decoder.cc revision 13759
19022Sgblack@eecs.umich.edu/* 212763Sgiacomo.travaglini@arm.com * Copyright (c) 2012-2014,2018 ARM Limited 310037SARM gem5 Developers * All rights reserved 410037SARM gem5 Developers * 510037SARM gem5 Developers * The license below extends only to copyright in the software and shall 610037SARM gem5 Developers * not be construed as granting a license to any other intellectual 710037SARM gem5 Developers * property including but not limited to intellectual property relating 810037SARM gem5 Developers * to a hardware implementation of the functionality of the software 910037SARM gem5 Developers * licensed hereunder. You may use the software subject to the license 1010037SARM gem5 Developers * terms below provided that you ensure that this notice is replicated 1110037SARM gem5 Developers * unmodified and in its entirety in all distributions of the software, 1210037SARM gem5 Developers * modified or unmodified, in source code or in binary form. 1310037SARM gem5 Developers * 149023Sgblack@eecs.umich.edu * Copyright (c) 2012 Google 159022Sgblack@eecs.umich.edu * All rights reserved. 169022Sgblack@eecs.umich.edu * 179022Sgblack@eecs.umich.edu * Redistribution and use in source and binary forms, with or without 189022Sgblack@eecs.umich.edu * modification, are permitted provided that the following conditions are 199022Sgblack@eecs.umich.edu * met: redistributions of source code must retain the above copyright 209022Sgblack@eecs.umich.edu * notice, this list of conditions and the following disclaimer; 219022Sgblack@eecs.umich.edu * redistributions in binary form must reproduce the above copyright 229022Sgblack@eecs.umich.edu * notice, this list of conditions and the following disclaimer in the 239022Sgblack@eecs.umich.edu * documentation and/or other materials provided with the distribution; 249022Sgblack@eecs.umich.edu * neither the name of the copyright holders nor the names of its 259022Sgblack@eecs.umich.edu * contributors may be used to endorse or promote products derived from 269022Sgblack@eecs.umich.edu * this software without specific prior written permission. 279022Sgblack@eecs.umich.edu * 289022Sgblack@eecs.umich.edu * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 299022Sgblack@eecs.umich.edu * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 309022Sgblack@eecs.umich.edu * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 319022Sgblack@eecs.umich.edu * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 329022Sgblack@eecs.umich.edu * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 339022Sgblack@eecs.umich.edu * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 349022Sgblack@eecs.umich.edu * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 359022Sgblack@eecs.umich.edu * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 369022Sgblack@eecs.umich.edu * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 379022Sgblack@eecs.umich.edu * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 389022Sgblack@eecs.umich.edu * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 399022Sgblack@eecs.umich.edu * 409022Sgblack@eecs.umich.edu * Authors: Gabe Black 419022Sgblack@eecs.umich.edu */ 429022Sgblack@eecs.umich.edu 439022Sgblack@eecs.umich.edu#include "arch/arm/decoder.hh" 4411165SRekai.GonzalezAlberquilla@arm.com 4511165SRekai.GonzalezAlberquilla@arm.com#include "arch/arm/isa.hh" 469023Sgblack@eecs.umich.edu#include "arch/arm/isa_traits.hh" 479023Sgblack@eecs.umich.edu#include "arch/arm/utility.hh" 489023Sgblack@eecs.umich.edu#include "base/trace.hh" 499023Sgblack@eecs.umich.edu#include "debug/Decoder.hh" 5013759Sgiacomo.gabrielli@arm.com#include "sim/full_system.hh" 519022Sgblack@eecs.umich.edu 529022Sgblack@eecs.umich.edunamespace ArmISA 539022Sgblack@eecs.umich.edu{ 549022Sgblack@eecs.umich.edu 559024Sgblack@eecs.umich.eduGenericISA::BasicDecodeCache Decoder::defaultCache; 569022Sgblack@eecs.umich.edu 5711165SRekai.GonzalezAlberquilla@arm.comDecoder::Decoder(ISA* isa) 5813759Sgiacomo.gabrielli@arm.com : data(0), fpscrLen(0), fpscrStride(0), 5913759Sgiacomo.gabrielli@arm.com decoderFlavour(isa->decoderFlavour()) 6010610SAndreas.Sandberg@ARM.com{ 6110610SAndreas.Sandberg@ARM.com reset(); 6213759Sgiacomo.gabrielli@arm.com 6313759Sgiacomo.gabrielli@arm.com // Initialize SVE vector length 6413759Sgiacomo.gabrielli@arm.com sveLen = (isa->getCurSveVecLenInBitsAtReset() >> 7) - 1; 6510610SAndreas.Sandberg@ARM.com} 6610610SAndreas.Sandberg@ARM.com 6710610SAndreas.Sandberg@ARM.comvoid 6810610SAndreas.Sandberg@ARM.comDecoder::reset() 6910610SAndreas.Sandberg@ARM.com{ 7010610SAndreas.Sandberg@ARM.com bigThumb = false; 7110610SAndreas.Sandberg@ARM.com offset = 0; 7210610SAndreas.Sandberg@ARM.com emi = 0; 7310610SAndreas.Sandberg@ARM.com instDone = false; 7410610SAndreas.Sandberg@ARM.com outOfBytes = true; 7510610SAndreas.Sandberg@ARM.com foundIt = false; 7610610SAndreas.Sandberg@ARM.com} 7710610SAndreas.Sandberg@ARM.com 789023Sgblack@eecs.umich.eduvoid 799023Sgblack@eecs.umich.eduDecoder::process() 809023Sgblack@eecs.umich.edu{ 819023Sgblack@eecs.umich.edu // emi is typically ready, with some caveats below... 829023Sgblack@eecs.umich.edu instDone = true; 839023Sgblack@eecs.umich.edu 849023Sgblack@eecs.umich.edu if (!emi.thumb) { 859023Sgblack@eecs.umich.edu emi.instBits = data; 8610037SARM gem5 Developers if (!emi.aarch64) { 8710037SARM gem5 Developers emi.sevenAndFour = bits(data, 7) && bits(data, 4); 8810037SARM gem5 Developers emi.isMisc = (bits(data, 24, 23) == 0x2 && 8910037SARM gem5 Developers bits(data, 20) == 0); 9010037SARM gem5 Developers } 919023Sgblack@eecs.umich.edu consumeBytes(4); 929023Sgblack@eecs.umich.edu DPRINTF(Decoder, "Arm inst: %#x.\n", (uint64_t)emi); 939023Sgblack@eecs.umich.edu } else { 949023Sgblack@eecs.umich.edu uint16_t word = (data >> (offset * 8)); 959023Sgblack@eecs.umich.edu if (bigThumb) { 969023Sgblack@eecs.umich.edu // A 32 bit thumb inst is half collected. 979023Sgblack@eecs.umich.edu emi.instBits = emi.instBits | word; 989023Sgblack@eecs.umich.edu bigThumb = false; 999023Sgblack@eecs.umich.edu consumeBytes(2); 1009023Sgblack@eecs.umich.edu DPRINTF(Decoder, "Second half of 32 bit Thumb: %#x.\n", 1019023Sgblack@eecs.umich.edu emi.instBits); 1029023Sgblack@eecs.umich.edu } else { 1039023Sgblack@eecs.umich.edu uint16_t highBits = word & 0xF800; 1049023Sgblack@eecs.umich.edu if (highBits == 0xE800 || highBits == 0xF000 || 1059023Sgblack@eecs.umich.edu highBits == 0xF800) { 1069023Sgblack@eecs.umich.edu // The start of a 32 bit thumb inst. 1079023Sgblack@eecs.umich.edu emi.bigThumb = 1; 1089023Sgblack@eecs.umich.edu if (offset == 0) { 1099023Sgblack@eecs.umich.edu // We've got the whole thing. 1109023Sgblack@eecs.umich.edu emi.instBits = (data >> 16) | (data << 16); 1119023Sgblack@eecs.umich.edu DPRINTF(Decoder, "All of 32 bit Thumb: %#x.\n", 1129023Sgblack@eecs.umich.edu emi.instBits); 1139023Sgblack@eecs.umich.edu consumeBytes(4); 1149023Sgblack@eecs.umich.edu } else { 1159023Sgblack@eecs.umich.edu // We only have the first half word. 1169023Sgblack@eecs.umich.edu DPRINTF(Decoder, 1179023Sgblack@eecs.umich.edu "First half of 32 bit Thumb.\n"); 1189023Sgblack@eecs.umich.edu emi.instBits = (uint32_t)word << 16; 1199023Sgblack@eecs.umich.edu bigThumb = true; 1209023Sgblack@eecs.umich.edu consumeBytes(2); 1219023Sgblack@eecs.umich.edu // emi not ready yet. 1229023Sgblack@eecs.umich.edu instDone = false; 1239023Sgblack@eecs.umich.edu } 1249023Sgblack@eecs.umich.edu } else { 1259023Sgblack@eecs.umich.edu // A 16 bit thumb inst. 1269023Sgblack@eecs.umich.edu consumeBytes(2); 1279023Sgblack@eecs.umich.edu emi.instBits = word; 1289023Sgblack@eecs.umich.edu // Set the condition code field artificially. 1299023Sgblack@eecs.umich.edu emi.condCode = COND_UC; 1309023Sgblack@eecs.umich.edu DPRINTF(Decoder, "16 bit Thumb: %#x.\n", 1319023Sgblack@eecs.umich.edu emi.instBits); 1329023Sgblack@eecs.umich.edu if (bits(word, 15, 8) == 0xbf && 1339023Sgblack@eecs.umich.edu bits(word, 3, 0) != 0x0) { 1349023Sgblack@eecs.umich.edu foundIt = true; 1359023Sgblack@eecs.umich.edu itBits = bits(word, 7, 0); 1369023Sgblack@eecs.umich.edu DPRINTF(Decoder, 1379023Sgblack@eecs.umich.edu "IT detected, cond = %#x, mask = %#x\n", 1389023Sgblack@eecs.umich.edu itBits.cond, itBits.mask); 1399023Sgblack@eecs.umich.edu } 1409023Sgblack@eecs.umich.edu } 1419023Sgblack@eecs.umich.edu } 1429023Sgblack@eecs.umich.edu } 1439022Sgblack@eecs.umich.edu} 1449023Sgblack@eecs.umich.edu 14510610SAndreas.Sandberg@ARM.comvoid 14610610SAndreas.Sandberg@ARM.comDecoder::consumeBytes(int numBytes) 14710610SAndreas.Sandberg@ARM.com{ 14810610SAndreas.Sandberg@ARM.com offset += numBytes; 14910611SAndreas.Sandberg@ARM.com assert(offset <= sizeof(MachInst) || emi.decoderFault); 15010610SAndreas.Sandberg@ARM.com if (offset == sizeof(MachInst)) 15110610SAndreas.Sandberg@ARM.com outOfBytes = true; 15210610SAndreas.Sandberg@ARM.com} 15310610SAndreas.Sandberg@ARM.com 1549023Sgblack@eecs.umich.eduvoid 1559023Sgblack@eecs.umich.eduDecoder::moreBytes(const PCState &pc, Addr fetchPC, MachInst inst) 1569023Sgblack@eecs.umich.edu{ 1579023Sgblack@eecs.umich.edu data = inst; 1589023Sgblack@eecs.umich.edu offset = (fetchPC >= pc.instAddr()) ? 0 : pc.instAddr() - fetchPC; 1599023Sgblack@eecs.umich.edu emi.thumb = pc.thumb(); 16010037SARM gem5 Developers emi.aarch64 = pc.aarch64(); 1619374Sgblack@eecs.umich.edu emi.fpscrLen = fpscrLen; 1629374Sgblack@eecs.umich.edu emi.fpscrStride = fpscrStride; 16313759Sgiacomo.gabrielli@arm.com emi.sveLen = sveLen; 1649023Sgblack@eecs.umich.edu 16510611SAndreas.Sandberg@ARM.com const Addr alignment(pc.thumb() ? 0x1 : 0x3); 16610611SAndreas.Sandberg@ARM.com emi.decoderFault = static_cast<uint8_t>( 16710611SAndreas.Sandberg@ARM.com pc.instAddr() & alignment ? DecoderFault::UNALIGNED : DecoderFault::OK); 16810611SAndreas.Sandberg@ARM.com 1699023Sgblack@eecs.umich.edu outOfBytes = false; 1709023Sgblack@eecs.umich.edu process(); 1719023Sgblack@eecs.umich.edu} 1729023Sgblack@eecs.umich.edu 17310610SAndreas.Sandberg@ARM.comStaticInstPtr 17410610SAndreas.Sandberg@ARM.comDecoder::decode(ArmISA::PCState &pc) 17510610SAndreas.Sandberg@ARM.com{ 17610610SAndreas.Sandberg@ARM.com if (!instDone) 17710610SAndreas.Sandberg@ARM.com return NULL; 17810610SAndreas.Sandberg@ARM.com 17910610SAndreas.Sandberg@ARM.com const int inst_size((!emi.thumb || emi.bigThumb) ? 4 : 2); 18010610SAndreas.Sandberg@ARM.com ExtMachInst this_emi(emi); 18110610SAndreas.Sandberg@ARM.com 18210610SAndreas.Sandberg@ARM.com pc.npc(pc.pc() + inst_size); 18310610SAndreas.Sandberg@ARM.com if (foundIt) 18410610SAndreas.Sandberg@ARM.com pc.nextItstate(itBits); 18510610SAndreas.Sandberg@ARM.com this_emi.itstate = pc.itstate(); 18612763Sgiacomo.travaglini@arm.com this_emi.illegalExecution = pc.illegalExec() ? 1 : 0; 18712763Sgiacomo.travaglini@arm.com 18810610SAndreas.Sandberg@ARM.com pc.size(inst_size); 18910610SAndreas.Sandberg@ARM.com 19010610SAndreas.Sandberg@ARM.com emi = 0; 19110610SAndreas.Sandberg@ARM.com instDone = false; 19210610SAndreas.Sandberg@ARM.com foundIt = false; 19310610SAndreas.Sandberg@ARM.com 19410610SAndreas.Sandberg@ARM.com return decode(this_emi, pc.instAddr()); 1959023Sgblack@eecs.umich.edu} 19610610SAndreas.Sandberg@ARM.com 19710610SAndreas.Sandberg@ARM.com} 198