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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef jit_StupidAllocator_h
+#define jit_StupidAllocator_h
+
+#include "jit/RegisterAllocator.h"
+
+// Simple register allocator that only carries registers within basic blocks.
+
+namespace js {
+namespace jit {
+
+class StupidAllocator : public RegisterAllocator
+{
+ static const uint32_t MAX_REGISTERS = AnyRegister::Total;
+ static const uint32_t MISSING_ALLOCATION = UINT32_MAX;
+
+ struct AllocatedRegister {
+ AnyRegister reg;
+
+ // The type of the value in the register.
+ LDefinition::Type type;
+
+ // Virtual register this physical reg backs, or MISSING_ALLOCATION.
+ uint32_t vreg;
+
+ // id of the instruction which most recently used this register.
+ uint32_t age;
+
+ // Whether the physical register is not synced with the backing stack slot.
+ bool dirty;
+
+ void set(uint32_t vreg, LInstruction* ins = nullptr, bool dirty = false) {
+ this->vreg = vreg;
+ this->age = ins ? ins->id() : 0;
+ this->dirty = dirty;
+ }
+ };
+
+ // Active allocation for the current code position.
+ mozilla::Array<AllocatedRegister, MAX_REGISTERS> registers;
+ uint32_t registerCount;
+
+ // Type indicating an index into registers.
+ typedef uint32_t RegisterIndex;
+
+ // Information about each virtual register.
+ Vector<LDefinition*, 0, SystemAllocPolicy> virtualRegisters;
+
+ public:
+ StupidAllocator(MIRGenerator* mir, LIRGenerator* lir, LIRGraph& graph)
+ : RegisterAllocator(mir, lir, graph)
+ {
+ }
+
+ MOZ_MUST_USE bool go();
+
+ private:
+ MOZ_MUST_USE bool init();
+
+ void syncForBlockEnd(LBlock* block, LInstruction* ins);
+ void allocateForInstruction(LInstruction* ins);
+ void allocateForDefinition(LInstruction* ins, LDefinition* def);
+
+ LAllocation* stackLocation(uint32_t vreg);
+
+ RegisterIndex registerIndex(AnyRegister reg);
+
+ AnyRegister ensureHasRegister(LInstruction* ins, uint32_t vreg);
+ RegisterIndex allocateRegister(LInstruction* ins, uint32_t vreg);
+
+ void syncRegister(LInstruction* ins, RegisterIndex index);
+ void evictRegister(LInstruction* ins, RegisterIndex index);
+ void evictAliasedRegister(LInstruction* ins, RegisterIndex index);
+ void loadRegister(LInstruction* ins, uint32_t vreg, RegisterIndex index, LDefinition::Type type);
+
+ RegisterIndex findExistingRegister(uint32_t vreg);
+
+ bool allocationRequiresRegister(const LAllocation* alloc, AnyRegister reg);
+ bool registerIsReserved(LInstruction* ins, AnyRegister reg);
+};
+
+} // namespace jit
+} // namespace js
+
+#endif /* jit_StupidAllocator_h */