stub-cache-x87.cc revision 014dc512cdd3e367bee49a713fdc5ed92584a3e5 
1// Copyright 2012 the V8 project authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#if V8_TARGET_ARCH_X87
6
7#include "src/codegen.h"
8#include "src/ic/ic.h"
9#include "src/ic/stub-cache.h"
10#include "src/interface-descriptors.h"
11
12namespace v8 {
13namespace internal {
14
15#define __ ACCESS_MASM(masm)
16
17
18static void ProbeTable(Isolate* isolate, MacroAssembler* masm,
19                       Code::Kind ic_kind, Code::Flags flags,
20                       StubCache::Table table, Register name, Register receiver,
21                       // Number of the cache entry pointer-size scaled.
22                       Register offset, Register extra) {
23  ExternalReference key_offset(isolate->stub_cache()->key_reference(table));
24  ExternalReference value_offset(isolate->stub_cache()->value_reference(table));
25  ExternalReference map_offset(isolate->stub_cache()->map_reference(table));
26  ExternalReference virtual_register =
27      ExternalReference::virtual_handler_register(masm->isolate());
28
29  Label miss;
30  bool is_vector_store =
31      IC::ICUseVector(ic_kind) &&
32      (ic_kind == Code::STORE_IC || ic_kind == Code::KEYED_STORE_IC);
33
34  // Multiply by 3 because there are 3 fields per entry (name, code, map).
35  __ lea(offset, Operand(offset, offset, times_2, 0));
36
37  if (extra.is_valid()) {
38    // Get the code entry from the cache.
39    __ mov(extra, Operand::StaticArray(offset, times_1, value_offset));
40
41    // Check that the key in the entry matches the name.
42    __ cmp(name, Operand::StaticArray(offset, times_1, key_offset));
43    __ j(not_equal, &miss);
44
45    // Check the map matches.
46    __ mov(offset, Operand::StaticArray(offset, times_1, map_offset));
47    __ cmp(offset, FieldOperand(receiver, HeapObject::kMapOffset));
48    __ j(not_equal, &miss);
49
50    // Check that the flags match what we're looking for.
51    __ mov(offset, FieldOperand(extra, Code::kFlagsOffset));
52    __ and_(offset, ~Code::kFlagsNotUsedInLookup);
53    __ cmp(offset, flags);
54    __ j(not_equal, &miss);
55
56#ifdef DEBUG
57    if (FLAG_test_secondary_stub_cache && table == StubCache::kPrimary) {
58      __ jmp(&miss);
59    } else if (FLAG_test_primary_stub_cache && table == StubCache::kSecondary) {
60      __ jmp(&miss);
61    }
62#endif
63
64    // The vector and slot were pushed onto the stack before starting the
65    // probe, and need to be dropped before calling the handler.
66    if (is_vector_store) {
67      // The overlap here is rather embarrassing. One does what one must.
68      Register vector = VectorStoreICDescriptor::VectorRegister();
69      DCHECK(extra.is(VectorStoreICDescriptor::SlotRegister()));
70      __ add(extra, Immediate(Code::kHeaderSize - kHeapObjectTag));
71      __ pop(vector);
72      __ mov(Operand::StaticVariable(virtual_register), extra);
73      __ pop(extra);  // Pop "slot".
74      // Jump to the first instruction in the code stub.
75      __ jmp(Operand::StaticVariable(virtual_register));
76    } else {
77      __ pop(LoadWithVectorDescriptor::VectorRegister());
78      __ pop(LoadDescriptor::SlotRegister());
79      __ add(extra, Immediate(Code::kHeaderSize - kHeapObjectTag));
80      __ jmp(extra);
81    }
82
83    __ bind(&miss);
84  } else {
85    DCHECK(ic_kind == Code::STORE_IC || ic_kind == Code::KEYED_STORE_IC);
86
87    // Save the offset on the stack.
88    __ push(offset);
89
90    // Check that the key in the entry matches the name.
91    __ cmp(name, Operand::StaticArray(offset, times_1, key_offset));
92    __ j(not_equal, &miss);
93
94    // Check the map matches.
95    __ mov(offset, Operand::StaticArray(offset, times_1, map_offset));
96    __ cmp(offset, FieldOperand(receiver, HeapObject::kMapOffset));
97    __ j(not_equal, &miss);
98
99    // Restore offset register.
100    __ mov(offset, Operand(esp, 0));
101
102    // Get the code entry from the cache.
103    __ mov(offset, Operand::StaticArray(offset, times_1, value_offset));
104
105    // Check that the flags match what we're looking for.
106    __ mov(offset, FieldOperand(offset, Code::kFlagsOffset));
107    __ and_(offset, ~Code::kFlagsNotUsedInLookup);
108    __ cmp(offset, flags);
109    __ j(not_equal, &miss);
110
111#ifdef DEBUG
112    if (FLAG_test_secondary_stub_cache && table == StubCache::kPrimary) {
113      __ jmp(&miss);
114    } else if (FLAG_test_primary_stub_cache && table == StubCache::kSecondary) {
115      __ jmp(&miss);
116    }
117#endif
118
119    // Restore offset and re-load code entry from cache.
120    __ pop(offset);
121    __ mov(offset, Operand::StaticArray(offset, times_1, value_offset));
122
123    // Jump to the first instruction in the code stub.
124    if (is_vector_store) {
125      // The vector and slot were pushed onto the stack before starting the
126      // probe, and need to be dropped before calling the handler.
127      Register vector = VectorStoreICDescriptor::VectorRegister();
128      DCHECK(offset.is(VectorStoreICDescriptor::SlotRegister()));
129      __ add(offset, Immediate(Code::kHeaderSize - kHeapObjectTag));
130      __ mov(Operand::StaticVariable(virtual_register), offset);
131      __ pop(vector);
132      __ pop(offset);  // Pop "slot".
133      __ jmp(Operand::StaticVariable(virtual_register));
134    } else {
135      __ add(offset, Immediate(Code::kHeaderSize - kHeapObjectTag));
136      __ jmp(offset);
137    }
138
139    // Pop at miss.
140    __ bind(&miss);
141    __ pop(offset);
142  }
143}
144
145
146void StubCache::GenerateProbe(MacroAssembler* masm, Code::Kind ic_kind,
147                              Code::Flags flags, Register receiver,
148                              Register name, Register scratch, Register extra,
149                              Register extra2, Register extra3) {
150  Label miss;
151
152  // Assert that code is valid.  The multiplying code relies on the entry size
153  // being 12.
154  DCHECK(sizeof(Entry) == 12);
155
156  // Assert the flags do not name a specific type.
157  DCHECK(Code::ExtractTypeFromFlags(flags) == 0);
158
159  // Assert that there are no register conflicts.
160  DCHECK(!scratch.is(receiver));
161  DCHECK(!scratch.is(name));
162  DCHECK(!extra.is(receiver));
163  DCHECK(!extra.is(name));
164  DCHECK(!extra.is(scratch));
165
166  // Assert scratch and extra registers are valid, and extra2/3 are unused.
167  DCHECK(!scratch.is(no_reg));
168  DCHECK(extra2.is(no_reg));
169  DCHECK(extra3.is(no_reg));
170
171  Register offset = scratch;
172  scratch = no_reg;
173
174  Counters* counters = masm->isolate()->counters();
175  __ IncrementCounter(counters->megamorphic_stub_cache_probes(), 1);
176
177  // Check that the receiver isn't a smi.
178  __ JumpIfSmi(receiver, &miss);
179
180  // Get the map of the receiver and compute the hash.
181  __ mov(offset, FieldOperand(name, Name::kHashFieldOffset));
182  __ add(offset, FieldOperand(receiver, HeapObject::kMapOffset));
183  __ xor_(offset, flags);
184  // We mask out the last two bits because they are not part of the hash and
185  // they are always 01 for maps.  Also in the two 'and' instructions below.
186  __ and_(offset, (kPrimaryTableSize - 1) << kCacheIndexShift);
187  // ProbeTable expects the offset to be pointer scaled, which it is, because
188  // the heap object tag size is 2 and the pointer size log 2 is also 2.
189  DCHECK(kCacheIndexShift == kPointerSizeLog2);
190
191  // Probe the primary table.
192  ProbeTable(isolate(), masm, ic_kind, flags, kPrimary, name, receiver, offset,
193             extra);
194
195  // Primary miss: Compute hash for secondary probe.
196  __ mov(offset, FieldOperand(name, Name::kHashFieldOffset));
197  __ add(offset, FieldOperand(receiver, HeapObject::kMapOffset));
198  __ xor_(offset, flags);
199  __ and_(offset, (kPrimaryTableSize - 1) << kCacheIndexShift);
200  __ sub(offset, name);
201  __ add(offset, Immediate(flags));
202  __ and_(offset, (kSecondaryTableSize - 1) << kCacheIndexShift);
203
204  // Probe the secondary table.
205  ProbeTable(isolate(), masm, ic_kind, flags, kSecondary, name, receiver,
206             offset, extra);
207
208  // Cache miss: Fall-through and let caller handle the miss by
209  // entering the runtime system.
210  __ bind(&miss);
211  __ IncrementCounter(counters->megamorphic_stub_cache_misses(), 1);
212}
213
214
215#undef __
216}  // namespace internal
217}  // namespace v8
218
219#endif  // V8_TARGET_ARCH_X87
220