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_X64
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 receiver,Register name,Register offset)18 static void ProbeTable(Isolate* isolate, MacroAssembler* masm,
19 Code::Kind ic_kind, Code::Flags flags,
20 StubCache::Table table, Register receiver, Register name,
21 // The offset is scaled by 4, based on
22 // kCacheIndexShift, which is two bits
23 Register offset) {
24 // We need to scale up the pointer by 2 when the offset is scaled by less
25 // than the pointer size.
26 DCHECK(kPointerSize == kInt64Size
27 ? kPointerSizeLog2 == StubCache::kCacheIndexShift + 1
28 : kPointerSizeLog2 == StubCache::kCacheIndexShift);
29 ScaleFactor scale_factor = kPointerSize == kInt64Size ? times_2 : times_1;
30
31 DCHECK_EQ(3u * kPointerSize, sizeof(StubCache::Entry));
32 // The offset register holds the entry offset times four (due to masking
33 // and shifting optimizations).
34 ExternalReference key_offset(isolate->stub_cache()->key_reference(table));
35 ExternalReference value_offset(isolate->stub_cache()->value_reference(table));
36 Label miss;
37
38 // Multiply by 3 because there are 3 fields per entry (name, code, map).
39 __ leap(offset, Operand(offset, offset, times_2, 0));
40
41 __ LoadAddress(kScratchRegister, key_offset);
42
43 // Check that the key in the entry matches the name.
44 __ cmpp(name, Operand(kScratchRegister, offset, scale_factor, 0));
45 __ j(not_equal, &miss);
46
47 // Get the map entry from the cache.
48 // Use key_offset + kPointerSize * 2, rather than loading map_offset.
49 DCHECK(isolate->stub_cache()->map_reference(table).address() -
50 isolate->stub_cache()->key_reference(table).address() ==
51 kPointerSize * 2);
52 __ movp(kScratchRegister,
53 Operand(kScratchRegister, offset, scale_factor, kPointerSize * 2));
54 __ cmpp(kScratchRegister, FieldOperand(receiver, HeapObject::kMapOffset));
55 __ j(not_equal, &miss);
56
57 // Get the code entry from the cache.
58 __ LoadAddress(kScratchRegister, value_offset);
59 __ movp(kScratchRegister, Operand(kScratchRegister, offset, scale_factor, 0));
60
61 // Check that the flags match what we're looking for.
62 __ movl(offset, FieldOperand(kScratchRegister, Code::kFlagsOffset));
63 __ andp(offset, Immediate(~Code::kFlagsNotUsedInLookup));
64 __ cmpl(offset, Immediate(flags));
65 __ j(not_equal, &miss);
66
67 #ifdef DEBUG
68 if (FLAG_test_secondary_stub_cache && table == StubCache::kPrimary) {
69 __ jmp(&miss);
70 } else if (FLAG_test_primary_stub_cache && table == StubCache::kSecondary) {
71 __ jmp(&miss);
72 }
73 #endif
74
75 // Jump to the first instruction in the code stub.
76 __ addp(kScratchRegister, Immediate(Code::kHeaderSize - kHeapObjectTag));
77 __ jmp(kScratchRegister);
78
79 __ bind(&miss);
80 }
81
82
GenerateProbe(MacroAssembler * masm,Code::Kind ic_kind,Code::Flags flags,Register receiver,Register name,Register scratch,Register extra,Register extra2,Register extra3)83 void StubCache::GenerateProbe(MacroAssembler* masm, Code::Kind ic_kind,
84 Code::Flags flags, Register receiver,
85 Register name, Register scratch, Register extra,
86 Register extra2, Register extra3) {
87 Isolate* isolate = masm->isolate();
88 Label miss;
89 USE(extra); // The register extra is not used on the X64 platform.
90 USE(extra2); // The register extra2 is not used on the X64 platform.
91 USE(extra3); // The register extra2 is not used on the X64 platform.
92 // Make sure that code is valid. The multiplying code relies on the
93 // entry size being 3 * kPointerSize.
94 DCHECK(sizeof(Entry) == 3 * kPointerSize);
95
96 // Make sure the flags do not name a specific type.
97 DCHECK(Code::ExtractTypeFromFlags(flags) == 0);
98
99 // Make sure that there are no register conflicts.
100 DCHECK(!scratch.is(receiver));
101 DCHECK(!scratch.is(name));
102
103 // Check scratch register is valid, extra and extra2 are unused.
104 DCHECK(!scratch.is(no_reg));
105 DCHECK(extra2.is(no_reg));
106 DCHECK(extra3.is(no_reg));
107
108 #ifdef DEBUG
109 // If vector-based ics are in use, ensure that scratch doesn't conflict with
110 // the vector and slot registers, which need to be preserved for a handler
111 // call or miss.
112 if (IC::ICUseVector(ic_kind)) {
113 if (ic_kind == Code::LOAD_IC || ic_kind == Code::KEYED_LOAD_IC) {
114 Register vector = LoadWithVectorDescriptor::VectorRegister();
115 Register slot = LoadDescriptor::SlotRegister();
116 DCHECK(!AreAliased(vector, slot, scratch));
117 } else {
118 DCHECK(ic_kind == Code::STORE_IC || ic_kind == Code::KEYED_STORE_IC);
119 Register vector = VectorStoreICDescriptor::VectorRegister();
120 Register slot = VectorStoreICDescriptor::SlotRegister();
121 DCHECK(!AreAliased(vector, slot, scratch));
122 }
123 }
124 #endif
125
126 Counters* counters = masm->isolate()->counters();
127 __ IncrementCounter(counters->megamorphic_stub_cache_probes(), 1);
128
129 // Check that the receiver isn't a smi.
130 __ JumpIfSmi(receiver, &miss);
131
132 // Get the map of the receiver and compute the hash.
133 __ movl(scratch, FieldOperand(name, Name::kHashFieldOffset));
134 // Use only the low 32 bits of the map pointer.
135 __ addl(scratch, FieldOperand(receiver, HeapObject::kMapOffset));
136 __ xorp(scratch, Immediate(flags));
137 // We mask out the last two bits because they are not part of the hash and
138 // they are always 01 for maps. Also in the two 'and' instructions below.
139 __ andp(scratch, Immediate((kPrimaryTableSize - 1) << kCacheIndexShift));
140
141 // Probe the primary table.
142 ProbeTable(isolate, masm, ic_kind, flags, kPrimary, receiver, name, scratch);
143
144 // Primary miss: Compute hash for secondary probe.
145 __ movl(scratch, FieldOperand(name, Name::kHashFieldOffset));
146 __ addl(scratch, FieldOperand(receiver, HeapObject::kMapOffset));
147 __ xorp(scratch, Immediate(flags));
148 __ andp(scratch, Immediate((kPrimaryTableSize - 1) << kCacheIndexShift));
149 __ subl(scratch, name);
150 __ addl(scratch, Immediate(flags));
151 __ andp(scratch, Immediate((kSecondaryTableSize - 1) << kCacheIndexShift));
152
153 // Probe the secondary table.
154 ProbeTable(isolate, masm, ic_kind, flags, kSecondary, receiver, name,
155 scratch);
156
157 // Cache miss: Fall-through and let caller handle the miss by
158 // entering the runtime system.
159 __ bind(&miss);
160 __ IncrementCounter(counters->megamorphic_stub_cache_misses(), 1);
161 }
162
163
164 #undef __
165 } // namespace internal
166 } // namespace v8
167
168 #endif // V8_TARGET_ARCH_X64
169