1 // Copyright 2013 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_ARM64
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
16 #define __ ACCESS_MASM(masm)
17
18
19 // Probe primary or secondary table.
20 // If the entry is found in the cache, the generated code jump to the first
21 // instruction of the stub in the cache.
22 // If there is a miss the code fall trough.
23 //
24 // 'receiver', 'name' and 'offset' registers are preserved on miss.
ProbeTable(Isolate * isolate,MacroAssembler * masm,Code::Kind ic_kind,Code::Flags flags,StubCache::Table table,Register receiver,Register name,Register offset,Register scratch,Register scratch2,Register scratch3)25 static void ProbeTable(Isolate* isolate, MacroAssembler* masm,
26 Code::Kind ic_kind, Code::Flags flags,
27 StubCache::Table table, Register receiver, Register name,
28 Register offset, Register scratch, Register scratch2,
29 Register scratch3) {
30 // Some code below relies on the fact that the Entry struct contains
31 // 3 pointers (name, code, map).
32 STATIC_ASSERT(sizeof(StubCache::Entry) == (3 * kPointerSize));
33
34 ExternalReference key_offset(isolate->stub_cache()->key_reference(table));
35 ExternalReference value_offset(isolate->stub_cache()->value_reference(table));
36 ExternalReference map_offset(isolate->stub_cache()->map_reference(table));
37
38 uintptr_t key_off_addr = reinterpret_cast<uintptr_t>(key_offset.address());
39 uintptr_t value_off_addr =
40 reinterpret_cast<uintptr_t>(value_offset.address());
41 uintptr_t map_off_addr = reinterpret_cast<uintptr_t>(map_offset.address());
42
43 Label miss;
44
45 DCHECK(!AreAliased(name, offset, scratch, scratch2, scratch3));
46
47 // Multiply by 3 because there are 3 fields per entry.
48 __ Add(scratch3, offset, Operand(offset, LSL, 1));
49
50 // Calculate the base address of the entry.
51 __ Mov(scratch, key_offset);
52 __ Add(scratch, scratch, Operand(scratch3, LSL, kPointerSizeLog2));
53
54 // Check that the key in the entry matches the name.
55 __ Ldr(scratch2, MemOperand(scratch));
56 __ Cmp(name, scratch2);
57 __ B(ne, &miss);
58
59 // Check the map matches.
60 __ Ldr(scratch2, MemOperand(scratch, map_off_addr - key_off_addr));
61 __ Ldr(scratch3, FieldMemOperand(receiver, HeapObject::kMapOffset));
62 __ Cmp(scratch2, scratch3);
63 __ B(ne, &miss);
64
65 // Get the code entry from the cache.
66 __ Ldr(scratch, MemOperand(scratch, value_off_addr - key_off_addr));
67
68 // Check that the flags match what we're looking for.
69 __ Ldr(scratch2.W(), FieldMemOperand(scratch, Code::kFlagsOffset));
70 __ Bic(scratch2.W(), scratch2.W(), Code::kFlagsNotUsedInLookup);
71 __ Cmp(scratch2.W(), flags);
72 __ B(ne, &miss);
73
74 #ifdef DEBUG
75 if (FLAG_test_secondary_stub_cache && table == StubCache::kPrimary) {
76 __ B(&miss);
77 } else if (FLAG_test_primary_stub_cache && table == StubCache::kSecondary) {
78 __ B(&miss);
79 }
80 #endif
81
82 // Jump to the first instruction in the code stub.
83 __ Add(scratch, scratch, Code::kHeaderSize - kHeapObjectTag);
84 __ Br(scratch);
85
86 // Miss: fall through.
87 __ Bind(&miss);
88 }
89
90
GenerateProbe(MacroAssembler * masm,Code::Kind ic_kind,Code::Flags flags,Register receiver,Register name,Register scratch,Register extra,Register extra2,Register extra3)91 void StubCache::GenerateProbe(MacroAssembler* masm, Code::Kind ic_kind,
92 Code::Flags flags, Register receiver,
93 Register name, Register scratch, Register extra,
94 Register extra2, Register extra3) {
95 Isolate* isolate = masm->isolate();
96 Label miss;
97
98 // Make sure the flags does not name a specific type.
99 DCHECK(Code::ExtractTypeFromFlags(flags) == 0);
100
101 // Make sure that there are no register conflicts.
102 DCHECK(!AreAliased(receiver, name, scratch, extra, extra2, extra3));
103
104 // Make sure extra and extra2 registers are valid.
105 DCHECK(!extra.is(no_reg));
106 DCHECK(!extra2.is(no_reg));
107 DCHECK(!extra3.is(no_reg));
108
109 #ifdef DEBUG
110 // If vector-based ics are in use, ensure that scratch, extra, extra2 and
111 // extra3 don't conflict with the vector and slot registers, which need
112 // to be preserved for a handler call or miss.
113 if (IC::ICUseVector(ic_kind)) {
114 Register vector, slot;
115 if (ic_kind == Code::STORE_IC || ic_kind == Code::KEYED_STORE_IC) {
116 vector = VectorStoreICDescriptor::VectorRegister();
117 slot = VectorStoreICDescriptor::SlotRegister();
118 } else {
119 vector = LoadWithVectorDescriptor::VectorRegister();
120 slot = LoadWithVectorDescriptor::SlotRegister();
121 }
122 DCHECK(!AreAliased(vector, slot, scratch, extra, extra2, extra3));
123 }
124 #endif
125
126 Counters* counters = masm->isolate()->counters();
127 __ IncrementCounter(counters->megamorphic_stub_cache_probes(), 1, extra2,
128 extra3);
129
130 // Check that the receiver isn't a smi.
131 __ JumpIfSmi(receiver, &miss);
132
133 // Compute the hash for primary table.
134 __ Ldr(scratch, FieldMemOperand(name, Name::kHashFieldOffset));
135 __ Ldr(extra, FieldMemOperand(receiver, HeapObject::kMapOffset));
136 __ Add(scratch, scratch, extra);
137 __ Eor(scratch, scratch, flags);
138 // We shift out the last two bits because they are not part of the hash.
139 __ Ubfx(scratch, scratch, kCacheIndexShift,
140 CountTrailingZeros(kPrimaryTableSize, 64));
141
142 // Probe the primary table.
143 ProbeTable(isolate, masm, ic_kind, flags, kPrimary, receiver, name, scratch,
144 extra, extra2, extra3);
145
146 // Primary miss: Compute hash for secondary table.
147 __ Sub(scratch, scratch, Operand(name, LSR, kCacheIndexShift));
148 __ Add(scratch, scratch, flags >> kCacheIndexShift);
149 __ And(scratch, scratch, kSecondaryTableSize - 1);
150
151 // Probe the secondary table.
152 ProbeTable(isolate, masm, ic_kind, flags, kSecondary, receiver, name, scratch,
153 extra, extra2, extra3);
154
155 // Cache miss: Fall-through and let caller handle the miss by
156 // entering the runtime system.
157 __ Bind(&miss);
158 __ IncrementCounter(counters->megamorphic_stub_cache_misses(), 1, extra2,
159 extra3);
160 }
161 } // namespace internal
162 } // namespace v8
163
164 #endif // V8_TARGET_ARCH_ARM64
165