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_X87 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 18 static void ProbeTable(Isolate* isolate, MacroAssembler* masm, 19 Code::Kind ic_kind, Code::Flags flags, 20 StubCache::Table table, Register name, Register receiver, 21 // Number of the cache entry pointer-size scaled. 22 Register offset, Register extra) { 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 ExternalReference virtual_register = 27 ExternalReference::virtual_handler_register(masm->isolate()); 28 29 Label miss; 30 bool is_vector_store = 31 IC::ICUseVector(ic_kind) && 32 (ic_kind == Code::STORE_IC || ic_kind == Code::KEYED_STORE_IC); 33 34 // Multiply by 3 because there are 3 fields per entry (name, code, map). 35 __ lea(offset, Operand(offset, offset, times_2, 0)); 36 37 if (extra.is_valid()) { 38 // Get the code entry from the cache. 39 __ mov(extra, Operand::StaticArray(offset, times_1, value_offset)); 40 41 // Check that the key in the entry matches the name. 42 __ cmp(name, Operand::StaticArray(offset, times_1, key_offset)); 43 __ j(not_equal, &miss); 44 45 // Check the map matches. 46 __ mov(offset, Operand::StaticArray(offset, times_1, map_offset)); 47 __ cmp(offset, FieldOperand(receiver, HeapObject::kMapOffset)); 48 __ j(not_equal, &miss); 49 50 // Check that the flags match what we're looking for. 51 __ mov(offset, FieldOperand(extra, Code::kFlagsOffset)); 52 __ and_(offset, ~Code::kFlagsNotUsedInLookup); 53 __ cmp(offset, flags); 54 __ j(not_equal, &miss); 55 56 #ifdef DEBUG 57 if (FLAG_test_secondary_stub_cache && table == StubCache::kPrimary) { 58 __ jmp(&miss); 59 } else if (FLAG_test_primary_stub_cache && table == StubCache::kSecondary) { 60 __ jmp(&miss); 61 } 62 #endif 63 64 // The vector and slot were pushed onto the stack before starting the 65 // probe, and need to be dropped before calling the handler. 66 if (is_vector_store) { 67 // The overlap here is rather embarrassing. One does what one must. 68 Register vector = VectorStoreICDescriptor::VectorRegister(); 69 DCHECK(extra.is(VectorStoreICDescriptor::SlotRegister())); 70 __ add(extra, Immediate(Code::kHeaderSize - kHeapObjectTag)); 71 __ pop(vector); 72 __ mov(Operand::StaticVariable(virtual_register), extra); 73 __ pop(extra); // Pop "slot". 74 // Jump to the first instruction in the code stub. 75 __ jmp(Operand::StaticVariable(virtual_register)); 76 } else { 77 __ pop(LoadWithVectorDescriptor::VectorRegister()); 78 __ pop(LoadDescriptor::SlotRegister()); 79 __ add(extra, Immediate(Code::kHeaderSize - kHeapObjectTag)); 80 __ jmp(extra); 81 } 82 83 __ bind(&miss); 84 } else { 85 DCHECK(ic_kind == Code::STORE_IC || ic_kind == Code::KEYED_STORE_IC); 86 87 // Save the offset on the stack. 88 __ push(offset); 89 90 // Check that the key in the entry matches the name. 91 __ cmp(name, Operand::StaticArray(offset, times_1, key_offset)); 92 __ j(not_equal, &miss); 93 94 // Check the map matches. 95 __ mov(offset, Operand::StaticArray(offset, times_1, map_offset)); 96 __ cmp(offset, FieldOperand(receiver, HeapObject::kMapOffset)); 97 __ j(not_equal, &miss); 98 99 // Restore offset register. 100 __ mov(offset, Operand(esp, 0)); 101 102 // Get the code entry from the cache. 103 __ mov(offset, Operand::StaticArray(offset, times_1, value_offset)); 104 105 // Check that the flags match what we're looking for. 106 __ mov(offset, FieldOperand(offset, Code::kFlagsOffset)); 107 __ and_(offset, ~Code::kFlagsNotUsedInLookup); 108 __ cmp(offset, flags); 109 __ j(not_equal, &miss); 110 111 #ifdef DEBUG 112 if (FLAG_test_secondary_stub_cache && table == StubCache::kPrimary) { 113 __ jmp(&miss); 114 } else if (FLAG_test_primary_stub_cache && table == StubCache::kSecondary) { 115 __ jmp(&miss); 116 } 117 #endif 118 119 // Restore offset and re-load code entry from cache. 120 __ pop(offset); 121 __ mov(offset, Operand::StaticArray(offset, times_1, value_offset)); 122 123 // Jump to the first instruction in the code stub. 124 if (is_vector_store) { 125 // The vector and slot were pushed onto the stack before starting the 126 // probe, and need to be dropped before calling the handler. 127 Register vector = VectorStoreICDescriptor::VectorRegister(); 128 DCHECK(offset.is(VectorStoreICDescriptor::SlotRegister())); 129 __ add(offset, Immediate(Code::kHeaderSize - kHeapObjectTag)); 130 __ mov(Operand::StaticVariable(virtual_register), offset); 131 __ pop(vector); 132 __ pop(offset); // Pop "slot". 133 __ jmp(Operand::StaticVariable(virtual_register)); 134 } else { 135 __ add(offset, Immediate(Code::kHeaderSize - kHeapObjectTag)); 136 __ jmp(offset); 137 } 138 139 // Pop at miss. 140 __ bind(&miss); 141 __ pop(offset); 142 } 143 } 144 145 146 void StubCache::GenerateProbe(MacroAssembler* masm, Code::Kind ic_kind, 147 Code::Flags flags, Register receiver, 148 Register name, Register scratch, Register extra, 149 Register extra2, Register extra3) { 150 Label miss; 151 152 // Assert that code is valid. The multiplying code relies on the entry size 153 // being 12. 154 DCHECK(sizeof(Entry) == 12); 155 156 // Assert that there are no register conflicts. 157 DCHECK(!scratch.is(receiver)); 158 DCHECK(!scratch.is(name)); 159 DCHECK(!extra.is(receiver)); 160 DCHECK(!extra.is(name)); 161 DCHECK(!extra.is(scratch)); 162 163 // Assert scratch and extra registers are valid, and extra2/3 are unused. 164 DCHECK(!scratch.is(no_reg)); 165 DCHECK(extra2.is(no_reg)); 166 DCHECK(extra3.is(no_reg)); 167 168 Register offset = scratch; 169 scratch = no_reg; 170 171 Counters* counters = masm->isolate()->counters(); 172 __ IncrementCounter(counters->megamorphic_stub_cache_probes(), 1); 173 174 // Check that the receiver isn't a smi. 175 __ JumpIfSmi(receiver, &miss); 176 177 // Get the map of the receiver and compute the hash. 178 __ mov(offset, FieldOperand(name, Name::kHashFieldOffset)); 179 __ add(offset, FieldOperand(receiver, HeapObject::kMapOffset)); 180 __ xor_(offset, flags); 181 // We mask out the last two bits because they are not part of the hash and 182 // they are always 01 for maps. Also in the two 'and' instructions below. 183 __ and_(offset, (kPrimaryTableSize - 1) << kCacheIndexShift); 184 // ProbeTable expects the offset to be pointer scaled, which it is, because 185 // the heap object tag size is 2 and the pointer size log 2 is also 2. 186 DCHECK(kCacheIndexShift == kPointerSizeLog2); 187 188 // Probe the primary table. 189 ProbeTable(isolate(), masm, ic_kind, flags, kPrimary, name, receiver, offset, 190 extra); 191 192 // Primary miss: Compute hash for secondary probe. 193 __ mov(offset, FieldOperand(name, Name::kHashFieldOffset)); 194 __ add(offset, FieldOperand(receiver, HeapObject::kMapOffset)); 195 __ xor_(offset, flags); 196 __ and_(offset, (kPrimaryTableSize - 1) << kCacheIndexShift); 197 __ sub(offset, name); 198 __ add(offset, Immediate(flags)); 199 __ and_(offset, (kSecondaryTableSize - 1) << kCacheIndexShift); 200 201 // Probe the secondary table. 202 ProbeTable(isolate(), masm, ic_kind, flags, kSecondary, name, receiver, 203 offset, extra); 204 205 // Cache miss: Fall-through and let caller handle the miss by 206 // entering the runtime system. 207 __ bind(&miss); 208 __ IncrementCounter(counters->megamorphic_stub_cache_misses(), 1); 209 } 210 211 212 #undef __ 213 } // namespace internal 214 } // namespace v8 215 216 #endif // V8_TARGET_ARCH_X87 217
