| /* |
| * Copyright (C) 2011-2019 Apple Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. Neither the name of Apple Inc. ("Apple") nor the names of |
| * its contributors may be used to endorse or promote products derived |
| * from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY |
| * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #pragma once |
| |
| #include "ConcurrentJSLock.h" |
| #include "SpeculatedType.h" |
| #include "Structure.h" |
| #include <wtf/PrintStream.h> |
| #include <wtf/StringPrintStream.h> |
| |
| namespace JSC { |
| |
| template<unsigned numberOfBucketsArgument> |
| struct ValueProfileBase { |
| static constexpr unsigned numberOfBuckets = numberOfBucketsArgument; |
| static constexpr unsigned numberOfSpecFailBuckets = 1; |
| static constexpr unsigned bucketIndexMask = numberOfBuckets - 1; |
| static constexpr unsigned totalNumberOfBuckets = numberOfBuckets + numberOfSpecFailBuckets; |
| |
| ValueProfileBase() |
| { |
| for (unsigned i = 0; i < totalNumberOfBuckets; ++i) |
| m_buckets[i] = JSValue::encode(JSValue()); |
| } |
| |
| EncodedJSValue* specFailBucket(unsigned i) |
| { |
| ASSERT(numberOfBuckets + i < totalNumberOfBuckets); |
| return m_buckets + numberOfBuckets + i; |
| } |
| |
| const ClassInfo* classInfo(unsigned bucket) const |
| { |
| JSValue value = JSValue::decode(m_buckets[bucket]); |
| if (!!value) { |
| if (!value.isCell()) |
| return 0; |
| return value.asCell()->structure()->classInfo(); |
| } |
| return 0; |
| } |
| |
| unsigned numberOfSamples() const |
| { |
| unsigned result = 0; |
| for (unsigned i = 0; i < totalNumberOfBuckets; ++i) { |
| if (!!JSValue::decode(m_buckets[i])) |
| result++; |
| } |
| return result; |
| } |
| |
| unsigned totalNumberOfSamples() const |
| { |
| return numberOfSamples() + isSampledBefore(); |
| } |
| |
| bool isSampledBefore() const { return m_prediction != SpecNone; } |
| |
| bool isLive() const |
| { |
| for (unsigned i = 0; i < totalNumberOfBuckets; ++i) { |
| if (!!JSValue::decode(m_buckets[i])) |
| return true; |
| } |
| return false; |
| } |
| |
| CString briefDescription(const ConcurrentJSLocker& locker) |
| { |
| computeUpdatedPrediction(locker); |
| |
| StringPrintStream out; |
| out.print("predicting ", SpeculationDump(m_prediction)); |
| return out.toCString(); |
| } |
| |
| void dump(PrintStream& out) |
| { |
| out.print("sampled before = ", isSampledBefore(), " live samples = ", numberOfSamples(), " prediction = ", SpeculationDump(m_prediction)); |
| bool first = true; |
| for (unsigned i = 0; i < totalNumberOfBuckets; ++i) { |
| JSValue value = JSValue::decode(m_buckets[i]); |
| if (!!value) { |
| if (first) { |
| out.printf(": "); |
| first = false; |
| } else |
| out.printf(", "); |
| out.print(value); |
| } |
| } |
| } |
| |
| // Updates the prediction and returns the new one. Never call this from any thread |
| // that isn't executing the code. |
| SpeculatedType computeUpdatedPrediction(const ConcurrentJSLocker&) |
| { |
| for (unsigned i = 0; i < totalNumberOfBuckets; ++i) { |
| JSValue value = JSValue::decode(m_buckets[i]); |
| if (!value) |
| continue; |
| |
| mergeSpeculation(m_prediction, speculationFromValue(value)); |
| |
| m_buckets[i] = JSValue::encode(JSValue()); |
| } |
| |
| return m_prediction; |
| } |
| |
| EncodedJSValue m_buckets[totalNumberOfBuckets]; |
| |
| SpeculatedType m_prediction { SpecNone }; |
| }; |
| |
| struct MinimalValueProfile : public ValueProfileBase<0> { |
| MinimalValueProfile(): ValueProfileBase<0>() { } |
| }; |
| |
| template<unsigned logNumberOfBucketsArgument> |
| struct ValueProfileWithLogNumberOfBuckets : public ValueProfileBase<1 << logNumberOfBucketsArgument> { |
| static constexpr unsigned logNumberOfBuckets = logNumberOfBucketsArgument; |
| |
| ValueProfileWithLogNumberOfBuckets() |
| : ValueProfileBase<1 << logNumberOfBucketsArgument>() |
| { |
| } |
| }; |
| |
| struct ValueProfile : public ValueProfileWithLogNumberOfBuckets<0> { |
| ValueProfile() : ValueProfileWithLogNumberOfBuckets<0>() { } |
| }; |
| |
| // This is a mini value profile to catch pathologies. It is a counter that gets |
| // incremented when we take the slow path on any instruction. |
| struct RareCaseProfile { |
| RareCaseProfile(BytecodeIndex bytecodeIndex) |
| : m_bytecodeIndex(bytecodeIndex) |
| { |
| } |
| RareCaseProfile() = default; |
| |
| BytecodeIndex m_bytecodeIndex { }; |
| uint32_t m_counter { 0 }; |
| }; |
| |
| inline BytecodeIndex getRareCaseProfileBytecodeIndex(RareCaseProfile* rareCaseProfile) |
| { |
| return rareCaseProfile->m_bytecodeIndex; |
| } |
| |
| struct ValueProfileAndVirtualRegister : public ValueProfile { |
| VirtualRegister m_operand; |
| }; |
| |
| struct ValueProfileAndVirtualRegisterBuffer { |
| WTF_MAKE_STRUCT_FAST_ALLOCATED; |
| |
| ValueProfileAndVirtualRegisterBuffer(unsigned size) |
| : m_size(size) |
| { |
| // FIXME: ValueProfile has more stuff than we need. We could optimize these value profiles |
| // to be more space efficient. |
| // https://bugs.webkit.org/show_bug.cgi?id=175413 |
| m_buffer = MallocPtr<ValueProfileAndVirtualRegister, VMMalloc>::malloc(m_size * sizeof(ValueProfileAndVirtualRegister)); |
| for (unsigned i = 0; i < m_size; ++i) |
| new (&m_buffer.get()[i]) ValueProfileAndVirtualRegister(); |
| } |
| |
| ~ValueProfileAndVirtualRegisterBuffer() |
| { |
| for (unsigned i = 0; i < m_size; ++i) |
| m_buffer.get()[i].~ValueProfileAndVirtualRegister(); |
| } |
| |
| template <typename Function> |
| void forEach(Function function) |
| { |
| for (unsigned i = 0; i < m_size; ++i) |
| function(m_buffer.get()[i]); |
| } |
| |
| unsigned m_size; |
| MallocPtr<ValueProfileAndVirtualRegister, VMMalloc> m_buffer; |
| }; |
| |
| } // namespace JSC |