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. 11 define void @shadow_optimization_test() { 12 entry: 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 } 25 declare void @bar() 26 27 declare void @llvm.experimental.stackmap(i64, i32, ...) 28
