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llvm-mirror/test/CodeGen/SystemZ/stackmap-shadow-optimization.ll
Ulrich Weigand 6a6a68334a [SystemZ] Support stackmaps and patchpoints
This adds back-end support for the @llvm.experimental.stackmap and
@llvm.experimental.patchpoint intrinsics.

llvm-svn: 326611
2018-03-02 20:39:30 +00:00

28 lines
1.0 KiB
LLVM

; 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, ...)