• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1; RUN: opt -S -licm %s | FileCheck %s
2
3; Volatile register shouldn't be hoisted ourside loops.
4define i32 @test_read() {
5; CHECK-LABEL: define i32 @test_read()
6; CHECK:     br label %loop
7; CHECK: loop:
8; CHECK:     %counter = tail call i64 @llvm.read_volatile_register
9
10entry:
11  br label %loop
12
13loop:
14  %i = phi i32 [ 0, %entry ], [ %i.next, %inc ]
15  %counter = tail call i64 @llvm.read_volatile_register.i64(metadata !1)
16  %tst = icmp ult i64 %counter, 1000
17  br i1 %tst, label %inc, label %done
18
19inc:
20  %i.next = add nuw nsw i32 %i, 1
21  br label %loop
22
23done:
24  ret i32 %i
25}
26
27declare i64 @llvm.read_register.i64(metadata)
28declare i64 @llvm.read_volatile_register.i64(metadata)
29
30!1 = !{!"cntpct_el0"}
31