File: assume-edge-dom.ll

package info (click to toggle)
llvm-toolchain-13 1%3A13.0.1-6~deb11u1
  • links: PTS, VCS
  • area: main
  • in suites: bullseye
  • size: 1,418,812 kB
  • sloc: cpp: 5,290,827; ansic: 996,570; asm: 544,593; python: 188,212; objc: 72,027; lisp: 30,291; f90: 25,395; sh: 24,900; javascript: 9,780; pascal: 9,398; perl: 7,484; ml: 5,432; awk: 3,523; makefile: 2,892; xml: 953; cs: 573; fortran: 539
file content (39 lines) | stat: -rw-r--r-- 907 bytes parent folder | download | duplicates (22) 
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
 
; RUN: opt -S -jump-threading < %s | FileCheck %s

declare i8* @escape()
declare void @llvm.assume(i1)

define i1 @test1(i1 %cond) {
entry:
    br i1 %cond, label %taken, label %not_taken

; CHECK-LABEL: @test1
; CHECK: br i1 %cond, label %no, label %yes
; CHECK: ret i1 true

taken:
    %res1 = call i8* @escape()
    %a = icmp eq i8* %res1, null
    tail call void @llvm.assume(i1 %a)
    br label %done
not_taken:
    %res2 = call i8* @escape()
    %b = icmp ne i8* %res2, null
    tail call void @llvm.assume(i1 %b)
    br label %done

; An assume that can be used to simplify this comparison dominates each
; predecessor branch (although no assume dominates the cmp itself). Make sure
; this still can be simplified.

done:
    %res = phi i8* [ %res1, %taken ], [ %res2, %not_taken ]
    %cnd = icmp ne i8* %res, null
    br i1 %cnd, label %yes, label %no

yes:
    ret i1 true
no:
    ret i1 false
}