File: runtime-loop-known-exit.ll

package info (click to toggle)
llvm-toolchain-16 1%3A16.0.6-15~deb12u1
  • links: PTS, VCS
  • area: main
  • in suites: bookworm
  • size: 1,634,792 kB
  • sloc: cpp: 6,179,261; ansic: 1,216,205; asm: 741,319; python: 196,614; objc: 75,325; f90: 49,640; lisp: 32,396; pascal: 12,286; sh: 9,394; perl: 7,442; ml: 5,494; awk: 3,523; makefile: 2,723; javascript: 1,206; xml: 886; fortran: 581; cs: 573
file content (46 lines) | stat: -rw-r--r-- 1,494 bytes parent folder | download | duplicates (12)
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
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -S -passes=loop-unroll -unroll-runtime -unroll-runtime-multi-exit < %s | FileCheck %s

; This loop has a known trip count on the non-latch exit. When performing
; runtime unrolling (at least when using a prologue rather than epilogue) we
; should not fold that exit based on known trip count information prior to
; prologue insertion, as that may change the trip count for the modified loop.

define void @test(i32 %s, i32 %n) {
; CHECK-LABEL: @test(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[N2:%.*]] = add i32 [[S:%.*]], 123
; CHECK-NEXT:    br label [[LOOP:%.*]]
; CHECK:       loop:
; CHECK-NEXT:    [[I:%.*]] = phi i32 [ [[S]], [[ENTRY:%.*]] ], [ [[I_INC:%.*]], [[LATCH:%.*]] ]
; CHECK-NEXT:    [[C1:%.*]] = icmp eq i32 [[I]], [[N2]]
; CHECK-NEXT:    br i1 [[C1]], label [[EXIT1:%.*]], label [[LATCH]]
; CHECK:       latch:
; CHECK-NEXT:    [[C2:%.*]] = icmp eq i32 [[I]], [[N:%.*]]
; CHECK-NEXT:    [[I_INC]] = add i32 [[I]], 1
; CHECK-NEXT:    br i1 [[C2]], label [[EXIT2:%.*]], label [[LOOP]]
; CHECK:       exit1:
; CHECK-NEXT:    ret void
; CHECK:       exit2:
; CHECK-NEXT:    ret void
;
entry:
  %n2 = add i32 %s, 123
  br label %loop

loop:
  %i = phi i32 [ %s, %entry], [ %i.inc, %latch ]
  %c1 = icmp eq i32 %i, %n2
  br i1 %c1, label %exit1, label %latch

latch:
  %c2 = icmp eq i32 %i, %n
  %i.inc = add i32 %i, 1
  br i1 %c2, label %exit2, label %loop

exit1:
  ret void

exit2:
  ret void
}