1; RUN: llc -mtriple=i686-unknown-linux-gnu -O1 < %s | FileCheck %s 2; RUN: llc -mtriple=i686-unknown-linux-gnu -O0 < %s | FileCheck %s 3 4; The MSVC family of x86 calling conventions makes tail calls really tricky. 5; Tests of all the various combinations should live here. 6 7declare i32 @cdecl_i32() 8declare void @cdecl_void() 9 10; Don't allow tail calling these cdecl functions, because we need to clear the 11; incoming stack arguments for these argument-clearing conventions. 12 13define x86_thiscallcc void @thiscall_cdecl_notail(i32 %a, i32 %b, i32 %c) { 14 tail call void @cdecl_void() 15 ret void 16} 17; CHECK-LABEL: thiscall_cdecl_notail 18; CHECK: calll cdecl_void 19; CHECK: retl $8 20 21define x86_stdcallcc void @stdcall_cdecl_notail(i32 %a, i32 %b, i32 %c) { 22 tail call void @cdecl_void() 23 ret void 24} 25; CHECK-LABEL: stdcall_cdecl_notail 26; CHECK: calll cdecl_void 27; CHECK: retl $12 28 29define x86_vectorcallcc void @vectorcall_cdecl_notail(i32 inreg %a, i32 inreg %b, i32 %c) { 30 tail call void @cdecl_void() 31 ret void 32} 33; CHECK-LABEL: vectorcall_cdecl_notail 34; CHECK: calll cdecl_void 35; CHECK: retl $4 36 37define x86_fastcallcc void @fastcall_cdecl_notail(i32 inreg %a, i32 inreg %b, i32 %c) { 38 tail call void @cdecl_void() 39 ret void 40} 41; CHECK-LABEL: fastcall_cdecl_notail 42; CHECK: calll cdecl_void 43; CHECK: retl $4 44 45 46; Tail call to/from callee pop functions can work under the right circumstances: 47 48declare x86_thiscallcc void @no_args_method(ptr) 49declare x86_thiscallcc void @one_arg_method(ptr, i32) 50declare x86_thiscallcc void @two_args_method(ptr, i32, i32) 51declare void @ccall_func() 52declare void @ccall_func1(i32) 53 54define x86_thiscallcc void @thiscall_thiscall_tail(ptr %this) { 55entry: 56 tail call x86_thiscallcc void @no_args_method(ptr %this) 57 ret void 58} 59; CHECK-LABEL: thiscall_thiscall_tail: 60; CHECK: jmp no_args_method 61 62define x86_thiscallcc void @thiscall_thiscall_tail2(ptr %this, i32 %a, i32 %b) { 63entry: 64 tail call x86_thiscallcc void @two_args_method(ptr %this, i32 %a, i32 %b) 65 ret void 66} 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 70 71define x86_thiscallcc void @thiscall_thiscall_notail(ptr %this, i32 %a, i32 %b, i32 %x) { 72entry: 73 tail call x86_thiscallcc void @two_args_method(ptr %this, i32 %a, i32 %b) 74 ret void 75} 76; @two_args_method would not pop %x. 77; CHECK-LABEL: thiscall_thiscall_notail: 78; CHECK: calll two_args_method 79; CHECK: retl $12 80 81define x86_thiscallcc void @thiscall_thiscall_notail2(ptr %this, i32 %a) { 82entry: 83 tail call x86_thiscallcc void @no_args_method(ptr %this) 84 ret void 85} 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 90; CHECK: retl $4 91 92define void @ccall_thiscall_tail(ptr %x) { 93entry: 94 tail call x86_thiscallcc void @no_args_method(ptr %x) 95 ret void 96} 97; Tail calling from ccall to thiscall works. 98; CHECK-LABEL: ccall_thiscall_tail: 99; CHECK: jmp no_args_method 100 101define void @ccall_thiscall_notail(ptr %x, i32 %y) { 102entry: 103 tail call x86_thiscallcc void @one_arg_method(ptr %x, i32 %y); 104 ret void 105} 106; @one_arg_method would pop %y off the stack. 107; CHECK-LABEL: ccall_thiscall_notail: 108; CHECK: calll one_arg_method 109 110define x86_thiscallcc void @thiscall_ccall_tail(ptr %this) { 111entry: 112 tail call void @ccall_func() 113 ret void 114} 115; Tail call from thiscall to ccall works if no arguments need popping. 116; CHECK-LABEL: thiscall_ccall_tail: 117; CHECK: jmp ccall_func 118 119define x86_thiscallcc void @thiscall_ccall_notail(ptr %this, i32 %x) { 120entry: 121 tail call void @ccall_func1(i32 %x) 122 ret void 123} 124; No tail call: %x needs to be popped. 125; CHECK-LABEL: thiscall_ccall_notail: 126; CHECK: calll ccall_func1 127; CHECK: retl $4 128 129%S = type { ptr } 130define x86_thiscallcc void @tailcall_through_pointer(ptr %this, i32 %a) { 131entry: 132 %vtable = load ptr, ptr %this 133 %0 = load ptr, ptr %vtable 134 tail call x86_thiscallcc void %0(ptr %this, i32 %a) 135 ret void 136} 137; Tail calling works through function pointers too. 138; CHECK-LABEL: tailcall_through_pointer: 139; CHECK: jmpl 140 141define x86_stdcallcc void @stdcall_cdecl_tail() { 142 tail call void @ccall_func() 143 ret void 144} 145; stdcall to cdecl works if no arguments need popping. 146; CHECK-LABEL: stdcall_cdecl_tail 147; CHECK: jmp ccall_func 148 149define x86_vectorcallcc void @vectorcall_cdecl_tail(i32 inreg %a, i32 inreg %b) { 150 tail call void @ccall_func() 151 ret void 152} 153; vectorcall to cdecl works if no arguments need popping. 154; CHECK-LABEL: vectorcall_cdecl_tail 155; CHECK: jmp ccall_func 156 157define x86_fastcallcc void @fastcall_cdecl_tail(i32 inreg %a, i32 inreg %b) { 158 tail call void @ccall_func() 159 ret void 160} 161; fastcall to cdecl works if no arguments need popping. 162; CHECK-LABEL: fastcall_cdecl_tail 163; CHECK: jmp ccall_func 164 165define x86_stdcallcc void @stdcall_thiscall_notail(ptr %this, i32 %a, i32 %b) { 166 tail call x86_thiscallcc void @two_args_method(ptr %this, i32 %a, i32 %b) 167 ret void 168} 169; two_args_method will not pop %this. 170; CHECK-LABEL: stdcall_thiscall_notail 171; CHECK: calll two_args_method 172 173define x86_stdcallcc void @stdcall_thiscall_tail(i32 %a, i32 %b) { 174 tail call x86_thiscallcc void @two_args_method(ptr null, i32 %a, i32 %b) 175 ret void 176} 177; The callee pop amounts match up. 178; CHECK-LABEL: stdcall_thiscall_tail 179; CHECK: jmp two_args_method 180 181declare x86_fastcallcc void @fastcall2(i32 inreg %a, i32 inreg %b) 182define void @cdecl_fastcall_tail(i32 %a, i32 %b) { 183 tail call x86_fastcallcc void @fastcall2(i32 inreg %a, i32 inreg %b) 184 ret void 185} 186; fastcall2 won't pop anything. 187; CHECK-LABEL: cdecl_fastcall_tail 188; CHECK: jmp fastcall2 189