--- /dev/null
+// Copyright 2013, ARM Limited
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// * Redistributions of source code must retain the above copyright notice,
+// this list of conditions and the following disclaimer.
+// * 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.
+// * Neither the name of ARM Limited 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 THE COPYRIGHT HOLDERS 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 THE COPYRIGHT OWNER 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 VIXL_A64_DECODER_A64_H_
+#define VIXL_A64_DECODER_A64_H_
+
+#include <list>
+
+#include "globals.h"
+#include "a64/instructions-a64.h"
+
+
+// List macro containing all visitors needed by the decoder class.
+
+#define VISITOR_LIST(V) \
+ V(PCRelAddressing) \
+ V(AddSubImmediate) \
+ V(LogicalImmediate) \
+ V(MoveWideImmediate) \
+ V(Bitfield) \
+ V(Extract) \
+ V(UnconditionalBranch) \
+ V(UnconditionalBranchToRegister) \
+ V(CompareBranch) \
+ V(TestBranch) \
+ V(ConditionalBranch) \
+ V(System) \
+ V(Exception) \
+ V(LoadStorePairPostIndex) \
+ V(LoadStorePairOffset) \
+ V(LoadStorePairPreIndex) \
+ V(LoadStorePairNonTemporal) \
+ V(LoadLiteral) \
+ V(LoadStoreUnscaledOffset) \
+ V(LoadStorePostIndex) \
+ V(LoadStorePreIndex) \
+ V(LoadStoreRegisterOffset) \
+ V(LoadStoreUnsignedOffset) \
+ V(LoadStoreExclusive) \
+ V(LogicalShifted) \
+ V(AddSubShifted) \
+ V(AddSubExtended) \
+ V(AddSubWithCarry) \
+ V(ConditionalCompareRegister) \
+ V(ConditionalCompareImmediate) \
+ V(ConditionalSelect) \
+ V(DataProcessing1Source) \
+ V(DataProcessing2Source) \
+ V(DataProcessing3Source) \
+ V(FPCompare) \
+ V(FPConditionalCompare) \
+ V(FPConditionalSelect) \
+ V(FPImmediate) \
+ V(FPDataProcessing1Source) \
+ V(FPDataProcessing2Source) \
+ V(FPDataProcessing3Source) \
+ V(FPIntegerConvert) \
+ V(FPFixedPointConvert) \
+ V(Unallocated) \
+ V(Unimplemented)
+
+namespace vixl {
+
+// The Visitor interface. Disassembler and simulator (and other tools)
+// must provide implementations for all of these functions.
+class DecoderVisitor {
+ public:
+ enum VisitorConstness {
+ kConstVisitor,
+ kNonConstVisitor
+ };
+ explicit DecoderVisitor(VisitorConstness constness = kConstVisitor)
+ : constness_(constness) {}
+
+ virtual ~DecoderVisitor() {}
+
+ #define DECLARE(A) virtual void Visit##A(const Instruction* instr) = 0;
+ VISITOR_LIST(DECLARE)
+ #undef DECLARE
+
+ bool IsConstVisitor() const { return constness_ == kConstVisitor; }
+ Instruction* MutableInstruction(const Instruction* instr) {
+ VIXL_ASSERT(!IsConstVisitor());
+ return const_cast<Instruction*>(instr);
+ }
+
+ private:
+ const VisitorConstness constness_;
+};
+
+
+class Decoder {
+ public:
+ Decoder() {}
+
+ // Top-level wrappers around the actual decoding function.
+ void Decode(const Instruction* instr) {
+ std::list<DecoderVisitor*>::iterator it;
+ for (it = visitors_.begin(); it != visitors_.end(); it++) {
+ VIXL_ASSERT((*it)->IsConstVisitor());
+ }
+ DecodeInstruction(instr);
+ }
+ void Decode(Instruction* instr) {
+ DecodeInstruction(const_cast<const Instruction*>(instr));
+ }
+
+ // Register a new visitor class with the decoder.
+ // Decode() will call the corresponding visitor method from all registered
+ // visitor classes when decoding reaches the leaf node of the instruction
+ // decode tree.
+ // Visitors are called in order.
+ // A visitor can be registered multiple times.
+ //
+ // d.AppendVisitor(V1);
+ // d.AppendVisitor(V2);
+ // d.PrependVisitor(V2);
+ // d.AppendVisitor(V3);
+ //
+ // d.Decode(i);
+ //
+ // will call in order visitor methods in V2, V1, V2, V3.
+ void AppendVisitor(DecoderVisitor* visitor);
+ void PrependVisitor(DecoderVisitor* visitor);
+ // These helpers register `new_visitor` before or after the first instance of
+ // `registered_visiter` in the list.
+ // So if
+ // V1, V2, V1, V2
+ // are registered in this order in the decoder, calls to
+ // d.InsertVisitorAfter(V3, V1);
+ // d.InsertVisitorBefore(V4, V2);
+ // will yield the order
+ // V1, V3, V4, V2, V1, V2
+ //
+ // For more complex modifications of the order of registered visitors, one can
+ // directly access and modify the list of visitors via the `visitors()'
+ // accessor.
+ void InsertVisitorBefore(DecoderVisitor* new_visitor,
+ DecoderVisitor* registered_visitor);
+ void InsertVisitorAfter(DecoderVisitor* new_visitor,
+ DecoderVisitor* registered_visitor);
+
+ // Remove all instances of a previously registered visitor class from the list
+ // of visitors stored by the decoder.
+ void RemoveVisitor(DecoderVisitor* visitor);
+
+ #define DECLARE(A) void Visit##A(const Instruction* instr);
+ VISITOR_LIST(DECLARE)
+ #undef DECLARE
+
+
+ std::list<DecoderVisitor*>* visitors() { return &visitors_; }
+
+ private:
+ // Decodes an instruction and calls the visitor functions registered with the
+ // Decoder class.
+ void DecodeInstruction(const Instruction* instr);
+
+ // Decode the PC relative addressing instruction, and call the corresponding
+ // visitors.
+ // On entry, instruction bits 27:24 = 0x0.
+ void DecodePCRelAddressing(const Instruction* instr);
+
+ // Decode the add/subtract immediate instruction, and call the correspoding
+ // visitors.
+ // On entry, instruction bits 27:24 = 0x1.
+ void DecodeAddSubImmediate(const Instruction* instr);
+
+ // Decode the branch, system command, and exception generation parts of
+ // the instruction tree, and call the corresponding visitors.
+ // On entry, instruction bits 27:24 = {0x4, 0x5, 0x6, 0x7}.
+ void DecodeBranchSystemException(const Instruction* instr);
+
+ // Decode the load and store parts of the instruction tree, and call
+ // the corresponding visitors.
+ // On entry, instruction bits 27:24 = {0x8, 0x9, 0xC, 0xD}.
+ void DecodeLoadStore(const Instruction* instr);
+
+ // Decode the logical immediate and move wide immediate parts of the
+ // instruction tree, and call the corresponding visitors.
+ // On entry, instruction bits 27:24 = 0x2.
+ void DecodeLogical(const Instruction* instr);
+
+ // Decode the bitfield and extraction parts of the instruction tree,
+ // and call the corresponding visitors.
+ // On entry, instruction bits 27:24 = 0x3.
+ void DecodeBitfieldExtract(const Instruction* instr);
+
+ // Decode the data processing parts of the instruction tree, and call the
+ // corresponding visitors.
+ // On entry, instruction bits 27:24 = {0x1, 0xA, 0xB}.
+ void DecodeDataProcessing(const Instruction* instr);
+
+ // Decode the floating point parts of the instruction tree, and call the
+ // corresponding visitors.
+ // On entry, instruction bits 27:24 = {0xE, 0xF}.
+ void DecodeFP(const Instruction* instr);
+
+ // Decode the Advanced SIMD (NEON) load/store part of the instruction tree,
+ // and call the corresponding visitors.
+ // On entry, instruction bits 29:25 = 0x6.
+ void DecodeAdvSIMDLoadStore(const Instruction* instr);
+
+ // Decode the Advanced SIMD (NEON) data processing part of the instruction
+ // tree, and call the corresponding visitors.
+ // On entry, instruction bits 27:25 = 0x7.
+ void DecodeAdvSIMDDataProcessing(const Instruction* instr);
+
+ private:
+ // Visitors are registered in a list.
+ std::list<DecoderVisitor*> visitors_;
+};
+
+} // namespace vixl
+
+#endif // VIXL_A64_DECODER_A64_H_
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