decode.hh revision 10259
110259SAndrew.Bardsley@arm.com/* 210259SAndrew.Bardsley@arm.com * Copyright (c) 2013-2014 ARM Limited 310259SAndrew.Bardsley@arm.com * All rights reserved 410259SAndrew.Bardsley@arm.com * 510259SAndrew.Bardsley@arm.com * The license below extends only to copyright in the software and shall 610259SAndrew.Bardsley@arm.com * not be construed as granting a license to any other intellectual 710259SAndrew.Bardsley@arm.com * property including but not limited to intellectual property relating 810259SAndrew.Bardsley@arm.com * to a hardware implementation of the functionality of the software 910259SAndrew.Bardsley@arm.com * licensed hereunder. You may use the software subject to the license 1010259SAndrew.Bardsley@arm.com * terms below provided that you ensure that this notice is replicated 1110259SAndrew.Bardsley@arm.com * unmodified and in its entirety in all distributions of the software, 1210259SAndrew.Bardsley@arm.com * modified or unmodified, in source code or in binary form. 1310259SAndrew.Bardsley@arm.com * 1410259SAndrew.Bardsley@arm.com * Redistribution and use in source and binary forms, with or without 1510259SAndrew.Bardsley@arm.com * modification, are permitted provided that the following conditions are 1610259SAndrew.Bardsley@arm.com * met: redistributions of source code must retain the above copyright 1710259SAndrew.Bardsley@arm.com * notice, this list of conditions and the following disclaimer; 1810259SAndrew.Bardsley@arm.com * redistributions in binary form must reproduce the above copyright 1910259SAndrew.Bardsley@arm.com * notice, this list of conditions and the following disclaimer in the 2010259SAndrew.Bardsley@arm.com * documentation and/or other materials provided with the distribution; 2110259SAndrew.Bardsley@arm.com * neither the name of the copyright holders nor the names of its 2210259SAndrew.Bardsley@arm.com * contributors may be used to endorse or promote products derived from 2310259SAndrew.Bardsley@arm.com * this software without specific prior written permission. 2410259SAndrew.Bardsley@arm.com * 2510259SAndrew.Bardsley@arm.com * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 2610259SAndrew.Bardsley@arm.com * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 2710259SAndrew.Bardsley@arm.com * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 2810259SAndrew.Bardsley@arm.com * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 2910259SAndrew.Bardsley@arm.com * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 3010259SAndrew.Bardsley@arm.com * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 3110259SAndrew.Bardsley@arm.com * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 3210259SAndrew.Bardsley@arm.com * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 3310259SAndrew.Bardsley@arm.com * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 3410259SAndrew.Bardsley@arm.com * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 3510259SAndrew.Bardsley@arm.com * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 3610259SAndrew.Bardsley@arm.com * 3710259SAndrew.Bardsley@arm.com * Authors: Andrew Bardsley 3810259SAndrew.Bardsley@arm.com */ 3910259SAndrew.Bardsley@arm.com 4010259SAndrew.Bardsley@arm.com/** 4110259SAndrew.Bardsley@arm.com * @file 4210259SAndrew.Bardsley@arm.com * 4310259SAndrew.Bardsley@arm.com * Decode collects macro-ops from Fetch2 and splits them into micro-ops 4410259SAndrew.Bardsley@arm.com * passed to Execute. 4510259SAndrew.Bardsley@arm.com */ 4610259SAndrew.Bardsley@arm.com 4710259SAndrew.Bardsley@arm.com#ifndef __CPU_MINOR_DECODE_HH__ 4810259SAndrew.Bardsley@arm.com#define __CPU_MINOR_DECODE_HH__ 4910259SAndrew.Bardsley@arm.com 5010259SAndrew.Bardsley@arm.com#include "cpu/minor/buffers.hh" 5110259SAndrew.Bardsley@arm.com#include "cpu/minor/cpu.hh" 5210259SAndrew.Bardsley@arm.com#include "cpu/minor/dyn_inst.hh" 5310259SAndrew.Bardsley@arm.com#include "cpu/minor/pipe_data.hh" 5410259SAndrew.Bardsley@arm.com 5510259SAndrew.Bardsley@arm.comnamespace Minor 5610259SAndrew.Bardsley@arm.com{ 5710259SAndrew.Bardsley@arm.com 5810259SAndrew.Bardsley@arm.com/* Decode takes instructions from Fetch2 and decomposes them into micro-ops 5910259SAndrew.Bardsley@arm.com * to feed to Execute. It generates a new sequence number for each 6010259SAndrew.Bardsley@arm.com * instruction: execSeqNum. 6110259SAndrew.Bardsley@arm.com */ 6210259SAndrew.Bardsley@arm.comclass Decode : public Named 6310259SAndrew.Bardsley@arm.com{ 6410259SAndrew.Bardsley@arm.com protected: 6510259SAndrew.Bardsley@arm.com /** Pointer back to the containing CPU */ 6610259SAndrew.Bardsley@arm.com MinorCPU &cpu; 6710259SAndrew.Bardsley@arm.com 6810259SAndrew.Bardsley@arm.com /** Input port carrying macro instructions from Fetch2 */ 6910259SAndrew.Bardsley@arm.com Latch<ForwardInstData>::Output inp; 7010259SAndrew.Bardsley@arm.com /** Output port carrying micro-op decomposed instructions to Execute */ 7110259SAndrew.Bardsley@arm.com Latch<ForwardInstData>::Input out; 7210259SAndrew.Bardsley@arm.com 7310259SAndrew.Bardsley@arm.com /** Interface to reserve space in the next stage */ 7410259SAndrew.Bardsley@arm.com Reservable &nextStageReserve; 7510259SAndrew.Bardsley@arm.com 7610259SAndrew.Bardsley@arm.com /** Width of output of this stage/input of next in instructions */ 7710259SAndrew.Bardsley@arm.com unsigned int outputWidth; 7810259SAndrew.Bardsley@arm.com 7910259SAndrew.Bardsley@arm.com /** If true, more than one input word can be processed each cycle if 8010259SAndrew.Bardsley@arm.com * there is room in the output to contain its processed data */ 8110259SAndrew.Bardsley@arm.com bool processMoreThanOneInput; 8210259SAndrew.Bardsley@arm.com 8310259SAndrew.Bardsley@arm.com public: 8410259SAndrew.Bardsley@arm.com /* Public for Pipeline to be able to pass it to Fetch2 */ 8510259SAndrew.Bardsley@arm.com InputBuffer<ForwardInstData> inputBuffer; 8610259SAndrew.Bardsley@arm.com 8710259SAndrew.Bardsley@arm.com protected: 8810259SAndrew.Bardsley@arm.com /** Data members after this line are cycle-to-cycle state */ 8910259SAndrew.Bardsley@arm.com 9010259SAndrew.Bardsley@arm.com /** Index into the inputBuffer's head marking the start of unhandled 9110259SAndrew.Bardsley@arm.com * instructions */ 9210259SAndrew.Bardsley@arm.com unsigned int inputIndex; 9310259SAndrew.Bardsley@arm.com 9410259SAndrew.Bardsley@arm.com /** True when we're in the process of decomposing a micro-op and 9510259SAndrew.Bardsley@arm.com * microopPC will be valid. This is only the case when there isn't 9610259SAndrew.Bardsley@arm.com * sufficient space in Executes input buffer to take the whole of a 9710259SAndrew.Bardsley@arm.com * decomposed instruction and some of that instructions micro-ops must 9810259SAndrew.Bardsley@arm.com * be generated in a later cycle */ 9910259SAndrew.Bardsley@arm.com bool inMacroop; 10010259SAndrew.Bardsley@arm.com TheISA::PCState microopPC; 10110259SAndrew.Bardsley@arm.com 10210259SAndrew.Bardsley@arm.com /** Source of execSeqNums to number instructions. */ 10310259SAndrew.Bardsley@arm.com InstSeqNum execSeqNum; 10410259SAndrew.Bardsley@arm.com 10510259SAndrew.Bardsley@arm.com /** Blocked indication for report */ 10610259SAndrew.Bardsley@arm.com bool blocked; 10710259SAndrew.Bardsley@arm.com 10810259SAndrew.Bardsley@arm.com protected: 10910259SAndrew.Bardsley@arm.com /** Get a piece of data to work on, or 0 if there is no data. */ 11010259SAndrew.Bardsley@arm.com const ForwardInstData *getInput(); 11110259SAndrew.Bardsley@arm.com 11210259SAndrew.Bardsley@arm.com /** Pop an element off the input buffer, if there are any */ 11310259SAndrew.Bardsley@arm.com void popInput(); 11410259SAndrew.Bardsley@arm.com 11510259SAndrew.Bardsley@arm.com public: 11610259SAndrew.Bardsley@arm.com Decode(const std::string &name, 11710259SAndrew.Bardsley@arm.com MinorCPU &cpu_, 11810259SAndrew.Bardsley@arm.com MinorCPUParams ¶ms, 11910259SAndrew.Bardsley@arm.com Latch<ForwardInstData>::Output inp_, 12010259SAndrew.Bardsley@arm.com Latch<ForwardInstData>::Input out_, 12110259SAndrew.Bardsley@arm.com Reservable &next_stage_input_buffer); 12210259SAndrew.Bardsley@arm.com 12310259SAndrew.Bardsley@arm.com public: 12410259SAndrew.Bardsley@arm.com /** Pass on input/buffer data to the output if you can */ 12510259SAndrew.Bardsley@arm.com void evaluate(); 12610259SAndrew.Bardsley@arm.com 12710259SAndrew.Bardsley@arm.com void minorTrace() const; 12810259SAndrew.Bardsley@arm.com 12910259SAndrew.Bardsley@arm.com /** Is this stage drained? For Decoed, draining is initiated by 13010259SAndrew.Bardsley@arm.com * Execute halting Fetch1 causing Fetch2 to naturally drain 13110259SAndrew.Bardsley@arm.com * into Decode and on to Execute which is responsible for 13210259SAndrew.Bardsley@arm.com * actually killing instructions */ 13310259SAndrew.Bardsley@arm.com bool isDrained(); 13410259SAndrew.Bardsley@arm.com}; 13510259SAndrew.Bardsley@arm.com 13610259SAndrew.Bardsley@arm.com} 13710259SAndrew.Bardsley@arm.com 13810259SAndrew.Bardsley@arm.com#endif /* __CPU_MINOR_DECODE_HH__ */ 139