llvm/test/Transforms/InstCombine/may-alias-errno.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
; RUN: opt -S -passes=instcombine < %s | FileCheck %s

; sinf clobbering errno, but %p cannot alias errno per C/C++ strict aliasing rules via TBAA.
; Can do constant store-to-load forwarding.
define float @does_not_alias_errno(ptr %p, float %f) {
; CHECK-LABEL: define float @does_not_alias_errno(
; CHECK-SAME: ptr [[P:%.*]], float [[F:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*:]]
; CHECK-NEXT:    store float 0.000000e+00, ptr [[P]], align 4, !tbaa [[TBAA4:![0-9]+]]
; CHECK-NEXT:    [[CALL:%.*]] = call float @sinf(float [[F]])
; CHECK-NEXT:    ret float 0.000000e+00
;
entry:
  store float 0.000000e+00, ptr %p, align 4, !tbaa !4
  %call = call float @sinf(float %f)
  %0 = load float, ptr %p, align 4, !tbaa !4
  ret float %0
}

; sinf clobbering errno, but %p is alloca memory, wich can never aliases errno.
; Can do constant store-to-load forwarding.
define float @does_not_alias_errno_2(float %f) {
; CHECK-LABEL: define float @does_not_alias_errno_2(
; CHECK-SAME: float [[F:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*:]]
; CHECK-NEXT:    [[P:%.*]] = alloca float, align 4
; CHECK-NEXT:    call void @escape(ptr nonnull [[P]])
; CHECK-NEXT:    store float 0.000000e+00, ptr [[P]], align 4
; CHECK-NEXT:    [[TMP1:%.*]] = call float @sinf(float [[F]])
; CHECK-NEXT:    ret float 0.000000e+00
;
entry:
  %p = alloca float
  call void @escape(ptr %p)
  store float 0.0, ptr %p
  call float @sinf(float %f)
  %v = load float, ptr %p
  ret float %v
}

; sinf clobbering errno, but %p is memory accessed w/ size larger than errno.
; Can do constant store-to-load forwarding.
define double @does_not_alias_errno_3(ptr %p, float %f) {
; CHECK-LABEL: define double @does_not_alias_errno_3(
; CHECK-SAME: ptr [[P:%.*]], float [[F:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*:]]
; CHECK-NEXT:    call void @escape(ptr [[P]])
; CHECK-NEXT:    store double 0.000000e+00, ptr [[P]], align 8
; CHECK-NEXT:    [[TMP1:%.*]] = call float @sinf(float [[F]])
; CHECK-NEXT:    ret double 0.000000e+00
;
entry:
  call void @escape(ptr %p)
  store double 0.0, ptr %p
  call float @sinf(float %f)
  %v = load double, ptr %p
  ret double %v
}

; %p may alias errno, but read_errno does not clobber errno.
; Can do constant store-to-load forwarding.
define float @may_alias_errno_does_not_clobber(ptr %p, ptr byval(i8) %q) {
; CHECK-LABEL: define float @may_alias_errno_does_not_clobber(
; CHECK-SAME: ptr [[P:%.*]], ptr byval(i8) [[Q:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*:]]
; CHECK-NEXT:    store float 0.000000e+00, ptr [[P]], align 4
; CHECK-NEXT:    [[CALL:%.*]] = call float @read_errno(ptr nonnull [[Q]])
; CHECK-NEXT:    ret float 0.000000e+00
;
entry:
  store float 0.000000e+00, ptr %p, align 4
  %call = call float @read_errno(ptr %q)
  %0 = load float, ptr %p, align 4
  ret float %0
}

; sinf clobbering errno, unknown TBAA info, %p may alias errno.
; Cannot do constant store-to-load forwarding.
define float @may_alias_errno(ptr %p, float %f) {
; CHECK-LABEL: define float @may_alias_errno(
; CHECK-SAME: ptr [[P:%.*]], float [[F:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*:]]
; CHECK-NEXT:    store float 0.000000e+00, ptr [[P]], align 4
; CHECK-NEXT:    [[CALL:%.*]] = call float @sinf(float [[F]])
; CHECK-NEXT:    [[TMP0:%.*]] = load float, ptr [[P]], align 4
; CHECK-NEXT:    ret float [[TMP0]]
;
entry:
  store float 0.000000e+00, ptr %p, align 4
  %call = call float @sinf(float %f)
  %0 = load float, ptr %p, align 4
  ret float %0
}

; sinf clobbering errno, %p, a integer pointer, may alias errno.
; Cannot do constant store-to-load forwarding.
define i32 @may_alias_errno_2(ptr %p, float %f) {
; CHECK-LABEL: define i32 @may_alias_errno_2(
; CHECK-SAME: ptr [[P:%.*]], float [[F:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*:]]
; CHECK-NEXT:    store i32 0, ptr [[P]], align 4, !tbaa [[TBAA0:![0-9]+]]
; CHECK-NEXT:    [[CALL:%.*]] = call float @sinf(float [[F]])
; CHECK-NEXT:    [[TMP0:%.*]] = load i32, ptr [[P]], align 4, !tbaa [[TBAA0]]
; CHECK-NEXT:    ret i32 [[TMP0]]
;
entry:
  store i32 0, ptr %p, align 4, !tbaa !0
  %call = call float @sinf(float %f)
  %0 = load i32, ptr %p, align 4, !tbaa !0
  ret i32 %0
}

declare float @sinf(float) memory(errnomem: write)
declare float @read_errno(ptr) memory(argmem: write, errnomem: read)
declare void @escape(ptr %p)

!llvm.errno.tbaa = !{!0}

!0 = !{!1, !1, i64 0}
!1 = !{!"int", !2, i64 0}
!2 = !{!"omnipotent char", !3, i64 0}
!3 = !{!"Simple C/C++ TBAA"}
!4 = !{!5, !5, i64 0}
!5 = !{!"float", !2, i64 0}
;.
; CHECK: [[TBAA0]] = !{[[META1:![0-9]+]], [[META1]], i64 0}
; CHECK: [[META1]] = !{!"int", [[META2:![0-9]+]], i64 0}
; CHECK: [[META2]] = !{!"omnipotent char", [[META3:![0-9]+]], i64 0}
; CHECK: [[META3]] = !{!"Simple C/C++ TBAA"}
; CHECK: [[TBAA4]] = !{[[META5:![0-9]+]], [[META5]], i64 0}
; CHECK: [[META5]] = !{!"float", [[META2]], i64 0}
;.