xref: /llvm-project/llvm/test/Analysis/ScalarEvolution/solve-quadratic-overflow.ll (revision 0d38f21e4ab7fe7cebe76a9d7c218ec54dba1e98)
1; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py
2; RUN: opt -disable-output "-passes=print<scalar-evolution>" -S < %s 2>&1 | FileCheck %s
3
4; The exit value from this loop was originally calculated as 0.
5; The actual exit condition is 256*256 == 0 (in i16).
6
7@g0 = global i32 0, align 4
8@g1 = global i16 0, align 2
9
10define signext i32 @f0() {
11; CHECK-LABEL: 'f0'
12; CHECK-NEXT:  Classifying expressions for: @f0
13; CHECK-NEXT:    %v1 = phi i16 [ 0, %b0 ], [ %v2, %b1 ]
14; CHECK-NEXT:    --> {0,+,-1}<nsw><%b1> U: [-255,1) S: [-255,1) Exits: -255 LoopDispositions: { %b1: Computable }
15; CHECK-NEXT:    %v2 = add i16 %v1, -1
16; CHECK-NEXT:    --> {-1,+,-1}<nsw><%b1> U: [-256,0) S: [-256,0) Exits: -256 LoopDispositions: { %b1: Computable }
17; CHECK-NEXT:    %v3 = mul i16 %v2, %v2
18; CHECK-NEXT:    --> {1,+,3,+,2}<%b1> U: full-set S: full-set Exits: 0 LoopDispositions: { %b1: Computable }
19; CHECK-NEXT:    %v5 = phi i16 [ %v2, %b1 ]
20; CHECK-NEXT:    --> {-1,+,-1}<nsw><%b1> U: [-256,0) S: [-256,0) --> -256 U: [-256,-255) S: [-256,-255)
21; CHECK-NEXT:    %v6 = phi i16 [ %v3, %b1 ]
22; CHECK-NEXT:    --> {1,+,3,+,2}<%b1> U: full-set S: full-set --> 0 U: [0,1) S: [0,1)
23; CHECK-NEXT:    %v7 = sext i16 %v5 to i32
24; CHECK-NEXT:    --> {-1,+,-1}<nsw><%b1> U: [-256,0) S: [-256,0) --> -256 U: [-256,-255) S: [-256,-255)
25; CHECK-NEXT:  Determining loop execution counts for: @f0
26; CHECK-NEXT:  Loop %b1: backedge-taken count is i16 255
27; CHECK-NEXT:  Loop %b1: constant max backedge-taken count is i16 255
28; CHECK-NEXT:  Loop %b1: symbolic max backedge-taken count is i16 255
29; CHECK-NEXT:  Loop %b1: Trip multiple is 256
30;
31b0:
32  br label %b1
33
34b1:                                               ; preds = %b1, %b0
35  %v1 = phi i16 [ 0, %b0 ], [ %v2, %b1 ]
36  %v2 = add i16 %v1, -1
37  %v3 = mul i16 %v2, %v2
38  %v4 = icmp eq i16 %v3, 0
39  br i1 %v4, label %b2, label %b1
40
41b2:                                               ; preds = %b1
42  %v5 = phi i16 [ %v2, %b1 ]
43  %v6 = phi i16 [ %v3, %b1 ]
44  %v7 = sext i16 %v5 to i32
45  store i32 %v7, ptr @g0, align 4
46  store i16 %v6, ptr @g1, align 2
47  ret i32 0
48}
49
50