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
| ; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
; Check that the stackmap shadow optimization is only outputting a 2-byte
; nop here. 8-bytes are requested, but 6 are covered by the code for the call to
; bar. However, the frame teardown and the return do not count towards the
; stackmap shadow as the call return counts as a branch target so must flush
; the shadow.
; Note that in order for a thread to not return in to the patched space
; the call must be at the end of the shadow, so the required nop must be
; before the call, not after.
define void @shadow_optimization_test() {
entry:
; CHECK-LABEL: shadow_optimization_test:
; CHECK: brasl %r14, bar@PLT
; CHECK-NEXT: .Ltmp
; CHECK-NEXT: bcr 0, %r0
; CHECK-NEXT: brasl %r14, bar@PLT
; CHECK-NEXT: brasl %r14, bar@PLT
call void @bar()
tail call void (i64, i32, ...) @llvm.experimental.stackmap(i64 0, i32 8)
call void @bar()
call void @bar()
ret void
}
declare void @bar()
declare void @llvm.experimental.stackmap(i64, i32, ...)
|