llvm/test/Transforms/SeparateConstOffsetFromGEP/trunc-zero-offset.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
; RUN: opt -S -passes=separate-const-offset-from-gep -verify-each < %s | FileCheck %s --check-prefix=SPLIT
; RUN: opt -S -passes='separate-const-offset-from-gep<lower-gep>' -verify-each < %s | FileCheck %s --check-prefix=LOWER

target datalayout = "e-p:32:32"

; An extracted constant that truncates to zero still simplifies the index.
define ptr @trunc_add_zero_offset(ptr %base, i64 %x) {
; SPLIT-LABEL: define ptr @trunc_add_zero_offset(
; SPLIT-SAME: ptr [[BASE:%.*]], i64 [[X:%.*]]) {
; SPLIT-NEXT:    [[TMP1:%.*]] = trunc i64 [[X]] to i32
; SPLIT-NEXT:    [[P:%.*]] = getelementptr i8, ptr [[BASE]], i32 [[TMP1]]
; SPLIT-NEXT:    ret ptr [[P]]
;
; LOWER-LABEL: define ptr @trunc_add_zero_offset(
; LOWER-SAME: ptr [[BASE:%.*]], i64 [[X:%.*]]) {
; LOWER-NEXT:    [[TMP1:%.*]] = trunc i64 [[X]] to i32
; LOWER-NEXT:    [[UGLYGEP:%.*]] = getelementptr i8, ptr [[BASE]], i32 [[TMP1]]
; LOWER-NEXT:    ret ptr [[UGLYGEP]]
;
  %add = add i64 %x, 4294967296
  %index = trunc i64 %add to i32
  %p = getelementptr i8, ptr %base, i32 %index
  ret ptr %p
}

; Keep a successful extraction from the RHS even when its offset is zero.
define ptr @sub_trunc_add_zero_offset(ptr %base, i64 %x, i32 %y) {
; SPLIT-LABEL: define ptr @sub_trunc_add_zero_offset(
; SPLIT-SAME: ptr [[BASE:%.*]], i64 [[X:%.*]], i32 [[Y:%.*]]) {
; SPLIT-NEXT:    [[TMP1:%.*]] = trunc i64 [[X]] to i32
; SPLIT-NEXT:    [[INDEX2:%.*]] = sub i32 [[Y]], [[TMP1]]
; SPLIT-NEXT:    [[P:%.*]] = getelementptr i8, ptr [[BASE]], i32 [[INDEX2]]
; SPLIT-NEXT:    ret ptr [[P]]
;
; LOWER-LABEL: define ptr @sub_trunc_add_zero_offset(
; LOWER-SAME: ptr [[BASE:%.*]], i64 [[X:%.*]], i32 [[Y:%.*]]) {
; LOWER-NEXT:    [[TMP1:%.*]] = trunc i64 [[X]] to i32
; LOWER-NEXT:    [[INDEX2:%.*]] = sub i32 [[Y]], [[TMP1]]
; LOWER-NEXT:    [[UGLYGEP:%.*]] = getelementptr i8, ptr [[BASE]], i32 [[INDEX2]]
; LOWER-NEXT:    ret ptr [[UGLYGEP]]
;
  %add = add i64 %x, 4294967296
  %trunc = trunc i64 %add to i32
  %index = sub i32 %y, %trunc
  %p = getelementptr i8, ptr %base, i32 %index
  ret ptr %p
}

; Zero offset extraction also works for an inbounds GEP.
define ptr @sub_trunc_add_zero_offset_inbounds(ptr %base, i64 %x, i32 %y) {
; SPLIT-LABEL: define ptr @sub_trunc_add_zero_offset_inbounds(
; SPLIT-SAME: ptr [[BASE:%.*]], i64 [[X:%.*]], i32 [[Y:%.*]]) {
; SPLIT-NEXT:    [[TMP1:%.*]] = trunc i64 [[X]] to i32
; SPLIT-NEXT:    [[INDEX2:%.*]] = sub i32 [[Y]], [[TMP1]]
; SPLIT-NEXT:    [[P:%.*]] = getelementptr i8, ptr [[BASE]], i32 [[INDEX2]]
; SPLIT-NEXT:    ret ptr [[P]]
;
; LOWER-LABEL: define ptr @sub_trunc_add_zero_offset_inbounds(
; LOWER-SAME: ptr [[BASE:%.*]], i64 [[X:%.*]], i32 [[Y:%.*]]) {
; LOWER-NEXT:    [[TMP1:%.*]] = trunc i64 [[X]] to i32
; LOWER-NEXT:    [[INDEX2:%.*]] = sub i32 [[Y]], [[TMP1]]
; LOWER-NEXT:    [[UGLYGEP:%.*]] = getelementptr i8, ptr [[BASE]], i32 [[INDEX2]]
; LOWER-NEXT:    ret ptr [[UGLYGEP]]
;
  %add = add i64 %x, 4294967296
  %trunc = trunc i64 %add to i32
  %index = sub i32 %y, %trunc
  %p = getelementptr inbounds i8, ptr %base, i32 %index
  ret ptr %p
}