File: invariant.start.ll

package info (click to toggle)
llvm-toolchain-19 1%3A19.1.7-3~deb12u1
  • links: PTS, VCS
  • area: main
  • in suites: bookworm-proposed-updates
  • size: 1,998,492 kB
  • sloc: cpp: 6,951,680; ansic: 1,486,157; asm: 913,598; python: 232,024; f90: 80,126; objc: 75,281; lisp: 37,276; pascal: 16,990; sh: 10,009; ml: 5,058; perl: 4,724; awk: 3,523; makefile: 3,167; javascript: 2,504; xml: 892; fortran: 664; cs: 573
file content (37 lines) | stat: -rw-r--r-- 1,340 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
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; Test to make sure llvm.invariant.start calls are not treated as clobbers.
; RUN: opt < %s -passes=dse -S | FileCheck %s

declare ptr @llvm.invariant.start.p0(i64, ptr nocapture) nounwind readonly

; We could remove either store here. The first store is dead in the
; conventional sense, because there is a later killing store. The second store
; is undefined behavior by the semantics of invariant.start, and as such
; unreachable.
define void @test(ptr %p) {
; CHECK-LABEL: @test(
; CHECK-NEXT:    store i8 3, ptr [[P:%.*]], align 4
; CHECK-NEXT:    ret void
;
  store i8 1, ptr %p, align 4
  %i = call ptr @llvm.invariant.start.p0(i64 1, ptr %p)
  store i8 3, ptr %p, align 4
  ret void
}

; FIXME: We should be able to remove the first store to p, even though p and q
; may alias.
define void @test2(ptr %p, ptr %q) {
; CHECK-LABEL: @test2(
; CHECK-NEXT:    store i8 1, ptr [[P:%.*]], align 4
; CHECK-NEXT:    store i8 2, ptr [[Q:%.*]], align 4
; CHECK-NEXT:    [[I:%.*]] = call ptr @llvm.invariant.start.p0(i64 1, ptr [[Q]])
; CHECK-NEXT:    store i8 3, ptr [[P]], align 4
; CHECK-NEXT:    ret void
;
  store i8 1, ptr %p, align 4
  store i8 2, ptr %q, align 4
  %i = call ptr @llvm.invariant.start.p0(i64 1, ptr %q)
  store i8 3, ptr %p, align 4
  ret void
}