obj7.go raw
1 // cmd/7l/noop.c, cmd/7l/obj.c, cmd/ld/pass.c from Vita Nuova.
2 // https://code.google.com/p/ken-cc/source/browse/
3 //
4 // Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
5 // Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
6 // Portions Copyright © 1997-1999 Vita Nuova Limited
7 // Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
8 // Portions Copyright © 2004,2006 Bruce Ellis
9 // Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
10 // Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
11 // Portions Copyright © 2009 The Go Authors. All rights reserved.
12 //
13 // Permission is hereby granted, free of charge, to any person obtaining a copy
14 // of this software and associated documentation files (the "Software"), to deal
15 // in the Software without restriction, including without limitation the rights
16 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
17 // copies of the Software, and to permit persons to whom the Software is
18 // furnished to do so, subject to the following conditions:
19 //
20 // The above copyright notice and this permission notice shall be included in
21 // all copies or substantial portions of the Software.
22 //
23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
26 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
27 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
28 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
29 // THE SOFTWARE.
30
31 package arm64
32
33 import (
34 "github.com/twitchyliquid64/golang-asm/obj"
35 "github.com/twitchyliquid64/golang-asm/objabi"
36 "github.com/twitchyliquid64/golang-asm/src"
37 "github.com/twitchyliquid64/golang-asm/sys"
38 "math"
39 )
40
41 var complements = []obj.As{
42 AADD: ASUB,
43 AADDW: ASUBW,
44 ASUB: AADD,
45 ASUBW: AADDW,
46 ACMP: ACMN,
47 ACMPW: ACMNW,
48 ACMN: ACMP,
49 ACMNW: ACMPW,
50 }
51
52 func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
53 // MOV g_stackguard(g), R1
54 p = obj.Appendp(p, c.newprog)
55
56 p.As = AMOVD
57 p.From.Type = obj.TYPE_MEM
58 p.From.Reg = REGG
59 p.From.Offset = 2 * int64(c.ctxt.Arch.PtrSize) // G.stackguard0
60 if c.cursym.CFunc() {
61 p.From.Offset = 3 * int64(c.ctxt.Arch.PtrSize) // G.stackguard1
62 }
63 p.To.Type = obj.TYPE_REG
64 p.To.Reg = REG_R1
65
66 // Mark the stack bound check and morestack call async nonpreemptible.
67 // If we get preempted here, when resumed the preemption request is
68 // cleared, but we'll still call morestack, which will double the stack
69 // unnecessarily. See issue #35470.
70 p = c.ctxt.StartUnsafePoint(p, c.newprog)
71
72 q := (*obj.Prog)(nil)
73 if framesize <= objabi.StackSmall {
74 // small stack: SP < stackguard
75 // MOV SP, R2
76 // CMP stackguard, R2
77 p = obj.Appendp(p, c.newprog)
78
79 p.As = AMOVD
80 p.From.Type = obj.TYPE_REG
81 p.From.Reg = REGSP
82 p.To.Type = obj.TYPE_REG
83 p.To.Reg = REG_R2
84
85 p = obj.Appendp(p, c.newprog)
86 p.As = ACMP
87 p.From.Type = obj.TYPE_REG
88 p.From.Reg = REG_R1
89 p.Reg = REG_R2
90 } else if framesize <= objabi.StackBig {
91 // large stack: SP-framesize < stackguard-StackSmall
92 // SUB $(framesize-StackSmall), SP, R2
93 // CMP stackguard, R2
94 p = obj.Appendp(p, c.newprog)
95
96 p.As = ASUB
97 p.From.Type = obj.TYPE_CONST
98 p.From.Offset = int64(framesize) - objabi.StackSmall
99 p.Reg = REGSP
100 p.To.Type = obj.TYPE_REG
101 p.To.Reg = REG_R2
102
103 p = obj.Appendp(p, c.newprog)
104 p.As = ACMP
105 p.From.Type = obj.TYPE_REG
106 p.From.Reg = REG_R1
107 p.Reg = REG_R2
108 } else {
109 // Such a large stack we need to protect against wraparound
110 // if SP is close to zero.
111 // SP-stackguard+StackGuard < framesize + (StackGuard-StackSmall)
112 // The +StackGuard on both sides is required to keep the left side positive:
113 // SP is allowed to be slightly below stackguard. See stack.h.
114 // CMP $StackPreempt, R1
115 // BEQ label_of_call_to_morestack
116 // ADD $StackGuard, SP, R2
117 // SUB R1, R2
118 // MOV $(framesize+(StackGuard-StackSmall)), R3
119 // CMP R3, R2
120 p = obj.Appendp(p, c.newprog)
121
122 p.As = ACMP
123 p.From.Type = obj.TYPE_CONST
124 p.From.Offset = objabi.StackPreempt
125 p.Reg = REG_R1
126
127 p = obj.Appendp(p, c.newprog)
128 q = p
129 p.As = ABEQ
130 p.To.Type = obj.TYPE_BRANCH
131
132 p = obj.Appendp(p, c.newprog)
133 p.As = AADD
134 p.From.Type = obj.TYPE_CONST
135 p.From.Offset = int64(objabi.StackGuard)
136 p.Reg = REGSP
137 p.To.Type = obj.TYPE_REG
138 p.To.Reg = REG_R2
139
140 p = obj.Appendp(p, c.newprog)
141 p.As = ASUB
142 p.From.Type = obj.TYPE_REG
143 p.From.Reg = REG_R1
144 p.To.Type = obj.TYPE_REG
145 p.To.Reg = REG_R2
146
147 p = obj.Appendp(p, c.newprog)
148 p.As = AMOVD
149 p.From.Type = obj.TYPE_CONST
150 p.From.Offset = int64(framesize) + (int64(objabi.StackGuard) - objabi.StackSmall)
151 p.To.Type = obj.TYPE_REG
152 p.To.Reg = REG_R3
153
154 p = obj.Appendp(p, c.newprog)
155 p.As = ACMP
156 p.From.Type = obj.TYPE_REG
157 p.From.Reg = REG_R3
158 p.Reg = REG_R2
159 }
160
161 // BLS do-morestack
162 bls := obj.Appendp(p, c.newprog)
163 bls.As = ABLS
164 bls.To.Type = obj.TYPE_BRANCH
165
166 end := c.ctxt.EndUnsafePoint(bls, c.newprog, -1)
167
168 var last *obj.Prog
169 for last = c.cursym.Func.Text; last.Link != nil; last = last.Link {
170 }
171
172 // Now we are at the end of the function, but logically
173 // we are still in function prologue. We need to fix the
174 // SP data and PCDATA.
175 spfix := obj.Appendp(last, c.newprog)
176 spfix.As = obj.ANOP
177 spfix.Spadj = -framesize
178
179 pcdata := c.ctxt.EmitEntryStackMap(c.cursym, spfix, c.newprog)
180 pcdata = c.ctxt.StartUnsafePoint(pcdata, c.newprog)
181
182 // MOV LR, R3
183 movlr := obj.Appendp(pcdata, c.newprog)
184 movlr.As = AMOVD
185 movlr.From.Type = obj.TYPE_REG
186 movlr.From.Reg = REGLINK
187 movlr.To.Type = obj.TYPE_REG
188 movlr.To.Reg = REG_R3
189 if q != nil {
190 q.To.SetTarget(movlr)
191 }
192 bls.To.SetTarget(movlr)
193
194 debug := movlr
195 if false {
196 debug = obj.Appendp(debug, c.newprog)
197 debug.As = AMOVD
198 debug.From.Type = obj.TYPE_CONST
199 debug.From.Offset = int64(framesize)
200 debug.To.Type = obj.TYPE_REG
201 debug.To.Reg = REGTMP
202 }
203
204 // BL runtime.morestack(SB)
205 call := obj.Appendp(debug, c.newprog)
206 call.As = ABL
207 call.To.Type = obj.TYPE_BRANCH
208 morestack := "runtime.morestack"
209 switch {
210 case c.cursym.CFunc():
211 morestack = "runtime.morestackc"
212 case !c.cursym.Func.Text.From.Sym.NeedCtxt():
213 morestack = "runtime.morestack_noctxt"
214 }
215 call.To.Sym = c.ctxt.Lookup(morestack)
216
217 pcdata = c.ctxt.EndUnsafePoint(call, c.newprog, -1)
218
219 // B start
220 jmp := obj.Appendp(pcdata, c.newprog)
221 jmp.As = AB
222 jmp.To.Type = obj.TYPE_BRANCH
223 jmp.To.SetTarget(c.cursym.Func.Text.Link)
224 jmp.Spadj = +framesize
225
226 return end
227 }
228
229 func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
230 c := ctxt7{ctxt: ctxt, newprog: newprog}
231
232 p.From.Class = 0
233 p.To.Class = 0
234
235 // $0 results in C_ZCON, which matches both C_REG and various
236 // C_xCON, however the C_REG cases in asmout don't expect a
237 // constant, so they will use the register fields and assemble
238 // a R0. To prevent that, rewrite $0 as ZR.
239 if p.From.Type == obj.TYPE_CONST && p.From.Offset == 0 {
240 p.From.Type = obj.TYPE_REG
241 p.From.Reg = REGZERO
242 }
243 if p.To.Type == obj.TYPE_CONST && p.To.Offset == 0 {
244 p.To.Type = obj.TYPE_REG
245 p.To.Reg = REGZERO
246 }
247
248 // Rewrite BR/BL to symbol as TYPE_BRANCH.
249 switch p.As {
250 case AB,
251 ABL,
252 obj.ARET,
253 obj.ADUFFZERO,
254 obj.ADUFFCOPY:
255 if p.To.Sym != nil {
256 p.To.Type = obj.TYPE_BRANCH
257 }
258 break
259 }
260
261 // Rewrite float constants to values stored in memory.
262 switch p.As {
263 case AFMOVS:
264 if p.From.Type == obj.TYPE_FCONST {
265 f64 := p.From.Val.(float64)
266 f32 := float32(f64)
267 if c.chipfloat7(f64) > 0 {
268 break
269 }
270 if math.Float32bits(f32) == 0 {
271 p.From.Type = obj.TYPE_REG
272 p.From.Reg = REGZERO
273 break
274 }
275 p.From.Type = obj.TYPE_MEM
276 p.From.Sym = c.ctxt.Float32Sym(f32)
277 p.From.Name = obj.NAME_EXTERN
278 p.From.Offset = 0
279 }
280
281 case AFMOVD:
282 if p.From.Type == obj.TYPE_FCONST {
283 f64 := p.From.Val.(float64)
284 if c.chipfloat7(f64) > 0 {
285 break
286 }
287 if math.Float64bits(f64) == 0 {
288 p.From.Type = obj.TYPE_REG
289 p.From.Reg = REGZERO
290 break
291 }
292 p.From.Type = obj.TYPE_MEM
293 p.From.Sym = c.ctxt.Float64Sym(f64)
294 p.From.Name = obj.NAME_EXTERN
295 p.From.Offset = 0
296 }
297
298 break
299 }
300
301 // Rewrite negative immediates as positive immediates with
302 // complementary instruction.
303 switch p.As {
304 case AADD, ASUB, ACMP, ACMN:
305 if p.From.Type == obj.TYPE_CONST && p.From.Offset < 0 && p.From.Offset != -1<<63 {
306 p.From.Offset = -p.From.Offset
307 p.As = complements[p.As]
308 }
309 case AADDW, ASUBW, ACMPW, ACMNW:
310 if p.From.Type == obj.TYPE_CONST && p.From.Offset < 0 && int32(p.From.Offset) != -1<<31 {
311 p.From.Offset = -p.From.Offset
312 p.As = complements[p.As]
313 }
314 }
315
316 // For 32-bit logical instruction with constant,
317 // rewrite the high 32-bit to be a repetition of
318 // the low 32-bit, so that the BITCON test can be
319 // shared for both 32-bit and 64-bit. 32-bit ops
320 // will zero the high 32-bit of the destination
321 // register anyway.
322 if isANDWop(p.As) && p.From.Type == obj.TYPE_CONST {
323 v := p.From.Offset & 0xffffffff
324 p.From.Offset = v | v<<32
325 }
326
327 if c.ctxt.Flag_dynlink {
328 c.rewriteToUseGot(p)
329 }
330 }
331
332 // Rewrite p, if necessary, to access global data via the global offset table.
333 func (c *ctxt7) rewriteToUseGot(p *obj.Prog) {
334 if p.As == obj.ADUFFCOPY || p.As == obj.ADUFFZERO {
335 // ADUFFxxx $offset
336 // becomes
337 // MOVD runtime.duffxxx@GOT, REGTMP
338 // ADD $offset, REGTMP
339 // CALL REGTMP
340 var sym *obj.LSym
341 if p.As == obj.ADUFFZERO {
342 sym = c.ctxt.Lookup("runtime.duffzero")
343 } else {
344 sym = c.ctxt.Lookup("runtime.duffcopy")
345 }
346 offset := p.To.Offset
347 p.As = AMOVD
348 p.From.Type = obj.TYPE_MEM
349 p.From.Name = obj.NAME_GOTREF
350 p.From.Sym = sym
351 p.To.Type = obj.TYPE_REG
352 p.To.Reg = REGTMP
353 p.To.Name = obj.NAME_NONE
354 p.To.Offset = 0
355 p.To.Sym = nil
356 p1 := obj.Appendp(p, c.newprog)
357 p1.As = AADD
358 p1.From.Type = obj.TYPE_CONST
359 p1.From.Offset = offset
360 p1.To.Type = obj.TYPE_REG
361 p1.To.Reg = REGTMP
362 p2 := obj.Appendp(p1, c.newprog)
363 p2.As = obj.ACALL
364 p2.To.Type = obj.TYPE_REG
365 p2.To.Reg = REGTMP
366 }
367
368 // We only care about global data: NAME_EXTERN means a global
369 // symbol in the Go sense, and p.Sym.Local is true for a few
370 // internally defined symbols.
371 if p.From.Type == obj.TYPE_ADDR && p.From.Name == obj.NAME_EXTERN && !p.From.Sym.Local() {
372 // MOVD $sym, Rx becomes MOVD sym@GOT, Rx
373 // MOVD $sym+<off>, Rx becomes MOVD sym@GOT, Rx; ADD <off>, Rx
374 if p.As != AMOVD {
375 c.ctxt.Diag("do not know how to handle TYPE_ADDR in %v with -dynlink", p)
376 }
377 if p.To.Type != obj.TYPE_REG {
378 c.ctxt.Diag("do not know how to handle LEAQ-type insn to non-register in %v with -dynlink", p)
379 }
380 p.From.Type = obj.TYPE_MEM
381 p.From.Name = obj.NAME_GOTREF
382 if p.From.Offset != 0 {
383 q := obj.Appendp(p, c.newprog)
384 q.As = AADD
385 q.From.Type = obj.TYPE_CONST
386 q.From.Offset = p.From.Offset
387 q.To = p.To
388 p.From.Offset = 0
389 }
390 }
391 if p.GetFrom3() != nil && p.GetFrom3().Name == obj.NAME_EXTERN {
392 c.ctxt.Diag("don't know how to handle %v with -dynlink", p)
393 }
394 var source *obj.Addr
395 // MOVx sym, Ry becomes MOVD sym@GOT, REGTMP; MOVx (REGTMP), Ry
396 // MOVx Ry, sym becomes MOVD sym@GOT, REGTMP; MOVD Ry, (REGTMP)
397 // An addition may be inserted between the two MOVs if there is an offset.
398 if p.From.Name == obj.NAME_EXTERN && !p.From.Sym.Local() {
399 if p.To.Name == obj.NAME_EXTERN && !p.To.Sym.Local() {
400 c.ctxt.Diag("cannot handle NAME_EXTERN on both sides in %v with -dynlink", p)
401 }
402 source = &p.From
403 } else if p.To.Name == obj.NAME_EXTERN && !p.To.Sym.Local() {
404 source = &p.To
405 } else {
406 return
407 }
408 if p.As == obj.ATEXT || p.As == obj.AFUNCDATA || p.As == obj.ACALL || p.As == obj.ARET || p.As == obj.AJMP {
409 return
410 }
411 if source.Sym.Type == objabi.STLSBSS {
412 return
413 }
414 if source.Type != obj.TYPE_MEM {
415 c.ctxt.Diag("don't know how to handle %v with -dynlink", p)
416 }
417 p1 := obj.Appendp(p, c.newprog)
418 p2 := obj.Appendp(p1, c.newprog)
419 p1.As = AMOVD
420 p1.From.Type = obj.TYPE_MEM
421 p1.From.Sym = source.Sym
422 p1.From.Name = obj.NAME_GOTREF
423 p1.To.Type = obj.TYPE_REG
424 p1.To.Reg = REGTMP
425
426 p2.As = p.As
427 p2.From = p.From
428 p2.To = p.To
429 if p.From.Name == obj.NAME_EXTERN {
430 p2.From.Reg = REGTMP
431 p2.From.Name = obj.NAME_NONE
432 p2.From.Sym = nil
433 } else if p.To.Name == obj.NAME_EXTERN {
434 p2.To.Reg = REGTMP
435 p2.To.Name = obj.NAME_NONE
436 p2.To.Sym = nil
437 } else {
438 return
439 }
440 obj.Nopout(p)
441 }
442
443 func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
444 if cursym.Func.Text == nil || cursym.Func.Text.Link == nil {
445 return
446 }
447
448 c := ctxt7{ctxt: ctxt, newprog: newprog, cursym: cursym}
449
450 p := c.cursym.Func.Text
451 textstksiz := p.To.Offset
452 if textstksiz == -8 {
453 // Historical way to mark NOFRAME.
454 p.From.Sym.Set(obj.AttrNoFrame, true)
455 textstksiz = 0
456 }
457 if textstksiz < 0 {
458 c.ctxt.Diag("negative frame size %d - did you mean NOFRAME?", textstksiz)
459 }
460 if p.From.Sym.NoFrame() {
461 if textstksiz != 0 {
462 c.ctxt.Diag("NOFRAME functions must have a frame size of 0, not %d", textstksiz)
463 }
464 }
465
466 c.cursym.Func.Args = p.To.Val.(int32)
467 c.cursym.Func.Locals = int32(textstksiz)
468
469 /*
470 * find leaf subroutines
471 */
472 for p := c.cursym.Func.Text; p != nil; p = p.Link {
473 switch p.As {
474 case obj.ATEXT:
475 p.Mark |= LEAF
476
477 case ABL,
478 obj.ADUFFZERO,
479 obj.ADUFFCOPY:
480 c.cursym.Func.Text.Mark &^= LEAF
481 }
482 }
483
484 var q *obj.Prog
485 var q1 *obj.Prog
486 var retjmp *obj.LSym
487 for p := c.cursym.Func.Text; p != nil; p = p.Link {
488 o := p.As
489 switch o {
490 case obj.ATEXT:
491 c.cursym.Func.Text = p
492 c.autosize = int32(textstksiz)
493
494 if p.Mark&LEAF != 0 && c.autosize == 0 {
495 // A leaf function with no locals has no frame.
496 p.From.Sym.Set(obj.AttrNoFrame, true)
497 }
498
499 if !p.From.Sym.NoFrame() {
500 // If there is a stack frame at all, it includes
501 // space to save the LR.
502 c.autosize += 8
503 }
504
505 if c.autosize != 0 {
506 extrasize := int32(0)
507 if c.autosize%16 == 8 {
508 // Allocate extra 8 bytes on the frame top to save FP
509 extrasize = 8
510 } else if c.autosize&(16-1) == 0 {
511 // Allocate extra 16 bytes to save FP for the old frame whose size is 8 mod 16
512 extrasize = 16
513 } else {
514 c.ctxt.Diag("%v: unaligned frame size %d - must be 16 aligned", p, c.autosize-8)
515 }
516 c.autosize += extrasize
517 c.cursym.Func.Locals += extrasize
518
519 // low 32 bits for autosize
520 // high 32 bits for extrasize
521 p.To.Offset = int64(c.autosize) | int64(extrasize)<<32
522 } else {
523 // NOFRAME
524 p.To.Offset = 0
525 }
526
527 if c.autosize == 0 && c.cursym.Func.Text.Mark&LEAF == 0 {
528 if c.ctxt.Debugvlog {
529 c.ctxt.Logf("save suppressed in: %s\n", c.cursym.Func.Text.From.Sym.Name)
530 }
531 c.cursym.Func.Text.Mark |= LEAF
532 }
533
534 if cursym.Func.Text.Mark&LEAF != 0 {
535 cursym.Set(obj.AttrLeaf, true)
536 if p.From.Sym.NoFrame() {
537 break
538 }
539 }
540
541 if !p.From.Sym.NoSplit() {
542 p = c.stacksplit(p, c.autosize) // emit split check
543 }
544
545 var prologueEnd *obj.Prog
546
547 aoffset := c.autosize
548 if aoffset > 0xF0 {
549 aoffset = 0xF0
550 }
551
552 // Frame is non-empty. Make sure to save link register, even if
553 // it is a leaf function, so that traceback works.
554 q = p
555 if c.autosize > aoffset {
556 // Frame size is too large for a MOVD.W instruction.
557 // Store link register before decrementing SP, so if a signal comes
558 // during the execution of the function prologue, the traceback
559 // code will not see a half-updated stack frame.
560 // This sequence is not async preemptible, as if we open a frame
561 // at the current SP, it will clobber the saved LR.
562 q = c.ctxt.StartUnsafePoint(q, c.newprog)
563
564 q = obj.Appendp(q, c.newprog)
565 q.Pos = p.Pos
566 q.As = ASUB
567 q.From.Type = obj.TYPE_CONST
568 q.From.Offset = int64(c.autosize)
569 q.Reg = REGSP
570 q.To.Type = obj.TYPE_REG
571 q.To.Reg = REGTMP
572
573 prologueEnd = q
574
575 q = obj.Appendp(q, c.newprog)
576 q.Pos = p.Pos
577 q.As = AMOVD
578 q.From.Type = obj.TYPE_REG
579 q.From.Reg = REGLINK
580 q.To.Type = obj.TYPE_MEM
581 q.To.Reg = REGTMP
582
583 q1 = obj.Appendp(q, c.newprog)
584 q1.Pos = p.Pos
585 q1.As = AMOVD
586 q1.From.Type = obj.TYPE_REG
587 q1.From.Reg = REGTMP
588 q1.To.Type = obj.TYPE_REG
589 q1.To.Reg = REGSP
590 q1.Spadj = c.autosize
591
592 if c.ctxt.Headtype == objabi.Hdarwin {
593 // iOS does not support SA_ONSTACK. We will run the signal handler
594 // on the G stack. If we write below SP, it may be clobbered by
595 // the signal handler. So we save LR after decrementing SP.
596 q1 = obj.Appendp(q1, c.newprog)
597 q1.Pos = p.Pos
598 q1.As = AMOVD
599 q1.From.Type = obj.TYPE_REG
600 q1.From.Reg = REGLINK
601 q1.To.Type = obj.TYPE_MEM
602 q1.To.Reg = REGSP
603 }
604
605 q1 = c.ctxt.EndUnsafePoint(q1, c.newprog, -1)
606 } else {
607 // small frame, update SP and save LR in a single MOVD.W instruction
608 q1 = obj.Appendp(q, c.newprog)
609 q1.As = AMOVD
610 q1.Pos = p.Pos
611 q1.From.Type = obj.TYPE_REG
612 q1.From.Reg = REGLINK
613 q1.To.Type = obj.TYPE_MEM
614 q1.Scond = C_XPRE
615 q1.To.Offset = int64(-aoffset)
616 q1.To.Reg = REGSP
617 q1.Spadj = aoffset
618
619 prologueEnd = q1
620 }
621
622 prologueEnd.Pos = prologueEnd.Pos.WithXlogue(src.PosPrologueEnd)
623
624 if objabi.Framepointer_enabled {
625 q1 = obj.Appendp(q1, c.newprog)
626 q1.Pos = p.Pos
627 q1.As = AMOVD
628 q1.From.Type = obj.TYPE_REG
629 q1.From.Reg = REGFP
630 q1.To.Type = obj.TYPE_MEM
631 q1.To.Reg = REGSP
632 q1.To.Offset = -8
633
634 q1 = obj.Appendp(q1, c.newprog)
635 q1.Pos = p.Pos
636 q1.As = ASUB
637 q1.From.Type = obj.TYPE_CONST
638 q1.From.Offset = 8
639 q1.Reg = REGSP
640 q1.To.Type = obj.TYPE_REG
641 q1.To.Reg = REGFP
642 }
643
644 if c.cursym.Func.Text.From.Sym.Wrapper() {
645 // if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame
646 //
647 // MOV g_panic(g), R1
648 // CBNZ checkargp
649 // end:
650 // NOP
651 // ... function body ...
652 // checkargp:
653 // MOV panic_argp(R1), R2
654 // ADD $(autosize+8), RSP, R3
655 // CMP R2, R3
656 // BNE end
657 // ADD $8, RSP, R4
658 // MOVD R4, panic_argp(R1)
659 // B end
660 //
661 // The NOP is needed to give the jumps somewhere to land.
662 // It is a liblink NOP, not an ARM64 NOP: it encodes to 0 instruction bytes.
663 q = q1
664
665 // MOV g_panic(g), R1
666 q = obj.Appendp(q, c.newprog)
667 q.As = AMOVD
668 q.From.Type = obj.TYPE_MEM
669 q.From.Reg = REGG
670 q.From.Offset = 4 * int64(c.ctxt.Arch.PtrSize) // G.panic
671 q.To.Type = obj.TYPE_REG
672 q.To.Reg = REG_R1
673
674 // CBNZ R1, checkargp
675 cbnz := obj.Appendp(q, c.newprog)
676 cbnz.As = ACBNZ
677 cbnz.From.Type = obj.TYPE_REG
678 cbnz.From.Reg = REG_R1
679 cbnz.To.Type = obj.TYPE_BRANCH
680
681 // Empty branch target at the top of the function body
682 end := obj.Appendp(cbnz, c.newprog)
683 end.As = obj.ANOP
684
685 // find the end of the function
686 var last *obj.Prog
687 for last = end; last.Link != nil; last = last.Link {
688 }
689
690 // MOV panic_argp(R1), R2
691 mov := obj.Appendp(last, c.newprog)
692 mov.As = AMOVD
693 mov.From.Type = obj.TYPE_MEM
694 mov.From.Reg = REG_R1
695 mov.From.Offset = 0 // Panic.argp
696 mov.To.Type = obj.TYPE_REG
697 mov.To.Reg = REG_R2
698
699 // CBNZ branches to the MOV above
700 cbnz.To.SetTarget(mov)
701
702 // ADD $(autosize+8), SP, R3
703 q = obj.Appendp(mov, c.newprog)
704 q.As = AADD
705 q.From.Type = obj.TYPE_CONST
706 q.From.Offset = int64(c.autosize) + 8
707 q.Reg = REGSP
708 q.To.Type = obj.TYPE_REG
709 q.To.Reg = REG_R3
710
711 // CMP R2, R3
712 q = obj.Appendp(q, c.newprog)
713 q.As = ACMP
714 q.From.Type = obj.TYPE_REG
715 q.From.Reg = REG_R2
716 q.Reg = REG_R3
717
718 // BNE end
719 q = obj.Appendp(q, c.newprog)
720 q.As = ABNE
721 q.To.Type = obj.TYPE_BRANCH
722 q.To.SetTarget(end)
723
724 // ADD $8, SP, R4
725 q = obj.Appendp(q, c.newprog)
726 q.As = AADD
727 q.From.Type = obj.TYPE_CONST
728 q.From.Offset = 8
729 q.Reg = REGSP
730 q.To.Type = obj.TYPE_REG
731 q.To.Reg = REG_R4
732
733 // MOV R4, panic_argp(R1)
734 q = obj.Appendp(q, c.newprog)
735 q.As = AMOVD
736 q.From.Type = obj.TYPE_REG
737 q.From.Reg = REG_R4
738 q.To.Type = obj.TYPE_MEM
739 q.To.Reg = REG_R1
740 q.To.Offset = 0 // Panic.argp
741
742 // B end
743 q = obj.Appendp(q, c.newprog)
744 q.As = AB
745 q.To.Type = obj.TYPE_BRANCH
746 q.To.SetTarget(end)
747 }
748
749 case obj.ARET:
750 nocache(p)
751 if p.From.Type == obj.TYPE_CONST {
752 c.ctxt.Diag("using BECOME (%v) is not supported!", p)
753 break
754 }
755
756 retjmp = p.To.Sym
757 p.To = obj.Addr{}
758 if c.cursym.Func.Text.Mark&LEAF != 0 {
759 if c.autosize != 0 {
760 p.As = AADD
761 p.From.Type = obj.TYPE_CONST
762 p.From.Offset = int64(c.autosize)
763 p.To.Type = obj.TYPE_REG
764 p.To.Reg = REGSP
765 p.Spadj = -c.autosize
766
767 if objabi.Framepointer_enabled {
768 p = obj.Appendp(p, c.newprog)
769 p.As = ASUB
770 p.From.Type = obj.TYPE_CONST
771 p.From.Offset = 8
772 p.Reg = REGSP
773 p.To.Type = obj.TYPE_REG
774 p.To.Reg = REGFP
775 }
776 }
777 } else {
778 /* want write-back pre-indexed SP+autosize -> SP, loading REGLINK*/
779
780 if objabi.Framepointer_enabled {
781 p.As = AMOVD
782 p.From.Type = obj.TYPE_MEM
783 p.From.Reg = REGSP
784 p.From.Offset = -8
785 p.To.Type = obj.TYPE_REG
786 p.To.Reg = REGFP
787 p = obj.Appendp(p, c.newprog)
788 }
789
790 aoffset := c.autosize
791
792 if aoffset <= 0xF0 {
793 p.As = AMOVD
794 p.From.Type = obj.TYPE_MEM
795 p.Scond = C_XPOST
796 p.From.Offset = int64(aoffset)
797 p.From.Reg = REGSP
798 p.To.Type = obj.TYPE_REG
799 p.To.Reg = REGLINK
800 p.Spadj = -aoffset
801 } else {
802 p.As = AMOVD
803 p.From.Type = obj.TYPE_MEM
804 p.From.Offset = 0
805 p.From.Reg = REGSP
806 p.To.Type = obj.TYPE_REG
807 p.To.Reg = REGLINK
808
809 q = newprog()
810 q.As = AADD
811 q.From.Type = obj.TYPE_CONST
812 q.From.Offset = int64(aoffset)
813 q.To.Type = obj.TYPE_REG
814 q.To.Reg = REGSP
815 q.Link = p.Link
816 q.Spadj = int32(-q.From.Offset)
817 q.Pos = p.Pos
818 p.Link = q
819 p = q
820 }
821 }
822
823 if p.As != obj.ARET {
824 q = newprog()
825 q.Pos = p.Pos
826 q.Link = p.Link
827 p.Link = q
828 p = q
829 }
830
831 if retjmp != nil { // retjmp
832 p.As = AB
833 p.To.Type = obj.TYPE_BRANCH
834 p.To.Sym = retjmp
835 p.Spadj = +c.autosize
836 break
837 }
838
839 p.As = obj.ARET
840 p.To.Type = obj.TYPE_MEM
841 p.To.Offset = 0
842 p.To.Reg = REGLINK
843 p.Spadj = +c.autosize
844
845 case AADD, ASUB:
846 if p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP && p.From.Type == obj.TYPE_CONST {
847 if p.As == AADD {
848 p.Spadj = int32(-p.From.Offset)
849 } else {
850 p.Spadj = int32(+p.From.Offset)
851 }
852 }
853
854 case obj.AGETCALLERPC:
855 if cursym.Leaf() {
856 /* MOVD LR, Rd */
857 p.As = AMOVD
858 p.From.Type = obj.TYPE_REG
859 p.From.Reg = REGLINK
860 } else {
861 /* MOVD (RSP), Rd */
862 p.As = AMOVD
863 p.From.Type = obj.TYPE_MEM
864 p.From.Reg = REGSP
865 }
866
867 case obj.ADUFFCOPY:
868 if objabi.Framepointer_enabled {
869 // ADR ret_addr, R27
870 // STP (FP, R27), -24(SP)
871 // SUB 24, SP, FP
872 // DUFFCOPY
873 // ret_addr:
874 // SUB 8, SP, FP
875
876 q1 := p
877 // copy DUFFCOPY from q1 to q4
878 q4 := obj.Appendp(p, c.newprog)
879 q4.Pos = p.Pos
880 q4.As = obj.ADUFFCOPY
881 q4.To = p.To
882
883 q1.As = AADR
884 q1.From.Type = obj.TYPE_BRANCH
885 q1.To.Type = obj.TYPE_REG
886 q1.To.Reg = REG_R27
887
888 q2 := obj.Appendp(q1, c.newprog)
889 q2.Pos = p.Pos
890 q2.As = ASTP
891 q2.From.Type = obj.TYPE_REGREG
892 q2.From.Reg = REGFP
893 q2.From.Offset = int64(REG_R27)
894 q2.To.Type = obj.TYPE_MEM
895 q2.To.Reg = REGSP
896 q2.To.Offset = -24
897
898 // maintaine FP for DUFFCOPY
899 q3 := obj.Appendp(q2, c.newprog)
900 q3.Pos = p.Pos
901 q3.As = ASUB
902 q3.From.Type = obj.TYPE_CONST
903 q3.From.Offset = 24
904 q3.Reg = REGSP
905 q3.To.Type = obj.TYPE_REG
906 q3.To.Reg = REGFP
907
908 q5 := obj.Appendp(q4, c.newprog)
909 q5.Pos = p.Pos
910 q5.As = ASUB
911 q5.From.Type = obj.TYPE_CONST
912 q5.From.Offset = 8
913 q5.Reg = REGSP
914 q5.To.Type = obj.TYPE_REG
915 q5.To.Reg = REGFP
916 q1.From.SetTarget(q5)
917 p = q5
918 }
919
920 case obj.ADUFFZERO:
921 if objabi.Framepointer_enabled {
922 // ADR ret_addr, R27
923 // STP (FP, R27), -24(SP)
924 // SUB 24, SP, FP
925 // DUFFZERO
926 // ret_addr:
927 // SUB 8, SP, FP
928
929 q1 := p
930 // copy DUFFZERO from q1 to q4
931 q4 := obj.Appendp(p, c.newprog)
932 q4.Pos = p.Pos
933 q4.As = obj.ADUFFZERO
934 q4.To = p.To
935
936 q1.As = AADR
937 q1.From.Type = obj.TYPE_BRANCH
938 q1.To.Type = obj.TYPE_REG
939 q1.To.Reg = REG_R27
940
941 q2 := obj.Appendp(q1, c.newprog)
942 q2.Pos = p.Pos
943 q2.As = ASTP
944 q2.From.Type = obj.TYPE_REGREG
945 q2.From.Reg = REGFP
946 q2.From.Offset = int64(REG_R27)
947 q2.To.Type = obj.TYPE_MEM
948 q2.To.Reg = REGSP
949 q2.To.Offset = -24
950
951 // maintaine FP for DUFFZERO
952 q3 := obj.Appendp(q2, c.newprog)
953 q3.Pos = p.Pos
954 q3.As = ASUB
955 q3.From.Type = obj.TYPE_CONST
956 q3.From.Offset = 24
957 q3.Reg = REGSP
958 q3.To.Type = obj.TYPE_REG
959 q3.To.Reg = REGFP
960
961 q5 := obj.Appendp(q4, c.newprog)
962 q5.Pos = p.Pos
963 q5.As = ASUB
964 q5.From.Type = obj.TYPE_CONST
965 q5.From.Offset = 8
966 q5.Reg = REGSP
967 q5.To.Type = obj.TYPE_REG
968 q5.To.Reg = REGFP
969 q1.From.SetTarget(q5)
970 p = q5
971 }
972 }
973 }
974 }
975
976 func nocache(p *obj.Prog) {
977 p.Optab = 0
978 p.From.Class = 0
979 p.To.Class = 0
980 }
981
982 var unaryDst = map[obj.As]bool{
983 AWORD: true,
984 ADWORD: true,
985 ABL: true,
986 AB: true,
987 ACLREX: true,
988 }
989
990 var Linkarm64 = obj.LinkArch{
991 Arch: sys.ArchARM64,
992 Init: buildop,
993 Preprocess: preprocess,
994 Assemble: span7,
995 Progedit: progedit,
996 UnaryDst: unaryDst,
997 DWARFRegisters: ARM64DWARFRegisters,
998 }
999