| /* |
| * Copyright (C) 2011 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. |
| */ |
| |
| #ifndef DFGCorrectableJumpPoint_h |
| #define DFGCorrectableJumpPoint_h |
| |
| #if ENABLE(DFG_JIT) |
| |
| #include "LinkBuffer.h" |
| #include "MacroAssembler.h" |
| |
| namespace JSC { namespace DFG { |
| |
| // This is a type-safe union of MacroAssembler::Jump and CodeLocationJump. |
| // Furthermore, it supports the notion of branching (possibly conditionally, but |
| // also possibly jumping unconditionally) to an out-of-line patchable jump. |
| // Thus it goes through three states: |
| // |
| // 1) Label of unpatchable branch or jump (i.e. MacroAssembler::Jump). |
| // 2) Label of patchable jump (i.e. MacroAssembler::PatchableJump). |
| // 3) Corrected post-linking label of patchable jump (i.e. CodeLocationJump). |
| // |
| // The setting of state (1) corresponds to planting the in-line unpatchable |
| // branch or jump. The state transition (1)->(2) corresponds to linking the |
| // in-line branch or jump to the out-of-line patchable jump, and recording |
| // the latter's label. The state transition (2)->(3) corresponds to recording |
| // the out-of-line patchable jump's location after branch compaction has |
| // completed. |
| // |
| // You can also go directly from the first state to the third state, if you |
| // wish to use this class for in-line patchable jumps. |
| |
| class CorrectableJumpPoint { |
| public: |
| CorrectableJumpPoint(MacroAssembler::Jump check) |
| : m_codeOffset(check.m_label.m_offset) |
| #ifndef NDEBUG |
| , m_mode(InitialJump) |
| #endif |
| { |
| #if CPU(ARM_THUMB2) |
| m_type = check.m_type; |
| m_condition = check.m_condition; |
| #endif |
| } |
| |
| bool isSet() |
| { |
| return m_codeOffset != std::numeric_limits<uint32_t>::max(); |
| } |
| |
| void switchToLateJump(MacroAssembler::PatchableJump check) |
| { |
| #ifndef NDEBUG |
| ASSERT(m_mode == InitialJump); |
| m_mode = LateJump; |
| #endif |
| // Late jumps should only ever be real jumps. |
| #if CPU(ARM_THUMB2) |
| ASSERT(check.m_jump.m_type == ARMv7Assembler::JumpNoConditionFixedSize); |
| ASSERT(check.m_jump.m_condition == ARMv7Assembler::ConditionInvalid); |
| m_type = ARMv7Assembler::JumpNoConditionFixedSize; |
| m_condition = ARMv7Assembler::ConditionInvalid; |
| #endif |
| m_codeOffset = check.m_jump.m_label.m_offset; |
| } |
| |
| void correctInitialJump(LinkBuffer& linkBuffer) |
| { |
| ASSERT(m_mode == InitialJump); |
| #if CPU(ARM_THUMB2) |
| ASSERT(m_type == ARMv7Assembler::JumpNoConditionFixedSize); |
| ASSERT(m_condition == ARMv7Assembler::ConditionInvalid); |
| #endif |
| correctJump(linkBuffer); |
| } |
| |
| void correctLateJump(LinkBuffer& linkBuffer) |
| { |
| ASSERT(m_mode == LateJump); |
| correctJump(linkBuffer); |
| } |
| |
| MacroAssembler::Jump initialJump() const |
| { |
| ASSERT(m_mode == InitialJump); |
| return getJump(); |
| } |
| |
| MacroAssembler::Jump lateJump() const |
| { |
| ASSERT(m_mode == LateJump); |
| return getJump(); |
| } |
| |
| CodeLocationJump codeLocationForRepatch(CodeBlock*) const; |
| |
| private: |
| void correctJump(LinkBuffer& linkBuffer) |
| { |
| #ifndef NDEBUG |
| m_mode = CorrectedJump; |
| #endif |
| MacroAssembler::Label label; |
| label.m_label.m_offset = m_codeOffset; |
| m_codeOffset = linkBuffer.offsetOf(label); |
| } |
| |
| MacroAssembler::Jump getJump() const |
| { |
| MacroAssembler::Jump jump; |
| jump.m_label.m_offset = m_codeOffset; |
| #if CPU(ARM_THUMB2) |
| jump.m_type = m_type; |
| jump.m_condition = m_condition; |
| #endif |
| return jump; |
| } |
| |
| unsigned m_codeOffset; |
| |
| #if CPU(ARM_THUMB2) |
| ARMv7Assembler::JumpType m_type : 8; |
| ARMv7Assembler::Condition m_condition : 8; |
| #endif |
| |
| #ifndef NDEBUG |
| enum Mode { |
| InitialJump, |
| LateJump, |
| CorrectedJump |
| }; |
| |
| Mode m_mode; |
| #endif |
| }; |
| |
| } } // namespace JSC::DFG |
| |
| #endif // ENABLE(DFG_JIT) |
| |
| #endif // DFGCorrectableJumpPoint_h |