File: solve-quadratic-overflow.ll

package info (click to toggle)
llvm-toolchain-17 1%3A17.0.6-22
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid, trixie
  • size: 1,799,624 kB
  • sloc: cpp: 6,428,607; ansic: 1,383,196; asm: 793,408; python: 223,504; objc: 75,364; f90: 60,502; lisp: 33,869; pascal: 15,282; sh: 9,684; perl: 7,453; ml: 4,937; awk: 3,523; makefile: 2,889; javascript: 2,149; xml: 888; fortran: 619; cs: 573
file content (51 lines) | stat: -rw-r--r-- 2,198 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py
; RUN: opt -disable-output "-passes=print<scalar-evolution>" -S < %s 2>&1 | FileCheck %s

; The exit value from this loop was originally calculated as 0.
; The actual exit condition is 256*256 == 0 (in i16).

@g0 = global i32 0, align 4
@g1 = global i16 0, align 2

define signext i32 @f0() {
; CHECK-LABEL: 'f0'
; CHECK-NEXT:  Classifying expressions for: @f0
; CHECK-NEXT:    %v1 = phi i16 [ 0, %b0 ], [ %v2, %b1 ]
; CHECK-NEXT:    --> {0,+,-1}<nsw><%b1> U: [-255,1) S: [-255,1) Exits: -255 LoopDispositions: { %b1: Computable }
; CHECK-NEXT:    %v2 = add i16 %v1, -1
; CHECK-NEXT:    --> {-1,+,-1}<nsw><%b1> U: [-256,0) S: [-256,0) Exits: -256 LoopDispositions: { %b1: Computable }
; CHECK-NEXT:    %v3 = mul i16 %v2, %v2
; CHECK-NEXT:    --> {1,+,3,+,2}<%b1> U: full-set S: full-set Exits: 0 LoopDispositions: { %b1: Computable }
; CHECK-NEXT:    %v5 = phi i16 [ %v2, %b1 ]
; CHECK-NEXT:    --> {-1,+,-1}<nsw><%b1> U: [-256,0) S: [-256,0) --> -256 U: [-256,-255) S: [-256,-255)
; CHECK-NEXT:    %v6 = phi i16 [ %v3, %b1 ]
; CHECK-NEXT:    --> {1,+,3,+,2}<%b1> U: full-set S: full-set --> 0 U: [0,1) S: [0,1)
; CHECK-NEXT:    %v7 = sext i16 %v5 to i32
; CHECK-NEXT:    --> {-1,+,-1}<nsw><%b1> U: [-256,0) S: [-256,0) --> -256 U: [-256,-255) S: [-256,-255)
; CHECK-NEXT:  Determining loop execution counts for: @f0
; CHECK-NEXT:  Loop %b1: backedge-taken count is 255
; CHECK-NEXT:  Loop %b1: constant max backedge-taken count is 255
; CHECK-NEXT:  Loop %b1: symbolic max backedge-taken count is 255
; CHECK-NEXT:  Loop %b1: Predicated backedge-taken count is 255
; CHECK-NEXT:   Predicates:
; CHECK:       Loop %b1: Trip multiple is 256
;
b0:
  br label %b1

b1:                                               ; preds = %b1, %b0
  %v1 = phi i16 [ 0, %b0 ], [ %v2, %b1 ]
  %v2 = add i16 %v1, -1
  %v3 = mul i16 %v2, %v2
  %v4 = icmp eq i16 %v3, 0
  br i1 %v4, label %b2, label %b1

b2:                                               ; preds = %b1
  %v5 = phi i16 [ %v2, %b1 ]
  %v6 = phi i16 [ %v3, %b1 ]
  %v7 = sext i16 %v5 to i32
  store i32 %v7, ptr @g0, align 4
  store i16 %v6, ptr @g1, align 2
  ret i32 0
}