37 lines
		
	
	
		
			833 B
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			37 lines
		
	
	
		
			833 B
		
	
	
	
		
			LLVM
		
	
	
	
| ; 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: rex64 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)
 |