llvm-project/llvm/test/CodeGen/X86/tail-call-win64.ll

37 lines
835 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)