aboutsummaryrefslogtreecommitdiff
path: root/src/cmd/compile/internal/ssa/gen/RISCV64Ops.go
blob: 8a3fdf75f7838ef41d3f83b47adde44a70c3f64a (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
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build ignore
// +build ignore

package main

import (
	"fmt"
)

// Notes:
//  - Boolean types occupy the entire register. 0=false, 1=true.

// Suffixes encode the bit width of various instructions:
//
// D (double word) = 64 bit int
// W (word)        = 32 bit int
// H (half word)   = 16 bit int
// B (byte)        = 8 bit int
// S (single)      = 32 bit float
// D (double)      = 64 bit float
// L               = 64 bit int, used when the opcode starts with F

const (
	riscv64REG_G    = 27
	riscv64REG_CTXT = 20
	riscv64REG_LR   = 1
	riscv64REG_SP   = 2
	riscv64REG_TP   = 4
	riscv64REG_TMP  = 31
	riscv64REG_ZERO = 0
)

func riscv64RegName(r int) string {
	switch {
	case r == riscv64REG_G:
		return "g"
	case r == riscv64REG_SP:
		return "SP"
	case 0 <= r && r <= 31:
		return fmt.Sprintf("X%d", r)
	case 32 <= r && r <= 63:
		return fmt.Sprintf("F%d", r-32)
	default:
		panic(fmt.Sprintf("unknown register %d", r))
	}
}

func init() {
	var regNamesRISCV64 []string
	var gpMask, fpMask, gpgMask, gpspMask, gpspsbMask, gpspsbgMask regMask
	regNamed := make(map[string]regMask)

	// Build the list of register names, creating an appropriately indexed
	// regMask for the gp and fp registers as we go.
	//
	// If name is specified, use it rather than the riscv reg number.
	addreg := func(r int, name string) regMask {
		mask := regMask(1) << uint(len(regNamesRISCV64))
		if name == "" {
			name = riscv64RegName(r)
		}
		regNamesRISCV64 = append(regNamesRISCV64, name)
		regNamed[name] = mask
		return mask
	}

	// General purpose registers.
	for r := 0; r <= 31; r++ {
		if r == riscv64REG_LR {
			// LR is not used by regalloc, so we skip it to leave
			// room for pseudo-register SB.
			continue
		}

		mask := addreg(r, "")

		// Add general purpose registers to gpMask.
		switch r {
		// ZERO, TP and TMP are not in any gp mask.
		case riscv64REG_ZERO, riscv64REG_TP, riscv64REG_TMP:
		case riscv64REG_G:
			gpgMask |= mask
			gpspsbgMask |= mask
		case riscv64REG_SP:
			gpspMask |= mask
			gpspsbMask |= mask
			gpspsbgMask |= mask
		default:
			gpMask |= mask
			gpgMask |= mask
			gpspMask |= mask
			gpspsbMask |= mask
			gpspsbgMask |= mask
		}
	}

	// Floating pointer registers.
	for r := 32; r <= 63; r++ {
		mask := addreg(r, "")
		fpMask |= mask
	}

	// Pseudo-register: SB
	mask := addreg(-1, "SB")
	gpspsbMask |= mask
	gpspsbgMask |= mask

	if len(regNamesRISCV64) > 64 {
		// regMask is only 64 bits.
		panic("Too many RISCV64 registers")
	}

	regCtxt := regNamed["X20"]
	callerSave := gpMask | fpMask | regNamed["g"]

	var (
		gpstore  = regInfo{inputs: []regMask{gpspsbMask, gpspMask, 0}} // SB in first input so we can load from a global, but not in second to avoid using SB as a temporary register
		gpstore0 = regInfo{inputs: []regMask{gpspsbMask}}
		gp01     = regInfo{outputs: []regMask{gpMask}}
		gp11     = regInfo{inputs: []regMask{gpMask}, outputs: []regMask{gpMask}}
		gp21     = regInfo{inputs: []regMask{gpMask, gpMask}, outputs: []regMask{gpMask}}
		gp22     = regInfo{inputs: []regMask{gpMask, gpMask}, outputs: []regMask{gpMask, gpMask}}
		gpload   = regInfo{inputs: []regMask{gpspsbMask, 0}, outputs: []regMask{gpMask}}
		gp11sb   = regInfo{inputs: []regMask{gpspsbMask}, outputs: []regMask{gpMask}}
		gpxchg   = regInfo{inputs: []regMask{gpspsbgMask, gpgMask}, outputs: []regMask{gpMask}}
		gpcas    = regInfo{inputs: []regMask{gpspsbgMask, gpgMask, gpgMask}, outputs: []regMask{gpMask}}
		gpatomic = regInfo{inputs: []regMask{gpspsbgMask, gpgMask}}

		fp11    = regInfo{inputs: []regMask{fpMask}, outputs: []regMask{fpMask}}
		fp21    = regInfo{inputs: []regMask{fpMask, fpMask}, outputs: []regMask{fpMask}}
		fp31    = regInfo{inputs: []regMask{fpMask, fpMask, fpMask}, outputs: []regMask{fpMask}}
		gpfp    = regInfo{inputs: []regMask{gpMask}, outputs: []regMask{fpMask}}
		fpgp    = regInfo{inputs: []regMask{fpMask}, outputs: []regMask{gpMask}}
		fpstore = regInfo{inputs: []regMask{gpspsbMask, fpMask, 0}}
		fpload  = regInfo{inputs: []regMask{gpspsbMask, 0}, outputs: []regMask{fpMask}}
		fp2gp   = regInfo{inputs: []regMask{fpMask, fpMask}, outputs: []regMask{gpMask}}

		call        = regInfo{clobbers: callerSave}
		callClosure = regInfo{inputs: []regMask{gpspMask, regCtxt, 0}, clobbers: callerSave}
		callInter   = regInfo{inputs: []regMask{gpMask}, clobbers: callerSave}
	)

	RISCV64ops := []opData{
		{name: "ADD", argLength: 2, reg: gp21, asm: "ADD", commutative: true}, // arg0 + arg1
		{name: "ADDI", argLength: 1, reg: gp11sb, asm: "ADDI", aux: "Int64"},  // arg0 + auxint
		{name: "ADDIW", argLength: 1, reg: gp11, asm: "ADDIW", aux: "Int64"},  // 32 low bits of arg0 + auxint, sign extended to 64 bits
		{name: "NEG", argLength: 1, reg: gp11, asm: "NEG"},                    // -arg0
		{name: "NEGW", argLength: 1, reg: gp11, asm: "NEGW"},                  // -arg0 of 32 bits, sign extended to 64 bits
		{name: "SUB", argLength: 2, reg: gp21, asm: "SUB"},                    // arg0 - arg1
		{name: "SUBW", argLength: 2, reg: gp21, asm: "SUBW"},                  // 32 low bits of arg 0 - 32 low bits of arg 1, sign extended to 64 bits

		// M extension. H means high (i.e., it returns the top bits of
		// the result). U means unsigned. W means word (i.e., 32-bit).
		{name: "MUL", argLength: 2, reg: gp21, asm: "MUL", commutative: true, typ: "Int64"}, // arg0 * arg1
		{name: "MULW", argLength: 2, reg: gp21, asm: "MULW", commutative: true, typ: "Int32"},
		{name: "MULH", argLength: 2, reg: gp21, asm: "MULH", commutative: true, typ: "Int64"},
		{name: "MULHU", argLength: 2, reg: gp21, asm: "MULHU", commutative: true, typ: "UInt64"},
		{name: "LoweredMuluhilo", argLength: 2, reg: gp22, resultNotInArgs: true}, // arg0 * arg1, return (hi, lo)
		{name: "LoweredMuluover", argLength: 2, reg: gp22, resultNotInArgs: true}, // arg0 * arg1, return (64 bits of arg0*arg1, overflow)

		{name: "DIV", argLength: 2, reg: gp21, asm: "DIV", typ: "Int64"}, // arg0 / arg1
		{name: "DIVU", argLength: 2, reg: gp21, asm: "DIVU", typ: "UInt64"},
		{name: "DIVW", argLength: 2, reg: gp21, asm: "DIVW", typ: "Int32"},
		{name: "DIVUW", argLength: 2, reg: gp21, asm: "DIVUW", typ: "UInt32"},
		{name: "REM", argLength: 2, reg: gp21, asm: "REM", typ: "Int64"}, // arg0 % arg1
		{name: "REMU", argLength: 2, reg: gp21, asm: "REMU", typ: "UInt64"},
		{name: "REMW", argLength: 2, reg: gp21, asm: "REMW", typ: "Int32"},
		{name: "REMUW", argLength: 2, reg: gp21, asm: "REMUW", typ: "UInt32"},

		{name: "MOVaddr", argLength: 1, reg: gp11sb, asm: "MOV", aux: "SymOff", rematerializeable: true, symEffect: "RdWr"}, // arg0 + auxint + offset encoded in aux
		// auxint+aux == add auxint and the offset of the symbol in aux (if any) to the effective address

		{name: "MOVDconst", reg: gp01, asm: "MOV", typ: "UInt64", aux: "Int64", rematerializeable: true}, // auxint

		// Loads: load <size> bits from arg0+auxint+aux and extend to 64 bits; arg1=mem
		{name: "MOVBload", argLength: 2, reg: gpload, asm: "MOVB", aux: "SymOff", typ: "Int8", faultOnNilArg0: true, symEffect: "Read"},     //  8 bits, sign extend
		{name: "MOVHload", argLength: 2, reg: gpload, asm: "MOVH", aux: "SymOff", typ: "Int16", faultOnNilArg0: true, symEffect: "Read"},    // 16 bits, sign extend
		{name: "MOVWload", argLength: 2, reg: gpload, asm: "MOVW", aux: "SymOff", typ: "Int32", faultOnNilArg0: true, symEffect: "Read"},    // 32 bits, sign extend
		{name: "MOVDload", argLength: 2, reg: gpload, asm: "MOV", aux: "SymOff", typ: "Int64", faultOnNilArg0: true, symEffect: "Read"},     // 64 bits
		{name: "MOVBUload", argLength: 2, reg: gpload, asm: "MOVBU", aux: "SymOff", typ: "UInt8", faultOnNilArg0: true, symEffect: "Read"},  //  8 bits, zero extend
		{name: "MOVHUload", argLength: 2, reg: gpload, asm: "MOVHU", aux: "SymOff", typ: "UInt16", faultOnNilArg0: true, symEffect: "Read"}, // 16 bits, zero extend
		{name: "MOVWUload", argLength: 2, reg: gpload, asm: "MOVWU", aux: "SymOff", typ: "UInt32", faultOnNilArg0: true, symEffect: "Read"}, // 32 bits, zero extend

		// Stores: store <size> lowest bits in arg1 to arg0+auxint+aux; arg2=mem
		{name: "MOVBstore", argLength: 3, reg: gpstore, asm: "MOVB", aux: "SymOff", typ: "Mem", faultOnNilArg0: true, symEffect: "Write"}, //  8 bits
		{name: "MOVHstore", argLength: 3, reg: gpstore, asm: "MOVH", aux: "SymOff", typ: "Mem", faultOnNilArg0: true, symEffect: "Write"}, // 16 bits
		{name: "MOVWstore", argLength: 3, reg: gpstore, asm: "MOVW", aux: "SymOff", typ: "Mem", faultOnNilArg0: true, symEffect: "Write"}, // 32 bits
		{name: "MOVDstore", argLength: 3, reg: gpstore, asm: "MOV", aux: "SymOff", typ: "Mem", faultOnNilArg0: true, symEffect: "Write"},  // 64 bits

		// Stores: store <size> of zero in arg0+auxint+aux; arg1=mem
		{name: "MOVBstorezero", argLength: 2, reg: gpstore0, aux: "SymOff", asm: "MOVB", typ: "Mem", faultOnNilArg0: true, symEffect: "Write"}, //  8 bits
		{name: "MOVHstorezero", argLength: 2, reg: gpstore0, aux: "SymOff", asm: "MOVH", typ: "Mem", faultOnNilArg0: true, symEffect: "Write"}, // 16 bits
		{name: "MOVWstorezero", argLength: 2, reg: gpstore0, aux: "SymOff", asm: "MOVW", typ: "Mem", faultOnNilArg0: true, symEffect: "Write"}, // 32 bits
		{name: "MOVDstorezero", argLength: 2, reg: gpstore0, aux: "SymOff", asm: "MOV", typ: "Mem", faultOnNilArg0: true, symEffect: "Write"},  // 64 bits

		// Conversions
		{name: "MOVBreg", argLength: 1, reg: gp11, asm: "MOVB"},   // move from arg0, sign-extended from byte
		{name: "MOVHreg", argLength: 1, reg: gp11, asm: "MOVH"},   // move from arg0, sign-extended from half
		{name: "MOVWreg", argLength: 1, reg: gp11, asm: "MOVW"},   // move from arg0, sign-extended from word
		{name: "MOVDreg", argLength: 1, reg: gp11, asm: "MOV"},    // move from arg0
		{name: "MOVBUreg", argLength: 1, reg: gp11, asm: "MOVBU"}, // move from arg0, unsign-extended from byte
		{name: "MOVHUreg", argLength: 1, reg: gp11, asm: "MOVHU"}, // move from arg0, unsign-extended from half
		{name: "MOVWUreg", argLength: 1, reg: gp11, asm: "MOVWU"}, // move from arg0, unsign-extended from word

		{name: "MOVDnop", argLength: 1, reg: regInfo{inputs: []regMask{gpMask}, outputs: []regMask{gpMask}}, resultInArg0: true}, // nop, return arg0 in same register

		// Shift ops
		{name: "SLL", argLength: 2, reg: gp21, asm: "SLL"},                 // arg0 << (aux1 & 63)
		{name: "SRA", argLength: 2, reg: gp21, asm: "SRA"},                 // arg0 >> (aux1 & 63), signed
		{name: "SRL", argLength: 2, reg: gp21, asm: "SRL"},                 // arg0 >> (aux1 & 63), unsigned
		{name: "SLLI", argLength: 1, reg: gp11, asm: "SLLI", aux: "Int64"}, // arg0 << auxint, shift amount 0-63
		{name: "SRAI", argLength: 1, reg: gp11, asm: "SRAI", aux: "Int64"}, // arg0 >> auxint, signed, shift amount 0-63
		{name: "SRLI", argLength: 1, reg: gp11, asm: "SRLI", aux: "Int64"}, // arg0 >> auxint, unsigned, shift amount 0-63

		// Bitwise ops
		{name: "XOR", argLength: 2, reg: gp21, asm: "XOR", commutative: true}, // arg0 ^ arg1
		{name: "XORI", argLength: 1, reg: gp11, asm: "XORI", aux: "Int64"},    // arg0 ^ auxint
		{name: "OR", argLength: 2, reg: gp21, asm: "OR", commutative: true},   // arg0 | arg1
		{name: "ORI", argLength: 1, reg: gp11, asm: "ORI", aux: "Int64"},      // arg0 | auxint
		{name: "AND", argLength: 2, reg: gp21, asm: "AND", commutative: true}, // arg0 & arg1
		{name: "ANDI", argLength: 1, reg: gp11, asm: "ANDI", aux: "Int64"},    // arg0 & auxint
		{name: "NOT", argLength: 1, reg: gp11, asm: "NOT"},                    // ^arg0

		// Generate boolean values
		{name: "SEQZ", argLength: 1, reg: gp11, asm: "SEQZ"},                 // arg0 == 0, result is 0 or 1
		{name: "SNEZ", argLength: 1, reg: gp11, asm: "SNEZ"},                 // arg0 != 0, result is 0 or 1
		{name: "SLT", argLength: 2, reg: gp21, asm: "SLT"},                   // arg0 < arg1, result is 0 or 1
		{name: "SLTI", argLength: 1, reg: gp11, asm: "SLTI", aux: "Int64"},   // arg0 < auxint, result is 0 or 1
		{name: "SLTU", argLength: 2, reg: gp21, asm: "SLTU"},                 // arg0 < arg1, unsigned, result is 0 or 1
		{name: "SLTIU", argLength: 1, reg: gp11, asm: "SLTIU", aux: "Int64"}, // arg0 < auxint, unsigned, result is 0 or 1

		// MOVconvert converts between pointers and integers.
		// We have a special op for this so as to not confuse GC
		// (particularly stack maps). It takes a memory arg so it
		// gets correctly ordered with respect to GC safepoints.
		{name: "MOVconvert", argLength: 2, reg: gp11, asm: "MOV"}, // arg0, but converted to int/ptr as appropriate; arg1=mem

		// Calls
		{name: "CALLstatic", argLength: 1, reg: call, aux: "CallOff", call: true},         // call static function aux.(*gc.Sym). arg0=mem, auxint=argsize, returns mem
		{name: "CALLtail", argLength: 1, reg: call, aux: "CallOff", call: true},           // tail call static function aux.(*gc.Sym). arg0=mem, auxint=argsize, returns mem
		{name: "CALLclosure", argLength: 3, reg: callClosure, aux: "CallOff", call: true}, // call function via closure. arg0=codeptr, arg1=closure, arg2=mem, auxint=argsize, returns mem
		{name: "CALLinter", argLength: 2, reg: callInter, aux: "CallOff", call: true},     // call fn by pointer. arg0=codeptr, arg1=mem, auxint=argsize, returns mem

		// duffzero
		// arg0 = address of memory to zero (in X10, changed as side effect)
		// arg1 = mem
		// auxint = offset into duffzero code to start executing
		// X1 (link register) changed because of function call
		// returns mem
		{
			name:      "DUFFZERO",
			aux:       "Int64",
			argLength: 2,
			reg: regInfo{
				inputs:   []regMask{regNamed["X10"]},
				clobbers: regNamed["X1"] | regNamed["X10"],
			},
			typ:            "Mem",
			faultOnNilArg0: true,
		},

		// duffcopy
		// arg0 = address of dst memory (in X11, changed as side effect)
		// arg1 = address of src memory (in X10, changed as side effect)
		// arg2 = mem
		// auxint = offset into duffcopy code to start executing
		// X1 (link register) changed because of function call
		// returns mem
		{
			name:      "DUFFCOPY",
			aux:       "Int64",
			argLength: 3,
			reg: regInfo{
				inputs:   []regMask{regNamed["X11"], regNamed["X10"]},
				clobbers: regNamed["X1"] | regNamed["X10"] | regNamed["X11"],
			},
			typ:            "Mem",
			faultOnNilArg0: true,
			faultOnNilArg1: true,
		},

		// Generic moves and zeros

		// general unaligned zeroing
		// arg0 = address of memory to zero (in X5, changed as side effect)
		// arg1 = address of the last element to zero (inclusive)
		// arg2 = mem
		// auxint = element size
		// returns mem
		//	mov	ZERO, (X5)
		//	ADD	$sz, X5
		//	BGEU	Rarg1, X5, -2(PC)
		{
			name:      "LoweredZero",
			aux:       "Int64",
			argLength: 3,
			reg: regInfo{
				inputs:   []regMask{regNamed["X5"], gpMask},
				clobbers: regNamed["X5"],
			},
			typ:            "Mem",
			faultOnNilArg0: true,
		},

		// general unaligned move
		// arg0 = address of dst memory (in X5, changed as side effect)
		// arg1 = address of src memory (in X6, changed as side effect)
		// arg2 = address of the last element of src (can't be X7 as we clobber it before using arg2)
		// arg3 = mem
		// auxint = alignment
		// clobbers X7 as a tmp register.
		// returns mem
		//	mov	(X6), X7
		//	mov	X7, (X5)
		//	ADD	$sz, X5
		//	ADD	$sz, X6
		//	BGEU	Rarg2, X5, -4(PC)
		{
			name:      "LoweredMove",
			aux:       "Int64",
			argLength: 4,
			reg: regInfo{
				inputs:   []regMask{regNamed["X5"], regNamed["X6"], gpMask &^ regNamed["X7"]},
				clobbers: regNamed["X5"] | regNamed["X6"] | regNamed["X7"],
			},
			typ:            "Mem",
			faultOnNilArg0: true,
			faultOnNilArg1: true,
		},

		// Atomic loads.
		// load from arg0. arg1=mem.
		// returns <value,memory> so they can be properly ordered with other loads.
		{name: "LoweredAtomicLoad8", argLength: 2, reg: gpload, faultOnNilArg0: true},
		{name: "LoweredAtomicLoad32", argLength: 2, reg: gpload, faultOnNilArg0: true},
		{name: "LoweredAtomicLoad64", argLength: 2, reg: gpload, faultOnNilArg0: true},

		// Atomic stores.
		// store arg1 to *arg0. arg2=mem. returns memory.
		{name: "LoweredAtomicStore8", argLength: 3, reg: gpstore, faultOnNilArg0: true, hasSideEffects: true},
		{name: "LoweredAtomicStore32", argLength: 3, reg: gpstore, faultOnNilArg0: true, hasSideEffects: true},
		{name: "LoweredAtomicStore64", argLength: 3, reg: gpstore, faultOnNilArg0: true, hasSideEffects: true},

		// Atomic exchange.
		// store arg1 to *arg0. arg2=mem. returns <old content of *arg0, memory>.
		{name: "LoweredAtomicExchange32", argLength: 3, reg: gpxchg, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true},
		{name: "LoweredAtomicExchange64", argLength: 3, reg: gpxchg, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true},

		// Atomic add.
		// *arg0 += arg1. arg2=mem. returns <new content of *arg0, memory>.
		{name: "LoweredAtomicAdd32", argLength: 3, reg: gpxchg, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true, unsafePoint: true},
		{name: "LoweredAtomicAdd64", argLength: 3, reg: gpxchg, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true, unsafePoint: true},

		// Atomic compare and swap.
		// arg0 = pointer, arg1 = old value, arg2 = new value, arg3 = memory.
		// if *arg0 == arg1 {
		//   *arg0 = arg2
		//   return (true, memory)
		// } else {
		//   return (false, memory)
		// }
		// MOV  $0, Rout
		// LR	(Rarg0), Rtmp
		// BNE	Rtmp, Rarg1, 3(PC)
		// SC	Rarg2, (Rarg0), Rtmp
		// BNE	Rtmp, ZERO, -3(PC)
		// MOV  $1, Rout
		{name: "LoweredAtomicCas32", argLength: 4, reg: gpcas, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true, unsafePoint: true},
		{name: "LoweredAtomicCas64", argLength: 4, reg: gpcas, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true, unsafePoint: true},

		// Atomic 32 bit AND/OR.
		// *arg0 &= (|=) arg1. arg2=mem. returns nil.
		{name: "LoweredAtomicAnd32", argLength: 3, reg: gpatomic, asm: "AMOANDW", faultOnNilArg0: true, hasSideEffects: true},
		{name: "LoweredAtomicOr32", argLength: 3, reg: gpatomic, asm: "AMOORW", faultOnNilArg0: true, hasSideEffects: true},

		// Lowering pass-throughs
		{name: "LoweredNilCheck", argLength: 2, faultOnNilArg0: true, nilCheck: true, reg: regInfo{inputs: []regMask{gpspMask}}}, // arg0=ptr,arg1=mem, returns void.  Faults if ptr is nil.
		{name: "LoweredGetClosurePtr", reg: regInfo{outputs: []regMask{regCtxt}}},                                                // scheduler ensures only at beginning of entry block

		// LoweredGetCallerSP returns the SP of the caller of the current function.
		{name: "LoweredGetCallerSP", reg: gp01, rematerializeable: true},

		// LoweredGetCallerPC evaluates to the PC to which its "caller" will return.
		// I.e., if f calls g "calls" getcallerpc,
		// the result should be the PC within f that g will return to.
		// See runtime/stubs.go for a more detailed discussion.
		{name: "LoweredGetCallerPC", reg: gp01, rematerializeable: true},

		// LoweredWB invokes runtime.gcWriteBarrier. arg0=destptr, arg1=srcptr, arg2=mem, aux=runtime.gcWriteBarrier
		// It saves all GP registers if necessary,
		// but clobbers RA (LR) because it's a call
		// and T6 (REG_TMP).
		{name: "LoweredWB", argLength: 3, reg: regInfo{inputs: []regMask{regNamed["X5"], regNamed["X6"]}, clobbers: (callerSave &^ (gpMask | regNamed["g"])) | regNamed["X1"]}, clobberFlags: true, aux: "Sym", symEffect: "None"},

		// There are three of these functions so that they can have three different register inputs.
		// When we check 0 <= c <= cap (A), then 0 <= b <= c (B), then 0 <= a <= b (C), we want the
		// default registers to match so we don't need to copy registers around unnecessarily.
		{name: "LoweredPanicBoundsA", argLength: 3, aux: "Int64", reg: regInfo{inputs: []regMask{regNamed["X7"], regNamed["X28"]}}, typ: "Mem", call: true}, // arg0=idx, arg1=len, arg2=mem, returns memory. AuxInt contains report code (see PanicBounds in genericOps.go).
		{name: "LoweredPanicBoundsB", argLength: 3, aux: "Int64", reg: regInfo{inputs: []regMask{regNamed["X6"], regNamed["X7"]}}, typ: "Mem", call: true},  // arg0=idx, arg1=len, arg2=mem, returns memory. AuxInt contains report code (see PanicBounds in genericOps.go).
		{name: "LoweredPanicBoundsC", argLength: 3, aux: "Int64", reg: regInfo{inputs: []regMask{regNamed["X5"], regNamed["X6"]}}, typ: "Mem", call: true},  // arg0=idx, arg1=len, arg2=mem, returns memory. AuxInt contains report code (see PanicBounds in genericOps.go).

		// F extension.
		{name: "FADDS", argLength: 2, reg: fp21, asm: "FADDS", commutative: true, typ: "Float32"},                                           // arg0 + arg1
		{name: "FSUBS", argLength: 2, reg: fp21, asm: "FSUBS", commutative: false, typ: "Float32"},                                          // arg0 - arg1
		{name: "FMULS", argLength: 2, reg: fp21, asm: "FMULS", commutative: true, typ: "Float32"},                                           // arg0 * arg1
		{name: "FDIVS", argLength: 2, reg: fp21, asm: "FDIVS", commutative: false, typ: "Float32"},                                          // arg0 / arg1
		{name: "FSQRTS", argLength: 1, reg: fp11, asm: "FSQRTS", typ: "Float32"},                                                            // sqrt(arg0)
		{name: "FNEGS", argLength: 1, reg: fp11, asm: "FNEGS", typ: "Float32"},                                                              // -arg0
		{name: "FMVSX", argLength: 1, reg: gpfp, asm: "FMVSX", typ: "Float32"},                                                              // reinterpret arg0 as float
		{name: "FCVTSW", argLength: 1, reg: gpfp, asm: "FCVTSW", typ: "Float32"},                                                            // float32(low 32 bits of arg0)
		{name: "FCVTSL", argLength: 1, reg: gpfp, asm: "FCVTSL", typ: "Float32"},                                                            // float32(arg0)
		{name: "FCVTWS", argLength: 1, reg: fpgp, asm: "FCVTWS", typ: "Int32"},                                                              // int32(arg0)
		{name: "FCVTLS", argLength: 1, reg: fpgp, asm: "FCVTLS", typ: "Int64"},                                                              // int64(arg0)
		{name: "FMOVWload", argLength: 2, reg: fpload, asm: "MOVF", aux: "SymOff", typ: "Float32", faultOnNilArg0: true, symEffect: "Read"}, // load float32 from arg0+auxint+aux
		{name: "FMOVWstore", argLength: 3, reg: fpstore, asm: "MOVF", aux: "SymOff", typ: "Mem", faultOnNilArg0: true, symEffect: "Write"},  // store float32 to arg0+auxint+aux
		{name: "FEQS", argLength: 2, reg: fp2gp, asm: "FEQS", commutative: true},                                                            // arg0 == arg1
		{name: "FNES", argLength: 2, reg: fp2gp, asm: "FNES", commutative: true},                                                            // arg0 != arg1
		{name: "FLTS", argLength: 2, reg: fp2gp, asm: "FLTS"},                                                                               // arg0 < arg1
		{name: "FLES", argLength: 2, reg: fp2gp, asm: "FLES"},                                                                               // arg0 <= arg1

		// D extension.
		{name: "FADDD", argLength: 2, reg: fp21, asm: "FADDD", commutative: true, typ: "Float64"},                                           // arg0 + arg1
		{name: "FSUBD", argLength: 2, reg: fp21, asm: "FSUBD", commutative: false, typ: "Float64"},                                          // arg0 - arg1
		{name: "FMULD", argLength: 2, reg: fp21, asm: "FMULD", commutative: true, typ: "Float64"},                                           // arg0 * arg1
		{name: "FDIVD", argLength: 2, reg: fp21, asm: "FDIVD", commutative: false, typ: "Float64"},                                          // arg0 / arg1
		{name: "FMADDD", argLength: 3, reg: fp31, asm: "FMADDD", commutative: true, typ: "Float64"},                                         // (arg0 * arg1) + arg2
		{name: "FMSUBD", argLength: 3, reg: fp31, asm: "FMSUBD", commutative: true, typ: "Float64"},                                         // (arg0 * arg1) - arg2
		{name: "FNMADDD", argLength: 3, reg: fp31, asm: "FNMADDD", commutative: true, typ: "Float64"},                                       // -(arg0 * arg1) + arg2
		{name: "FNMSUBD", argLength: 3, reg: fp31, asm: "FNMSUBD", commutative: true, typ: "Float64"},                                       // -(arg0 * arg1) - arg2
		{name: "FSQRTD", argLength: 1, reg: fp11, asm: "FSQRTD", typ: "Float64"},                                                            // sqrt(arg0)
		{name: "FNEGD", argLength: 1, reg: fp11, asm: "FNEGD", typ: "Float64"},                                                              // -arg0
		{name: "FABSD", argLength: 1, reg: fp11, asm: "FABSD", typ: "Float64"},                                                              // abs(arg0)
		{name: "FSGNJD", argLength: 2, reg: fp21, asm: "FSGNJD", typ: "Float64"},                                                            // copy sign of arg1 to arg0
		{name: "FMVDX", argLength: 1, reg: gpfp, asm: "FMVDX", typ: "Float64"},                                                              // reinterpret arg0 as float
		{name: "FCVTDW", argLength: 1, reg: gpfp, asm: "FCVTDW", typ: "Float64"},                                                            // float64(low 32 bits of arg0)
		{name: "FCVTDL", argLength: 1, reg: gpfp, asm: "FCVTDL", typ: "Float64"},                                                            // float64(arg0)
		{name: "FCVTWD", argLength: 1, reg: fpgp, asm: "FCVTWD", typ: "Int32"},                                                              // int32(arg0)
		{name: "FCVTLD", argLength: 1, reg: fpgp, asm: "FCVTLD", typ: "Int64"},                                                              // int64(arg0)
		{name: "FCVTDS", argLength: 1, reg: fp11, asm: "FCVTDS", typ: "Float64"},                                                            // float64(arg0)
		{name: "FCVTSD", argLength: 1, reg: fp11, asm: "FCVTSD", typ: "Float32"},                                                            // float32(arg0)
		{name: "FMOVDload", argLength: 2, reg: fpload, asm: "MOVD", aux: "SymOff", typ: "Float64", faultOnNilArg0: true, symEffect: "Read"}, // load float64 from arg0+auxint+aux
		{name: "FMOVDstore", argLength: 3, reg: fpstore, asm: "MOVD", aux: "SymOff", typ: "Mem", faultOnNilArg0: true, symEffect: "Write"},  // store float6 to arg0+auxint+aux
		{name: "FEQD", argLength: 2, reg: fp2gp, asm: "FEQD", commutative: true},                                                            // arg0 == arg1
		{name: "FNED", argLength: 2, reg: fp2gp, asm: "FNED", commutative: true},                                                            // arg0 != arg1
		{name: "FLTD", argLength: 2, reg: fp2gp, asm: "FLTD"},                                                                               // arg0 < arg1
		{name: "FLED", argLength: 2, reg: fp2gp, asm: "FLED"},                                                                               // arg0 <= arg1
	}

	RISCV64blocks := []blockData{
		{name: "BEQ", controls: 2},
		{name: "BNE", controls: 2},
		{name: "BLT", controls: 2},
		{name: "BGE", controls: 2},
		{name: "BLTU", controls: 2},
		{name: "BGEU", controls: 2},

		{name: "BEQZ", controls: 1},
		{name: "BNEZ", controls: 1},
		{name: "BLEZ", controls: 1},
		{name: "BGEZ", controls: 1},
		{name: "BLTZ", controls: 1},
		{name: "BGTZ", controls: 1},
	}

	archs = append(archs, arch{
		name:            "RISCV64",
		pkg:             "cmd/internal/obj/riscv",
		genfile:         "../../riscv64/ssa.go",
		ops:             RISCV64ops,
		blocks:          RISCV64blocks,
		regnames:        regNamesRISCV64,
		gpregmask:       gpMask,
		fpregmask:       fpMask,
		framepointerreg: -1, // not used
	})
}