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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_ARM | |
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 static void ProbeTable(StubCache* stub_cache, MacroAssembler* masm, | |
18 StubCache::Table table, Register receiver, Register name, | |
19 // The offset is scaled by 4, based on | |
20 // kCacheIndexShift, which is two bits | |
21 Register offset, Register scratch, Register scratch2, | |
22 Register offset_scratch) { | |
23 ExternalReference key_offset(stub_cache->key_reference(table)); | |
24 ExternalReference value_offset(stub_cache->value_reference(table)); | |
25 ExternalReference map_offset(stub_cache->map_reference(table)); | |
26 | |
27 uint32_t key_off_addr = reinterpret_cast<uint32_t>(key_offset.address()); | |
28 uint32_t value_off_addr = reinterpret_cast<uint32_t>(value_offset.address()); | |
29 uint32_t map_off_addr = reinterpret_cast<uint32_t>(map_offset.address()); | |
30 | |
31 // Check the relative positions of the address fields. | |
32 DCHECK(value_off_addr > key_off_addr); | |
33 DCHECK((value_off_addr - key_off_addr) % 4 == 0); | |
34 DCHECK((value_off_addr - key_off_addr) < (256 * 4)); | |
35 DCHECK(map_off_addr > key_off_addr); | |
36 DCHECK((map_off_addr - key_off_addr) % 4 == 0); | |
37 DCHECK((map_off_addr - key_off_addr) < (256 * 4)); | |
38 | |
39 Label miss; | |
40 Register base_addr = scratch; | |
41 scratch = no_reg; | |
42 | |
43 // Multiply by 3 because there are 3 fields per entry (name, code, map). | |
44 __ add(offset_scratch, offset, Operand(offset, LSL, 1)); | |
45 | |
46 // Calculate the base address of the entry. | |
47 __ add(base_addr, offset_scratch, Operand(key_offset)); | |
48 | |
49 // Check that the key in the entry matches the name. | |
50 __ ldr(ip, MemOperand(base_addr, 0)); | |
51 __ cmp(name, ip); | |
52 __ b(ne, &miss); | |
53 | |
54 // Check the map matches. | |
55 __ ldr(ip, MemOperand(base_addr, map_off_addr - key_off_addr)); | |
56 __ ldr(scratch2, FieldMemOperand(receiver, HeapObject::kMapOffset)); | |
57 __ cmp(ip, scratch2); | |
58 __ b(ne, &miss); | |
59 | |
60 // Get the code entry from the cache. | |
61 Register code = scratch2; | |
62 scratch2 = no_reg; | |
63 __ ldr(code, MemOperand(base_addr, value_off_addr - key_off_addr)); | |
64 | |
65 #ifdef DEBUG | |
66 if (FLAG_test_secondary_stub_cache && table == StubCache::kPrimary) { | |
67 __ jmp(&miss); | |
68 } else if (FLAG_test_primary_stub_cache && table == StubCache::kSecondary) { | |
69 __ jmp(&miss); | |
70 } | |
71 #endif | |
72 | |
73 // Jump to the first instruction in the code stub. | |
74 __ add(pc, code, Operand(Code::kHeaderSize - kHeapObjectTag)); | |
75 | |
76 // Miss: fall through. | |
77 __ bind(&miss); | |
78 } | |
79 | |
80 void StubCache::GenerateProbe(MacroAssembler* masm, Register receiver, | |
81 Register name, Register scratch, Register extra, | |
82 Register extra2, Register extra3) { | |
83 Label miss; | |
84 | |
85 // Make sure that code is valid. The multiplying code relies on the | |
86 // entry size being 12. | |
87 DCHECK(sizeof(Entry) == 12); | |
88 | |
89 // Make sure that there are no register conflicts. | |
90 DCHECK(!AreAliased(receiver, name, scratch, extra, extra2, extra3)); | |
91 | |
92 // Check scratch, extra and extra2 registers are valid. | |
93 DCHECK(!scratch.is(no_reg)); | |
94 DCHECK(!extra.is(no_reg)); | |
95 DCHECK(!extra2.is(no_reg)); | |
96 DCHECK(!extra3.is(no_reg)); | |
97 | |
98 #ifdef DEBUG | |
99 // If vector-based ics are in use, ensure that scratch, extra, extra2 and | |
100 // extra3 don't conflict with the vector and slot registers, which need | |
101 // to be preserved for a handler call or miss. | |
102 if (IC::ICUseVector(ic_kind_)) { | |
103 Register vector, slot; | |
104 if (ic_kind_ == Code::STORE_IC || ic_kind_ == Code::KEYED_STORE_IC) { | |
105 vector = StoreWithVectorDescriptor::VectorRegister(); | |
106 slot = StoreWithVectorDescriptor::SlotRegister(); | |
107 } else { | |
108 DCHECK(ic_kind_ == Code::LOAD_IC || ic_kind_ == Code::KEYED_LOAD_IC); | |
109 vector = LoadWithVectorDescriptor::VectorRegister(); | |
110 slot = LoadWithVectorDescriptor::SlotRegister(); | |
111 } | |
112 DCHECK(!AreAliased(vector, slot, scratch, extra, extra2, extra3)); | |
113 } | |
114 #endif | |
115 | |
116 Counters* counters = masm->isolate()->counters(); | |
117 __ IncrementCounter(counters->megamorphic_stub_cache_probes(), 1, extra2, | |
118 extra3); | |
119 | |
120 // Check that the receiver isn't a smi. | |
121 __ JumpIfSmi(receiver, &miss); | |
122 | |
123 // Get the map of the receiver and compute the hash. | |
124 __ ldr(scratch, FieldMemOperand(name, Name::kHashFieldOffset)); | |
125 __ ldr(ip, FieldMemOperand(receiver, HeapObject::kMapOffset)); | |
126 __ add(scratch, scratch, Operand(ip)); | |
127 __ eor(scratch, scratch, Operand(kPrimaryMagic)); | |
128 __ mov(ip, Operand(kPrimaryTableSize - 1)); | |
129 __ and_(scratch, scratch, Operand(ip, LSL, kCacheIndexShift)); | |
130 | |
131 // Probe the primary table. | |
132 ProbeTable(this, masm, kPrimary, receiver, name, scratch, extra, extra2, | |
133 extra3); | |
134 | |
135 // Primary miss: Compute hash for secondary probe. | |
136 __ sub(scratch, scratch, Operand(name)); | |
137 __ add(scratch, scratch, Operand(kSecondaryMagic)); | |
138 __ mov(ip, Operand(kSecondaryTableSize - 1)); | |
139 __ and_(scratch, scratch, Operand(ip, LSL, kCacheIndexShift)); | |
140 | |
141 // Probe the secondary table. | |
142 ProbeTable(this, masm, kSecondary, receiver, name, scratch, extra, extra2, | |
143 extra3); | |
144 | |
145 // Cache miss: Fall-through and let caller handle the miss by | |
146 // entering the runtime system. | |
147 __ bind(&miss); | |
148 __ IncrementCounter(counters->megamorphic_stub_cache_misses(), 1, extra2, | |
149 extra3); | |
150 } | |
151 | |
152 | |
153 #undef __ | |
154 } // namespace internal | |
155 } // namespace v8 | |
156 | |
157 #endif // V8_TARGET_ARCH_ARM | |
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