test/Transforms/InstCombine/gep-inbounds-null.ll

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

;; Start by showing the results of constant folding (which doesn't use
;; the poison implied by gep for the nonnull cases).

define i1 @test_ne_constants_null() {
; CHECK-LABEL: @test_ne_constants_null(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    ret i1 false
;
entry:
  %cnd = icmp ne ptr null, null
  ret i1 %cnd
}

define i1 @test_ne_constants_nonnull() {
; CHECK-LABEL: @test_ne_constants_nonnull(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    ret i1 true
;
entry:
  %gep = getelementptr inbounds i8, ptr null, i64 1
  %cnd = icmp ne ptr %gep, null
  ret i1 %cnd
}

define i1 @test_eq_constants_null() {
; CHECK-LABEL: @test_eq_constants_null(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    ret i1 true
;
entry:
  %cnd = icmp eq ptr null, null
  ret i1 %cnd
}

define i1 @test_eq_constants_nonnull() {
; CHECK-LABEL: @test_eq_constants_nonnull(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    ret i1 false
;
entry:
  %gep = getelementptr inbounds i8, ptr null, i64 1
  %cnd = icmp eq ptr %gep, null
  ret i1 %cnd
}

;; Then show the results for non-constants.  These use the inbounds provided
;; UB fact to ignore the possible overflow cases.

define i1 @test_ne(ptr %base, i64 %idx) {
; CHECK-LABEL: @test_ne(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[CND:%.*]] = icmp ne ptr [[BASE:%.*]], null
; CHECK-NEXT:    ret i1 [[CND]]
;
entry:
  %gep = getelementptr inbounds i8, ptr %base, i64 %idx
  %cnd = icmp ne ptr %gep, null
  ret i1 %cnd
}

define i1 @test_eq(ptr %base, i64 %idx) {
; CHECK-LABEL: @test_eq(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[CND:%.*]] = icmp eq ptr [[BASE:%.*]], null
; CHECK-NEXT:    ret i1 [[CND]]
;
entry:
  %gep = getelementptr inbounds i8, ptr %base, i64 %idx
  %cnd = icmp eq ptr %gep, null
  ret i1 %cnd
}

define <2 x i1> @test_vector_base(<2 x ptr> %base, i64 %idx) {
; CHECK-LABEL: @test_vector_base(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[CND:%.*]] = icmp eq <2 x ptr> [[BASE:%.*]], zeroinitializer
; CHECK-NEXT:    ret <2 x i1> [[CND]]
;
entry:
  %gep = getelementptr inbounds i8, <2 x ptr> %base, i64 %idx
  %cnd = icmp eq <2 x ptr> %gep, zeroinitializer
  ret <2 x i1> %cnd
}

define <2 x i1> @test_vector_index(ptr %base, <2 x i64> %idx) {
; CHECK-LABEL: @test_vector_index(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[DOTSPLATINSERT:%.*]] = insertelement <2 x ptr> poison, ptr [[BASE:%.*]], i64 0
; CHECK-NEXT:    [[TMP0:%.*]] = icmp eq <2 x ptr> [[DOTSPLATINSERT]], zeroinitializer
; CHECK-NEXT:    [[CND:%.*]] = shufflevector <2 x i1> [[TMP0]], <2 x i1> poison, <2 x i32> zeroinitializer
; CHECK-NEXT:    ret <2 x i1> [[CND]]
;
entry:
  %gep = getelementptr inbounds i8, ptr %base, <2 x i64> %idx
  %cnd = icmp eq <2 x ptr> %gep, zeroinitializer
  ret <2 x i1> %cnd
}

define <2 x i1> @test_vector_both(<2 x ptr> %base, <2 x i64> %idx) {
; CHECK-LABEL: @test_vector_both(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[CND:%.*]] = icmp eq <2 x ptr> [[BASE:%.*]], zeroinitializer
; CHECK-NEXT:    ret <2 x i1> [[CND]]
;
entry:
  %gep = getelementptr inbounds i8, <2 x ptr> %base, <2 x i64> %idx
  %cnd = icmp eq <2 x ptr> %gep, zeroinitializer
  ret <2 x i1> %cnd
}

;; These two show instsimplify's reasoning getting to the non-zero offsets
;; before instcombine does.

define i1 @test_eq_pos_idx(ptr %base) {
; CHECK-LABEL: @test_eq_pos_idx(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    ret i1 false
;
entry:
  %gep = getelementptr inbounds i8, ptr %base, i64 1
  %cnd = icmp eq ptr %gep, null
  ret i1 %cnd
}

define i1 @test_eq_neg_idx(ptr %base) {
; CHECK-LABEL: @test_eq_neg_idx(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    ret i1 false
;
entry:
  %gep = getelementptr inbounds i8, ptr %base, i64 -1
  %cnd = icmp eq ptr %gep, null
  ret i1 %cnd
}

;; Show an example with a zero sized type since that's
;; a cornercase which keeps getting mentioned.  The GEP
;; produces %base regardless of the value of the index
;; expression.
define i1 @test_size0(ptr %base, i64 %idx) {
; CHECK-LABEL: @test_size0(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[CND:%.*]] = icmp ne ptr [[BASE:%.*]], null
; CHECK-NEXT:    ret i1 [[CND]]
;
entry:
  %gep = getelementptr inbounds {}, ptr %base, i64 %idx
  %cnd = icmp ne ptr %gep, null
  ret i1 %cnd
}
define i1 @test_size0_nonzero_offset(ptr %base) {
; CHECK-LABEL: @test_size0_nonzero_offset(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[CND:%.*]] = icmp ne ptr [[BASE:%.*]], null
; CHECK-NEXT:    ret i1 [[CND]]
;
entry:
  %gep = getelementptr inbounds {}, ptr %base, i64 15
  %cnd = icmp ne ptr %gep, null
  ret i1 %cnd
}


define i1 @test_index_type(ptr %base, i64 %idx) {
; CHECK-LABEL: @test_index_type(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[CND:%.*]] = icmp eq ptr [[BASE:%.*]], null
; CHECK-NEXT:    ret i1 [[CND]]
;
entry:
  %gep = getelementptr inbounds [10 x i8], ptr %base, i64 %idx, i64 %idx
  %cnd = icmp eq ptr %gep, null
  ret i1 %cnd
}


;; Finally, some negative tests for basic correctness checking.

define i1 @neq_noinbounds(ptr %base, i64 %idx) {
; CHECK-LABEL: @neq_noinbounds(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[GEP:%.*]] = getelementptr i8, ptr [[BASE:%.*]], i64 [[IDX:%.*]]
; CHECK-NEXT:    [[CND:%.*]] = icmp ne ptr [[GEP]], null
; CHECK-NEXT:    ret i1 [[CND]]
;
entry:
  %gep = getelementptr i8, ptr %base, i64 %idx
  %cnd = icmp ne ptr %gep, null
  ret i1 %cnd
}

define i1 @neg_objectatnull(ptr addrspace(2) %base, i64 %idx) {
; CHECK-LABEL: @neg_objectatnull(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[GEP:%.*]] = getelementptr inbounds i8, ptr addrspace(2) [[BASE:%.*]], i64 [[IDX:%.*]]
; CHECK-NEXT:    [[CND:%.*]] = icmp eq ptr addrspace(2) [[GEP]], null
; CHECK-NEXT:    ret i1 [[CND]]
;
entry:
  %gep = getelementptr inbounds i8, ptr addrspace(2) %base, i64 %idx
  %cnd = icmp eq ptr addrspace(2) %gep, null
  ret i1 %cnd
}

; Test for an assert from trying to create an invalid constantexpr
; bitcast between different address spaces. The addrspacecast is
; stripped off and the addrspace(0) null can be treated as invalid.
; FIXME: This should be able to fold to ret i1 false
define i1 @invalid_bitcast_icmp_addrspacecast_as0_null(ptr addrspace(5) %ptr) {
; CHECK-LABEL: @invalid_bitcast_icmp_addrspacecast_as0_null(
; CHECK-NEXT:  bb:
; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq ptr addrspace(5) [[PTR:%.*]], addrspacecast (ptr null to ptr addrspace(5))
; CHECK-NEXT:    ret i1 [[TMP2]]
;
bb:
  %tmp1 = getelementptr inbounds i32, ptr addrspace(5) %ptr, i32 1
  %tmp2 = icmp eq ptr addrspace(5) %tmp1, addrspacecast (ptr null to ptr addrspace(5))
  ret i1 %tmp2
}

define i1 @invalid_bitcast_icmp_addrspacecast_as0_null_var(ptr addrspace(5) %ptr, i32 %idx) {
; CHECK-LABEL: @invalid_bitcast_icmp_addrspacecast_as0_null_var(
; CHECK-NEXT:  bb:
; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq ptr addrspace(5) [[PTR:%.*]], addrspacecast (ptr null to ptr addrspace(5))
; CHECK-NEXT:    ret i1 [[TMP2]]
;
bb:
  %tmp1 = getelementptr inbounds i32, ptr addrspace(5) %ptr, i32 %idx
  %tmp2 = icmp eq ptr addrspace(5) %tmp1, addrspacecast (ptr null to ptr addrspace(5))
  ret i1 %tmp2
}