1 /*
2  * Copyright (C) 2014 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 #include "assembler_arm64.h"
18 #include "base/logging.h"
19 #include "entrypoints/quick/quick_entrypoints.h"
20 #include "offsets.h"
21 #include "thread.h"
22 
23 using namespace vixl;  // NOLINT(build/namespaces)
24 
25 namespace art {
26 namespace arm64 {
27 
28 #ifdef ___
29 #error "ARM64 Assembler macro already defined."
30 #else
31 #define ___   vixl_masm_->
32 #endif
33 
EmitSlowPaths()34 void Arm64Assembler::EmitSlowPaths() {
35   if (!exception_blocks_.empty()) {
36     for (size_t i = 0; i < exception_blocks_.size(); i++) {
37       EmitExceptionPoll(exception_blocks_.at(i));
38     }
39   }
40   ___ FinalizeCode();
41 }
42 
CodeSize() const43 size_t Arm64Assembler::CodeSize() const {
44   return vixl_masm_->BufferCapacity() - vixl_masm_->RemainingBufferSpace();
45 }
46 
FinalizeInstructions(const MemoryRegion & region)47 void Arm64Assembler::FinalizeInstructions(const MemoryRegion& region) {
48   // Copy the instructions from the buffer.
49   MemoryRegion from(vixl_masm_->GetStartAddress<void*>(), CodeSize());
50   region.CopyFrom(0, from);
51 }
52 
GetCurrentThread(ManagedRegister tr)53 void Arm64Assembler::GetCurrentThread(ManagedRegister tr) {
54   ___ Mov(reg_x(tr.AsArm64().AsXRegister()), reg_x(ETR));
55 }
56 
GetCurrentThread(FrameOffset offset,ManagedRegister)57 void Arm64Assembler::GetCurrentThread(FrameOffset offset, ManagedRegister /* scratch */) {
58   StoreToOffset(ETR, SP, offset.Int32Value());
59 }
60 
61 // See Arm64 PCS Section 5.2.2.1.
IncreaseFrameSize(size_t adjust)62 void Arm64Assembler::IncreaseFrameSize(size_t adjust) {
63   CHECK_ALIGNED(adjust, kStackAlignment);
64   AddConstant(SP, -adjust);
65   cfi().AdjustCFAOffset(adjust);
66 }
67 
68 // See Arm64 PCS Section 5.2.2.1.
DecreaseFrameSize(size_t adjust)69 void Arm64Assembler::DecreaseFrameSize(size_t adjust) {
70   CHECK_ALIGNED(adjust, kStackAlignment);
71   AddConstant(SP, adjust);
72   cfi().AdjustCFAOffset(-adjust);
73 }
74 
AddConstant(XRegister rd,int32_t value,Condition cond)75 void Arm64Assembler::AddConstant(XRegister rd, int32_t value, Condition cond) {
76   AddConstant(rd, rd, value, cond);
77 }
78 
AddConstant(XRegister rd,XRegister rn,int32_t value,Condition cond)79 void Arm64Assembler::AddConstant(XRegister rd, XRegister rn, int32_t value,
80                                  Condition cond) {
81   if ((cond == al) || (cond == nv)) {
82     // VIXL macro-assembler handles all variants.
83     ___ Add(reg_x(rd), reg_x(rn), value);
84   } else {
85     // temp = rd + value
86     // rd = cond ? temp : rn
87     vixl::UseScratchRegisterScope temps(vixl_masm_);
88     temps.Exclude(reg_x(rd), reg_x(rn));
89     vixl::Register temp = temps.AcquireX();
90     ___ Add(temp, reg_x(rn), value);
91     ___ Csel(reg_x(rd), temp, reg_x(rd), cond);
92   }
93 }
94 
StoreWToOffset(StoreOperandType type,WRegister source,XRegister base,int32_t offset)95 void Arm64Assembler::StoreWToOffset(StoreOperandType type, WRegister source,
96                                     XRegister base, int32_t offset) {
97   switch (type) {
98     case kStoreByte:
99       ___ Strb(reg_w(source), MEM_OP(reg_x(base), offset));
100       break;
101     case kStoreHalfword:
102       ___ Strh(reg_w(source), MEM_OP(reg_x(base), offset));
103       break;
104     case kStoreWord:
105       ___ Str(reg_w(source), MEM_OP(reg_x(base), offset));
106       break;
107     default:
108       LOG(FATAL) << "UNREACHABLE";
109   }
110 }
111 
StoreToOffset(XRegister source,XRegister base,int32_t offset)112 void Arm64Assembler::StoreToOffset(XRegister source, XRegister base, int32_t offset) {
113   CHECK_NE(source, SP);
114   ___ Str(reg_x(source), MEM_OP(reg_x(base), offset));
115 }
116 
StoreSToOffset(SRegister source,XRegister base,int32_t offset)117 void Arm64Assembler::StoreSToOffset(SRegister source, XRegister base, int32_t offset) {
118   ___ Str(reg_s(source), MEM_OP(reg_x(base), offset));
119 }
120 
StoreDToOffset(DRegister source,XRegister base,int32_t offset)121 void Arm64Assembler::StoreDToOffset(DRegister source, XRegister base, int32_t offset) {
122   ___ Str(reg_d(source), MEM_OP(reg_x(base), offset));
123 }
124 
Store(FrameOffset offs,ManagedRegister m_src,size_t size)125 void Arm64Assembler::Store(FrameOffset offs, ManagedRegister m_src, size_t size) {
126   Arm64ManagedRegister src = m_src.AsArm64();
127   if (src.IsNoRegister()) {
128     CHECK_EQ(0u, size);
129   } else if (src.IsWRegister()) {
130     CHECK_EQ(4u, size);
131     StoreWToOffset(kStoreWord, src.AsWRegister(), SP, offs.Int32Value());
132   } else if (src.IsXRegister()) {
133     CHECK_EQ(8u, size);
134     StoreToOffset(src.AsXRegister(), SP, offs.Int32Value());
135   } else if (src.IsSRegister()) {
136     StoreSToOffset(src.AsSRegister(), SP, offs.Int32Value());
137   } else {
138     CHECK(src.IsDRegister()) << src;
139     StoreDToOffset(src.AsDRegister(), SP, offs.Int32Value());
140   }
141 }
142 
StoreRef(FrameOffset offs,ManagedRegister m_src)143 void Arm64Assembler::StoreRef(FrameOffset offs, ManagedRegister m_src) {
144   Arm64ManagedRegister src = m_src.AsArm64();
145   CHECK(src.IsXRegister()) << src;
146   StoreWToOffset(kStoreWord, src.AsOverlappingWRegister(), SP,
147                  offs.Int32Value());
148 }
149 
StoreRawPtr(FrameOffset offs,ManagedRegister m_src)150 void Arm64Assembler::StoreRawPtr(FrameOffset offs, ManagedRegister m_src) {
151   Arm64ManagedRegister src = m_src.AsArm64();
152   CHECK(src.IsXRegister()) << src;
153   StoreToOffset(src.AsXRegister(), SP, offs.Int32Value());
154 }
155 
StoreImmediateToFrame(FrameOffset offs,uint32_t imm,ManagedRegister m_scratch)156 void Arm64Assembler::StoreImmediateToFrame(FrameOffset offs, uint32_t imm,
157                                            ManagedRegister m_scratch) {
158   Arm64ManagedRegister scratch = m_scratch.AsArm64();
159   CHECK(scratch.IsXRegister()) << scratch;
160   LoadImmediate(scratch.AsXRegister(), imm);
161   StoreWToOffset(kStoreWord, scratch.AsOverlappingWRegister(), SP,
162                  offs.Int32Value());
163 }
164 
StoreImmediateToThread64(ThreadOffset<8> offs,uint32_t imm,ManagedRegister m_scratch)165 void Arm64Assembler::StoreImmediateToThread64(ThreadOffset<8> offs, uint32_t imm,
166                                             ManagedRegister m_scratch) {
167   Arm64ManagedRegister scratch = m_scratch.AsArm64();
168   CHECK(scratch.IsXRegister()) << scratch;
169   LoadImmediate(scratch.AsXRegister(), imm);
170   StoreToOffset(scratch.AsXRegister(), ETR, offs.Int32Value());
171 }
172 
StoreStackOffsetToThread64(ThreadOffset<8> tr_offs,FrameOffset fr_offs,ManagedRegister m_scratch)173 void Arm64Assembler::StoreStackOffsetToThread64(ThreadOffset<8> tr_offs,
174                                               FrameOffset fr_offs,
175                                               ManagedRegister m_scratch) {
176   Arm64ManagedRegister scratch = m_scratch.AsArm64();
177   CHECK(scratch.IsXRegister()) << scratch;
178   AddConstant(scratch.AsXRegister(), SP, fr_offs.Int32Value());
179   StoreToOffset(scratch.AsXRegister(), ETR, tr_offs.Int32Value());
180 }
181 
StoreStackPointerToThread64(ThreadOffset<8> tr_offs)182 void Arm64Assembler::StoreStackPointerToThread64(ThreadOffset<8> tr_offs) {
183   vixl::UseScratchRegisterScope temps(vixl_masm_);
184   vixl::Register temp = temps.AcquireX();
185   ___ Mov(temp, reg_x(SP));
186   ___ Str(temp, MEM_OP(reg_x(ETR), tr_offs.Int32Value()));
187 }
188 
StoreSpanning(FrameOffset dest_off,ManagedRegister m_source,FrameOffset in_off,ManagedRegister m_scratch)189 void Arm64Assembler::StoreSpanning(FrameOffset dest_off, ManagedRegister m_source,
190                                    FrameOffset in_off, ManagedRegister m_scratch) {
191   Arm64ManagedRegister source = m_source.AsArm64();
192   Arm64ManagedRegister scratch = m_scratch.AsArm64();
193   StoreToOffset(source.AsXRegister(), SP, dest_off.Int32Value());
194   LoadFromOffset(scratch.AsXRegister(), SP, in_off.Int32Value());
195   StoreToOffset(scratch.AsXRegister(), SP, dest_off.Int32Value() + 8);
196 }
197 
198 // Load routines.
LoadImmediate(XRegister dest,int32_t value,Condition cond)199 void Arm64Assembler::LoadImmediate(XRegister dest, int32_t value,
200                                    Condition cond) {
201   if ((cond == al) || (cond == nv)) {
202     ___ Mov(reg_x(dest), value);
203   } else {
204     // temp = value
205     // rd = cond ? temp : rd
206     if (value != 0) {
207       vixl::UseScratchRegisterScope temps(vixl_masm_);
208       temps.Exclude(reg_x(dest));
209       vixl::Register temp = temps.AcquireX();
210       ___ Mov(temp, value);
211       ___ Csel(reg_x(dest), temp, reg_x(dest), cond);
212     } else {
213       ___ Csel(reg_x(dest), reg_x(XZR), reg_x(dest), cond);
214     }
215   }
216 }
217 
LoadWFromOffset(LoadOperandType type,WRegister dest,XRegister base,int32_t offset)218 void Arm64Assembler::LoadWFromOffset(LoadOperandType type, WRegister dest,
219                                      XRegister base, int32_t offset) {
220   switch (type) {
221     case kLoadSignedByte:
222       ___ Ldrsb(reg_w(dest), MEM_OP(reg_x(base), offset));
223       break;
224     case kLoadSignedHalfword:
225       ___ Ldrsh(reg_w(dest), MEM_OP(reg_x(base), offset));
226       break;
227     case kLoadUnsignedByte:
228       ___ Ldrb(reg_w(dest), MEM_OP(reg_x(base), offset));
229       break;
230     case kLoadUnsignedHalfword:
231       ___ Ldrh(reg_w(dest), MEM_OP(reg_x(base), offset));
232       break;
233     case kLoadWord:
234       ___ Ldr(reg_w(dest), MEM_OP(reg_x(base), offset));
235       break;
236     default:
237         LOG(FATAL) << "UNREACHABLE";
238   }
239 }
240 
241 // Note: We can extend this member by adding load type info - see
242 // sign extended A64 load variants.
LoadFromOffset(XRegister dest,XRegister base,int32_t offset)243 void Arm64Assembler::LoadFromOffset(XRegister dest, XRegister base,
244                                     int32_t offset) {
245   CHECK_NE(dest, SP);
246   ___ Ldr(reg_x(dest), MEM_OP(reg_x(base), offset));
247 }
248 
LoadSFromOffset(SRegister dest,XRegister base,int32_t offset)249 void Arm64Assembler::LoadSFromOffset(SRegister dest, XRegister base,
250                                      int32_t offset) {
251   ___ Ldr(reg_s(dest), MEM_OP(reg_x(base), offset));
252 }
253 
LoadDFromOffset(DRegister dest,XRegister base,int32_t offset)254 void Arm64Assembler::LoadDFromOffset(DRegister dest, XRegister base,
255                                      int32_t offset) {
256   ___ Ldr(reg_d(dest), MEM_OP(reg_x(base), offset));
257 }
258 
Load(Arm64ManagedRegister dest,XRegister base,int32_t offset,size_t size)259 void Arm64Assembler::Load(Arm64ManagedRegister dest, XRegister base,
260                           int32_t offset, size_t size) {
261   if (dest.IsNoRegister()) {
262     CHECK_EQ(0u, size) << dest;
263   } else if (dest.IsWRegister()) {
264     CHECK_EQ(4u, size) << dest;
265     ___ Ldr(reg_w(dest.AsWRegister()), MEM_OP(reg_x(base), offset));
266   } else if (dest.IsXRegister()) {
267     CHECK_NE(dest.AsXRegister(), SP) << dest;
268     if (size == 4u) {
269       ___ Ldr(reg_w(dest.AsOverlappingWRegister()), MEM_OP(reg_x(base), offset));
270     } else {
271       CHECK_EQ(8u, size) << dest;
272       ___ Ldr(reg_x(dest.AsXRegister()), MEM_OP(reg_x(base), offset));
273     }
274   } else if (dest.IsSRegister()) {
275     ___ Ldr(reg_s(dest.AsSRegister()), MEM_OP(reg_x(base), offset));
276   } else {
277     CHECK(dest.IsDRegister()) << dest;
278     ___ Ldr(reg_d(dest.AsDRegister()), MEM_OP(reg_x(base), offset));
279   }
280 }
281 
Load(ManagedRegister m_dst,FrameOffset src,size_t size)282 void Arm64Assembler::Load(ManagedRegister m_dst, FrameOffset src, size_t size) {
283   return Load(m_dst.AsArm64(), SP, src.Int32Value(), size);
284 }
285 
LoadFromThread64(ManagedRegister m_dst,ThreadOffset<8> src,size_t size)286 void Arm64Assembler::LoadFromThread64(ManagedRegister m_dst, ThreadOffset<8> src, size_t size) {
287   return Load(m_dst.AsArm64(), ETR, src.Int32Value(), size);
288 }
289 
LoadRef(ManagedRegister m_dst,FrameOffset offs)290 void Arm64Assembler::LoadRef(ManagedRegister m_dst, FrameOffset offs) {
291   Arm64ManagedRegister dst = m_dst.AsArm64();
292   CHECK(dst.IsXRegister()) << dst;
293   LoadWFromOffset(kLoadWord, dst.AsOverlappingWRegister(), SP, offs.Int32Value());
294 }
295 
LoadRef(ManagedRegister m_dst,ManagedRegister m_base,MemberOffset offs,bool poison_reference)296 void Arm64Assembler::LoadRef(ManagedRegister m_dst, ManagedRegister m_base, MemberOffset offs,
297                              bool poison_reference) {
298   Arm64ManagedRegister dst = m_dst.AsArm64();
299   Arm64ManagedRegister base = m_base.AsArm64();
300   CHECK(dst.IsXRegister() && base.IsXRegister());
301   LoadWFromOffset(kLoadWord, dst.AsOverlappingWRegister(), base.AsXRegister(),
302                   offs.Int32Value());
303   if (kPoisonHeapReferences && poison_reference) {
304     WRegister ref_reg = dst.AsOverlappingWRegister();
305     ___ Neg(reg_w(ref_reg), vixl::Operand(reg_w(ref_reg)));
306   }
307 }
308 
LoadRawPtr(ManagedRegister m_dst,ManagedRegister m_base,Offset offs)309 void Arm64Assembler::LoadRawPtr(ManagedRegister m_dst, ManagedRegister m_base, Offset offs) {
310   Arm64ManagedRegister dst = m_dst.AsArm64();
311   Arm64ManagedRegister base = m_base.AsArm64();
312   CHECK(dst.IsXRegister() && base.IsXRegister());
313   // Remove dst and base form the temp list - higher level API uses IP1, IP0.
314   vixl::UseScratchRegisterScope temps(vixl_masm_);
315   temps.Exclude(reg_x(dst.AsXRegister()), reg_x(base.AsXRegister()));
316   ___ Ldr(reg_x(dst.AsXRegister()), MEM_OP(reg_x(base.AsXRegister()), offs.Int32Value()));
317 }
318 
LoadRawPtrFromThread64(ManagedRegister m_dst,ThreadOffset<8> offs)319 void Arm64Assembler::LoadRawPtrFromThread64(ManagedRegister m_dst, ThreadOffset<8> offs) {
320   Arm64ManagedRegister dst = m_dst.AsArm64();
321   CHECK(dst.IsXRegister()) << dst;
322   LoadFromOffset(dst.AsXRegister(), ETR, offs.Int32Value());
323 }
324 
325 // Copying routines.
Move(ManagedRegister m_dst,ManagedRegister m_src,size_t size)326 void Arm64Assembler::Move(ManagedRegister m_dst, ManagedRegister m_src, size_t size) {
327   Arm64ManagedRegister dst = m_dst.AsArm64();
328   Arm64ManagedRegister src = m_src.AsArm64();
329   if (!dst.Equals(src)) {
330     if (dst.IsXRegister()) {
331       if (size == 4) {
332         CHECK(src.IsWRegister());
333         ___ Mov(reg_w(dst.AsOverlappingWRegister()), reg_w(src.AsWRegister()));
334       } else {
335         if (src.IsXRegister()) {
336           ___ Mov(reg_x(dst.AsXRegister()), reg_x(src.AsXRegister()));
337         } else {
338           ___ Mov(reg_x(dst.AsXRegister()), reg_x(src.AsOverlappingXRegister()));
339         }
340       }
341     } else if (dst.IsWRegister()) {
342       CHECK(src.IsWRegister()) << src;
343       ___ Mov(reg_w(dst.AsWRegister()), reg_w(src.AsWRegister()));
344     } else if (dst.IsSRegister()) {
345       CHECK(src.IsSRegister()) << src;
346       ___ Fmov(reg_s(dst.AsSRegister()), reg_s(src.AsSRegister()));
347     } else {
348       CHECK(dst.IsDRegister()) << dst;
349       CHECK(src.IsDRegister()) << src;
350       ___ Fmov(reg_d(dst.AsDRegister()), reg_d(src.AsDRegister()));
351     }
352   }
353 }
354 
CopyRawPtrFromThread64(FrameOffset fr_offs,ThreadOffset<8> tr_offs,ManagedRegister m_scratch)355 void Arm64Assembler::CopyRawPtrFromThread64(FrameOffset fr_offs,
356                                           ThreadOffset<8> tr_offs,
357                                           ManagedRegister m_scratch) {
358   Arm64ManagedRegister scratch = m_scratch.AsArm64();
359   CHECK(scratch.IsXRegister()) << scratch;
360   LoadFromOffset(scratch.AsXRegister(), ETR, tr_offs.Int32Value());
361   StoreToOffset(scratch.AsXRegister(), SP, fr_offs.Int32Value());
362 }
363 
CopyRawPtrToThread64(ThreadOffset<8> tr_offs,FrameOffset fr_offs,ManagedRegister m_scratch)364 void Arm64Assembler::CopyRawPtrToThread64(ThreadOffset<8> tr_offs,
365                                         FrameOffset fr_offs,
366                                         ManagedRegister m_scratch) {
367   Arm64ManagedRegister scratch = m_scratch.AsArm64();
368   CHECK(scratch.IsXRegister()) << scratch;
369   LoadFromOffset(scratch.AsXRegister(), SP, fr_offs.Int32Value());
370   StoreToOffset(scratch.AsXRegister(), ETR, tr_offs.Int32Value());
371 }
372 
CopyRef(FrameOffset dest,FrameOffset src,ManagedRegister m_scratch)373 void Arm64Assembler::CopyRef(FrameOffset dest, FrameOffset src,
374                              ManagedRegister m_scratch) {
375   Arm64ManagedRegister scratch = m_scratch.AsArm64();
376   CHECK(scratch.IsXRegister()) << scratch;
377   LoadWFromOffset(kLoadWord, scratch.AsOverlappingWRegister(),
378                   SP, src.Int32Value());
379   StoreWToOffset(kStoreWord, scratch.AsOverlappingWRegister(),
380                  SP, dest.Int32Value());
381 }
382 
Copy(FrameOffset dest,FrameOffset src,ManagedRegister m_scratch,size_t size)383 void Arm64Assembler::Copy(FrameOffset dest, FrameOffset src,
384                           ManagedRegister m_scratch, size_t size) {
385   Arm64ManagedRegister scratch = m_scratch.AsArm64();
386   CHECK(scratch.IsXRegister()) << scratch;
387   CHECK(size == 4 || size == 8) << size;
388   if (size == 4) {
389     LoadWFromOffset(kLoadWord, scratch.AsOverlappingWRegister(), SP, src.Int32Value());
390     StoreWToOffset(kStoreWord, scratch.AsOverlappingWRegister(), SP, dest.Int32Value());
391   } else if (size == 8) {
392     LoadFromOffset(scratch.AsXRegister(), SP, src.Int32Value());
393     StoreToOffset(scratch.AsXRegister(), SP, dest.Int32Value());
394   } else {
395     UNIMPLEMENTED(FATAL) << "We only support Copy() of size 4 and 8";
396   }
397 }
398 
Copy(FrameOffset dest,ManagedRegister src_base,Offset src_offset,ManagedRegister m_scratch,size_t size)399 void Arm64Assembler::Copy(FrameOffset dest, ManagedRegister src_base, Offset src_offset,
400                           ManagedRegister m_scratch, size_t size) {
401   Arm64ManagedRegister scratch = m_scratch.AsArm64();
402   Arm64ManagedRegister base = src_base.AsArm64();
403   CHECK(base.IsXRegister()) << base;
404   CHECK(scratch.IsXRegister() || scratch.IsWRegister()) << scratch;
405   CHECK(size == 4 || size == 8) << size;
406   if (size == 4) {
407     LoadWFromOffset(kLoadWord, scratch.AsWRegister(), base.AsXRegister(),
408                    src_offset.Int32Value());
409     StoreWToOffset(kStoreWord, scratch.AsWRegister(), SP, dest.Int32Value());
410   } else if (size == 8) {
411     LoadFromOffset(scratch.AsXRegister(), base.AsXRegister(), src_offset.Int32Value());
412     StoreToOffset(scratch.AsXRegister(), SP, dest.Int32Value());
413   } else {
414     UNIMPLEMENTED(FATAL) << "We only support Copy() of size 4 and 8";
415   }
416 }
417 
Copy(ManagedRegister m_dest_base,Offset dest_offs,FrameOffset src,ManagedRegister m_scratch,size_t size)418 void Arm64Assembler::Copy(ManagedRegister m_dest_base, Offset dest_offs, FrameOffset src,
419                           ManagedRegister m_scratch, size_t size) {
420   Arm64ManagedRegister scratch = m_scratch.AsArm64();
421   Arm64ManagedRegister base = m_dest_base.AsArm64();
422   CHECK(base.IsXRegister()) << base;
423   CHECK(scratch.IsXRegister() || scratch.IsWRegister()) << scratch;
424   CHECK(size == 4 || size == 8) << size;
425   if (size == 4) {
426     LoadWFromOffset(kLoadWord, scratch.AsWRegister(), SP, src.Int32Value());
427     StoreWToOffset(kStoreWord, scratch.AsWRegister(), base.AsXRegister(),
428                    dest_offs.Int32Value());
429   } else if (size == 8) {
430     LoadFromOffset(scratch.AsXRegister(), SP, src.Int32Value());
431     StoreToOffset(scratch.AsXRegister(), base.AsXRegister(), dest_offs.Int32Value());
432   } else {
433     UNIMPLEMENTED(FATAL) << "We only support Copy() of size 4 and 8";
434   }
435 }
436 
Copy(FrameOffset,FrameOffset,Offset,ManagedRegister,size_t)437 void Arm64Assembler::Copy(FrameOffset /*dst*/, FrameOffset /*src_base*/, Offset /*src_offset*/,
438                           ManagedRegister /*mscratch*/, size_t /*size*/) {
439   UNIMPLEMENTED(FATAL) << "Unimplemented Copy() variant";
440 }
441 
Copy(ManagedRegister m_dest,Offset dest_offset,ManagedRegister m_src,Offset src_offset,ManagedRegister m_scratch,size_t size)442 void Arm64Assembler::Copy(ManagedRegister m_dest, Offset dest_offset,
443                           ManagedRegister m_src, Offset src_offset,
444                           ManagedRegister m_scratch, size_t size) {
445   Arm64ManagedRegister scratch = m_scratch.AsArm64();
446   Arm64ManagedRegister src = m_src.AsArm64();
447   Arm64ManagedRegister dest = m_dest.AsArm64();
448   CHECK(dest.IsXRegister()) << dest;
449   CHECK(src.IsXRegister()) << src;
450   CHECK(scratch.IsXRegister() || scratch.IsWRegister()) << scratch;
451   CHECK(size == 4 || size == 8) << size;
452   if (size == 4) {
453     if (scratch.IsWRegister()) {
454       LoadWFromOffset(kLoadWord, scratch.AsWRegister(), src.AsXRegister(),
455                     src_offset.Int32Value());
456       StoreWToOffset(kStoreWord, scratch.AsWRegister(), dest.AsXRegister(),
457                    dest_offset.Int32Value());
458     } else {
459       LoadWFromOffset(kLoadWord, scratch.AsOverlappingWRegister(), src.AsXRegister(),
460                     src_offset.Int32Value());
461       StoreWToOffset(kStoreWord, scratch.AsOverlappingWRegister(), dest.AsXRegister(),
462                    dest_offset.Int32Value());
463     }
464   } else if (size == 8) {
465     LoadFromOffset(scratch.AsXRegister(), src.AsXRegister(), src_offset.Int32Value());
466     StoreToOffset(scratch.AsXRegister(), dest.AsXRegister(), dest_offset.Int32Value());
467   } else {
468     UNIMPLEMENTED(FATAL) << "We only support Copy() of size 4 and 8";
469   }
470 }
471 
Copy(FrameOffset,Offset,FrameOffset,Offset,ManagedRegister,size_t)472 void Arm64Assembler::Copy(FrameOffset /*dst*/, Offset /*dest_offset*/,
473                           FrameOffset /*src*/, Offset /*src_offset*/,
474                           ManagedRegister /*scratch*/, size_t /*size*/) {
475   UNIMPLEMENTED(FATAL) << "Unimplemented Copy() variant";
476 }
477 
MemoryBarrier(ManagedRegister m_scratch ATTRIBUTE_UNUSED)478 void Arm64Assembler::MemoryBarrier(ManagedRegister m_scratch ATTRIBUTE_UNUSED) {
479   // TODO: Should we check that m_scratch is IP? - see arm.
480   ___ Dmb(vixl::InnerShareable, vixl::BarrierAll);
481 }
482 
SignExtend(ManagedRegister mreg,size_t size)483 void Arm64Assembler::SignExtend(ManagedRegister mreg, size_t size) {
484   Arm64ManagedRegister reg = mreg.AsArm64();
485   CHECK(size == 1 || size == 2) << size;
486   CHECK(reg.IsWRegister()) << reg;
487   if (size == 1) {
488     ___ Sxtb(reg_w(reg.AsWRegister()), reg_w(reg.AsWRegister()));
489   } else {
490     ___ Sxth(reg_w(reg.AsWRegister()), reg_w(reg.AsWRegister()));
491   }
492 }
493 
ZeroExtend(ManagedRegister mreg,size_t size)494 void Arm64Assembler::ZeroExtend(ManagedRegister mreg, size_t size) {
495   Arm64ManagedRegister reg = mreg.AsArm64();
496   CHECK(size == 1 || size == 2) << size;
497   CHECK(reg.IsWRegister()) << reg;
498   if (size == 1) {
499     ___ Uxtb(reg_w(reg.AsWRegister()), reg_w(reg.AsWRegister()));
500   } else {
501     ___ Uxth(reg_w(reg.AsWRegister()), reg_w(reg.AsWRegister()));
502   }
503 }
504 
VerifyObject(ManagedRegister,bool)505 void Arm64Assembler::VerifyObject(ManagedRegister /*src*/, bool /*could_be_null*/) {
506   // TODO: not validating references.
507 }
508 
VerifyObject(FrameOffset,bool)509 void Arm64Assembler::VerifyObject(FrameOffset /*src*/, bool /*could_be_null*/) {
510   // TODO: not validating references.
511 }
512 
Call(ManagedRegister m_base,Offset offs,ManagedRegister m_scratch)513 void Arm64Assembler::Call(ManagedRegister m_base, Offset offs, ManagedRegister m_scratch) {
514   Arm64ManagedRegister base = m_base.AsArm64();
515   Arm64ManagedRegister scratch = m_scratch.AsArm64();
516   CHECK(base.IsXRegister()) << base;
517   CHECK(scratch.IsXRegister()) << scratch;
518   LoadFromOffset(scratch.AsXRegister(), base.AsXRegister(), offs.Int32Value());
519   ___ Blr(reg_x(scratch.AsXRegister()));
520 }
521 
JumpTo(ManagedRegister m_base,Offset offs,ManagedRegister m_scratch)522 void Arm64Assembler::JumpTo(ManagedRegister m_base, Offset offs, ManagedRegister m_scratch) {
523   Arm64ManagedRegister base = m_base.AsArm64();
524   Arm64ManagedRegister scratch = m_scratch.AsArm64();
525   CHECK(base.IsXRegister()) << base;
526   CHECK(scratch.IsXRegister()) << scratch;
527   // Remove base and scratch form the temp list - higher level API uses IP1, IP0.
528   vixl::UseScratchRegisterScope temps(vixl_masm_);
529   temps.Exclude(reg_x(base.AsXRegister()), reg_x(scratch.AsXRegister()));
530   ___ Ldr(reg_x(scratch.AsXRegister()), MEM_OP(reg_x(base.AsXRegister()), offs.Int32Value()));
531   ___ Br(reg_x(scratch.AsXRegister()));
532 }
533 
Call(FrameOffset base,Offset offs,ManagedRegister m_scratch)534 void Arm64Assembler::Call(FrameOffset base, Offset offs, ManagedRegister m_scratch) {
535   Arm64ManagedRegister scratch = m_scratch.AsArm64();
536   CHECK(scratch.IsXRegister()) << scratch;
537   // Call *(*(SP + base) + offset)
538   LoadFromOffset(scratch.AsXRegister(), SP, base.Int32Value());
539   LoadFromOffset(scratch.AsXRegister(), scratch.AsXRegister(), offs.Int32Value());
540   ___ Blr(reg_x(scratch.AsXRegister()));
541 }
542 
CallFromThread64(ThreadOffset<8>,ManagedRegister)543 void Arm64Assembler::CallFromThread64(ThreadOffset<8> /*offset*/, ManagedRegister /*scratch*/) {
544   UNIMPLEMENTED(FATAL) << "Unimplemented Call() variant";
545 }
546 
CreateHandleScopeEntry(ManagedRegister m_out_reg,FrameOffset handle_scope_offs,ManagedRegister m_in_reg,bool null_allowed)547 void Arm64Assembler::CreateHandleScopeEntry(
548     ManagedRegister m_out_reg, FrameOffset handle_scope_offs, ManagedRegister m_in_reg,
549     bool null_allowed) {
550   Arm64ManagedRegister out_reg = m_out_reg.AsArm64();
551   Arm64ManagedRegister in_reg = m_in_reg.AsArm64();
552   // For now we only hold stale handle scope entries in x registers.
553   CHECK(in_reg.IsNoRegister() || in_reg.IsXRegister()) << in_reg;
554   CHECK(out_reg.IsXRegister()) << out_reg;
555   if (null_allowed) {
556     // Null values get a handle scope entry value of 0.  Otherwise, the handle scope entry is
557     // the address in the handle scope holding the reference.
558     // e.g. out_reg = (handle == 0) ? 0 : (SP+handle_offset)
559     if (in_reg.IsNoRegister()) {
560       LoadWFromOffset(kLoadWord, out_reg.AsOverlappingWRegister(), SP,
561                       handle_scope_offs.Int32Value());
562       in_reg = out_reg;
563     }
564     ___ Cmp(reg_w(in_reg.AsOverlappingWRegister()), 0);
565     if (!out_reg.Equals(in_reg)) {
566       LoadImmediate(out_reg.AsXRegister(), 0, eq);
567     }
568     AddConstant(out_reg.AsXRegister(), SP, handle_scope_offs.Int32Value(), ne);
569   } else {
570     AddConstant(out_reg.AsXRegister(), SP, handle_scope_offs.Int32Value(), al);
571   }
572 }
573 
CreateHandleScopeEntry(FrameOffset out_off,FrameOffset handle_scope_offset,ManagedRegister m_scratch,bool null_allowed)574 void Arm64Assembler::CreateHandleScopeEntry(FrameOffset out_off, FrameOffset handle_scope_offset,
575                                             ManagedRegister m_scratch, bool null_allowed) {
576   Arm64ManagedRegister scratch = m_scratch.AsArm64();
577   CHECK(scratch.IsXRegister()) << scratch;
578   if (null_allowed) {
579     LoadWFromOffset(kLoadWord, scratch.AsOverlappingWRegister(), SP,
580                     handle_scope_offset.Int32Value());
581     // Null values get a handle scope entry value of 0.  Otherwise, the handle scope entry is
582     // the address in the handle scope holding the reference.
583     // e.g. scratch = (scratch == 0) ? 0 : (SP+handle_scope_offset)
584     ___ Cmp(reg_w(scratch.AsOverlappingWRegister()), 0);
585     // Move this logic in add constants with flags.
586     AddConstant(scratch.AsXRegister(), SP, handle_scope_offset.Int32Value(), ne);
587   } else {
588     AddConstant(scratch.AsXRegister(), SP, handle_scope_offset.Int32Value(), al);
589   }
590   StoreToOffset(scratch.AsXRegister(), SP, out_off.Int32Value());
591 }
592 
LoadReferenceFromHandleScope(ManagedRegister m_out_reg,ManagedRegister m_in_reg)593 void Arm64Assembler::LoadReferenceFromHandleScope(ManagedRegister m_out_reg,
594                                                   ManagedRegister m_in_reg) {
595   Arm64ManagedRegister out_reg = m_out_reg.AsArm64();
596   Arm64ManagedRegister in_reg = m_in_reg.AsArm64();
597   CHECK(out_reg.IsXRegister()) << out_reg;
598   CHECK(in_reg.IsXRegister()) << in_reg;
599   vixl::Label exit;
600   if (!out_reg.Equals(in_reg)) {
601     // FIXME: Who sets the flags here?
602     LoadImmediate(out_reg.AsXRegister(), 0, eq);
603   }
604   ___ Cbz(reg_x(in_reg.AsXRegister()), &exit);
605   LoadFromOffset(out_reg.AsXRegister(), in_reg.AsXRegister(), 0);
606   ___ Bind(&exit);
607 }
608 
ExceptionPoll(ManagedRegister m_scratch,size_t stack_adjust)609 void Arm64Assembler::ExceptionPoll(ManagedRegister m_scratch, size_t stack_adjust) {
610   CHECK_ALIGNED(stack_adjust, kStackAlignment);
611   Arm64ManagedRegister scratch = m_scratch.AsArm64();
612   Arm64Exception *current_exception = new Arm64Exception(scratch, stack_adjust);
613   exception_blocks_.push_back(current_exception);
614   LoadFromOffset(scratch.AsXRegister(), ETR, Thread::ExceptionOffset<8>().Int32Value());
615   ___ Cbnz(reg_x(scratch.AsXRegister()), current_exception->Entry());
616 }
617 
EmitExceptionPoll(Arm64Exception * exception)618 void Arm64Assembler::EmitExceptionPoll(Arm64Exception *exception) {
619   vixl::UseScratchRegisterScope temps(vixl_masm_);
620   temps.Exclude(reg_x(exception->scratch_.AsXRegister()));
621   vixl::Register temp = temps.AcquireX();
622 
623   // Bind exception poll entry.
624   ___ Bind(exception->Entry());
625   if (exception->stack_adjust_ != 0) {  // Fix up the frame.
626     DecreaseFrameSize(exception->stack_adjust_);
627   }
628   // Pass exception object as argument.
629   // Don't care about preserving X0 as this won't return.
630   ___ Mov(reg_x(X0), reg_x(exception->scratch_.AsXRegister()));
631   ___ Ldr(temp, MEM_OP(reg_x(ETR), QUICK_ENTRYPOINT_OFFSET(8, pDeliverException).Int32Value()));
632 
633   // Move ETR(Callee saved) back to TR(Caller saved) reg. We use ETR on calls
634   // to external functions that might trash TR. We do not need the original
635   // ETR(X21) saved in BuildFrame().
636   ___ Mov(reg_x(TR), reg_x(ETR));
637 
638   ___ Blr(temp);
639   // Call should never return.
640   ___ Brk();
641 }
642 
DWARFReg(CPURegister reg)643 static inline dwarf::Reg DWARFReg(CPURegister reg) {
644   if (reg.IsFPRegister()) {
645     return dwarf::Reg::Arm64Fp(reg.code());
646   } else {
647     DCHECK_LT(reg.code(), 31u);  // X0 - X30.
648     return dwarf::Reg::Arm64Core(reg.code());
649   }
650 }
651 
SpillRegisters(vixl::CPURegList registers,int offset)652 void Arm64Assembler::SpillRegisters(vixl::CPURegList registers, int offset) {
653   int size = registers.RegisterSizeInBytes();
654   const Register sp = vixl_masm_->StackPointer();
655   while (registers.Count() >= 2) {
656     const CPURegister& dst0 = registers.PopLowestIndex();
657     const CPURegister& dst1 = registers.PopLowestIndex();
658     ___ Stp(dst0, dst1, MemOperand(sp, offset));
659     cfi_.RelOffset(DWARFReg(dst0), offset);
660     cfi_.RelOffset(DWARFReg(dst1), offset + size);
661     offset += 2 * size;
662   }
663   if (!registers.IsEmpty()) {
664     const CPURegister& dst0 = registers.PopLowestIndex();
665     ___ Str(dst0, MemOperand(sp, offset));
666     cfi_.RelOffset(DWARFReg(dst0), offset);
667   }
668   DCHECK(registers.IsEmpty());
669 }
670 
UnspillRegisters(vixl::CPURegList registers,int offset)671 void Arm64Assembler::UnspillRegisters(vixl::CPURegList registers, int offset) {
672   int size = registers.RegisterSizeInBytes();
673   const Register sp = vixl_masm_->StackPointer();
674   while (registers.Count() >= 2) {
675     const CPURegister& dst0 = registers.PopLowestIndex();
676     const CPURegister& dst1 = registers.PopLowestIndex();
677     ___ Ldp(dst0, dst1, MemOperand(sp, offset));
678     cfi_.Restore(DWARFReg(dst0));
679     cfi_.Restore(DWARFReg(dst1));
680     offset += 2 * size;
681   }
682   if (!registers.IsEmpty()) {
683     const CPURegister& dst0 = registers.PopLowestIndex();
684     ___ Ldr(dst0, MemOperand(sp, offset));
685     cfi_.Restore(DWARFReg(dst0));
686   }
687   DCHECK(registers.IsEmpty());
688 }
689 
BuildFrame(size_t frame_size,ManagedRegister method_reg,const std::vector<ManagedRegister> & callee_save_regs,const ManagedRegisterEntrySpills & entry_spills)690 void Arm64Assembler::BuildFrame(size_t frame_size, ManagedRegister method_reg,
691                                 const std::vector<ManagedRegister>& callee_save_regs,
692                                 const ManagedRegisterEntrySpills& entry_spills) {
693   // Setup VIXL CPURegList for callee-saves.
694   CPURegList core_reg_list(CPURegister::kRegister, kXRegSize, 0);
695   CPURegList fp_reg_list(CPURegister::kFPRegister, kDRegSize, 0);
696   for (auto r : callee_save_regs) {
697     Arm64ManagedRegister reg = r.AsArm64();
698     if (reg.IsXRegister()) {
699       core_reg_list.Combine(reg_x(reg.AsXRegister()).code());
700     } else {
701       DCHECK(reg.IsDRegister());
702       fp_reg_list.Combine(reg_d(reg.AsDRegister()).code());
703     }
704   }
705   size_t core_reg_size = core_reg_list.TotalSizeInBytes();
706   size_t fp_reg_size = fp_reg_list.TotalSizeInBytes();
707 
708   // Increase frame to required size.
709   DCHECK_ALIGNED(frame_size, kStackAlignment);
710   DCHECK_GE(frame_size, core_reg_size + fp_reg_size + kArm64PointerSize);
711   IncreaseFrameSize(frame_size);
712 
713   // Save callee-saves.
714   SpillRegisters(core_reg_list, frame_size - core_reg_size);
715   SpillRegisters(fp_reg_list, frame_size - core_reg_size - fp_reg_size);
716 
717   // Note: This is specific to JNI method frame.
718   // We will need to move TR(Caller saved in AAPCS) to ETR(Callee saved in AAPCS). The original
719   // (ETR)X21 has been saved on stack. In this way, we can restore TR later.
720   DCHECK(!core_reg_list.IncludesAliasOf(reg_x(TR)));
721   DCHECK(core_reg_list.IncludesAliasOf(reg_x(ETR)));
722   ___ Mov(reg_x(ETR), reg_x(TR));
723 
724   // Write ArtMethod*
725   DCHECK(X0 == method_reg.AsArm64().AsXRegister());
726   StoreToOffset(X0, SP, 0);
727 
728   // Write out entry spills
729   int32_t offset = frame_size + kArm64PointerSize;
730   for (size_t i = 0; i < entry_spills.size(); ++i) {
731     Arm64ManagedRegister reg = entry_spills.at(i).AsArm64();
732     if (reg.IsNoRegister()) {
733       // only increment stack offset.
734       ManagedRegisterSpill spill = entry_spills.at(i);
735       offset += spill.getSize();
736     } else if (reg.IsXRegister()) {
737       StoreToOffset(reg.AsXRegister(), SP, offset);
738       offset += 8;
739     } else if (reg.IsWRegister()) {
740       StoreWToOffset(kStoreWord, reg.AsWRegister(), SP, offset);
741       offset += 4;
742     } else if (reg.IsDRegister()) {
743       StoreDToOffset(reg.AsDRegister(), SP, offset);
744       offset += 8;
745     } else if (reg.IsSRegister()) {
746       StoreSToOffset(reg.AsSRegister(), SP, offset);
747       offset += 4;
748     }
749   }
750 }
751 
RemoveFrame(size_t frame_size,const std::vector<ManagedRegister> & callee_save_regs)752 void Arm64Assembler::RemoveFrame(size_t frame_size,
753                                  const std::vector<ManagedRegister>& callee_save_regs) {
754   // Setup VIXL CPURegList for callee-saves.
755   CPURegList core_reg_list(CPURegister::kRegister, kXRegSize, 0);
756   CPURegList fp_reg_list(CPURegister::kFPRegister, kDRegSize, 0);
757   for (auto r : callee_save_regs) {
758     Arm64ManagedRegister reg = r.AsArm64();
759     if (reg.IsXRegister()) {
760       core_reg_list.Combine(reg_x(reg.AsXRegister()).code());
761     } else {
762       DCHECK(reg.IsDRegister());
763       fp_reg_list.Combine(reg_d(reg.AsDRegister()).code());
764     }
765   }
766   size_t core_reg_size = core_reg_list.TotalSizeInBytes();
767   size_t fp_reg_size = fp_reg_list.TotalSizeInBytes();
768 
769   // For now we only check that the size of the frame is large enough to hold spills and method
770   // reference.
771   DCHECK_GE(frame_size, core_reg_size + fp_reg_size + kArm64PointerSize);
772   DCHECK_ALIGNED(frame_size, kStackAlignment);
773 
774   // Note: This is specific to JNI method frame.
775   // Restore TR(Caller saved in AAPCS) from ETR(Callee saved in AAPCS).
776   DCHECK(!core_reg_list.IncludesAliasOf(reg_x(TR)));
777   DCHECK(core_reg_list.IncludesAliasOf(reg_x(ETR)));
778   ___ Mov(reg_x(TR), reg_x(ETR));
779 
780   cfi_.RememberState();
781 
782   // Restore callee-saves.
783   UnspillRegisters(core_reg_list, frame_size - core_reg_size);
784   UnspillRegisters(fp_reg_list, frame_size - core_reg_size - fp_reg_size);
785 
786   // Decrease frame size to start of callee saved regs.
787   DecreaseFrameSize(frame_size);
788 
789   // Pop callee saved and return to LR.
790   ___ Ret();
791 
792   // The CFI should be restored for any code that follows the exit block.
793   cfi_.RestoreState();
794   cfi_.DefCFAOffset(frame_size);
795 }
796 
797 }  // namespace arm64
798 }  // namespace art
799