xref: /llvm-project/llvm/test/Transforms/InstCombine/assume-icmp-null-select.ll (revision 4def99e642806f3f8e94cb2aa9356d63cd233dd0)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt < %s -passes=instcombine -S | FileCheck %s
3target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
4target triple = "x86_64-unknown-linux-gnu"
5
6define ptr @example(ptr dereferenceable(24) %x) {
7; CHECK-LABEL: @example(
8; CHECK-NEXT:    ret ptr [[X:%.*]]
9;
10  %y = load ptr, ptr %x, align 8
11  %y_is_null = icmp eq ptr %y, null
12
13  %res = select i1 %y_is_null, ptr null, ptr %x
14
15  %nonnull = icmp ne ptr %res, null
16  call void @llvm.assume(i1 %nonnull)
17
18  ret ptr %res
19}
20
21; TODO: this should be folded to `ret ptr %x` as well.
22define ptr @example2(ptr %x) {
23; CHECK-LABEL: @example2(
24; CHECK-NEXT:    [[Y:%.*]] = load ptr, ptr [[X:%.*]], align 8
25; CHECK-NEXT:    [[Y_IS_NULL:%.*]] = icmp eq ptr [[Y]], null
26; CHECK-NEXT:    [[RES:%.*]] = select i1 [[Y_IS_NULL]], ptr null, ptr [[X]]
27; CHECK-NEXT:    [[NONNULL:%.*]] = icmp ne ptr [[RES]], null
28; CHECK-NEXT:    call void @llvm.assume(i1 [[NONNULL]])
29; CHECK-NEXT:    ret ptr [[RES]]
30;
31  %y = load ptr, ptr %x, align 8
32  %y_is_null = icmp eq ptr %y, null
33
34  %res = select i1 %y_is_null, ptr null, ptr %x
35
36  %nonnull = icmp ne ptr %res, null
37  call void @llvm.assume(i1 %nonnull)
38
39  ret ptr %res
40}
41
42declare void @llvm.assume(i1)
43