llvm/test/Transforms/DeadStoreElimination/lifetime.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -S -passes=dse < %s | FileCheck %s

target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"

declare void @llvm.lifetime.start.p0(ptr nocapture) nounwind
declare void @llvm.lifetime.end.p0(ptr nocapture) nounwind
declare void @llvm.memset.p0.i8(ptr nocapture, i8, i8, i1) nounwind

define void @test1() {
; CHECK-LABEL: @test1(
; CHECK-NEXT:    [[A:%.*]] = alloca i8, align 1
; CHECK-NEXT:    call void @llvm.lifetime.end.p0(ptr [[A]])
; CHECK-NEXT:    ret void
;
  %A = alloca i8

  store i8 0, ptr %A  ;; Written to by memset
  call void @llvm.lifetime.end.p0(ptr %A)

  call void @llvm.memset.p0.i8(ptr %A, i8 0, i8 -1, i1 false)

  ret void
}

define void @test2(ptr %P) {
; CHECK-LABEL: @test2(
; CHECK-NEXT:    [[Q:%.*]] = alloca i32, align 4
; CHECK-NEXT:    call void @llvm.lifetime.start.p0(ptr [[Q]])
; CHECK-NEXT:    call void @llvm.lifetime.end.p0(ptr [[Q]])
; CHECK-NEXT:    ret void
;
  %Q = alloca i32
  call void @llvm.lifetime.start.p0(ptr %Q)
  store i32 0, ptr %Q  ;; This store is dead.
  call void @llvm.lifetime.end.p0(ptr %Q)
  ret void
}

declare void @use(ptr) readonly