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
|
// Copyright 2013, ARM Limited
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of ARM Limited nor the names of its contributors may be
// used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef jit_arm64_vixl_MozBaseAssembler_vixl_h
#define jit_arm64_vixl_MozBaseAssembler_vixl_h
#include "jit/arm64/vixl/Constants-vixl.h"
#include "jit/arm64/vixl/Instructions-vixl.h"
#include "jit/shared/Assembler-shared.h"
#include "jit/shared/IonAssemblerBufferWithConstantPools.h"
namespace vixl {
using js::jit::BufferOffset;
class MozBaseAssembler;
typedef js::jit::AssemblerBufferWithConstantPools<1024, 4, Instruction, MozBaseAssembler,
NumShortBranchRangeTypes> ARMBuffer;
// Base class for vixl::Assembler, for isolating Moz-specific changes to VIXL.
class MozBaseAssembler : public js::jit::AssemblerShared {
// Buffer initialization constants.
static const unsigned BufferGuardSize = 1;
static const unsigned BufferHeaderSize = 1;
static const size_t BufferCodeAlignment = 8;
static const size_t BufferMaxPoolOffset = 1024;
static const unsigned BufferPCBias = 0;
static const uint32_t BufferAlignmentFillInstruction = BRK | (0xdead << ImmException_offset);
static const uint32_t BufferNopFillInstruction = HINT | (31 << Rt_offset);
static const unsigned BufferNumDebugNopsToInsert = 0;
public:
MozBaseAssembler()
: armbuffer_(BufferGuardSize,
BufferHeaderSize,
BufferCodeAlignment,
BufferMaxPoolOffset,
BufferPCBias,
BufferAlignmentFillInstruction,
BufferNopFillInstruction,
BufferNumDebugNopsToInsert)
{ }
public:
// Helper function for use with the ARMBuffer.
// The MacroAssembler must create an AutoJitContextAlloc before initializing the buffer.
void initWithAllocator() {
armbuffer_.initWithAllocator();
}
// Return the Instruction at a given byte offset.
Instruction* getInstructionAt(BufferOffset offset) {
return armbuffer_.getInst(offset);
}
// Return the byte offset of a bound label.
template <typename T>
inline T GetLabelByteOffset(const js::jit::Label* label) {
VIXL_ASSERT(label->bound());
JS_STATIC_ASSERT(sizeof(T) >= sizeof(uint32_t));
return reinterpret_cast<T>(label->offset());
}
protected:
// Get the buffer offset of the next inserted instruction. This may flush
// constant pools.
BufferOffset nextInstrOffset() {
return armbuffer_.nextInstrOffset();
}
// Get the next usable buffer offset. Note that a constant pool may be placed
// here before the next instruction is emitted.
BufferOffset nextOffset() const {
return armbuffer_.nextOffset();
}
// Allocate memory in the buffer by forwarding to armbuffer_.
// Propagate OOM errors.
BufferOffset allocEntry(size_t numInst, unsigned numPoolEntries,
uint8_t* inst, uint8_t* data,
ARMBuffer::PoolEntry* pe = nullptr,
bool markAsBranch = false)
{
BufferOffset offset = armbuffer_.allocEntry(numInst, numPoolEntries, inst,
data, pe, markAsBranch);
propagateOOM(offset.assigned());
return offset;
}
// Emit the instruction, returning its offset.
BufferOffset Emit(Instr instruction, bool isBranch = false) {
JS_STATIC_ASSERT(sizeof(instruction) == kInstructionSize);
return armbuffer_.putInt(*(uint32_t*)(&instruction), isBranch);
}
BufferOffset EmitBranch(Instr instruction) {
return Emit(instruction, true);
}
public:
// Emit the instruction at |at|.
static void Emit(Instruction* at, Instr instruction) {
JS_STATIC_ASSERT(sizeof(instruction) == kInstructionSize);
memcpy(at, &instruction, sizeof(instruction));
}
static void EmitBranch(Instruction* at, Instr instruction) {
// TODO: Assert that the buffer already has the instruction marked as a branch.
Emit(at, instruction);
}
// Emit data inline in the instruction stream.
BufferOffset EmitData(void const * data, unsigned size) {
VIXL_ASSERT(size % 4 == 0);
return armbuffer_.allocEntry(size / sizeof(uint32_t), 0, (uint8_t*)(data), nullptr);
}
public:
// Size of the code generated in bytes, including pools.
size_t SizeOfCodeGenerated() const {
return armbuffer_.size();
}
// Move the pool into the instruction stream.
void flushBuffer() {
armbuffer_.flushPool();
}
// Inhibit pool flushing for the given number of instructions.
// Generating more than |maxInst| instructions in a no-pool region
// triggers an assertion within the ARMBuffer.
// Does not nest.
void enterNoPool(size_t maxInst) {
armbuffer_.enterNoPool(maxInst);
}
// Marks the end of a no-pool region.
void leaveNoPool() {
armbuffer_.leaveNoPool();
}
public:
// Static interface used by IonAssemblerBufferWithConstantPools.
static void InsertIndexIntoTag(uint8_t* load, uint32_t index);
static bool PatchConstantPoolLoad(void* loadAddr, void* constPoolAddr);
static void PatchShortRangeBranchToVeneer(ARMBuffer*, unsigned rangeIdx, BufferOffset deadline,
BufferOffset veneer);
static uint32_t PlaceConstantPoolBarrier(int offset);
static void WritePoolHeader(uint8_t* start, js::jit::Pool* p, bool isNatural);
static void WritePoolFooter(uint8_t* start, js::jit::Pool* p, bool isNatural);
static void WritePoolGuard(BufferOffset branch, Instruction* inst, BufferOffset dest);
static ptrdiff_t GetBranchOffset(const Instruction* i);
static void RetargetNearBranch(Instruction* i, int offset, Condition cond, bool final = true);
static void RetargetNearBranch(Instruction* i, int offset, bool final = true);
static void RetargetFarBranch(Instruction* i, uint8_t** slot, uint8_t* dest, Condition cond);
protected:
// Functions for managing Labels and linked lists of Label uses.
// Get the next Label user in the linked list of Label uses.
// Return an unassigned BufferOffset when the end of the list is reached.
BufferOffset NextLink(BufferOffset cur);
// Patch the instruction at cur to link to the instruction at next.
void SetNextLink(BufferOffset cur, BufferOffset next);
// Link the current (not-yet-emitted) instruction to the specified label,
// then return a raw offset to be encoded in the instruction.
ptrdiff_t LinkAndGetByteOffsetTo(BufferOffset branch, js::jit::Label* label);
ptrdiff_t LinkAndGetInstructionOffsetTo(BufferOffset branch, ImmBranchRangeType branchRange,
js::jit::Label* label);
ptrdiff_t LinkAndGetPageOffsetTo(BufferOffset branch, js::jit::Label* label);
// A common implementation for the LinkAndGet<Type>OffsetTo helpers.
ptrdiff_t LinkAndGetOffsetTo(BufferOffset branch, ImmBranchRangeType branchRange,
unsigned elementSizeBits, js::jit::Label* label);
protected:
// The buffer into which code and relocation info are generated.
ARMBuffer armbuffer_;
};
} // namespace vixl
#endif // jit_arm64_vixl_MozBaseAssembler_vixl_h
|
