diff options
Diffstat (limited to 'llvm/test/CodeGen/SystemZ/stackmap-shadow-optimization.ll')
| -rw-r--r-- | llvm/test/CodeGen/SystemZ/stackmap-shadow-optimization.ll | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/llvm/test/CodeGen/SystemZ/stackmap-shadow-optimization.ll b/llvm/test/CodeGen/SystemZ/stackmap-shadow-optimization.ll new file mode 100644 index 00000000000..5b828e73eb9 --- /dev/null +++ b/llvm/test/CodeGen/SystemZ/stackmap-shadow-optimization.ll @@ -0,0 +1,27 @@ +; 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, ...) |
