Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame^] | 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 | #include "src/v8.h" |
| 6 | |
| 7 | #if V8_TARGET_ARCH_ARM64 |
| 8 | |
| 9 | #include "src/codegen.h" |
| 10 | #include "src/ic/stub-cache.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. |
| 25 | static void ProbeTable(Isolate* isolate, MacroAssembler* masm, |
| 26 | Code::Flags flags, bool leave_frame, |
| 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 | if (leave_frame) __ LeaveFrame(StackFrame::INTERNAL); |
| 83 | |
| 84 | // Jump to the first instruction in the code stub. |
| 85 | __ Add(scratch, scratch, Code::kHeaderSize - kHeapObjectTag); |
| 86 | __ Br(scratch); |
| 87 | |
| 88 | // Miss: fall through. |
| 89 | __ Bind(&miss); |
| 90 | } |
| 91 | |
| 92 | |
| 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 the flags does not name a specific type. |
| 101 | DCHECK(Code::ExtractTypeFromFlags(flags) == 0); |
| 102 | |
| 103 | // Make sure that there are no register conflicts. |
| 104 | DCHECK(!AreAliased(receiver, name, scratch, extra, extra2, extra3)); |
| 105 | |
| 106 | // Make sure extra and extra2 registers are valid. |
| 107 | DCHECK(!extra.is(no_reg)); |
| 108 | DCHECK(!extra2.is(no_reg)); |
| 109 | DCHECK(!extra3.is(no_reg)); |
| 110 | |
| 111 | Counters* counters = masm->isolate()->counters(); |
| 112 | __ IncrementCounter(counters->megamorphic_stub_cache_probes(), 1, extra2, |
| 113 | extra3); |
| 114 | |
| 115 | // Check that the receiver isn't a smi. |
| 116 | __ JumpIfSmi(receiver, &miss); |
| 117 | |
| 118 | // Compute the hash for primary table. |
| 119 | __ Ldr(scratch, FieldMemOperand(name, Name::kHashFieldOffset)); |
| 120 | __ Ldr(extra, FieldMemOperand(receiver, HeapObject::kMapOffset)); |
| 121 | __ Add(scratch, scratch, extra); |
| 122 | __ Eor(scratch, scratch, flags); |
| 123 | // We shift out the last two bits because they are not part of the hash. |
| 124 | __ Ubfx(scratch, scratch, kCacheIndexShift, |
| 125 | CountTrailingZeros(kPrimaryTableSize, 64)); |
| 126 | |
| 127 | // Probe the primary table. |
| 128 | ProbeTable(isolate, masm, flags, leave_frame, kPrimary, receiver, name, |
| 129 | scratch, extra, extra2, extra3); |
| 130 | |
| 131 | // Primary miss: Compute hash for secondary table. |
| 132 | __ Sub(scratch, scratch, Operand(name, LSR, kCacheIndexShift)); |
| 133 | __ Add(scratch, scratch, flags >> kCacheIndexShift); |
| 134 | __ And(scratch, scratch, kSecondaryTableSize - 1); |
| 135 | |
| 136 | // Probe the secondary table. |
| 137 | ProbeTable(isolate, masm, flags, leave_frame, kSecondary, receiver, name, |
| 138 | scratch, extra, extra2, extra3); |
| 139 | |
| 140 | // Cache miss: Fall-through and let caller handle the miss by |
| 141 | // entering the runtime system. |
| 142 | __ Bind(&miss); |
| 143 | __ IncrementCounter(counters->megamorphic_stub_cache_misses(), 1, extra2, |
| 144 | extra3); |
| 145 | } |
| 146 | } |
| 147 | } // namespace v8::internal |
| 148 | |
| 149 | #endif // V8_TARGET_ARCH_ARM64 |