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
12 namespace v8 {
13 namespace internal {
14
15 #define __ ACCESS_MASM(masm)
16
17
ProbeTable(Isolate * isolate,MacroAssembler * masm,Code::Kind ic_kind,Code::Flags flags,StubCache::Table table,Register name,Register receiver,Register offset,Register extra)18 static 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
GenerateProbe(MacroAssembler * masm,Code::Kind ic_kind,Code::Flags flags,Register receiver,Register name,Register scratch,Register extra,Register extra2,Register extra3)146 void 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