1; RUN: llc -mtriple=x86_64-windows -show-mc-encoding < %s | FileCheck %s
2
3; The Win64 ABI wants tail jmps to use a REX_W prefix so it can distinguish
4; in-function jumps from function exiting jumps.
5
6define void @tail_jmp_reg(i32, i32, void ()* %fptr) {
7  tail call void () %fptr()
8  ret void
9}
10
11; Check that we merge the REX prefixes into 0x49 instead of 0x48, 0x41.
12
13; CHECK-LABEL: tail_jmp_reg:
14; CHECK: rex64 jmpq *%r8
15; CHECK: 	encoding: [0x49,0xff,0xe0]
16
17declare void @tail_tgt()
18
19define void @tail_jmp_imm() {
20  tail call void @tail_tgt()
21  ret void
22}
23
24; CHECK-LABEL: tail_jmp_imm:
25; CHECK: jmp tail_tgt
26
27@g_fptr = global void ()* @tail_tgt
28
29define void @tail_jmp_mem() {
30  %fptr = load void ()*, void ()** @g_fptr
31  tail call void () %fptr()
32  ret void
33}
34
35; CHECK-LABEL: tail_jmp_mem:
36; CHECK: rex64 jmpq *g_fptr(%rip)
37