ; CHECK-NEXT: store i8 3, i8* %p, align 4 ; CHECK-NEXT: ret void }