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1//===-- MipsCallingConv.td - Calling Conventions for Mips --*- 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 Mips architecture.
9//===----------------------------------------------------------------------===//
10
11/// CCIfSubtarget - Match if the current subtarget has a feature F.
12class CCIfSubtarget<string F, CCAction A, string Invert = "">
13    : CCIf<!strconcat(Invert,
14                      "static_cast<const MipsSubtarget&>"
15			"(State.getMachineFunction().getSubtarget()).",
16                      F),
17           A>;
18
19// The inverse of CCIfSubtarget
20class CCIfSubtargetNot<string F, CCAction A> : CCIfSubtarget<F, A, "!">;
21
22/// Match if the original argument (before lowering) was a float.
23/// For example, this is true for i32's that were lowered from soft-float.
24class CCIfOrigArgWasNotFloat<CCAction A>
25    : CCIf<"!static_cast<MipsCCState *>(&State)->WasOriginalArgFloat(ValNo)",
26           A>;
27
28/// Match if the original argument (before lowering) was a 128-bit float (i.e.
29/// long double).
30class CCIfOrigArgWasF128<CCAction A>
31    : CCIf<"static_cast<MipsCCState *>(&State)->WasOriginalArgF128(ValNo)", A>;
32
33/// Match if this specific argument is a vararg.
34/// This is slightly different fro CCIfIsVarArg which matches if any argument is
35/// a vararg.
36class CCIfArgIsVarArg<CCAction A>
37    : CCIf<"!static_cast<MipsCCState *>(&State)->IsCallOperandFixed(ValNo)", A>;
38
39/// Match if the return was a floating point vector.
40class CCIfOrigArgWasNotVectorFloat<CCAction A>
41    : CCIf<"!static_cast<MipsCCState *>(&State)"
42                "->WasOriginalRetVectorFloat(ValNo)", A>;
43
44/// Match if the special calling conv is the specified value.
45class CCIfSpecialCallingConv<string CC, CCAction A>
46    : CCIf<"static_cast<MipsCCState *>(&State)->getSpecialCallingConv() == "
47               "MipsCCState::" # CC, A>;
48
49// For soft-float, f128 values are returned in A0_64 rather than V1_64.
50def RetCC_F128SoftFloat : CallingConv<[
51  CCAssignToReg<[V0_64, A0_64]>
52]>;
53
54// For hard-float, f128 values are returned as a pair of f64's rather than a
55// pair of i64's.
56def RetCC_F128HardFloat : CallingConv<[
57  CCBitConvertToType<f64>,
58
59  // Contrary to the ABI documentation, a struct containing a long double is
60  // returned in $f0, and $f1 instead of the usual $f0, and $f2. This is to
61  // match the de facto ABI as implemented by GCC.
62  CCIfInReg<CCAssignToReg<[D0_64, D1_64]>>,
63
64  CCAssignToReg<[D0_64, D2_64]>
65]>;
66
67// Handle F128 specially since we can't identify the original type during the
68// tablegen-erated code.
69def RetCC_F128 : CallingConv<[
70  CCIfSubtarget<"useSoftFloat()",
71      CCIfType<[i64], CCDelegateTo<RetCC_F128SoftFloat>>>,
72  CCIfSubtargetNot<"useSoftFloat()",
73      CCIfType<[i64], CCDelegateTo<RetCC_F128HardFloat>>>
74]>;
75
76//===----------------------------------------------------------------------===//
77// Mips O32 Calling Convention
78//===----------------------------------------------------------------------===//
79
80def CC_MipsO32 : CallingConv<[
81  // Promote i8/i16 arguments to i32.
82  CCIfType<[i1, i8, i16], CCPromoteToType<i32>>,
83
84  // Integer values get stored in stack slots that are 4 bytes in
85  // size and 4-byte aligned.
86  CCIfType<[i32, f32], CCAssignToStack<4, 4>>,
87
88  // Integer values get stored in stack slots that are 8 bytes in
89  // size and 8-byte aligned.
90  CCIfType<[f64], CCAssignToStack<8, 8>>
91]>;
92
93// Only the return rules are defined here for O32. The rules for argument
94// passing are defined in MipsISelLowering.cpp.
95def RetCC_MipsO32 : CallingConv<[
96  // Promote i1/i8/i16 return values to i32.
97  CCIfType<[i1, i8, i16], CCPromoteToType<i32>>,
98
99  // i32 are returned in registers V0, V1, A0, A1, unless the original return
100  // type was a vector of floats.
101  CCIfOrigArgWasNotVectorFloat<CCIfType<[i32],
102                                        CCAssignToReg<[V0, V1, A0, A1]>>>,
103
104  // f32 are returned in registers F0, F2
105  CCIfType<[f32], CCAssignToReg<[F0, F2]>>,
106
107  // f64 arguments are returned in D0_64 and D2_64 in FP64bit mode or
108  // in D0 and D1 in FP32bit mode.
109  CCIfType<[f64], CCIfSubtarget<"isFP64bit()", CCAssignToReg<[D0_64, D2_64]>>>,
110  CCIfType<[f64], CCIfSubtargetNot<"isFP64bit()", CCAssignToReg<[D0, D1]>>>
111]>;
112
113def CC_MipsO32_FP32 : CustomCallingConv;
114def CC_MipsO32_FP64 : CustomCallingConv;
115
116def CC_MipsO32_FP : CallingConv<[
117  CCIfSubtargetNot<"isFP64bit()", CCDelegateTo<CC_MipsO32_FP32>>,
118  CCIfSubtarget<"isFP64bit()", CCDelegateTo<CC_MipsO32_FP64>>
119]>;
120
121//===----------------------------------------------------------------------===//
122// Mips N32/64 Calling Convention
123//===----------------------------------------------------------------------===//
124
125def CC_MipsN_SoftFloat : CallingConv<[
126  CCAssignToRegWithShadow<[A0, A1, A2, A3,
127                           T0, T1, T2, T3],
128                          [D12_64, D13_64, D14_64, D15_64,
129                           D16_64, D17_64, D18_64, D19_64]>,
130  CCAssignToStack<4, 8>
131]>;
132
133def CC_MipsN : CallingConv<[
134  CCIfType<[i8, i16, i32, i64],
135      CCIfSubtargetNot<"isLittle()",
136          CCIfInReg<CCPromoteToUpperBitsInType<i64>>>>,
137
138  // All integers (except soft-float integers) are promoted to 64-bit.
139  CCIfType<[i8, i16, i32], CCIfOrigArgWasNotFloat<CCPromoteToType<i64>>>,
140
141  // The only i32's we have left are soft-float arguments.
142  CCIfSubtarget<"useSoftFloat()", CCIfType<[i32],
143                CCDelegateTo<CC_MipsN_SoftFloat>>>,
144
145  // Integer arguments are passed in integer registers.
146  CCIfType<[i64], CCAssignToRegWithShadow<[A0_64, A1_64, A2_64, A3_64,
147                                           T0_64, T1_64, T2_64, T3_64],
148                                          [D12_64, D13_64, D14_64, D15_64,
149                                           D16_64, D17_64, D18_64, D19_64]>>,
150
151  // f32 arguments are passed in single precision FP registers.
152  CCIfType<[f32], CCAssignToRegWithShadow<[F12, F13, F14, F15,
153                                           F16, F17, F18, F19],
154                                          [A0_64, A1_64, A2_64, A3_64,
155                                           T0_64, T1_64, T2_64, T3_64]>>,
156
157  // f64 arguments are passed in double precision FP registers.
158  CCIfType<[f64], CCAssignToRegWithShadow<[D12_64, D13_64, D14_64, D15_64,
159                                           D16_64, D17_64, D18_64, D19_64],
160                                          [A0_64, A1_64, A2_64, A3_64,
161                                           T0_64, T1_64, T2_64, T3_64]>>,
162
163  // All stack parameter slots become 64-bit doublewords and are 8-byte aligned.
164  CCIfType<[f32], CCAssignToStack<4, 8>>,
165  CCIfType<[i64, f64], CCAssignToStack<8, 8>>
166]>;
167
168// N32/64 variable arguments.
169// All arguments are passed in integer registers.
170def CC_MipsN_VarArg : CallingConv<[
171  CCIfType<[i8, i16, i32, i64],
172      CCIfSubtargetNot<"isLittle()",
173          CCIfInReg<CCPromoteToUpperBitsInType<i64>>>>,
174
175  // All integers are promoted to 64-bit.
176  CCIfType<[i8, i16, i32], CCPromoteToType<i64>>,
177
178  CCIfType<[f32], CCAssignToReg<[A0, A1, A2, A3, T0, T1, T2, T3]>>,
179
180  CCIfType<[i64, f64], CCAssignToReg<[A0_64, A1_64, A2_64, A3_64,
181                                      T0_64, T1_64, T2_64, T3_64]>>,
182
183  // All stack parameter slots become 64-bit doublewords and are 8-byte aligned.
184  CCIfType<[f32], CCAssignToStack<4, 8>>,
185  CCIfType<[i64, f64], CCAssignToStack<8, 8>>
186]>;
187
188def RetCC_MipsN : CallingConv<[
189  // f128 needs to be handled similarly to f32 and f64. However, f128 is not
190  // legal and is lowered to i128 which is further lowered to a pair of i64's.
191  // This presents us with a problem for the calling convention since hard-float
192  // still needs to pass them in FPU registers, and soft-float needs to use $v0,
193  // and $a0 instead of the usual $v0, and $v1. We therefore resort to a
194  // pre-analyze (see PreAnalyzeReturnForF128()) step to pass information on
195  // whether the result was originally an f128 into the tablegen-erated code.
196  //
197  // f128 should only occur for the N64 ABI where long double is 128-bit. On
198  // N32, long double is equivalent to double.
199  CCIfType<[i64], CCIfOrigArgWasF128<CCDelegateTo<RetCC_F128>>>,
200
201  // Aggregate returns are positioned at the lowest address in the slot for
202  // both little and big-endian targets. When passing in registers, this
203  // requires that big-endian targets shift the value into the upper bits.
204  CCIfSubtarget<"isLittle()",
205      CCIfType<[i8, i16, i32, i64], CCIfInReg<CCPromoteToType<i64>>>>,
206  CCIfSubtargetNot<"isLittle()",
207      CCIfType<[i8, i16, i32, i64],
208          CCIfInReg<CCPromoteToUpperBitsInType<i64>>>>,
209
210  // i64 are returned in registers V0_64, V1_64
211  CCIfType<[i64], CCAssignToReg<[V0_64, V1_64]>>,
212
213  // f32 are returned in registers F0, F2
214  CCIfType<[f32], CCAssignToReg<[F0, F2]>>,
215
216  // f64 are returned in registers D0, D2
217  CCIfType<[f64], CCAssignToReg<[D0_64, D2_64]>>
218]>;
219
220//===----------------------------------------------------------------------===//
221// Mips FastCC Calling Convention
222//===----------------------------------------------------------------------===//
223def CC_MipsO32_FastCC : CallingConv<[
224  // f64 arguments are passed in double-precision floating pointer registers.
225  CCIfType<[f64], CCIfSubtargetNot<"isFP64bit()",
226                                   CCAssignToReg<[D0, D1, D2, D3, D4, D5, D6,
227                                                  D7, D8, D9]>>>,
228  CCIfType<[f64], CCIfSubtarget<"isFP64bit()", CCIfSubtarget<"useOddSPReg()",
229                                CCAssignToReg<[D0_64, D1_64, D2_64, D3_64,
230                                               D4_64, D5_64, D6_64, D7_64,
231                                               D8_64, D9_64, D10_64, D11_64,
232                                               D12_64, D13_64, D14_64, D15_64,
233                                               D16_64, D17_64, D18_64,
234                                               D19_64]>>>>,
235  CCIfType<[f64], CCIfSubtarget<"isFP64bit()", CCIfSubtarget<"noOddSPReg()",
236                                CCAssignToReg<[D0_64, D2_64, D4_64, D6_64,
237                                               D8_64, D10_64, D12_64, D14_64,
238                                               D16_64, D18_64]>>>>,
239
240  // Stack parameter slots for f64 are 64-bit doublewords and 8-byte aligned.
241  CCIfType<[f64], CCAssignToStack<8, 8>>
242]>;
243
244def CC_MipsN_FastCC : CallingConv<[
245  // Integer arguments are passed in integer registers.
246  CCIfType<[i64], CCAssignToReg<[A0_64, A1_64, A2_64, A3_64, T0_64, T1_64,
247                                 T2_64, T3_64, T4_64, T5_64, T6_64, T7_64,
248                                 T8_64, V1_64]>>,
249
250  // f64 arguments are passed in double-precision floating pointer registers.
251  CCIfType<[f64], CCAssignToReg<[D0_64, D1_64, D2_64, D3_64, D4_64, D5_64,
252                                 D6_64, D7_64, D8_64, D9_64, D10_64, D11_64,
253                                 D12_64, D13_64, D14_64, D15_64, D16_64, D17_64,
254                                 D18_64, D19_64]>>,
255
256  // Stack parameter slots for i64 and f64 are 64-bit doublewords and
257  // 8-byte aligned.
258  CCIfType<[i64, f64], CCAssignToStack<8, 8>>
259]>;
260
261def CC_Mips_FastCC : CallingConv<[
262  // Handles byval parameters.
263  CCIfByVal<CCPassByVal<4, 4>>,
264
265  // Promote i8/i16 arguments to i32.
266  CCIfType<[i8, i16], CCPromoteToType<i32>>,
267
268  // Integer arguments are passed in integer registers. All scratch registers,
269  // except for AT, V0 and T9, are available to be used as argument registers.
270  CCIfType<[i32], CCIfSubtargetNot<"isTargetNaCl()",
271      CCAssignToReg<[A0, A1, A2, A3, T0, T1, T2, T3, T4, T5, T6, T7, T8, V1]>>>,
272
273  // In NaCl, T6, T7 and T8 are reserved and not available as argument
274  // registers for fastcc.  T6 contains the mask for sandboxing control flow
275  // (indirect jumps and calls).  T7 contains the mask for sandboxing memory
276  // accesses (loads and stores).  T8 contains the thread pointer.
277  CCIfType<[i32], CCIfSubtarget<"isTargetNaCl()",
278      CCAssignToReg<[A0, A1, A2, A3, T0, T1, T2, T3, T4, T5, V1]>>>,
279
280  // f32 arguments are passed in single-precision floating pointer registers.
281  CCIfType<[f32], CCIfSubtarget<"useOddSPReg()",
282      CCAssignToReg<[F0, F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, F12, F13,
283                     F14, F15, F16, F17, F18, F19]>>>,
284
285  // Don't use odd numbered single-precision registers for -mno-odd-spreg.
286  CCIfType<[f32], CCIfSubtarget<"noOddSPReg()",
287      CCAssignToReg<[F0, F2, F4, F6, F8, F10, F12, F14, F16, F18]>>>,
288
289  // Stack parameter slots for i32 and f32 are 32-bit words and 4-byte aligned.
290  CCIfType<[i32, f32], CCAssignToStack<4, 4>>,
291
292  CCIfSubtarget<"isABI_O32()", CCDelegateTo<CC_MipsO32_FastCC>>,
293  CCDelegateTo<CC_MipsN_FastCC>
294]>;
295
296//===----------------------------------------------------------------------===//
297// Mips Calling Convention Dispatch
298//===----------------------------------------------------------------------===//
299
300def RetCC_Mips : CallingConv<[
301  CCIfSubtarget<"isABI_N32()", CCDelegateTo<RetCC_MipsN>>,
302  CCIfSubtarget<"isABI_N64()", CCDelegateTo<RetCC_MipsN>>,
303  CCDelegateTo<RetCC_MipsO32>
304]>;
305
306def CC_Mips_ByVal : CallingConv<[
307  CCIfSubtarget<"isABI_O32()", CCIfByVal<CCPassByVal<4, 4>>>,
308  CCIfByVal<CCPassByVal<8, 8>>
309]>;
310
311def CC_Mips16RetHelper : CallingConv<[
312  CCIfByVal<CCDelegateTo<CC_Mips_ByVal>>,
313
314  // Integer arguments are passed in integer registers.
315  CCIfType<[i32], CCAssignToReg<[V0, V1, A0, A1]>>
316]>;
317
318def CC_Mips_FixedArg : CallingConv<[
319  // Mips16 needs special handling on some functions.
320  CCIf<"State.getCallingConv() != CallingConv::Fast",
321      CCIfSpecialCallingConv<"Mips16RetHelperConv",
322           CCDelegateTo<CC_Mips16RetHelper>>>,
323
324  CCIfByVal<CCDelegateTo<CC_Mips_ByVal>>,
325
326  // f128 needs to be handled similarly to f32 and f64 on hard-float. However,
327  // f128 is not legal and is lowered to i128 which is further lowered to a pair
328  // of i64's.
329  // This presents us with a problem for the calling convention since hard-float
330  // still needs to pass them in FPU registers. We therefore resort to a
331  // pre-analyze (see PreAnalyzeFormalArgsForF128()) step to pass information on
332  // whether the argument was originally an f128 into the tablegen-erated code.
333  //
334  // f128 should only occur for the N64 ABI where long double is 128-bit. On
335  // N32, long double is equivalent to double.
336  CCIfType<[i64],
337      CCIfSubtargetNot<"useSoftFloat()",
338          CCIfOrigArgWasF128<CCBitConvertToType<f64>>>>,
339
340  CCIfCC<"CallingConv::Fast", CCDelegateTo<CC_Mips_FastCC>>,
341
342  CCIfSubtarget<"isABI_O32()", CCDelegateTo<CC_MipsO32_FP>>,
343  CCDelegateTo<CC_MipsN>
344]>;
345
346def CC_Mips_VarArg : CallingConv<[
347  CCIfByVal<CCDelegateTo<CC_Mips_ByVal>>,
348
349  CCIfSubtarget<"isABI_O32()", CCDelegateTo<CC_MipsO32_FP>>,
350  CCDelegateTo<CC_MipsN_VarArg>
351]>;
352
353def CC_Mips : CallingConv<[
354  CCIfVarArg<CCIfArgIsVarArg<CCDelegateTo<CC_Mips_VarArg>>>,
355  CCDelegateTo<CC_Mips_FixedArg>
356]>;
357
358//===----------------------------------------------------------------------===//
359// Callee-saved register lists.
360//===----------------------------------------------------------------------===//
361
362def CSR_SingleFloatOnly : CalleeSavedRegs<(add (sequence "F%u", 31, 20), RA, FP,
363                                               (sequence "S%u", 7, 0))>;
364
365def CSR_O32_FPXX : CalleeSavedRegs<(add (sequence "D%u", 15, 10), RA, FP,
366                                        (sequence "S%u", 7, 0))> {
367  let OtherPreserved = (add (decimate (sequence "F%u", 30, 20), 2));
368}
369
370def CSR_O32 : CalleeSavedRegs<(add (sequence "D%u", 15, 10), RA, FP,
371                                   (sequence "S%u", 7, 0))>;
372
373def CSR_O32_FP64 :
374  CalleeSavedRegs<(add (decimate (sequence "D%u_64", 30, 20), 2), RA, FP,
375                       (sequence "S%u", 7, 0))>;
376
377def CSR_N32 : CalleeSavedRegs<(add D20_64, D22_64, D24_64, D26_64, D28_64,
378                                   D30_64, RA_64, FP_64, GP_64,
379                                   (sequence "S%u_64", 7, 0))>;
380
381def CSR_N64 : CalleeSavedRegs<(add (sequence "D%u_64", 31, 24), RA_64, FP_64,
382                                   GP_64, (sequence "S%u_64", 7, 0))>;
383
384def CSR_Mips16RetHelper :
385  CalleeSavedRegs<(add V0, V1, FP,
386                   (sequence "A%u", 3, 0), (sequence "S%u", 7, 0),
387                   (sequence "D%u", 15, 10))>;
388
389def CSR_Interrupt_32R6 : CalleeSavedRegs<(add (sequence "A%u", 3, 0),
390                                              (sequence "S%u", 7, 0),
391                                              (sequence "V%u", 1, 0),
392                                              (sequence "T%u", 9, 0),
393                                              RA, FP, GP, AT)>;
394
395def CSR_Interrupt_32 : CalleeSavedRegs<(add (sequence "A%u", 3, 0),
396                                            (sequence "S%u", 7, 0),
397                                            (sequence "V%u", 1, 0),
398                                            (sequence "T%u", 9, 0),
399                                            RA, FP, GP, AT, LO0, HI0)>;
400
401def CSR_Interrupt_64R6 : CalleeSavedRegs<(add (sequence "A%u_64", 3, 0),
402                                              (sequence "V%u_64", 1, 0),
403                                              (sequence "S%u_64", 7, 0),
404                                              (sequence "T%u_64", 9, 0),
405                                              RA_64, FP_64, GP_64, AT_64)>;
406
407def CSR_Interrupt_64 : CalleeSavedRegs<(add (sequence "A%u_64", 3, 0),
408                                            (sequence "S%u_64", 7, 0),
409                                            (sequence "T%u_64", 9, 0),
410                                            (sequence "V%u_64", 1, 0),
411                                            RA_64, FP_64, GP_64, AT_64,
412                                            LO0_64, HI0_64)>;
413