| ; RUN: llc -mtriple=x86_64-windows -show-mc-encoding < %s | FileCheck %s | |
| ; The Win64 ABI wants tail jmps to use a REX_W prefix so it can distinguish | |
| ; in-function jumps from function exiting jumps. | |
| define void @tail_jmp_reg(i32, i32, void ()* %fptr) { | |
| tail call void () %fptr() | |
| ret void | |
| } | |
| ; Check that we merge the REX prefixes into 0x49 instead of 0x48, 0x41. | |
| ; CHECK-LABEL: tail_jmp_reg: | |
| ; CHECK: rex64 jmpq *%r8 | |
| ; CHECK: encoding: [0x49,0xff,0xe0] | |
| declare void @tail_tgt() | |
| define void @tail_jmp_imm() { | |
| tail call void @tail_tgt() | |
| ret void | |
| } | |
| ; CHECK-LABEL: tail_jmp_imm: | |
| ; CHECK: jmp tail_tgt | |
| @g_fptr = global void ()* @tail_tgt | |
| define void @tail_jmp_mem() { | |
| %fptr = load void ()*, void ()** @g_fptr | |
| tail call void () %fptr() | |
| ret void | |
| } | |
| ; CHECK-LABEL: tail_jmp_mem: | |
| ; CHECK: rex64 jmpq *g_fptr(%rip) |