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 #include "src/v8.h"
6
7 #if V8_TARGET_ARCH_MIPS
8
9 #include "src/codegen.h"
10 #include "src/ic/stub-cache.h"
11
12 namespace v8 {
13 namespace internal {
14
15 #define __ ACCESS_MASM(masm)
16
17
ProbeTable(Isolate * isolate,MacroAssembler * masm,Code::Flags flags,bool leave_frame,StubCache::Table table,Register receiver,Register name,Register offset,Register scratch,Register scratch2,Register offset_scratch)18 static void ProbeTable(Isolate* isolate, MacroAssembler* masm,
19 Code::Flags flags, bool leave_frame,
20 StubCache::Table table, Register receiver, Register name,
21 // Number of the cache entry, not scaled.
22 Register offset, Register scratch, Register scratch2,
23 Register offset_scratch) {
24 ExternalReference key_offset(isolate->stub_cache()->key_reference(table));
25 ExternalReference value_offset(isolate->stub_cache()->value_reference(table));
26 ExternalReference map_offset(isolate->stub_cache()->map_reference(table));
27
28 uint32_t key_off_addr = reinterpret_cast<uint32_t>(key_offset.address());
29 uint32_t value_off_addr = reinterpret_cast<uint32_t>(value_offset.address());
30 uint32_t map_off_addr = reinterpret_cast<uint32_t>(map_offset.address());
31
32 // Check the relative positions of the address fields.
33 DCHECK(value_off_addr > key_off_addr);
34 DCHECK((value_off_addr - key_off_addr) % 4 == 0);
35 DCHECK((value_off_addr - key_off_addr) < (256 * 4));
36 DCHECK(map_off_addr > key_off_addr);
37 DCHECK((map_off_addr - key_off_addr) % 4 == 0);
38 DCHECK((map_off_addr - key_off_addr) < (256 * 4));
39
40 Label miss;
41 Register base_addr = scratch;
42 scratch = no_reg;
43
44 // Multiply by 3 because there are 3 fields per entry (name, code, map).
45 __ sll(offset_scratch, offset, 1);
46 __ Addu(offset_scratch, offset_scratch, offset);
47
48 // Calculate the base address of the entry.
49 __ li(base_addr, Operand(key_offset));
50 __ sll(at, offset_scratch, kPointerSizeLog2);
51 __ Addu(base_addr, base_addr, at);
52
53 // Check that the key in the entry matches the name.
54 __ lw(at, MemOperand(base_addr, 0));
55 __ Branch(&miss, ne, name, Operand(at));
56
57 // Check the map matches.
58 __ lw(at, MemOperand(base_addr, map_off_addr - key_off_addr));
59 __ lw(scratch2, FieldMemOperand(receiver, HeapObject::kMapOffset));
60 __ Branch(&miss, ne, at, Operand(scratch2));
61
62 // Get the code entry from the cache.
63 Register code = scratch2;
64 scratch2 = no_reg;
65 __ lw(code, MemOperand(base_addr, value_off_addr - key_off_addr));
66
67 // Check that the flags match what we're looking for.
68 Register flags_reg = base_addr;
69 base_addr = no_reg;
70 __ lw(flags_reg, FieldMemOperand(code, Code::kFlagsOffset));
71 __ And(flags_reg, flags_reg, Operand(~Code::kFlagsNotUsedInLookup));
72 __ Branch(&miss, ne, flags_reg, Operand(flags));
73
74 #ifdef DEBUG
75 if (FLAG_test_secondary_stub_cache && table == StubCache::kPrimary) {
76 __ jmp(&miss);
77 } else if (FLAG_test_primary_stub_cache && table == StubCache::kSecondary) {
78 __ jmp(&miss);
79 }
80 #endif
81
82 if (leave_frame) __ LeaveFrame(StackFrame::INTERNAL);
83
84 // Jump to the first instruction in the code stub.
85 __ Addu(at, code, Operand(Code::kHeaderSize - kHeapObjectTag));
86 __ Jump(at);
87
88 // Miss: fall through.
89 __ bind(&miss);
90 }
91
92
GenerateProbe(MacroAssembler * masm,Code::Flags flags,bool leave_frame,Register receiver,Register name,Register scratch,Register extra,Register extra2,Register extra3)93 void StubCache::GenerateProbe(MacroAssembler* masm, Code::Flags flags,
94 bool leave_frame, Register receiver,
95 Register name, Register scratch, Register extra,
96 Register extra2, Register extra3) {
97 Isolate* isolate = masm->isolate();
98 Label miss;
99
100 // Make sure that code is valid. The multiplying code relies on the
101 // entry size being 12.
102 DCHECK(sizeof(Entry) == 12);
103
104 // Make sure the flags does not name a specific type.
105 DCHECK(Code::ExtractTypeFromFlags(flags) == 0);
106
107 // Make sure that there are no register conflicts.
108 DCHECK(!scratch.is(receiver));
109 DCHECK(!scratch.is(name));
110 DCHECK(!extra.is(receiver));
111 DCHECK(!extra.is(name));
112 DCHECK(!extra.is(scratch));
113 DCHECK(!extra2.is(receiver));
114 DCHECK(!extra2.is(name));
115 DCHECK(!extra2.is(scratch));
116 DCHECK(!extra2.is(extra));
117
118 // Check register validity.
119 DCHECK(!scratch.is(no_reg));
120 DCHECK(!extra.is(no_reg));
121 DCHECK(!extra2.is(no_reg));
122 DCHECK(!extra3.is(no_reg));
123
124 Counters* counters = masm->isolate()->counters();
125 __ IncrementCounter(counters->megamorphic_stub_cache_probes(), 1, extra2,
126 extra3);
127
128 // Check that the receiver isn't a smi.
129 __ JumpIfSmi(receiver, &miss);
130
131 // Get the map of the receiver and compute the hash.
132 __ lw(scratch, FieldMemOperand(name, Name::kHashFieldOffset));
133 __ lw(at, FieldMemOperand(receiver, HeapObject::kMapOffset));
134 __ Addu(scratch, scratch, at);
135 uint32_t mask = kPrimaryTableSize - 1;
136 // We shift out the last two bits because they are not part of the hash and
137 // they are always 01 for maps.
138 __ srl(scratch, scratch, kCacheIndexShift);
139 __ Xor(scratch, scratch, Operand((flags >> kCacheIndexShift) & mask));
140 __ And(scratch, scratch, Operand(mask));
141
142 // Probe the primary table.
143 ProbeTable(isolate, masm, flags, leave_frame, kPrimary, receiver, name,
144 scratch, extra, extra2, extra3);
145
146 // Primary miss: Compute hash for secondary probe.
147 __ srl(at, name, kCacheIndexShift);
148 __ Subu(scratch, scratch, at);
149 uint32_t mask2 = kSecondaryTableSize - 1;
150 __ Addu(scratch, scratch, Operand((flags >> kCacheIndexShift) & mask2));
151 __ And(scratch, scratch, Operand(mask2));
152
153 // Probe the secondary table.
154 ProbeTable(isolate, masm, flags, leave_frame, kSecondary, receiver, name,
155 scratch, extra, extra2, extra3);
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, extra2,
161 extra3);
162 }
163
164
165 #undef __
166 }
167 } // namespace v8::internal
168
169 #endif // V8_TARGET_ARCH_MIPS
170