+++ /dev/null
-/*
- * Copyright (C) 2013 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.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 INC. OR
- * 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.
- */
-
-#include "config.h"
-#include "DFGBinarySwitch.h"
-
-#if ENABLE(DFG_JIT)
-
-#include "JSCInlines.h"
-
-namespace JSC { namespace DFG {
-
-BinarySwitch::BinarySwitch(GPRReg value, const Vector<int64_t>& cases, Type type)
- : m_value(value)
- , m_index(0)
- , m_caseIndex(UINT_MAX)
- , m_medianBias(0)
- , m_type(type)
-{
- if (cases.isEmpty())
- return;
-
- for (unsigned i = 0; i < cases.size(); ++i)
- m_cases.append(Case(cases[i], i));
- std::sort(m_cases.begin(), m_cases.end());
- build(0, m_cases.size());
-}
-
-bool BinarySwitch::advance(MacroAssembler& jit)
-{
- if (m_cases.isEmpty()) {
- m_fallThrough.append(jit.jump());
- return false;
- }
-
- if (m_index == m_branches.size()) {
- RELEASE_ASSERT(m_jumpStack.isEmpty());
- return false;
- }
-
- for (;;) {
- const BranchCode& code = m_branches[m_index++];
- switch (code.kind) {
- case NotEqualToFallThrough:
- switch (m_type) {
- case Int32:
- m_fallThrough.append(jit.branch32(
- MacroAssembler::NotEqual, m_value,
- MacroAssembler::Imm32(static_cast<int32_t>(m_cases[code.index].value))));
- break;
- case IntPtr:
- m_fallThrough.append(jit.branchPtr(
- MacroAssembler::NotEqual, m_value,
- MacroAssembler::ImmPtr(bitwise_cast<const void*>(static_cast<intptr_t>(m_cases[code.index].value)))));
- break;
- }
- break;
- case NotEqualToPush:
- switch (m_type) {
- case Int32:
- m_jumpStack.append(jit.branch32(
- MacroAssembler::NotEqual, m_value,
- MacroAssembler::Imm32(static_cast<int32_t>(m_cases[code.index].value))));
- break;
- case IntPtr:
- m_jumpStack.append(jit.branchPtr(
- MacroAssembler::NotEqual, m_value,
- MacroAssembler::ImmPtr(bitwise_cast<const void*>(static_cast<intptr_t>(m_cases[code.index].value)))));
- break;
- }
- break;
- case LessThanToPush:
- switch (m_type) {
- case Int32:
- m_jumpStack.append(jit.branch32(
- MacroAssembler::LessThan, m_value,
- MacroAssembler::Imm32(static_cast<int32_t>(m_cases[code.index].value))));
- break;
- case IntPtr:
- m_jumpStack.append(jit.branchPtr(
- MacroAssembler::LessThan, m_value,
- MacroAssembler::ImmPtr(bitwise_cast<const void*>(static_cast<intptr_t>(m_cases[code.index].value)))));
- break;
- }
- break;
- case Pop:
- m_jumpStack.takeLast().link(&jit);
- break;
- case ExecuteCase:
- m_caseIndex = code.index;
- return true;
- }
- }
-}
-
-void BinarySwitch::build(unsigned start, unsigned end)
-{
- unsigned size = end - start;
-
- switch (size) {
- case 0: {
- RELEASE_ASSERT_NOT_REACHED();
- break;
- }
-
- case 1: {
- if (start
- && m_cases[start - 1].value == m_cases[start].value - 1
- && start + 1 < m_cases.size()
- && m_cases[start + 1].value == m_cases[start].value + 1) {
- m_branches.append(BranchCode(ExecuteCase, start));
- break;
- }
-
- m_branches.append(BranchCode(NotEqualToFallThrough, start));
- m_branches.append(BranchCode(ExecuteCase, start));
- break;
- }
-
- case 2: {
- if (m_cases[start].value + 1 == m_cases[start + 1].value
- && start
- && m_cases[start - 1].value == m_cases[start].value - 1
- && start + 2 < m_cases.size()
- && m_cases[start + 2].value == m_cases[start + 1].value + 1) {
- m_branches.append(BranchCode(NotEqualToPush, start));
- m_branches.append(BranchCode(ExecuteCase, start));
- m_branches.append(BranchCode(Pop));
- m_branches.append(BranchCode(ExecuteCase, start + 1));
- break;
- }
-
- unsigned firstCase = start;
- unsigned secondCase = start + 1;
- if (m_medianBias)
- std::swap(firstCase, secondCase);
- m_medianBias ^= 1;
-
- m_branches.append(BranchCode(NotEqualToPush, firstCase));
- m_branches.append(BranchCode(ExecuteCase, firstCase));
- m_branches.append(BranchCode(Pop));
- m_branches.append(BranchCode(NotEqualToFallThrough, secondCase));
- m_branches.append(BranchCode(ExecuteCase, secondCase));
- break;
- }
-
- default: {
- unsigned medianIndex = (start + end) / 2;
- if (!(size & 1)) {
- // Because end is exclusive, in the even case, this rounds up by
- // default. Hence median bias sometimes flips to subtracing one
- // in order to get round-down behavior.
- medianIndex -= m_medianBias;
- m_medianBias ^= 1;
- }
-
- RELEASE_ASSERT(medianIndex > start);
- RELEASE_ASSERT(medianIndex + 1 < end);
-
- m_branches.append(BranchCode(LessThanToPush, medianIndex));
- m_branches.append(BranchCode(NotEqualToPush, medianIndex));
- m_branches.append(BranchCode(ExecuteCase, medianIndex));
-
- m_branches.append(BranchCode(Pop));
- build(medianIndex + 1, end);
-
- m_branches.append(BranchCode(Pop));
- build(start, medianIndex);
- break;
- } }
-}
-
-} } // namespace JSC::DFG
-
-#endif // ENABLE(DFG_JIT)
-
projects / apple / javascriptcore.git / blobdiff