xref: /freebsd/contrib/llvm-project/llvm/lib/Target/ARM/ARMCallingConv.td (revision 8881d206f4e68b564c2c5f50fc717086fc3e827a)
1//===-- ARMCallingConv.td - Calling Conventions for ARM ----*- tablegen -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8// This describes the calling conventions for ARM architecture.
9//===----------------------------------------------------------------------===//
10
11/// CCIfAlign - Match of the original alignment of the arg
12class CCIfAlign<string Align, CCAction A>:
13  CCIf<!strconcat("ArgFlags.getNonZeroOrigAlign() == ", Align), A>;
14
15//===----------------------------------------------------------------------===//
16// ARM APCS Calling Convention
17//===----------------------------------------------------------------------===//
18let Entry = 1 in
19def CC_ARM_APCS : CallingConv<[
20
21  // Handles byval parameters.
22  CCIfByVal<CCPassByVal<4, 4>>,
23
24  CCIfType<[i1, i8, i16], CCPromoteToType<i32>>,
25
26  // Pass SwiftSelf in a callee saved register.
27  CCIfSwiftSelf<CCIfType<[i32], CCAssignToReg<[R10]>>>,
28
29  // A SwiftError is passed in R8.
30  CCIfSwiftError<CCIfType<[i32], CCAssignToReg<[R8]>>>,
31
32  // Handle all vector types as either f64 or v2f64.
33  CCIfType<[v1i64, v2i32, v4i16, v4f16, v4bf16, v8i8, v2f32], CCBitConvertToType<f64>>,
34  CCIfType<[v2i64, v4i32, v8i16, v8f16, v8bf16, v16i8, v4f32], CCBitConvertToType<v2f64>>,
35
36  // f64 and v2f64 are passed in adjacent GPRs, possibly split onto the stack
37  CCIfType<[f64, v2f64], CCCustom<"CC_ARM_APCS_Custom_f64">>,
38
39  CCIfType<[f32], CCBitConvertToType<i32>>,
40  CCIfType<[i32], CCAssignToReg<[R0, R1, R2, R3]>>,
41
42  CCIfType<[i32], CCAssignToStack<4, 4>>,
43  CCIfType<[f64], CCAssignToStack<8, 4>>,
44  CCIfType<[v2f64], CCAssignToStack<16, 4>>
45]>;
46
47let Entry = 1 in
48def RetCC_ARM_APCS : CallingConv<[
49  CCIfType<[i1, i8, i16], CCPromoteToType<i32>>,
50  CCIfType<[f32], CCBitConvertToType<i32>>,
51
52  // Pass SwiftSelf in a callee saved register.
53  CCIfSwiftSelf<CCIfType<[i32], CCAssignToReg<[R10]>>>,
54
55  // A SwiftError is returned in R8.
56  CCIfSwiftError<CCIfType<[i32], CCAssignToReg<[R8]>>>,
57
58  // Handle all vector types as either f64 or v2f64.
59  CCIfType<[v1i64, v2i32, v4i16, v4f16, v4bf16, v8i8, v2f32], CCBitConvertToType<f64>>,
60  CCIfType<[v2i64, v4i32, v8i16, v8f16, v8bf16, v16i8, v4f32], CCBitConvertToType<v2f64>>,
61
62  CCIfType<[f64, v2f64], CCCustom<"RetCC_ARM_APCS_Custom_f64">>,
63
64  CCIfType<[i32], CCAssignToReg<[R0, R1, R2, R3]>>,
65  CCIfType<[i64], CCAssignToRegWithShadow<[R0, R2], [R1, R3]>>
66]>;
67
68//===----------------------------------------------------------------------===//
69// ARM APCS Calling Convention for FastCC (when VFP2 or later is available)
70//===----------------------------------------------------------------------===//
71let Entry = 1 in
72def FastCC_ARM_APCS : CallingConv<[
73  // Handle all vector types as either f64 or v2f64.
74  CCIfType<[v1i64, v2i32, v4i16, v4f16, v4bf16, v8i8, v2f32], CCBitConvertToType<f64>>,
75  CCIfType<[v2i64, v4i32, v8i16, v8f16, v8bf16, v16i8, v4f32], CCBitConvertToType<v2f64>>,
76
77  CCIfType<[v2f64], CCAssignToReg<[Q0, Q1, Q2, Q3]>>,
78  CCIfType<[f64], CCAssignToReg<[D0, D1, D2, D3, D4, D5, D6, D7]>>,
79  CCIfType<[f32], CCAssignToReg<[S0, S1, S2, S3, S4, S5, S6, S7, S8,
80                                 S9, S10, S11, S12, S13, S14, S15]>>,
81
82  // CPRCs may be allocated to co-processor registers or the stack - they
83  // may never be allocated to core registers.
84  CCIfType<[f32], CCAssignToStackWithShadow<4, 4, [Q0, Q1, Q2, Q3]>>,
85  CCIfType<[f64], CCAssignToStackWithShadow<8, 4, [Q0, Q1, Q2, Q3]>>,
86  CCIfType<[v2f64], CCAssignToStackWithShadow<16, 4, [Q0, Q1, Q2, Q3]>>,
87
88  CCDelegateTo<CC_ARM_APCS>
89]>;
90
91let Entry = 1 in
92def RetFastCC_ARM_APCS : CallingConv<[
93  // Handle all vector types as either f64 or v2f64.
94  CCIfType<[v1i64, v2i32, v4i16, v4f16, v4bf16, v8i8, v2f32], CCBitConvertToType<f64>>,
95  CCIfType<[v2i64, v4i32, v8i16, v8f16, v8bf16, v16i8, v4f32], CCBitConvertToType<v2f64>>,
96
97  CCIfType<[v2f64], CCAssignToReg<[Q0, Q1, Q2, Q3]>>,
98  CCIfType<[f64], CCAssignToReg<[D0, D1, D2, D3, D4, D5, D6, D7]>>,
99  CCIfType<[f32], CCAssignToReg<[S0, S1, S2, S3, S4, S5, S6, S7, S8,
100                                 S9, S10, S11, S12, S13, S14, S15]>>,
101  CCDelegateTo<RetCC_ARM_APCS>
102]>;
103
104//===----------------------------------------------------------------------===//
105// ARM APCS Calling Convention for GHC
106//===----------------------------------------------------------------------===//
107
108let Entry = 1 in
109def CC_ARM_APCS_GHC : CallingConv<[
110  // Handle all vector types as either f64 or v2f64.
111  CCIfType<[v1i64, v2i32, v4i16, v4f16, v4bf16, v8i8, v2f32], CCBitConvertToType<f64>>,
112  CCIfType<[v2i64, v4i32, v8i16, v8f16, v8bf16, v16i8, v4f32], CCBitConvertToType<v2f64>>,
113
114  CCIfType<[v2f64], CCAssignToReg<[Q4, Q5]>>,
115  CCIfType<[f64], CCAssignToReg<[D8, D9, D10, D11]>>,
116  CCIfType<[f32], CCAssignToReg<[S16, S17, S18, S19, S20, S21, S22, S23]>>,
117
118  // Promote i8/i16 arguments to i32.
119  CCIfType<[i8, i16], CCPromoteToType<i32>>,
120
121  // Pass in STG registers: Base, Sp, Hp, R1, R2, R3, R4, SpLim
122  CCIfType<[i32], CCAssignToReg<[R4, R5, R6, R7, R8, R9, R10, R11]>>
123]>;
124
125//===----------------------------------------------------------------------===//
126// ARM AAPCS (EABI) Calling Convention, common parts
127//===----------------------------------------------------------------------===//
128
129def CC_ARM_AAPCS_Common : CallingConv<[
130
131  CCIfType<[i1, i8, i16], CCPromoteToType<i32>>,
132
133  // i64/f64 is passed in even pairs of GPRs
134  // i64 is 8-aligned i32 here, so we may need to eat R1 as a pad register
135  // (and the same is true for f64 if VFP is not enabled)
136  CCIfType<[i32], CCIfAlign<"8", CCAssignToRegWithShadow<[R0, R2], [R0, R1]>>>,
137  CCIfType<[i32], CCIf<"ArgFlags.getNonZeroOrigAlign() != Align(8)",
138                       CCAssignToReg<[R0, R1, R2, R3]>>>,
139
140  CCIfType<[i32], CCIfAlign<"8", CCAssignToStackWithShadow<4, 8, [R0, R1, R2, R3]>>>,
141  CCIfType<[i32], CCAssignToStackWithShadow<4, 4, [R0, R1, R2, R3]>>,
142  CCIfType<[f16, bf16, f32], CCAssignToStackWithShadow<4, 4, [Q0, Q1, Q2, Q3]>>,
143  CCIfType<[f64], CCAssignToStackWithShadow<8, 8, [Q0, Q1, Q2, Q3]>>,
144  CCIfType<[v2f64], CCIfAlign<"16",
145           CCAssignToStackWithShadow<16, 16, [Q0, Q1, Q2, Q3]>>>,
146  CCIfType<[v2f64], CCAssignToStackWithShadow<16, 8, [Q0, Q1, Q2, Q3]>>
147]>;
148
149def RetCC_ARM_AAPCS_Common : CallingConv<[
150  CCIfType<[i1, i8, i16], CCPromoteToType<i32>>,
151  CCIfType<[i32], CCAssignToReg<[R0, R1, R2, R3]>>,
152  CCIfType<[i64], CCAssignToRegWithShadow<[R0, R2], [R1, R3]>>
153]>;
154
155//===----------------------------------------------------------------------===//
156// ARM AAPCS (EABI) Calling Convention
157//===----------------------------------------------------------------------===//
158
159let Entry = 1 in
160def CC_ARM_AAPCS : CallingConv<[
161  // Handles byval parameters.
162  CCIfByVal<CCPassByVal<4, 4>>,
163
164  // The 'nest' parameter, if any, is passed in R12.
165  CCIfNest<CCAssignToReg<[R12]>>,
166
167  // Handle all vector types as either f64 or v2f64.
168  CCIfType<[v1i64, v2i32, v4i16, v4f16, v4bf16, v8i8, v2f32], CCBitConvertToType<f64>>,
169  CCIfType<[v2i64, v4i32, v8i16, v8f16, v8bf16, v16i8, v4f32], CCBitConvertToType<v2f64>>,
170
171  // Pass SwiftSelf in a callee saved register.
172  CCIfSwiftSelf<CCIfType<[i32], CCAssignToReg<[R10]>>>,
173
174  // A SwiftError is passed in R8.
175  CCIfSwiftError<CCIfType<[i32], CCAssignToReg<[R8]>>>,
176
177  CCIfType<[f64, v2f64], CCCustom<"CC_ARM_AAPCS_Custom_f64">>,
178  CCIfType<[f32], CCBitConvertToType<i32>>,
179  CCIfType<[f16, bf16], CCCustom<"CC_ARM_AAPCS_Custom_f16">>,
180  CCDelegateTo<CC_ARM_AAPCS_Common>
181]>;
182
183let Entry = 1 in
184def RetCC_ARM_AAPCS : CallingConv<[
185  // Handle all vector types as either f64 or v2f64.
186  CCIfType<[v1i64, v2i32, v4i16, v4f16, v4bf16, v8i8, v2f32], CCBitConvertToType<f64>>,
187  CCIfType<[v2i64, v4i32, v8i16, v8f16, v8bf16, v16i8, v4f32], CCBitConvertToType<v2f64>>,
188
189  // Pass SwiftSelf in a callee saved register.
190  CCIfSwiftSelf<CCIfType<[i32], CCAssignToReg<[R10]>>>,
191
192  // A SwiftError is returned in R8.
193  CCIfSwiftError<CCIfType<[i32], CCAssignToReg<[R8]>>>,
194
195  CCIfType<[f64, v2f64], CCCustom<"RetCC_ARM_AAPCS_Custom_f64">>,
196  CCIfType<[f32], CCBitConvertToType<i32>>,
197  CCIfType<[f16, bf16], CCCustom<"CC_ARM_AAPCS_Custom_f16">>,
198
199  CCDelegateTo<RetCC_ARM_AAPCS_Common>
200]>;
201
202//===----------------------------------------------------------------------===//
203// ARM AAPCS-VFP (EABI) Calling Convention
204// Also used for FastCC (when VFP2 or later is available)
205//===----------------------------------------------------------------------===//
206
207let Entry = 1 in
208def CC_ARM_AAPCS_VFP : CallingConv<[
209  // Handles byval parameters.
210  CCIfByVal<CCPassByVal<4, 4>>,
211
212  // Handle all vector types as either f64 or v2f64.
213  CCIfType<[v1i64, v2i32, v4i16, v4f16, v4bf16, v8i8, v2f32], CCBitConvertToType<f64>>,
214  CCIfType<[v2i64, v4i32, v8i16, v8f16, v8bf16, v16i8, v4f32], CCBitConvertToType<v2f64>>,
215
216  // Pass SwiftSelf in a callee saved register.
217  CCIfSwiftSelf<CCIfType<[i32], CCAssignToReg<[R10]>>>,
218
219  // A SwiftError is passed in R8.
220  CCIfSwiftError<CCIfType<[i32], CCAssignToReg<[R8]>>>,
221
222  // HFAs are passed in a contiguous block of registers, or on the stack
223  CCIfConsecutiveRegs<CCCustom<"CC_ARM_AAPCS_Custom_Aggregate">>,
224
225  CCIfType<[v2f64], CCAssignToReg<[Q0, Q1, Q2, Q3]>>,
226  CCIfType<[f64], CCAssignToReg<[D0, D1, D2, D3, D4, D5, D6, D7]>>,
227  CCIfType<[f32], CCAssignToReg<[S0, S1, S2, S3, S4, S5, S6, S7, S8,
228                                 S9, S10, S11, S12, S13, S14, S15]>>,
229  CCIfType<[f16, bf16], CCCustom<"CC_ARM_AAPCS_VFP_Custom_f16">>,
230  CCDelegateTo<CC_ARM_AAPCS_Common>
231]>;
232
233let Entry = 1 in
234def RetCC_ARM_AAPCS_VFP : CallingConv<[
235  // Handle all vector types as either f64 or v2f64.
236  CCIfType<[v1i64, v2i32, v4i16, v4f16, v4bf16, v8i8, v2f32], CCBitConvertToType<f64>>,
237  CCIfType<[v2i64, v4i32, v8i16, v8f16, v8bf16, v16i8, v4f32], CCBitConvertToType<v2f64>>,
238
239  // Pass SwiftSelf in a callee saved register.
240  CCIfSwiftSelf<CCIfType<[i32], CCAssignToReg<[R10]>>>,
241
242  // A SwiftError is returned in R8.
243  CCIfSwiftError<CCIfType<[i32], CCAssignToReg<[R8]>>>,
244
245  CCIfType<[v2f64], CCAssignToReg<[Q0, Q1, Q2, Q3]>>,
246  CCIfType<[f64], CCAssignToReg<[D0, D1, D2, D3, D4, D5, D6, D7]>>,
247  CCIfType<[f32], CCAssignToReg<[S0, S1, S2, S3, S4, S5, S6, S7, S8,
248                                 S9, S10, S11, S12, S13, S14, S15]>>,
249  CCIfType<[f16, bf16], CCCustom<"CC_ARM_AAPCS_VFP_Custom_f16">>,
250  CCDelegateTo<RetCC_ARM_AAPCS_Common>
251]>;
252
253
254// Windows Control Flow Guard checks take a single argument (the target function
255// address) and have no return value.
256let Entry = 1 in
257def CC_ARM_Win32_CFGuard_Check : CallingConv<[
258  CCIfType<[i32], CCAssignToReg<[R0]>>
259]>;
260
261
262
263//===----------------------------------------------------------------------===//
264// Callee-saved register lists.
265//===----------------------------------------------------------------------===//
266
267def CSR_NoRegs : CalleeSavedRegs<(add)>;
268def CSR_FPRegs : CalleeSavedRegs<(add (sequence "D%u", 0, 31))>;
269
270def CSR_AAPCS : CalleeSavedRegs<(add LR, R11, R10, R9, R8, R7, R6, R5, R4,
271                                     (sequence "D%u", 15, 8))>;
272
273// The Windows Control Flow Guard Check function preserves the same registers as
274// AAPCS, and also preserves all floating point registers.
275def CSR_Win_AAPCS_CFGuard_Check : CalleeSavedRegs<(add LR, R11, R10, R9, R8, R7,
276                                     R6, R5, R4, (sequence "D%u", 15, 0))>;
277
278// R8 is used to pass swifterror, remove it from CSR.
279def CSR_AAPCS_SwiftError : CalleeSavedRegs<(sub CSR_AAPCS, R8)>;
280
281// R10 is used to pass swiftself, remove it from CSR.
282def CSR_AAPCS_SwiftTail : CalleeSavedRegs<(sub CSR_AAPCS, R10)>;
283
284// The order of callee-saved registers needs to match the order we actually push
285// them in FrameLowering, because this order is what's used by
286// PrologEpilogInserter to allocate frame index slots. So when R7 is the frame
287// pointer, we use this AAPCS alternative.
288def CSR_AAPCS_SplitPush : CalleeSavedRegs<(add LR, R7, R6, R5, R4,
289                                               R11, R10, R9, R8,
290                                               (sequence "D%u", 15, 8))>;
291
292// R8 is used to pass swifterror, remove it from CSR.
293def CSR_AAPCS_SplitPush_SwiftError : CalleeSavedRegs<(sub CSR_AAPCS_SplitPush,
294                                                      R8)>;
295
296// R10 is used to pass swifterror, remove it from CSR.
297def CSR_AAPCS_SplitPush_SwiftTail : CalleeSavedRegs<(sub CSR_AAPCS_SplitPush,
298                                                     R10)>;
299
300// Constructors and destructors return 'this' in the ARM C++ ABI; since 'this'
301// and the pointer return value are both passed in R0 in these cases, this can
302// be partially modelled by treating R0 as a callee-saved register
303// Only the resulting RegMask is used; the SaveList is ignored
304def CSR_AAPCS_ThisReturn : CalleeSavedRegs<(add LR, R11, R10, R9, R8, R7, R6,
305                                            R5, R4, (sequence "D%u", 15, 8),
306                                            R0)>;
307
308// iOS ABI deviates from ARM standard ABI. R9 is not a callee-saved register.
309// Also save R7-R4 first to match the stack frame fixed spill areas.
310def CSR_iOS : CalleeSavedRegs<(add LR, R7, R6, R5, R4, (sub CSR_AAPCS, R9))>;
311
312// R8 is used to pass swifterror, remove it from CSR.
313def CSR_iOS_SwiftError : CalleeSavedRegs<(sub CSR_iOS, R8)>;
314
315// R10 is used to pass swiftself, remove it from CSR.
316def CSR_iOS_SwiftTail : CalleeSavedRegs<(sub CSR_iOS, R10)>;
317
318def CSR_iOS_ThisReturn : CalleeSavedRegs<(add LR, R7, R6, R5, R4,
319                                         (sub CSR_AAPCS_ThisReturn, R9))>;
320
321def CSR_iOS_TLSCall
322    : CalleeSavedRegs<(add LR, SP, (sub(sequence "R%u", 12, 1), R9, R12),
323                      (sequence "D%u", 31, 0))>;
324
325// C++ TLS access function saves all registers except SP. Try to match
326// the order of CSRs in CSR_iOS.
327def CSR_iOS_CXX_TLS : CalleeSavedRegs<(add CSR_iOS, (sequence "R%u", 12, 1),
328                                           (sequence "D%u", 31, 0))>;
329
330// CSRs that are handled by prologue, epilogue.
331def CSR_iOS_CXX_TLS_PE : CalleeSavedRegs<(add LR, R12, R11, R7, R5, R4)>;
332
333// CSRs that are handled explicitly via copies.
334def CSR_iOS_CXX_TLS_ViaCopy : CalleeSavedRegs<(sub CSR_iOS_CXX_TLS,
335                                                   CSR_iOS_CXX_TLS_PE)>;
336
337// The "interrupt" attribute is used to generate code that is acceptable in
338// exception-handlers of various kinds. It makes us use a different return
339// instruction (handled elsewhere) and affects which registers we must return to
340// our "caller" in the same state as we receive them.
341
342// For most interrupts, all registers except SP and LR are shared with
343// user-space. We mark LR to be saved anyway, since this is what the ARM backend
344// generally does rather than tracking its liveness as a normal register.
345def CSR_GenericInt : CalleeSavedRegs<(add LR, (sequence "R%u", 12, 0))>;
346
347// The fast interrupt handlers have more private state and get their own copies
348// of R8-R12, in addition to SP and LR. As before, mark LR for saving too.
349
350// FIXME: we mark R11 as callee-saved since it's often the frame-pointer, and
351// current frame lowering expects to encounter it while processing callee-saved
352// registers.
353def CSR_FIQ : CalleeSavedRegs<(add LR, R11, (sequence "R%u", 7, 0))>;
354
355
356