1/*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17/*
18  Art assembly interpreter notes:
19
20  First validate assembly code by implementing ExecuteXXXImpl() style body (doesn't
21  handle invoke, allows higher-level code to create frame & shadow frame.
22
23  Once that's working, support direct entry code & eliminate shadow frame (and
24  excess locals allocation.
25
26  Some (hopefully) temporary ugliness.  We'll treat rFP as pointing to the
27  base of the vreg array within the shadow frame.  Access the other fields,
28  dex_pc_, method_ and number_of_vregs_ via negative offsets.  For now, we'll continue
29  the shadow frame mechanism of double-storing object references - via rFP &
30  number_of_vregs_.
31
32 */
33
34#include "asm_support.h"
35
36#if (__mips==32) && (__mips_isa_rev>=2)
37#define MIPS32REVGE2    /* mips32r2 and greater */
38#if (__mips==32) && (__mips_isa_rev>=5)
39#define FPU64           /* 64 bit FPU */
40#if (__mips==32) && (__mips_isa_rev>=6)
41#define MIPS32REVGE6    /* mips32r6 and greater */
42#endif
43#endif
44#endif
45
46/* MIPS definitions and declarations
47
48   reg  nick      purpose
49   s0   rPC       interpreted program counter, used for fetching instructions
50   s1   rFP       interpreted frame pointer, used for accessing locals and args
51   s2   rSELF     self (Thread) pointer
52   s3   rIBASE    interpreted instruction base pointer, used for computed goto
53   s4   rINST     first 16-bit code unit of current instruction
54   s6   rREFS     base of object references in shadow frame (ideally, we'll get rid of this later).
55*/
56
57/* single-purpose registers, given names for clarity */
58#define rPC s0
59#define rFP s1
60#define rSELF s2
61#define rIBASE s3
62#define rINST s4
63#define rOBJ s5
64#define rREFS s6
65#define rTEMP s7
66
67#define rARG0 a0
68#define rARG1 a1
69#define rARG2 a2
70#define rARG3 a3
71#define rRESULT0 v0
72#define rRESULT1 v1
73
74/* GP register definitions */
75#define zero    $$0      /* always zero */
76#define AT      $$at     /* assembler temp */
77#define v0      $$2      /* return value */
78#define v1      $$3
79#define a0      $$4      /* argument registers */
80#define a1      $$5
81#define a2      $$6
82#define a3      $$7
83#define t0      $$8      /* temp registers (not saved across subroutine calls) */
84#define t1      $$9
85#define t2      $$10
86#define t3      $$11
87#define t4      $$12
88#define t5      $$13
89#define t6      $$14
90#define t7      $$15
91#define ta0     $$12     /* alias */
92#define ta1     $$13
93#define ta2     $$14
94#define ta3     $$15
95#define s0      $$16     /* saved across subroutine calls (callee saved) */
96#define s1      $$17
97#define s2      $$18
98#define s3      $$19
99#define s4      $$20
100#define s5      $$21
101#define s6      $$22
102#define s7      $$23
103#define t8      $$24     /* two more temp registers */
104#define t9      $$25
105#define k0      $$26     /* kernel temporary */
106#define k1      $$27
107#define gp      $$28     /* global pointer */
108#define sp      $$29     /* stack pointer */
109#define s8      $$30     /* one more callee saved */
110#define ra      $$31     /* return address */
111
112/* FP register definitions */
113#define fv0    $$f0
114#define fv0f   $$f1
115#define fv1    $$f2
116#define fv1f   $$f3
117#define fa0    $$f12
118#define fa0f   $$f13
119#define fa1    $$f14
120#define fa1f   $$f15
121#define ft0    $$f4
122#define ft0f   $$f5
123#define ft1    $$f6
124#define ft1f   $$f7
125#define ft2    $$f8
126#define ft2f   $$f9
127#define ft3    $$f10
128#define ft3f   $$f11
129#define ft4    $$f16
130#define ft4f   $$f17
131#define ft5    $$f18
132#define ft5f   $$f19
133#define fs0    $$f20
134#define fs0f   $$f21
135#define fs1    $$f22
136#define fs1f   $$f23
137#define fs2    $$f24
138#define fs2f   $$f25
139#define fs3    $$f26
140#define fs3f   $$f27
141#define fs4    $$f28
142#define fs4f   $$f29
143#define fs5    $$f30
144#define fs5f   $$f31
145
146#ifndef MIPS32REVGE6
147#define fcc0   $$fcc0
148#define fcc1   $$fcc1
149#endif
150
151/*
152 * Instead of holding a pointer to the shadow frame, we keep rFP at the base of the vregs.  So,
153 * to access other shadow frame fields, we need to use a backwards offset.  Define those here.
154 */
155#define OFF_FP(a) (a - SHADOWFRAME_VREGS_OFFSET)
156#define OFF_FP_NUMBER_OF_VREGS OFF_FP(SHADOWFRAME_NUMBER_OF_VREGS_OFFSET)
157#define OFF_FP_DEX_PC OFF_FP(SHADOWFRAME_DEX_PC_OFFSET)
158#define OFF_FP_LINK OFF_FP(SHADOWFRAME_LINK_OFFSET)
159#define OFF_FP_METHOD OFF_FP(SHADOWFRAME_METHOD_OFFSET)
160#define OFF_FP_RESULT_REGISTER OFF_FP(SHADOWFRAME_RESULT_REGISTER_OFFSET)
161#define OFF_FP_DEX_PC_PTR OFF_FP(SHADOWFRAME_DEX_PC_PTR_OFFSET)
162#define OFF_FP_CODE_ITEM OFF_FP(SHADOWFRAME_CODE_ITEM_OFFSET)
163#define OFF_FP_SHADOWFRAME (-SHADOWFRAME_VREGS_OFFSET)
164
165#define MTERP_PROFILE_BRANCHES 1
166#define MTERP_LOGGING 0
167
168/*
169 * "export" the PC to dex_pc field in the shadow frame, f/b/o future exception objects.  Must
170 * be done *before* something throws.
171 *
172 * It's okay to do this more than once.
173 *
174 * NOTE: the fast interpreter keeps track of dex pc as a direct pointer to the mapped
175 * dex byte codes.  However, the rest of the runtime expects dex pc to be an instruction
176 * offset into the code_items_[] array.  For effiency, we will "export" the
177 * current dex pc as a direct pointer using the EXPORT_PC macro, and rely on GetDexPC
178 * to convert to a dex pc when needed.
179 */
180#define EXPORT_PC() \
181    sw        rPC, OFF_FP_DEX_PC_PTR(rFP)
182
183#define EXPORT_DEX_PC(tmp) \
184    lw   tmp, OFF_FP_CODE_ITEM(rFP) \
185    sw   rPC, OFF_FP_DEX_PC_PTR(rFP) \
186    addu tmp, CODEITEM_INSNS_OFFSET \
187    subu tmp, rPC, tmp \
188    sra  tmp, tmp, 1 \
189    sw   tmp, OFF_FP_DEX_PC(rFP)
190
191/*
192 * Fetch the next instruction from rPC into rINST.  Does not advance rPC.
193 */
194#define FETCH_INST() lhu rINST, (rPC)
195
196/*
197 * Fetch the next instruction from the specified offset.  Advances rPC
198 * to point to the next instruction.  "_count" is in 16-bit code units.
199 *
200 * This must come AFTER anything that can throw an exception, or the
201 * exception catch may miss.  (This also implies that it must come after
202 * EXPORT_PC().)
203 */
204#define FETCH_ADVANCE_INST(_count) lhu rINST, ((_count)*2)(rPC); \
205    addu      rPC, rPC, ((_count) * 2)
206
207/*
208 * The operation performed here is similar to FETCH_ADVANCE_INST, except the
209 * src and dest registers are parameterized (not hard-wired to rPC and rINST).
210 */
211#define PREFETCH_ADVANCE_INST(_dreg, _sreg, _count) \
212    lhu       _dreg, ((_count)*2)(_sreg) ;            \
213    addu      _sreg, _sreg, (_count)*2
214
215/*
216 * Similar to FETCH_ADVANCE_INST, but does not update rPC.  Used to load
217 * rINST ahead of possible exception point.  Be sure to manually advance rPC
218 * later.
219 */
220#define PREFETCH_INST(_count) lhu rINST, ((_count)*2)(rPC)
221
222/* Advance rPC by some number of code units. */
223#define ADVANCE(_count) addu rPC, rPC, ((_count) * 2)
224
225/*
226 * Fetch the next instruction from an offset specified by rd.  Updates
227 * rPC to point to the next instruction.  "rd" must specify the distance
228 * in bytes, *not* 16-bit code units, and may be a signed value.
229 */
230#define FETCH_ADVANCE_INST_RB(rd) addu rPC, rPC, rd; \
231    lhu       rINST, (rPC)
232
233/*
234 * Fetch a half-word code unit from an offset past the current PC.  The
235 * "_count" value is in 16-bit code units.  Does not advance rPC.
236 *
237 * The "_S" variant works the same but treats the value as signed.
238 */
239#define FETCH(rd, _count) lhu rd, ((_count) * 2)(rPC)
240#define FETCH_S(rd, _count) lh rd, ((_count) * 2)(rPC)
241
242/*
243 * Fetch one byte from an offset past the current PC.  Pass in the same
244 * "_count" as you would for FETCH, and an additional 0/1 indicating which
245 * byte of the halfword you want (lo/hi).
246 */
247#define FETCH_B(rd, _count, _byte) lbu rd, ((_count) * 2 + _byte)(rPC)
248
249/*
250 * Put the instruction's opcode field into the specified register.
251 */
252#define GET_INST_OPCODE(rd) and rd, rINST, 0xFF
253
254/*
255 * Put the prefetched instruction's opcode field into the specified register.
256 */
257#define GET_PREFETCHED_OPCODE(dreg, sreg)   andi     dreg, sreg, 255
258
259/*
260 * Begin executing the opcode in rd.
261 */
262#define GOTO_OPCODE(rd) sll rd, rd, ${handler_size_bits}; \
263    addu      rd, rIBASE, rd; \
264    jalr      zero, rd
265
266#define GOTO_OPCODE_BASE(_base, rd)  sll rd, rd, ${handler_size_bits}; \
267    addu      rd, _base, rd; \
268    jalr      zero, rd
269
270/*
271 * Get/set the 32-bit value from a Dalvik register.
272 */
273#define GET_VREG(rd, rix) LOAD_eas2(rd, rFP, rix)
274
275#define GET_VREG_F(rd, rix) EAS2(AT, rFP, rix); \
276    .set noat; l.s rd, (AT); .set at
277
278#define SET_VREG(rd, rix) .set noat; \
279    sll       AT, rix, 2; \
280    addu      t8, rFP, AT; \
281    sw        rd, 0(t8); \
282    addu      t8, rREFS, AT; \
283    .set at; \
284    sw        zero, 0(t8)
285
286#define SET_VREG64(rlo, rhi, rix) .set noat; \
287    sll       AT, rix, 2; \
288    addu      t8, rFP, AT; \
289    sw        rlo, 0(t8); \
290    sw        rhi, 4(t8); \
291    addu      t8, rREFS, AT; \
292    .set at; \
293    sw        zero, 0(t8); \
294    sw        zero, 4(t8)
295
296#ifdef FPU64
297#define SET_VREG64_F(rlo, rhi, rix) .set noat; \
298    sll       AT, rix, 2; \
299    addu      t8, rREFS, AT; \
300    sw        zero, 0(t8); \
301    sw        zero, 4(t8); \
302    addu      t8, rFP, AT; \
303    mfhc1     AT, rlo; \
304    sw        AT, 4(t8); \
305    .set at; \
306    s.s       rlo, 0(t8)
307#else
308#define SET_VREG64_F(rlo, rhi, rix) .set noat; \
309    sll       AT, rix, 2; \
310    addu      t8, rFP, AT; \
311    s.s       rlo, 0(t8); \
312    s.s       rhi, 4(t8); \
313    addu      t8, rREFS, AT; \
314    .set at; \
315    sw        zero, 0(t8); \
316    sw        zero, 4(t8)
317#endif
318
319#define SET_VREG_OBJECT(rd, rix) .set noat; \
320    sll       AT, rix, 2; \
321    addu      t8, rFP, AT; \
322    sw        rd, 0(t8); \
323    addu      t8, rREFS, AT; \
324    .set at; \
325    sw        rd, 0(t8)
326
327/* Combination of the SET_VREG and GOTO_OPCODE functions to save 1 instruction */
328#define SET_VREG_GOTO(rd, rix, dst) .set noreorder; \
329    sll       dst, dst, ${handler_size_bits}; \
330    addu      dst, rIBASE, dst; \
331    .set noat; \
332    sll       AT, rix, 2; \
333    addu      t8, rFP, AT; \
334    sw        rd, 0(t8); \
335    addu      t8, rREFS, AT; \
336    .set at; \
337    jalr      zero, dst; \
338    sw        zero, 0(t8); \
339    .set reorder
340
341/* Combination of the SET_VREG64 and GOTO_OPCODE functions to save 1 instruction */
342#define SET_VREG64_GOTO(rlo, rhi, rix, dst) .set noreorder; \
343    sll       dst, dst, ${handler_size_bits}; \
344    addu      dst, rIBASE, dst; \
345    .set noat; \
346    sll       AT, rix, 2; \
347    addu      t8, rFP, AT; \
348    sw        rlo, 0(t8); \
349    sw        rhi, 4(t8); \
350    addu      t8, rREFS, AT; \
351    .set at; \
352    sw        zero, 0(t8); \
353    jalr      zero, dst; \
354    sw        zero, 4(t8); \
355    .set reorder
356
357#define SET_VREG_F(rd, rix) .set noat; \
358    sll       AT, rix, 2; \
359    addu      t8, rFP, AT; \
360    s.s       rd, 0(t8); \
361    addu      t8, rREFS, AT; \
362    .set at; \
363    sw        zero, 0(t8)
364
365#define GET_OPA(rd) srl rd, rINST, 8
366#ifdef MIPS32REVGE2
367#define GET_OPA4(rd) ext rd, rINST, 8, 4
368#else
369#define GET_OPA4(rd) GET_OPA(rd); and rd, 0xf
370#endif
371#define GET_OPB(rd) srl rd, rINST, 12
372
373/*
374 * Form an Effective Address rd = rbase + roff<<n;
375 * Uses reg AT
376 */
377#define EASN(rd, rbase, roff, rshift) .set noat; \
378    sll       AT, roff, rshift; \
379    addu      rd, rbase, AT; \
380    .set at
381
382#define EAS1(rd, rbase, roff) EASN(rd, rbase, roff, 1)
383#define EAS2(rd, rbase, roff) EASN(rd, rbase, roff, 2)
384#define EAS3(rd, rbase, roff) EASN(rd, rbase, roff, 3)
385#define EAS4(rd, rbase, roff) EASN(rd, rbase, roff, 4)
386
387/*
388 * Form an Effective Shift Right rd = rbase + roff>>n;
389 * Uses reg AT
390 */
391#define ESRN(rd, rbase, roff, rshift) .set noat; \
392    srl       AT, roff, rshift; \
393    addu      rd, rbase, AT; \
394    .set at
395
396#define LOAD_eas2(rd, rbase, roff) EAS2(AT, rbase, roff); \
397    .set noat; lw rd, 0(AT); .set at
398
399#define STORE_eas2(rd, rbase, roff) EAS2(AT, rbase, roff); \
400    .set noat; sw rd, 0(AT); .set at
401
402#define LOAD_RB_OFF(rd, rbase, off) lw rd, off(rbase)
403#define STORE_RB_OFF(rd, rbase, off) sw rd, off(rbase)
404
405#define STORE64_off(rlo, rhi, rbase, off) sw rlo, off(rbase); \
406    sw        rhi, (off+4)(rbase)
407#define LOAD64_off(rlo, rhi, rbase, off) lw rlo, off(rbase); \
408    lw        rhi, (off+4)(rbase)
409
410#define STORE64(rlo, rhi, rbase) STORE64_off(rlo, rhi, rbase, 0)
411#define LOAD64(rlo, rhi, rbase) LOAD64_off(rlo, rhi, rbase, 0)
412
413#ifdef FPU64
414#define STORE64_off_F(rlo, rhi, rbase, off) s.s rlo, off(rbase); \
415    .set noat; \
416    mfhc1     AT, rlo; \
417    sw        AT, (off+4)(rbase); \
418    .set at
419#define LOAD64_off_F(rlo, rhi, rbase, off) l.s rlo, off(rbase); \
420    .set noat; \
421    lw        AT, (off+4)(rbase); \
422    mthc1     AT, rlo; \
423    .set at
424#else
425#define STORE64_off_F(rlo, rhi, rbase, off) s.s rlo, off(rbase); \
426    s.s       rhi, (off+4)(rbase)
427#define LOAD64_off_F(rlo, rhi, rbase, off) l.s rlo, off(rbase); \
428    l.s       rhi, (off+4)(rbase)
429#endif
430
431#define STORE64_F(rlo, rhi, rbase) STORE64_off_F(rlo, rhi, rbase, 0)
432#define LOAD64_F(rlo, rhi, rbase) LOAD64_off_F(rlo, rhi, rbase, 0)
433
434
435#define LOAD_base_offMirrorArray_length(rd, rbase) LOAD_RB_OFF(rd, rbase, MIRROR_ARRAY_LENGTH_OFFSET)
436
437#define STACK_STORE(rd, off) sw rd, off(sp)
438#define STACK_LOAD(rd, off) lw rd, off(sp)
439#define CREATE_STACK(n) subu sp, sp, n
440#define DELETE_STACK(n) addu sp, sp, n
441
442#define LOAD_ADDR(dest, addr) la dest, addr
443#define LOAD_IMM(dest, imm) li dest, imm
444#define MOVE_REG(dest, src) move dest, src
445#define STACK_SIZE 128
446
447#define STACK_OFFSET_ARG04 16
448#define STACK_OFFSET_ARG05 20
449#define STACK_OFFSET_ARG06 24
450#define STACK_OFFSET_ARG07 28
451#define STACK_OFFSET_GP    84
452
453#define JAL(n) jal n
454#define BAL(n) bal n
455
456/*
457 * FP register usage restrictions:
458 * 1) We don't use the callee save FP registers so we don't have to save them.
459 * 2) We don't use the odd FP registers so we can share code with mips32r6.
460 */
461#define STACK_STORE_FULL() CREATE_STACK(STACK_SIZE); \
462    STACK_STORE(ra, 124); \
463    STACK_STORE(s8, 120); \
464    STACK_STORE(s0, 116); \
465    STACK_STORE(s1, 112); \
466    STACK_STORE(s2, 108); \
467    STACK_STORE(s3, 104); \
468    STACK_STORE(s4, 100); \
469    STACK_STORE(s5, 96); \
470    STACK_STORE(s6, 92); \
471    STACK_STORE(s7, 88);
472
473#define STACK_LOAD_FULL() STACK_LOAD(gp, STACK_OFFSET_GP); \
474    STACK_LOAD(s7, 88); \
475    STACK_LOAD(s6, 92); \
476    STACK_LOAD(s5, 96); \
477    STACK_LOAD(s4, 100); \
478    STACK_LOAD(s3, 104); \
479    STACK_LOAD(s2, 108); \
480    STACK_LOAD(s1, 112); \
481    STACK_LOAD(s0, 116); \
482    STACK_LOAD(s8, 120); \
483    STACK_LOAD(ra, 124); \
484    DELETE_STACK(STACK_SIZE)
485