xref: /llvm-project/llvm/test/CodeGen/SystemZ/stackmap-shadow-optimization.ll (revision 5eb64110d241cf2506f54ade3c2693beed42dd8f)
1; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
2
3; Check that the stackmap shadow optimization is only outputting a 2-byte
4; nop here. 8-bytes are requested, but 6 are covered by the code for the call to
5; bar.  However, the frame teardown and the return do not count towards the
6; stackmap shadow as the call return counts as a branch target so must flush
7; the shadow.
8; Note that in order for a thread to not return in to the patched space
9; the call must be at the end of the shadow, so the required nop must be
10; before the call, not after.
11define void @shadow_optimization_test() {
12entry:
13; CHECK-LABEL:  shadow_optimization_test:
14; CHECK:        brasl %r14, bar@PLT
15; CHECK-NEXT:   .Ltmp
16; CHECK-NEXT:   bcr 0, %r0
17; CHECK-NEXT:   brasl %r14, bar@PLT
18; CHECK-NEXT:   brasl %r14, bar@PLT
19  call void @bar()
20  tail call void (i64, i32, ...) @llvm.experimental.stackmap(i64 0, i32 8)
21  call void @bar()
22  call void @bar()
23  ret void
24}
25declare void @bar()
26
27declare void @llvm.experimental.stackmap(i64, i32, ...)
28