File: ephemeral.ll

package info (click to toggle)
llvm-toolchain-11 1%3A11.0.1-2
  • links: PTS, VCS
  • area: main
  • in suites: bullseye
  • size: 995,808 kB
  • sloc: cpp: 4,767,656; ansic: 760,916; asm: 477,436; python: 170,940; objc: 69,804; lisp: 29,914; sh: 23,855; f90: 18,173; pascal: 7,551; perl: 7,471; ml: 5,603; awk: 3,489; makefile: 2,573; xml: 915; cs: 573; fortran: 503; javascript: 452
file content (41 lines) | stat: -rw-r--r-- 898 bytes parent folder | download | duplicates (35) 
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
 
; RUN: opt < %s -loop-reduce -S | FileCheck %s

target datalayout = "e-i64:64-v16:16-v32:32-n16:32:64"

; for (int i = 0; i < n; ++i) {
;   use(i * 5 + 3);
;   // i * a + b is ephemeral and shouldn't be promoted by LSR
;   __builtin_assume(i * a + b >= 0);
; }
define void @ephemeral(i32 %a, i32 %b, i32 %n) {
; CHECK-LABEL: @ephemeral(
entry:
  br label %loop

loop:
  %i = phi i32 [ 0, %entry ], [ %inc, %loop ]
  ; Only i and i * 5 + 3 should be indvars, not i * a + b.
; CHECK: phi i32
; CHECK: phi i32
; CHECK-NOT: phi i32
  %inc = add nsw i32 %i, 1
  %exitcond = icmp eq i32 %inc, %n

  %0 = mul nsw i32 %i, 5
  %1 = add nsw i32 %0, 3
  call void @use(i32 %1)

  %2 = mul nsw i32 %i, %a
  %3 = add nsw i32 %2, %b
  %4 = icmp sgt i32 %3, -1
  call void @llvm.assume(i1 %4)

  br i1 %exitcond, label %exit, label %loop

exit:
  ret void
}

declare void @use(i32)

declare void @llvm.assume(i1)