1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/src/jit/StupidAllocator.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,89 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * vim: set ts=8 sts=4 et sw=4 tw=99:
1.6 + * This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef jit_StupidAllocator_h
1.11 +#define jit_StupidAllocator_h
1.12 +
1.13 +#include "jit/RegisterAllocator.h"
1.14 +
1.15 +// Simple register allocator that only carries registers within basic blocks.
1.16 +
1.17 +namespace js {
1.18 +namespace jit {
1.19 +
1.20 +class StupidAllocator : public RegisterAllocator
1.21 +{
1.22 + static const uint32_t MAX_REGISTERS = Registers::Allocatable + FloatRegisters::Allocatable;
1.23 + static const uint32_t MISSING_ALLOCATION = UINT32_MAX;
1.24 +
1.25 + struct AllocatedRegister {
1.26 + AnyRegister reg;
1.27 +
1.28 + // The type of the value in the register.
1.29 + LDefinition::Type type;
1.30 +
1.31 + // Virtual register this physical reg backs, or MISSING_ALLOCATION.
1.32 + uint32_t vreg;
1.33 +
1.34 + // id of the instruction which most recently used this register.
1.35 + uint32_t age;
1.36 +
1.37 + // Whether the physical register is not synced with the backing stack slot.
1.38 + bool dirty;
1.39 +
1.40 + void set(uint32_t vreg, LInstruction *ins = nullptr, bool dirty = false) {
1.41 + this->vreg = vreg;
1.42 + this->age = ins ? ins->id() : 0;
1.43 + this->dirty = dirty;
1.44 + }
1.45 + };
1.46 +
1.47 + // Active allocation for the current code position.
1.48 + mozilla::Array<AllocatedRegister, MAX_REGISTERS> registers;
1.49 + uint32_t registerCount;
1.50 +
1.51 + // Type indicating an index into registers.
1.52 + typedef uint32_t RegisterIndex;
1.53 +
1.54 + // Information about each virtual register.
1.55 + Vector<LDefinition*, 0, SystemAllocPolicy> virtualRegisters;
1.56 +
1.57 + public:
1.58 + StupidAllocator(MIRGenerator *mir, LIRGenerator *lir, LIRGraph &graph)
1.59 + : RegisterAllocator(mir, lir, graph)
1.60 + {
1.61 + }
1.62 +
1.63 + bool go();
1.64 +
1.65 + private:
1.66 + bool init();
1.67 +
1.68 + void syncForBlockEnd(LBlock *block, LInstruction *ins);
1.69 + void allocateForInstruction(LInstruction *ins);
1.70 + void allocateForDefinition(LInstruction *ins, LDefinition *def);
1.71 +
1.72 + LAllocation *stackLocation(uint32_t vreg);
1.73 +
1.74 + RegisterIndex registerIndex(AnyRegister reg);
1.75 +
1.76 + AnyRegister ensureHasRegister(LInstruction *ins, uint32_t vreg);
1.77 + RegisterIndex allocateRegister(LInstruction *ins, uint32_t vreg);
1.78 +
1.79 + void syncRegister(LInstruction *ins, RegisterIndex index);
1.80 + void evictRegister(LInstruction *ins, RegisterIndex index);
1.81 + void loadRegister(LInstruction *ins, uint32_t vreg, RegisterIndex index, LDefinition::Type type);
1.82 +
1.83 + RegisterIndex findExistingRegister(uint32_t vreg);
1.84 +
1.85 + bool allocationRequiresRegister(const LAllocation *alloc, AnyRegister reg);
1.86 + bool registerIsReserved(LInstruction *ins, AnyRegister reg);
1.87 +};
1.88 +
1.89 +} // namespace jit
1.90 +} // namespace js
1.91 +
1.92 +#endif /* jit_StupidAllocator_h */
