1 ; RUN: llc -mtriple=i686-unknown-linux-gnu -O1 < %s | FileCheck %s
2 ; RUN: llc -mtriple=i686-unknown-linux-gnu -O0 < %s | FileCheck %s
4 ; The MSVC family of x86 calling conventions makes tail calls really tricky.
5 ; Tests of all the various combinations should live here.
7 declare i32 @cdecl_i32()
8 declare void @cdecl_void()
10 ; Don't allow tail calling these cdecl functions, because we need to clear the
11 ; incoming stack arguments for these argument-clearing conventions.
13 define x86_thiscallcc void @thiscall_cdecl_notail(i32 %a, i32 %b, i32 %c) {
14 tail call void @cdecl_void()
17 ; CHECK-LABEL: thiscall_cdecl_notail
18 ; CHECK: calll cdecl_void
21 define x86_stdcallcc void @stdcall_cdecl_notail(i32 %a, i32 %b, i32 %c) {
22 tail call void @cdecl_void()
25 ; CHECK-LABEL: stdcall_cdecl_notail
26 ; CHECK: calll cdecl_void
29 define x86_vectorcallcc void @vectorcall_cdecl_notail(i32 inreg %a, i32 inreg %b, i32 %c) {
30 tail call void @cdecl_void()
33 ; CHECK-LABEL: vectorcall_cdecl_notail
34 ; CHECK: calll cdecl_void
37 define x86_fastcallcc void @fastcall_cdecl_notail(i32 inreg %a, i32 inreg %b, i32 %c) {
38 tail call void @cdecl_void()
41 ; CHECK-LABEL: fastcall_cdecl_notail
42 ; CHECK: calll cdecl_void
46 ; Tail call to/from callee pop functions can work under the right circumstances:
48 declare x86_thiscallcc void @no_args_method(i8*)
49 declare x86_thiscallcc void @one_arg_method(i8*, i32)
50 declare x86_thiscallcc void @two_args_method(i8*, i32, i32)
51 declare void @ccall_func()
52 declare void @ccall_func1(i32)
54 define x86_thiscallcc void @thiscall_thiscall_tail(i8* %this) {
56 tail call x86_thiscallcc void @no_args_method(i8* %this)
59 ; CHECK-LABEL: thiscall_thiscall_tail:
60 ; CHECK: jmp no_args_method
62 define x86_thiscallcc void @thiscall_thiscall_tail2(i8* %this, i32 %a, i32 %b) {
64 tail call x86_thiscallcc void @two_args_method(i8* %this, i32 %a, i32 %b)
67 ; @two_args_method will take care of popping %a and %b from the stack for us.
68 ; CHECK-LABEL: thiscall_thiscall_tail2:
69 ; CHECK: jmp two_args_method
71 define x86_thiscallcc void @thiscall_thiscall_notail(i8* %this, i32 %a, i32 %b, i32 %x) {
73 tail call x86_thiscallcc void @two_args_method(i8* %this, i32 %a, i32 %b)
76 ; @two_args_method would not pop %x.
77 ; CHECK-LABEL: thiscall_thiscall_notail:
78 ; CHECK: calll two_args_method
81 define x86_thiscallcc void @thiscall_thiscall_notail2(i8* %this, i32 %a) {
83 tail call x86_thiscallcc void @no_args_method(i8* %this)
86 ; @no_args_method would not pop %x for us. Make sure this is checked even
87 ; when there are no arguments to the call.
88 ; CHECK-LABEL: thiscall_thiscall_notail2:
89 ; CHECK: calll no_args_method
92 define void @ccall_thiscall_tail(i8* %x) {
94 tail call x86_thiscallcc void @no_args_method(i8* %x)
97 ; Tail calling from ccall to thiscall works.
98 ; CHECK-LABEL: ccall_thiscall_tail:
99 ; CHECK: jmp no_args_method
101 define void @ccall_thiscall_notail(i8* %x, i32 %y) {
103 tail call x86_thiscallcc void @one_arg_method(i8* %x, i32 %y);
106 ; @one_arg_method would pop %y off the stack.
107 ; CHECK-LABEL: ccall_thiscall_notail:
108 ; CHECK: calll one_arg_method
110 define x86_thiscallcc void @thiscall_ccall_tail(i8* %this) {
112 tail call void @ccall_func()
115 ; Tail call from thiscall to ccall works if no arguments need popping.
116 ; CHECK-LABEL: thiscall_ccall_tail:
117 ; CHECK: jmp ccall_func
119 define x86_thiscallcc void @thiscall_ccall_notail(i8* %this, i32 %x) {
121 tail call void @ccall_func1(i32 %x)
124 ; No tail call: %x needs to be popped.
125 ; CHECK-LABEL: thiscall_ccall_notail:
126 ; CHECK: calll ccall_func1
129 %S = type { i32 (...)** }
130 define x86_thiscallcc void @tailcall_through_pointer(%S* %this, i32 %a) {
132 %0 = bitcast %S* %this to void (%S*, i32)***
133 %vtable = load void (%S*, i32)**, void (%S*, i32)*** %0
134 %1 = load void (%S*, i32)*, void (%S*, i32)** %vtable
135 tail call x86_thiscallcc void %1(%S* %this, i32 %a)
138 ; Tail calling works through function pointers too.
139 ; CHECK-LABEL: tailcall_through_pointer:
142 define x86_stdcallcc void @stdcall_cdecl_tail() {
143 tail call void @ccall_func()
146 ; stdcall to cdecl works if no arguments need popping.
147 ; CHECK-LABEL: stdcall_cdecl_tail
148 ; CHECK: jmp ccall_func
150 define x86_vectorcallcc void @vectorcall_cdecl_tail(i32 inreg %a, i32 inreg %b) {
151 tail call void @ccall_func()
154 ; vectorcall to cdecl works if no arguments need popping.
155 ; CHECK-LABEL: vectorcall_cdecl_tail
156 ; CHECK: jmp ccall_func
158 define x86_fastcallcc void @fastcall_cdecl_tail(i32 inreg %a, i32 inreg %b) {
159 tail call void @ccall_func()
162 ; fastcall to cdecl works if no arguments need popping.
163 ; CHECK-LABEL: fastcall_cdecl_tail
164 ; CHECK: jmp ccall_func
166 define x86_stdcallcc void @stdcall_thiscall_notail(i8* %this, i32 %a, i32 %b) {
167 tail call x86_thiscallcc void @two_args_method(i8* %this, i32 %a, i32 %b)
170 ; two_args_method will not pop %this.
171 ; CHECK-LABEL: stdcall_thiscall_notail
172 ; CHECK: calll two_args_method
174 define x86_stdcallcc void @stdcall_thiscall_tail(i32 %a, i32 %b) {
175 tail call x86_thiscallcc void @two_args_method(i8* null, i32 %a, i32 %b)
178 ; The callee pop amounts match up.
179 ; CHECK-LABEL: stdcall_thiscall_tail
180 ; CHECK: jmp two_args_method
182 declare x86_fastcallcc void @fastcall2(i32 inreg %a, i32 inreg %b)
183 define void @cdecl_fastcall_tail(i32 %a, i32 %b) {
184 tail call x86_fastcallcc void @fastcall2(i32 %a, i32 %b)
187 ; fastcall2 won't pop anything.
188 ; CHECK-LABEL: cdecl_fastcall_tail
189 ; CHECK: jmp fastcall2