1; RUN: opt -analyze -scalar-evolution -S < %s | FileCheck %s
2
3; The exit value from this loop was originally calculated as 0.
4; The actual exit condition is 256*256 == 0 (in i16).
5
6; CHECK: Printing analysis 'Scalar Evolution Analysis' for function 'f0':
7; CHECK-NEXT: Classifying expressions for: @f0
8; CHECK-NEXT:   %v1 = phi i16 [ 0, %b0 ], [ %v2, %b1 ]
9; CHECK-NEXT:   -->  {0,+,-1}<%b1> U: [-255,1) S: [-255,1)            Exits: -255            LoopDispositions: { %b1: Computable }
10; CHECK-NEXT:   %v2 = add i16 %v1, -1
11; CHECK-NEXT:   -->  {-1,+,-1}<%b1> U: [-256,0) S: [-256,0)           Exits: -256            LoopDispositions: { %b1: Computable }
12; CHECK-NEXT:   %v3 = mul i16 %v2, %v2
13; CHECK-NEXT:   -->  {1,+,3,+,2}<%b1> U: full-set S: full-set         Exits: 0               LoopDispositions: { %b1: Computable }
14; CHECK-NEXT:   %v5 = phi i16 [ %v2, %b1 ]
15; CHECK-NEXT:   -->  %v5 U: [-256,0) S: [-256,0)
16; CHECK-NEXT:   %v6 = phi i16 [ %v3, %b1 ]
17; CHECK-NEXT:   -->  %v6 U: full-set S: full-set
18; CHECK-NEXT:   %v7 = sext i16 %v5 to i32
19; CHECK-NEXT:   -->  (sext i16 %v5 to i32) U: [-256,0) S: [-256,0)
20; CHECK-NEXT: Determining loop execution counts for: @f0
21; CHECK-NEXT: Loop %b1: backedge-taken count is 255
22; CHECK-NEXT: Loop %b1: max backedge-taken count is 255
23; CHECK-NEXT: Loop %b1: Predicated backedge-taken count is 255
24; CHECK-NEXT:  Predicates:
25; CHECK-EMPTY:
26; CHECK-NEXT: Loop %b1: Trip multiple is 256
27
28
29@g0 = global i32 0, align 4
30@g1 = global i16 0, align 2
31
32define signext i32 @f0() {
33b0:
34  br label %b1
35
36b1:                                               ; preds = %b1, %b0
37  %v1 = phi i16 [ 0, %b0 ], [ %v2, %b1 ]
38  %v2 = add i16 %v1, -1
39  %v3 = mul i16 %v2, %v2
40  %v4 = icmp eq i16 %v3, 0
41  br i1 %v4, label %b2, label %b1
42
43b2:                                               ; preds = %b1
44  %v5 = phi i16 [ %v2, %b1 ]
45  %v6 = phi i16 [ %v3, %b1 ]
46  %v7 = sext i16 %v5 to i32
47  store i32 %v7, i32* @g0, align 4
48  store i16 %v6, i16* @g1, align 2
49  ret i32 0
50}
51
52