xref: /llvm-project/llvm/test/Analysis/ScalarEvolution/trunc-simplify.ll (revision 92619956eb27ef08dd24045307593fc3d7f78db0)
1; RUN: opt < %s -disable-output "-passes=print<scalar-evolution>" 2>&1 | FileCheck %s
2
3; Check that we convert
4;   trunc(C * a) -> trunc(C) * trunc(a)
5; if C is a constant.
6; CHECK-LABEL: @trunc_of_mul
7define i8 @trunc_of_mul(i32 %a) {
8  %b = mul i32 %a, 100
9  ; CHECK: %c
10  ; CHECK-NEXT: --> (100 * (trunc i32 %a to i8))
11  %c = trunc i32 %b to i8
12  ret i8 %c
13}
14
15; Check that we convert
16;   trunc(C + a) -> trunc(C) + trunc(a)
17; if C is a constant.
18; CHECK-LABEL: @trunc_of_add
19define i8 @trunc_of_add(i32 %a) {
20  %b = add i32 %a, 100
21  ; CHECK: %c
22  ; CHECK-NEXT: --> (100 + (trunc i32 %a to i8))
23  %c = trunc i32 %b to i8
24  ret i8 %c
25}
26
27; Check that we truncate to zero values assumed to have at least as many
28; trailing zeros as the target type.
29; CHECK-LABEL: @trunc_to_assumed_zeros
30define i8 @trunc_to_assumed_zeros(ptr %p) {
31  %a = load i32, ptr %p
32  %and = and i32 %a, 255
33  %cmp = icmp eq i32 %and, 0
34  tail call void @llvm.assume(i1 %cmp)
35  ; CHECK: %c
36  ; CHECK-NEXT: --> 0
37  %c = trunc i32 %a to i8
38  ; CHECK: %d
39  ; CHECK-NEXT: --> false
40  %d = trunc i32 %a to i1
41  ; CHECK: %e
42  ; CHECK-NEXT: --> (trunc i32 %a to i16)
43  %e = trunc i32 %a to i16
44  ret i8 %c
45}
46
47declare void @llvm.assume(i1 noundef) nofree nosync nounwind willreturn
48