aboutsummaryrefslogtreecommitdiffstats
path: root/lib/Target/AArch64/AArch64CallingConvention.td
blob: 8e8bd3d0bcd88464a00d37d8f427f9cb2c811aa7 (plain)
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
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
//=- AArch64CallingConv.td - Calling Conventions for AArch64 -*- tablegen -*-=//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This describes the calling conventions for AArch64 architecture.
//
//===----------------------------------------------------------------------===//

/// CCIfAlign - Match of the original alignment of the arg
class CCIfAlign<string Align, CCAction A> :
  CCIf<!strconcat("ArgFlags.getOrigAlign() == ", Align), A>;
/// CCIfBigEndian - Match only if we're in big endian mode.
class CCIfBigEndian<CCAction A> :
  CCIf<"State.getTarget().getDataLayout()->isBigEndian()", A>;

//===----------------------------------------------------------------------===//
// ARM AAPCS64 Calling Convention
//===----------------------------------------------------------------------===//

def CC_AArch64_AAPCS : CallingConv<[
  CCIfType<[v2f32], CCBitConvertToType<v2i32>>,
  CCIfType<[v2f64, v4f32], CCBitConvertToType<v2i64>>,

  // Big endian vectors must be passed as if they were 1-element vectors so that
  // their lanes are in a consistent order.
  CCIfBigEndian<CCIfType<[v2i32, v2f32, v4i16, v4f16, v8i8],
                         CCBitConvertToType<f64>>>,
  CCIfBigEndian<CCIfType<[v2i64, v2f64, v4i32, v4f32, v8i16, v8f16, v16i8],
                         CCBitConvertToType<f128>>>,

  // An SRet is passed in X8, not X0 like a normal pointer parameter.
  CCIfSRet<CCIfType<[i64], CCAssignToRegWithShadow<[X8], [W8]>>>,

  // Put ByVal arguments directly on the stack. Minimum size and alignment of a
  // slot is 64-bit.
  CCIfByVal<CCPassByVal<8, 8>>,

  // Handle i1, i8, i16, i32, i64, f32, f64 and v2f64 by passing in registers,
  // up to eight each of GPR and FPR.
  CCIfType<[i1, i8, i16], CCPromoteToType<i32>>,
  CCIfType<[i32], CCAssignToRegWithShadow<[W0, W1, W2, W3, W4, W5, W6, W7],
                                          [X0, X1, X2, X3, X4, X5, X6, X7]>>,
  // i128 is split to two i64s, we can't fit half to register X7.
  CCIfType<[i64], CCIfSplit<CCAssignToRegWithShadow<[X0, X2, X4, X6],
                                                    [X0, X1, X3, X5]>>>,

  // i128 is split to two i64s, and its stack alignment is 16 bytes.
  CCIfType<[i64], CCIfSplit<CCAssignToStackWithShadow<8, 16, [X7]>>>,

  CCIfType<[i64], CCAssignToRegWithShadow<[X0, X1, X2, X3, X4, X5, X6, X7],
                                          [W0, W1, W2, W3, W4, W5, W6, W7]>>,
  CCIfType<[f32], CCAssignToRegWithShadow<[S0, S1, S2, S3, S4, S5, S6, S7],
                                          [Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7]>>,
  CCIfType<[f64], CCAssignToRegWithShadow<[D0, D1, D2, D3, D4, D5, D6, D7],
                                          [Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7]>>,
  CCIfType<[v1i64, v2i32, v4i16, v8i8, v1f64, v2f32],
           CCAssignToRegWithShadow<[D0, D1, D2, D3, D4, D5, D6, D7],
                                   [Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7]>>,
  CCIfType<[f128, v2i64, v4i32, v8i16, v16i8, v4f32, v2f64],
           CCAssignToReg<[Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7]>>,

  // If more than will fit in registers, pass them on the stack instead.
  CCIfType<[i1, i8, i16], CCAssignToStack<8, 8>>,
  CCIfType<[i32, f32], CCAssignToStack<8, 8>>,
  CCIfType<[i64, f64, v1f64, v2f32, v1i64, v2i32, v4i16, v8i8],
           CCAssignToStack<8, 8>>,
  CCIfType<[f128, v2i64, v4i32, v8i16, v16i8, v4f32, v2f64],
           CCAssignToStack<16, 16>>
]>;

def RetCC_AArch64_AAPCS : CallingConv<[
  CCIfType<[v2f32], CCBitConvertToType<v2i32>>,
  CCIfType<[v2f64, v4f32], CCBitConvertToType<v2i64>>,

  // Big endian vectors must be passed as if they were 1-element vectors so that
  // their lanes are in a consistent order.
  CCIfBigEndian<CCIfType<[v2i32, v2f32, v4i16, v4f16, v8i8],
                         CCBitConvertToType<f64>>>,
  CCIfBigEndian<CCIfType<[v2i64, v2f64, v4i32, v4f32, v8i16, v8f16, v16i8],
                         CCBitConvertToType<f128>>>,

  CCIfType<[i32], CCAssignToRegWithShadow<[W0, W1, W2, W3, W4, W5, W6, W7],
                                          [X0, X1, X2, X3, X4, X5, X6, X7]>>,
  CCIfType<[i64], CCAssignToRegWithShadow<[X0, X1, X2, X3, X4, X5, X6, X7],
                                          [W0, W1, W2, W3, W4, W5, W6, W7]>>,
  CCIfType<[f32], CCAssignToRegWithShadow<[S0, S1, S2, S3, S4, S5, S6, S7],
                                          [Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7]>>,
  CCIfType<[f64], CCAssignToRegWithShadow<[D0, D1, D2, D3, D4, D5, D6, D7],
                                          [Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7]>>,
  CCIfType<[v1i64, v2i32, v4i16, v8i8, v1f64, v2f32],
      CCAssignToRegWithShadow<[D0, D1, D2, D3, D4, D5, D6, D7],
                              [Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7]>>,
  CCIfType<[f128, v2i64, v4i32, v8i16, v16i8, v4f32, v2f64],
      CCAssignToReg<[Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7]>>
]>;


// Darwin uses a calling convention which differs in only two ways
// from the standard one at this level:
//     + i128s (i.e. split i64s) don't need even registers.
//     + Stack slots are sized as needed rather than being at least 64-bit.
def CC_AArch64_DarwinPCS : CallingConv<[
  CCIfType<[v2f32], CCBitConvertToType<v2i32>>,
  CCIfType<[v2f64, v4f32, f128], CCBitConvertToType<v2i64>>,

  // An SRet is passed in X8, not X0 like a normal pointer parameter.
  CCIfSRet<CCIfType<[i64], CCAssignToRegWithShadow<[X8], [W8]>>>,

  // Put ByVal arguments directly on the stack. Minimum size and alignment of a
  // slot is 64-bit.
  CCIfByVal<CCPassByVal<8, 8>>,

  // Handle i1, i8, i16, i32, i64, f32, f64 and v2f64 by passing in registers,
  // up to eight each of GPR and FPR.
  CCIfType<[i1, i8, i16], CCPromoteToType<i32>>,
  CCIfType<[i32], CCAssignToRegWithShadow<[W0, W1, W2, W3, W4, W5, W6, W7],
                                          [X0, X1, X2, X3, X4, X5, X6, X7]>>,
  // i128 is split to two i64s, we can't fit half to register X7.
  CCIfType<[i64],
           CCIfSplit<CCAssignToRegWithShadow<[X0, X1, X2, X3, X4, X5, X6],
                                             [W0, W1, W2, W3, W4, W5, W6]>>>,
  // i128 is split to two i64s, and its stack alignment is 16 bytes.
  CCIfType<[i64], CCIfSplit<CCAssignToStackWithShadow<8, 16, [X7]>>>,

  CCIfType<[i64], CCAssignToRegWithShadow<[X0, X1, X2, X3, X4, X5, X6, X7],
                                          [W0, W1, W2, W3, W4, W5, W6, W7]>>,
  CCIfType<[f32], CCAssignToRegWithShadow<[S0, S1, S2, S3, S4, S5, S6, S7],
                                          [Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7]>>,
  CCIfType<[f64], CCAssignToRegWithShadow<[D0, D1, D2, D3, D4, D5, D6, D7],
                                          [Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7]>>,
  CCIfType<[v1i64, v2i32, v4i16, v8i8, v1f64, v2f32],
           CCAssignToRegWithShadow<[D0, D1, D2, D3, D4, D5, D6, D7],
                                   [Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7]>>,
  CCIfType<[v2i64, v4i32, v8i16, v16i8, v4f32, v2f64],
           CCAssignToReg<[Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7]>>,

  // If more than will fit in registers, pass them on the stack instead.
  CCIf<"ValVT == MVT::i1 || ValVT == MVT::i8", CCAssignToStack<1, 1>>,
  CCIf<"ValVT == MVT::i16", CCAssignToStack<2, 2>>,
  CCIfType<[i32, f32], CCAssignToStack<4, 4>>,
  CCIfType<[i64, f64, v1f64, v2f32, v1i64, v2i32, v4i16, v8i8],
           CCAssignToStack<8, 8>>,
  CCIfType<[v2i64, v4i32, v8i16, v16i8, v4f32, v2f64], CCAssignToStack<16, 16>>
]>;

def CC_AArch64_DarwinPCS_VarArg : CallingConv<[
  CCIfType<[v2f32], CCBitConvertToType<v2i32>>,
  CCIfType<[v2f64, v4f32, f128], CCBitConvertToType<v2i64>>,

  // Handle all scalar types as either i64 or f64.
  CCIfType<[i8, i16, i32], CCPromoteToType<i64>>,
  CCIfType<[f32],          CCPromoteToType<f64>>,

  // Everything is on the stack.
  // i128 is split to two i64s, and its stack alignment is 16 bytes.
  CCIfType<[i64], CCIfSplit<CCAssignToStack<8, 16>>>,
  CCIfType<[i64, f64, v1i64, v2i32, v4i16, v8i8, v1f64, v2f32], CCAssignToStack<8, 8>>,
  CCIfType<[v2i64, v4i32, v8i16, v16i8, v4f32, v2f64],   CCAssignToStack<16, 16>>
]>;

// The WebKit_JS calling convention only passes the first argument (the callee)
// in register and the remaining arguments on stack. We allow 32bit stack slots,
// so that WebKit can write partial values in the stack and define the other
// 32bit quantity as undef.
def CC_AArch64_WebKit_JS : CallingConv<[
  // Handle i1, i8, i16, i32, and i64 passing in register X0 (W0).
  CCIfType<[i1, i8, i16], CCPromoteToType<i32>>,
  CCIfType<[i32], CCAssignToRegWithShadow<[W0], [X0]>>,
  CCIfType<[i64], CCAssignToRegWithShadow<[X0], [W0]>>,

  // Pass the remaining arguments on the stack instead.
  CCIfType<[i32, f32], CCAssignToStack<4, 4>>,
  CCIfType<[i64, f64], CCAssignToStack<8, 8>>
]>;

def RetCC_AArch64_WebKit_JS : CallingConv<[
  CCIfType<[i32], CCAssignToRegWithShadow<[W0, W1, W2, W3, W4, W5, W6, W7],
                                          [X0, X1, X2, X3, X4, X5, X6, X7]>>,
  CCIfType<[i64], CCAssignToRegWithShadow<[X0, X1, X2, X3, X4, X5, X6, X7],
                                          [W0, W1, W2, W3, W4, W5, W6, W7]>>,
  CCIfType<[f32], CCAssignToRegWithShadow<[S0, S1, S2, S3, S4, S5, S6, S7],
                                          [Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7]>>,
  CCIfType<[f64], CCAssignToRegWithShadow<[D0, D1, D2, D3, D4, D5, D6, D7],
                                          [Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7]>>
]>;

// FIXME: LR is only callee-saved in the sense that *we* preserve it and are
// presumably a callee to someone. External functions may not do so, but this
// is currently safe since BL has LR as an implicit-def and what happens after a
// tail call doesn't matter.
//
// It would be better to model its preservation semantics properly (create a
// vreg on entry, use it in RET & tail call generation; make that vreg def if we
// end up saving LR as part of a call frame). Watch this space...
def CSR_AArch64_AAPCS : CalleeSavedRegs<(add LR, FP, X19, X20, X21, X22,
                                           X23, X24, X25, X26, X27, X28,
                                           D8,  D9,  D10, D11,
                                           D12, D13, D14, D15)>;

// Constructors and destructors return 'this' in the iOS 64-bit C++ ABI; since
// 'this' and the pointer return value are both passed in X0 in these cases,
// this can be partially modelled by treating X0 as a callee-saved register;
// only the resulting RegMask is used; the SaveList is ignored
//
// (For generic ARM 64-bit ABI code, clang will not generate constructors or
// destructors with 'this' returns, so this RegMask will not be used in that
// case)
def CSR_AArch64_AAPCS_ThisReturn : CalleeSavedRegs<(add CSR_AArch64_AAPCS, X0)>;

// The function used by Darwin to obtain the address of a thread-local variable
// guarantees more than a normal AAPCS function. x16 and x17 are used on the
// fast path for calculation, but other registers except X0 (argument/return)
// and LR (it is a call, after all) are preserved.
def CSR_AArch64_TLS_Darwin
    : CalleeSavedRegs<(add (sub (sequence "X%u", 1, 28), X16, X17),
                           FP,
                           (sequence "Q%u", 0, 31))>;

// The ELF stub used for TLS-descriptor access saves every feasible
// register. Only X0 and LR are clobbered.
def CSR_AArch64_TLS_ELF
    : CalleeSavedRegs<(add (sequence "X%u", 1, 28), FP,
                           (sequence "Q%u", 0, 31))>;

def CSR_AArch64_AllRegs
    : CalleeSavedRegs<(add (sequence "W%u", 0, 30), WSP,
                           (sequence "X%u", 0, 28), FP, LR, SP,
                           (sequence "B%u", 0, 31), (sequence "H%u", 0, 31),
                           (sequence "S%u", 0, 31), (sequence "D%u", 0, 31),
                           (sequence "Q%u", 0, 31))>;