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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_MIPS64
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 
ProbeTable(Isolate * isolate,MacroAssembler * masm,Code::Flags flags,StubCache::Table table,Register receiver,Register name,Register offset,Register scratch,Register scratch2,Register offset_scratch)17 static void ProbeTable(Isolate* isolate, MacroAssembler* masm,
18                        Code::Flags flags, StubCache::Table table,
19                        Register receiver, Register name,
20                        // Number of the cache entry, not scaled.
21                        Register offset, Register scratch, Register scratch2,
22                        Register offset_scratch) {
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 
27   uint64_t key_off_addr = reinterpret_cast<uint64_t>(key_offset.address());
28   uint64_t value_off_addr = reinterpret_cast<uint64_t>(value_offset.address());
29   uint64_t map_off_addr = reinterpret_cast<uint64_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   __ Dlsa(offset_scratch, offset, offset, 1);
45 
46   // Calculate the base address of the entry.
47   __ li(base_addr, Operand(key_offset));
48   __ Dlsa(base_addr, base_addr, offset_scratch, kPointerSizeLog2);
49 
50   // Check that the key in the entry matches the name.
51   __ ld(at, MemOperand(base_addr, 0));
52   __ Branch(&miss, ne, name, Operand(at));
53 
54   // Check the map matches.
55   __ ld(at, MemOperand(base_addr,
56                        static_cast<int32_t>(map_off_addr - key_off_addr)));
57   __ ld(scratch2, FieldMemOperand(receiver, HeapObject::kMapOffset));
58   __ Branch(&miss, ne, at, Operand(scratch2));
59 
60   // Get the code entry from the cache.
61   Register code = scratch2;
62   scratch2 = no_reg;
63   __ ld(code, MemOperand(base_addr,
64                          static_cast<int32_t>(value_off_addr - key_off_addr)));
65 
66   // Check that the flags match what we're looking for.
67   Register flags_reg = base_addr;
68   base_addr = no_reg;
69   __ lw(flags_reg, FieldMemOperand(code, Code::kFlagsOffset));
70   __ And(flags_reg, flags_reg, Operand(~Code::kFlagsNotUsedInLookup));
71   __ Branch(&miss, ne, flags_reg, Operand(flags));
72 
73 #ifdef DEBUG
74   if (FLAG_test_secondary_stub_cache && table == StubCache::kPrimary) {
75     __ jmp(&miss);
76   } else if (FLAG_test_primary_stub_cache && table == StubCache::kSecondary) {
77     __ jmp(&miss);
78   }
79 #endif
80 
81   // Jump to the first instruction in the code stub.
82   __ Daddu(at, code, Operand(Code::kHeaderSize - kHeapObjectTag));
83   __ Jump(at);
84 
85   // Miss: fall through.
86   __ bind(&miss);
87 }
88 
89 
GenerateProbe(MacroAssembler * masm,Code::Kind ic_kind,Code::Flags flags,Register receiver,Register name,Register scratch,Register extra,Register extra2,Register extra3)90 void StubCache::GenerateProbe(MacroAssembler* masm, Code::Kind ic_kind,
91                               Code::Flags flags, Register receiver,
92                               Register name, Register scratch, Register extra,
93                               Register extra2, Register extra3) {
94   Isolate* isolate = masm->isolate();
95   Label miss;
96 
97   // Make sure that code is valid. The multiplying code relies on the
98   // entry size being 12.
99   // DCHECK(sizeof(Entry) == 12);
100   // DCHECK(sizeof(Entry) == 3 * kPointerSize);
101 
102   // Make sure that there are no register conflicts.
103   DCHECK(!AreAliased(receiver, name, scratch, extra, extra2, extra3));
104 
105   // Check register validity.
106   DCHECK(!scratch.is(no_reg));
107   DCHECK(!extra.is(no_reg));
108   DCHECK(!extra2.is(no_reg));
109   DCHECK(!extra3.is(no_reg));
110 
111 #ifdef DEBUG
112   // If vector-based ics are in use, ensure that scratch, extra, extra2 and
113   // extra3 don't conflict with the vector and slot registers, which need
114   // to be preserved for a handler call or miss.
115   if (IC::ICUseVector(ic_kind)) {
116     Register vector, slot;
117     if (ic_kind == Code::STORE_IC || ic_kind == Code::KEYED_STORE_IC) {
118       vector = VectorStoreICDescriptor::VectorRegister();
119       slot = VectorStoreICDescriptor::SlotRegister();
120     } else {
121       vector = LoadWithVectorDescriptor::VectorRegister();
122       slot = LoadWithVectorDescriptor::SlotRegister();
123     }
124     DCHECK(!AreAliased(vector, slot, scratch, extra, extra2, extra3));
125   }
126 #endif
127 
128   Counters* counters = masm->isolate()->counters();
129   __ IncrementCounter(counters->megamorphic_stub_cache_probes(), 1, extra2,
130                       extra3);
131 
132   // Check that the receiver isn't a smi.
133   __ JumpIfSmi(receiver, &miss);
134 
135   // Get the map of the receiver and compute the hash.
136   __ ld(scratch, FieldMemOperand(name, Name::kHashFieldOffset));
137   __ ld(at, FieldMemOperand(receiver, HeapObject::kMapOffset));
138   __ Daddu(scratch, scratch, at);
139   uint64_t mask = kPrimaryTableSize - 1;
140   // We shift out the last two bits because they are not part of the hash and
141   // they are always 01 for maps.
142   __ dsrl(scratch, scratch, kCacheIndexShift);
143   __ Xor(scratch, scratch, Operand((flags >> kCacheIndexShift) & mask));
144   __ And(scratch, scratch, Operand(mask));
145 
146   // Probe the primary table.
147   ProbeTable(isolate, masm, flags, kPrimary, receiver, name, scratch, extra,
148              extra2, extra3);
149 
150   // Primary miss: Compute hash for secondary probe.
151   __ dsrl(at, name, kCacheIndexShift);
152   __ Dsubu(scratch, scratch, at);
153   uint64_t mask2 = kSecondaryTableSize - 1;
154   __ Daddu(scratch, scratch, Operand((flags >> kCacheIndexShift) & mask2));
155   __ And(scratch, scratch, Operand(mask2));
156 
157   // Probe the secondary table.
158   ProbeTable(isolate, masm, flags, kSecondary, receiver, name, scratch, extra,
159              extra2, extra3);
160 
161   // Cache miss: Fall-through and let caller handle the miss by
162   // entering the runtime system.
163   __ bind(&miss);
164   __ IncrementCounter(counters->megamorphic_stub_cache_misses(), 1, extra2,
165                       extra3);
166 }
167 
168 
169 #undef __
170 }  // namespace internal
171 }  // namespace v8
172 
173 #endif  // V8_TARGET_ARCH_MIPS64
174