xref: /llvm-project/llvm/test/Analysis/ScalarEvolution/ashr.ll (revision f7d1baa414e6e4fca04092cb2f71e9b037c762f0)
1; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py
2; RUN: opt < %s --data-layout="e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" -S -disable-output "-passes=print<scalar-evolution>" 2>&1 | FileCheck %s
3; RUN: opt < %s --data-layout="e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-f64:32:64-f80:32-n8:16:32-S128" -S -disable-output "-passes=print<scalar-evolution>" 2>&1 | FileCheck %s
4
5; In general, we can't deal with ashr.
6define i32 @t0(i32 %x, i32 %y) {
7; CHECK-LABEL: 't0'
8; CHECK-NEXT:  Classifying expressions for: @t0
9; CHECK-NEXT:    %i0 = ashr i32 %x, %y
10; CHECK-NEXT:    --> %i0 U: full-set S: full-set
11; CHECK-NEXT:  Determining loop execution counts for: @t0
12;
13  %i0 = ashr i32 %x, %y
14  ret i32 %i0
15}
16; Not even if we know it's exact
17define i32 @t1(i32 %x, i32 %y) {
18; CHECK-LABEL: 't1'
19; CHECK-NEXT:  Classifying expressions for: @t1
20; CHECK-NEXT:    %i0 = ashr exact i32 %x, %y
21; CHECK-NEXT:    --> %i0 U: full-set S: full-set
22; CHECK-NEXT:  Determining loop execution counts for: @t1
23;
24  %i0 = ashr exact i32 %x, %y
25  ret i32 %i0
26}
27; Not even if the shift amount is a constant.
28define i32 @t2(i32 %x, i32 %y) {
29; CHECK-LABEL: 't2'
30; CHECK-NEXT:  Classifying expressions for: @t2
31; CHECK-NEXT:    %i0 = ashr i32 %x, 4
32; CHECK-NEXT:    --> %i0 U: [-134217728,134217728) S: [-134217728,134217728)
33; CHECK-NEXT:  Determining loop execution counts for: @t2
34;
35  %i0 = ashr i32 %x, 4
36  ret i32 %i0
37}
38; However, if it's a constant AND the shift is exact, we can model it!
39define i32 @t3(i32 %x, i32 %y) {
40; CHECK-LABEL: 't3'
41; CHECK-NEXT:  Classifying expressions for: @t3
42; CHECK-NEXT:    %i0 = ashr exact i32 %x, 4
43; CHECK-NEXT:    --> %i0 U: [-134217728,134217728) S: [-134217728,134217728)
44; CHECK-NEXT:  Determining loop execution counts for: @t3
45;
46  %i0 = ashr exact i32 %x, 4
47  ret i32 %i0
48}
49; As long as the shift amount is in-bounds
50define i32 @t4(i32 %x, i32 %y) {
51; CHECK-LABEL: 't4'
52; CHECK-NEXT:  Classifying expressions for: @t4
53; CHECK-NEXT:    %i0 = ashr exact i32 %x, 32
54; CHECK-NEXT:    --> %i0 U: [0,1) S: [0,1)
55; CHECK-NEXT:  Determining loop execution counts for: @t4
56;
57  %i0 = ashr exact i32 %x, 32
58  ret i32 %i0
59}
60
61; One more test, just to see that we model constant correctly
62define i32 @t5(i32 %x, i32 %y) {
63; CHECK-LABEL: 't5'
64; CHECK-NEXT:  Classifying expressions for: @t5
65; CHECK-NEXT:    %i0 = ashr exact i32 %x, 5
66; CHECK-NEXT:    --> %i0 U: [-67108864,67108864) S: [-67108864,67108864)
67; CHECK-NEXT:  Determining loop execution counts for: @t5
68;
69  %i0 = ashr exact i32 %x, 5
70  ret i32 %i0
71}
72