test/Transforms/DeadStoreElimination/calloc-store.ll

; RUN: opt < %s -basic-aa -dse -S | FileCheck %s

declare noalias i8* @calloc(i64, i64)

define i32* @test1() {
; CHECK-LABEL: test1
  %1 = tail call noalias i8* @calloc(i64 1, i64 4)
  %2 = bitcast i8* %1 to i32*
  ; This store is dead and should be removed
  store i32 0, i32* %2, align 4
; CHECK-NOT: store i32 0, i32* %2, align 4
  ret i32* %2
}

define i32* @test2() {
; CHECK-LABEL: test2
  %1 = tail call noalias i8* @calloc(i64 1, i64 4)
  %2 = bitcast i8* %1 to i32*
  %3 = getelementptr i32, i32* %2, i32 5
  store i32 0, i32* %3, align 4
; CHECK-NOT: store i32 0, i32* %2, align 4
  ret i32* %2
}

define i32* @test3(i32 *%arg) {
; CHECK-LABEL: test3
  store i32 0, i32* %arg, align 4
; CHECK: store i32 0, i32* %arg, align 4
  ret i32* %arg
}

declare void @clobber_memory(i8*)
define i8* @test4() {
; CHECK-LABEL: test4
  %1 = tail call noalias i8* @calloc(i64 1, i64 4)
  call void @clobber_memory(i8* %1)
  store i8 0, i8* %1, align 4
; CHECK: store i8 0, i8* %1, align 4
  ret i8* %1
}

define i32* @test5() {
; CHECK-LABEL: test5
  %1 = tail call noalias i8* @calloc(i64 1, i64 4)
  %2 = bitcast i8* %1 to i32*
  store volatile i32 0, i32* %2, align 4
; CHECK: store volatile i32 0, i32* %2, align 4
  ret i32* %2
}

define i8* @test6() {
; CHECK-LABEL: test6
  %1 = tail call noalias i8* @calloc(i64 1, i64 4)
  store i8 5, i8* %1, align 4
; CHECK: store i8 5, i8* %1, align 4
  ret i8* %1
}

define i8* @test7(i8 %arg) {
; CHECK-LABEL: test7
  %1 = tail call noalias i8* @calloc(i64 1, i64 4)
  store i8 %arg, i8* %1, align 4
; CHECK: store i8 %arg, i8* %1, align 4
  ret i8* %1
}

define i8* @test8() {
; CHECK-LABEL: test8
; CHECK-NOT: store
  %p = tail call noalias i8* @calloc(i64 1, i64 4)
  store i8 0, i8* %p, align 1
  %p.1 = getelementptr i8, i8* %p, i32 1
  store i8 0, i8* %p.1, align 1
  %p.3 = getelementptr i8, i8* %p, i32 3
  store i8 0, i8* %p.3, align 1
  %p.2 = getelementptr i8, i8* %p, i32 2
  store i8 0, i8* %p.2, align 1
  ret i8* %p
}

define i8* @test9() {
; CHECK-LABEL: test9
; CHECK-NEXT:    %p = tail call noalias i8* @calloc(i64 1, i64 4)
; CHECK-NEXT:    store i8 5, i8* %p, align 1
; CHECK-NEXT:    ret i8* %p

  %p = tail call noalias i8* @calloc(i64 1, i64 4)
  store i8 5, i8* %p, align 1
  %p.1 = getelementptr i8, i8* %p, i32 1
  store i8 0, i8* %p.1, align 1
  %p.3 = getelementptr i8, i8* %p, i32 3
  store i8 0, i8* %p.3, align 1
  %p.2 = getelementptr i8, i8* %p, i32 2
  store i8 0, i8* %p.2, align 1
  ret i8* %p
}

define i8* @test10() {
; CHECK-LABEL: @test10(
; CHECK-NEXT:    [[P:%.*]] = tail call noalias i8* @calloc(i64 1, i64 4)
; CHECK-NEXT:    [[P_3:%.*]] = getelementptr i8, i8* [[P]], i32 3
; CHECK-NEXT:    store i8 5, i8* [[P_3]], align 1
; CHECK-NEXT:    ret i8* [[P]]
;

  %p = tail call noalias i8* @calloc(i64 1, i64 4)
  store i8 0, i8* %p, align 1
  %p.1 = getelementptr i8, i8* %p, i32 1
  store i8 0, i8* %p.1, align 1
  %p.3 = getelementptr i8, i8* %p, i32 3
  store i8 5, i8* %p.3, align 1
  %p.2 = getelementptr i8, i8* %p, i32 2
  store i8 0, i8* %p.2, align 1
  ret i8* %p
}

define i8* @test11() {
; CHECK-LABEL: @test11(
; CHECK-NEXT:    [[P:%.*]] = tail call noalias i8* @calloc(i64 1, i64 4)
; CHECK-NEXT:    ret i8* [[P]]
;

  %p = tail call noalias i8* @calloc(i64 1, i64 4)
  store i8 0, i8* %p, align 1
  %p.1 = getelementptr i8, i8* %p, i32 1
  store i8 0, i8* %p.1, align 1
  %p.3 = getelementptr i8, i8* %p, i32 3
  store i8 5, i8* %p.3, align 1
  %p.2 = getelementptr i8, i8* %p, i32 2
  store i8 0, i8* %p.2, align 1
  %p.3.2 = getelementptr i8, i8* %p, i32 3
  store i8 0, i8* %p.3.2, align 1
  ret i8* %p
}

define i8* @test12() {
; CHECK-LABEL: @test12(
; CHECK-NEXT:    [[P:%.*]] = tail call noalias i8* @calloc(i64 1, i64 4)
; CHECK-NEXT:    [[P_3:%.*]] = getelementptr i8, i8* [[P]], i32 3
; CHECK-NEXT:    store i8 5, i8* [[P_3]], align 1
; CHECK-NEXT:    call void @use(i8* [[P]])
; CHECK-NEXT:    [[P_3_2:%.*]] = getelementptr i8, i8* [[P]], i32 3
; CHECK-NEXT:    store i8 0, i8* [[P_3_2]], align 1
; CHECK-NEXT:    ret i8* [[P]]
;

  %p = tail call noalias i8* @calloc(i64 1, i64 4)
  %p.3 = getelementptr i8, i8* %p, i32 3
  store i8 5, i8* %p.3, align 1
  call void @use(i8* %p)
  %p.3.2 = getelementptr i8, i8* %p, i32 3
  store i8 0, i8* %p.3.2, align 1
  ret i8* %p
}

declare void @use(i8*) readonly