1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
|
; RUN: llc -verify-machineinstrs < %s -mtriple=i686-win32 | FileCheck %s
; RUN: llc -verify-machineinstrs < %s -mtriple=i686-win32 -O0 | FileCheck %s
; IR simplified from the following C++ snippet compiled for i686-windows-msvc:
; struct A { A(); ~A(); int a; };
;
; struct B {
; virtual int f(int);
; virtual int g(A, int, A);
; virtual void h(A, int, A);
; virtual A i(A, int, A);
; virtual A j(int);
; };
;
; int (B::*mp_f)(int) = &B::f;
; int (B::*mp_g)(A, int, A) = &B::g;
; void (B::*mp_h)(A, int, A) = &B::h;
; A (B::*mp_i)(A, int, A) = &B::i;
; A (B::*mp_j)(int) = &B::j;
; Each member pointer creates a thunk. The ones with inalloca are required to
; tail calls by the ABI, even at O0.
%struct.B = type { ptr }
%struct.A = type { i32 }
; CHECK-LABEL: f_thunk:
; CHECK: jmpl
; CHECK-NOT: ret
define x86_thiscallcc i32 @f_thunk(ptr %this, i32) {
entry:
%vtable = load ptr, ptr %this
%1 = load ptr, ptr %vtable
%2 = musttail call x86_thiscallcc i32 %1(ptr %this, i32 %0)
ret i32 %2
}
; Inalloca thunks shouldn't require any stores to the stack.
; CHECK-LABEL: g_thunk:
; CHECK-NOT: mov %{{.*}}, {{.*(.*esp.*)}}
; CHECK: jmpl
; CHECK-NOT: ret
define x86_thiscallcc i32 @g_thunk(ptr %this, ptr inalloca(<{ %struct.A, i32, %struct.A }>)) {
entry:
%vtable = load ptr, ptr %this
%vfn = getelementptr inbounds ptr, ptr %vtable, i32 1
%1 = load ptr, ptr %vfn
%2 = musttail call x86_thiscallcc i32 %1(ptr %this, ptr inalloca(<{ %struct.A, i32, %struct.A }>) %0)
ret i32 %2
}
; Preallocated thunks shouldn't require any stores to the stack.
; CHECK-LABEL: g_thunk_preallocated:
; CHECK-NOT: mov %{{.*}}, {{.*(.*esp.*)}}
; CHECK: jmpl
; CHECK-NOT: ret
define x86_thiscallcc i32 @g_thunk_preallocated(ptr %this, ptr preallocated(<{ %struct.A, i32, %struct.A }>)) {
entry:
%vtable = load ptr, ptr %this
%vfn = getelementptr inbounds ptr, ptr %vtable, i32 1
%1 = load ptr, ptr %vfn
%2 = musttail call x86_thiscallcc i32 %1(ptr %this, ptr preallocated(<{ %struct.A, i32, %struct.A }>) %0)
ret i32 %2
}
; CHECK-LABEL: h_thunk:
; CHECK: jmpl
; CHECK-NOT: mov %{{.*}}, {{.*(.*esp.*)}}
; CHECK-NOT: ret
define x86_thiscallcc void @h_thunk(ptr %this, ptr inalloca(<{ %struct.A, i32, %struct.A }>)) {
entry:
%vtable = load ptr, ptr %this
%vfn = getelementptr inbounds ptr, ptr %vtable, i32 2
%1 = load ptr, ptr %vfn
musttail call x86_thiscallcc void %1(ptr %this, ptr inalloca(<{ %struct.A, i32, %struct.A }>) %0)
ret void
}
; CHECK-LABEL: h_thunk_preallocated:
; CHECK: jmpl
; CHECK-NOT: mov %{{.*}}, {{.*(.*esp.*)}}
; CHECK-NOT: ret
define x86_thiscallcc void @h_thunk_preallocated(ptr %this, ptr preallocated(<{ %struct.A, i32, %struct.A }>)) {
entry:
%vtable = load ptr, ptr %this
%vfn = getelementptr inbounds ptr, ptr %vtable, i32 2
%1 = load ptr, ptr %vfn
musttail call x86_thiscallcc void %1(ptr %this, ptr preallocated(<{ %struct.A, i32, %struct.A }>) %0)
ret void
}
; CHECK-LABEL: i_thunk:
; CHECK-NOT: mov %{{.*}}, {{.*(.*esp.*)}}
; CHECK: jmpl
; CHECK-NOT: ret
define x86_thiscallcc ptr @i_thunk(ptr %this, ptr inalloca(<{ ptr, %struct.A, i32, %struct.A }>)) {
entry:
%vtable = load ptr, ptr %this
%vfn = getelementptr inbounds ptr, ptr %vtable, i32 3
%1 = load ptr, ptr %vfn
%2 = musttail call x86_thiscallcc ptr %1(ptr %this, ptr inalloca(<{ ptr, %struct.A, i32, %struct.A }>) %0)
ret ptr %2
}
; CHECK-LABEL: i_thunk_preallocated:
; CHECK-NOT: mov %{{.*}}, {{.*(.*esp.*)}}
; CHECK: jmpl
; CHECK-NOT: ret
define x86_thiscallcc ptr @i_thunk_preallocated(ptr %this, ptr preallocated(<{ ptr, %struct.A, i32, %struct.A }>)) {
entry:
%vtable = load ptr, ptr %this
%vfn = getelementptr inbounds ptr, ptr %vtable, i32 3
%1 = load ptr, ptr %vfn
%2 = musttail call x86_thiscallcc ptr %1(ptr %this, ptr preallocated(<{ ptr, %struct.A, i32, %struct.A }>) %0)
ret ptr %2
}
; CHECK-LABEL: j_thunk:
; CHECK: jmpl
; CHECK-NOT: ret
define x86_thiscallcc void @j_thunk(ptr noalias sret(%struct.A) %agg.result, ptr %this, i32) {
entry:
%vtable = load ptr, ptr %this
%vfn = getelementptr inbounds ptr, ptr %vtable, i32 4
%1 = load ptr, ptr %vfn
musttail call x86_thiscallcc void %1(ptr sret(%struct.A) %agg.result, ptr %this, i32 %0)
ret void
}
; CHECK-LABEL: _stdcall_thunk@8:
; CHECK-NOT: mov %{{.*}}, {{.*(.*esp.*)}}
; CHECK: jmpl
; CHECK-NOT: ret
define x86_stdcallcc i32 @stdcall_thunk(ptr inalloca(<{ ptr, %struct.A }>)) {
entry:
%this_ptr = getelementptr inbounds <{ ptr, %struct.A }>, ptr %0, i32 0, i32 0
%this = load ptr, ptr %this_ptr
%vtable = load ptr, ptr %this
%vfn = getelementptr inbounds ptr, ptr %vtable, i32 1
%1 = load ptr, ptr %vfn
%2 = musttail call x86_stdcallcc i32 %1(ptr inalloca(<{ ptr, %struct.A }>) %0)
ret i32 %2
}
; CHECK-LABEL: _stdcall_thunk_preallocated@8:
; CHECK-NOT: mov %{{.*}}, {{.*(.*esp.*)}}
; CHECK: jmpl
; CHECK-NOT: ret
define x86_stdcallcc i32 @stdcall_thunk_preallocated(ptr preallocated(<{ ptr, %struct.A }>)) {
entry:
%this_ptr = getelementptr inbounds <{ ptr, %struct.A }>, ptr %0, i32 0, i32 0
%this = load ptr, ptr %this_ptr
%vtable = load ptr, ptr %this
%vfn = getelementptr inbounds ptr, ptr %vtable, i32 1
%1 = load ptr, ptr %vfn
%2 = musttail call x86_stdcallcc i32 %1(ptr preallocated(<{ ptr, %struct.A }>) %0)
ret i32 %2
}
; CHECK-LABEL: @fastcall_thunk@8:
; CHECK-NOT: mov %{{.*}}, {{.*(.*esp.*)}}
; CHECK: jmpl
; CHECK-NOT: ret
define x86_fastcallcc i32 @fastcall_thunk(ptr inreg %this, ptr inalloca(<{ %struct.A }>)) {
entry:
%vtable = load ptr, ptr %this
%vfn = getelementptr inbounds ptr, ptr %vtable, i32 1
%1 = load ptr, ptr %vfn
%2 = musttail call x86_fastcallcc i32 %1(ptr inreg %this, ptr inalloca(<{ %struct.A }>) %0)
ret i32 %2
}
; CHECK-LABEL: @fastcall_thunk_preallocated@8:
; CHECK-NOT: mov %{{.*}}, {{.*(.*esp.*)}}
; CHECK: jmpl
; CHECK-NOT: ret
define x86_fastcallcc i32 @fastcall_thunk_preallocated(ptr inreg %this, ptr preallocated(<{ %struct.A }>)) {
entry:
%vtable = load ptr, ptr %this
%vfn = getelementptr inbounds ptr, ptr %vtable, i32 1
%1 = load ptr, ptr %vfn
%2 = musttail call x86_fastcallcc i32 %1(ptr inreg %this, ptr preallocated(<{ %struct.A }>) %0)
ret i32 %2
}
|
