ftl/FTLAbstractHeap.cpp

   1 /*
   2  * Copyright (C) 2013 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27 #include "FTLAbstractHeap.h"
  28
  29 #if ENABLE(FTL_JIT)
  30
  31 #include "FTLAbbreviations.h"
  32 #include "FTLAbstractHeapRepository.h"
  33 #include "FTLOutput.h"
  34 #include "FTLTypedPointer.h"
  35 #include "JSCInlines.h"
  36 #include "Options.h"
  37
  38 namespace JSC { namespace FTL {
  39
  40 LValue AbstractHeap::tbaaMetadataSlow(const AbstractHeapRepository& repository) const
  41 {
  42     m_tbaaMetadata = mdNode(
  43         repository.m_context,
  44         mdString(repository.m_context, m_heapName),
  45         m_parent->tbaaMetadata(repository));
  46     return m_tbaaMetadata;
  47 }
  48
  49 void AbstractHeap::decorateInstruction(LValue instruction, const AbstractHeapRepository& repository) const
  50 {
  51     if (!Options::useFTLTBAA())
  52         return;
  53     setMetadata(instruction, repository.m_tbaaKind, tbaaMetadata(repository));
  54 }
  55
  56 IndexedAbstractHeap::IndexedAbstractHeap(LContext context, AbstractHeap* parent, const char* heapName, ptrdiff_t offset, size_t elementSize)
  57     : m_heapForAnyIndex(parent, heapName)
  58     , m_heapNameLength(strlen(heapName))
  59     , m_offset(offset)
  60     , m_elementSize(elementSize)
  61     , m_scaleTerm(0)
  62     , m_canShift(false)
  63 {
  64     // See if there is a common shift amount we could use instead of multiplying. Don't
  65     // try too hard. This is just a speculative optimization to reduce load on LLVM.
  66     for (unsigned i = 0; i < 4; ++i) {
  67         if (1U << i == m_elementSize) {
  68             if (i)
  69                 m_scaleTerm = constInt(intPtrType(context), i, ZeroExtend);
  70             m_canShift = true;
  71             break;
  72         }
  73     }
  74
  75     if (!m_canShift)
  76         m_scaleTerm = constInt(intPtrType(context), m_elementSize, ZeroExtend);
  77 }
  78
  79 IndexedAbstractHeap::~IndexedAbstractHeap()
  80 {
  81 }
  82
  83 TypedPointer IndexedAbstractHeap::baseIndex(Output& out, LValue base, LValue index, JSValue indexAsConstant, ptrdiff_t offset)
  84 {
  85     if (indexAsConstant.isInt32())
  86         return out.address(base, at(indexAsConstant.asInt32()), offset);
  87
  88     LValue result;
  89     if (m_canShift) {
  90         if (!m_scaleTerm)
  91             result = out.add(base, index);
  92         else
  93             result = out.add(base, out.shl(index, m_scaleTerm));
  94     } else
  95         result = out.add(base, out.mul(index, m_scaleTerm));
  96
  97     return TypedPointer(atAnyIndex(), out.addPtr(result, m_offset + offset));
  98 }
  99
 100 const AbstractField& IndexedAbstractHeap::atSlow(ptrdiff_t index)
 101 {
 102     ASSERT(static_cast<size_t>(index) >= m_smallIndices.size());
 103
 104     if (UNLIKELY(!m_largeIndices))
 105         m_largeIndices = adoptPtr(new MapType());
 106
 107     std::unique_ptr<AbstractField>& field = m_largeIndices->add(index, nullptr).iterator->value;
 108     if (!field) {
 109         field = std::make_unique<AbstractField>();
 110         initialize(*field, index);
 111     }
 112
 113     return *field;
 114 }
 115
 116 void IndexedAbstractHeap::initialize(AbstractField& field, ptrdiff_t signedIndex)
 117 {
 118     // Build up a name of the form:
 119     //
 120     //    heapName_hexIndex
 121     //
 122     // or:
 123     //
 124     //    heapName_neg_hexIndex
 125     //
 126     // For example if you access an indexed heap called FooBar at index 5, you'll
 127     // get:
 128     //
 129     //    FooBar_5
 130     //
 131     // Or if you access an indexed heap called Blah at index -10, you'll get:
 132     //
 133     //    Blah_neg_A
 134     //
 135     // This is important because LLVM uses the string to distinguish the types.
 136
 137     static const char* negSplit = "_neg_";
 138     static const char* posSplit = "_";
 139
 140     bool negative;
 141     size_t index;
 142     if (signedIndex < 0) {
 143         negative = true;
 144         index = -signedIndex;
 145     } else {
 146         negative = false;
 147         index = signedIndex;
 148     }
 149
 150     for (unsigned power = 4; power <= sizeof(void*) * 8; power += 4) {
 151         if (isGreaterThanNonZeroPowerOfTwo(index, power))
 152             continue;
 153
 154         unsigned numHexlets = power >> 2;
 155
 156         size_t stringLength = m_heapNameLength + (negative ? strlen(negSplit) : strlen(posSplit)) + numHexlets;
 157         char* characters;
 158         m_largeIndexNames.append(CString::newUninitialized(stringLength, characters));
 159
 160         memcpy(characters, m_heapForAnyIndex.heapName(), m_heapNameLength);
 161         if (negative)
 162             memcpy(characters + m_heapNameLength, negSplit, strlen(negSplit));
 163         else
 164             memcpy(characters + m_heapNameLength, posSplit, strlen(posSplit));
 165
 166         size_t accumulator = index;
 167         for (unsigned i = 0; i < numHexlets; ++i) {
 168             characters[stringLength - i - 1] = lowerNibbleToASCIIHexDigit(accumulator);
 169             accumulator >>= 4;
 170         }
 171
 172         field.initialize(&m_heapForAnyIndex, characters, m_offset + signedIndex * m_elementSize);
 173         return;
 174     }
 175
 176     RELEASE_ASSERT_NOT_REACHED();
 177 }
 178
 179 NumberedAbstractHeap::NumberedAbstractHeap(LContext context, AbstractHeap* heap, const char* heapName)
 180     : m_indexedHeap(context, heap, heapName, 0, 1)
 181 {
 182 }
 183
 184 NumberedAbstractHeap::~NumberedAbstractHeap()
 185 {
 186 }
 187
 188 AbsoluteAbstractHeap::AbsoluteAbstractHeap(LContext context, AbstractHeap* heap, const char* heapName)
 189     : m_indexedHeap(context, heap, heapName, 0, 1)
 190 {
 191 }
 192
 193 AbsoluteAbstractHeap::~AbsoluteAbstractHeap()
 194 {
 195 }
 196
 197 } } // namespace JSC::FTL
 198
 199 #endif // ENABLE(FTL_JIT)
 200