diff options
Diffstat (limited to 'src')
-rw-r--r-- | src/arch/arm/SConscript | 1 | ||||
-rw-r--r-- | src/arch/arm/predecoder.cc | 164 | ||||
-rw-r--r-- | src/arch/arm/predecoder.hh | 113 |
3 files changed, 171 insertions, 107 deletions
diff --git a/src/arch/arm/SConscript b/src/arch/arm/SConscript index 06554a6fd..6b13b4b74 100644 --- a/src/arch/arm/SConscript +++ b/src/arch/arm/SConscript @@ -57,6 +57,7 @@ if env['TARGET_ISA'] == 'arm': Source('insts/vfp.cc') Source('isa.cc') Source('miscregs.cc') + Source('predecoder.cc') Source('nativetrace.cc') Source('tlb.cc') Source('vtophys.cc') diff --git a/src/arch/arm/predecoder.cc b/src/arch/arm/predecoder.cc new file mode 100644 index 000000000..20c7058b0 --- /dev/null +++ b/src/arch/arm/predecoder.cc @@ -0,0 +1,164 @@ +/* + * Copyright (c) 2010 ARM Limited + * All rights reserved + * + * The license below extends only to copyright in the software and shall + * not be construed as granting a license to any other intellectual + * property including but not limited to intellectual property relating + * to a hardware implementation of the functionality of the software + * licensed hereunder. You may use the software subject to the license + * terms below provided that you ensure that this notice is replicated + * unmodified and in its entirety in all distributions of the software, + * modified or unmodified, in source code or in binary form. + * + * Copyright (c) 2006 The Regents of The University of Michigan + * Copyright (c) 2007-2008 The Florida State University + * 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 the copyright holders 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 AND 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. + * + * Authors: Gabe Black + */ + +#include "arch/arm/isa_traits.hh" +#include "arch/arm/predecoder.hh" +#include "base/trace.hh" +#include "cpu/thread_context.hh" + +namespace ArmISA +{ + +void +Predecoder::advanceThumbCond() +{ + uint8_t condMask = itstate.mask; + uint8_t thumbCond = itstate.cond; + DPRINTF(Predecoder, "Advancing ITSTATE from %#x, %#x.\n", + thumbCond, condMask); + condMask = condMask << 1; + uint8_t newBit = bits(condMask, 4); + condMask &= mask(4); + if (condMask == 0) { + thumbCond = 0; + } else { + replaceBits(thumbCond, 0, newBit); + } + DPRINTF(Predecoder, "Advancing ITSTATE to %#x, %#x.\n", + thumbCond, condMask); + itstate.mask = condMask; + itstate.cond = thumbCond; +} + +void +Predecoder::process() +{ + if (!emi.thumb) { + emi.instBits = data; + emi.sevenAndFour = bits(data, 7) && bits(data, 4); + emi.isMisc = (bits(data, 24, 23) == 0x2 && + bits(data, 20) == 0); + DPRINTF(Predecoder, "Arm inst: %#x.\n", (uint64_t)emi); + } else { + uint16_t word = (data >> (offset * 8)); + if (bigThumb) { + // A 32 bit thumb inst is half collected. + emi.instBits = emi.instBits | word; + bigThumb = false; + offset += 2; + DPRINTF(Predecoder, "Second half of 32 bit Thumb: %#x.\n", + emi.instBits); + if (itstate.mask) { + emi.itstate = itstate; + advanceThumbCond(); + emi.newItstate = itstate; + } + } else { + uint16_t highBits = word & 0xF800; + if (highBits == 0xE800 || highBits == 0xF000 || + highBits == 0xF800) { + // The start of a 32 bit thumb inst. + emi.bigThumb = 1; + if (offset == 0) { + // We've got the whole thing. + emi.instBits = (data >> 16) | (data << 16); + DPRINTF(Predecoder, "All of 32 bit Thumb: %#x.\n", + emi.instBits); + offset += 4; + if (itstate.mask) { + emi.itstate = itstate; + advanceThumbCond(); + emi.newItstate = itstate; + } + } else { + // We only have the first half word. + DPRINTF(Predecoder, + "First half of 32 bit Thumb.\n"); + emi.instBits = (uint32_t)word << 16; + bigThumb = true; + offset += 2; + } + } else { + // A 16 bit thumb inst. + offset += 2; + emi.instBits = word; + // Set the condition code field artificially. + emi.condCode = COND_UC; + DPRINTF(Predecoder, "16 bit Thumb: %#x.\n", + emi.instBits); + if (bits(word, 15, 8) == 0xbf && + bits(word, 3, 0) != 0x0) { + emi.itstate = itstate; + itstate = bits(word, 7, 0); + emi.newItstate = itstate; + DPRINTF(Predecoder, + "IT detected, cond = %#x, mask = %#x\n", + itstate.cond, itstate.mask); + } else if (itstate.mask) { + emi.itstate = itstate; + advanceThumbCond(); + emi.newItstate = itstate; + } + } + } + } +} + +//Use this to give data to the predecoder. This should be used +//when there is control flow. +void +Predecoder::moreBytes(Addr pc, Addr fetchPC, MachInst inst) +{ + data = inst; + offset = (fetchPC >= pc) ? 0 : pc - fetchPC; + emi.thumb = (pc & (ULL(1) << PcTBitShift)) ? 1 : 0; + FPSCR fpscr = tc->readMiscReg(MISCREG_FPSCR); + emi.fpscrLen = fpscr.len; + emi.fpscrStride = fpscr.stride; + CPSR cpsr = tc->readMiscReg(MISCREG_CPSR); + itstate.top6 = cpsr.it2; + itstate.bottom2 = cpsr.it1; + process(); +} + +} diff --git a/src/arch/arm/predecoder.hh b/src/arch/arm/predecoder.hh index f146c30f4..2db550024 100644 --- a/src/arch/arm/predecoder.hh +++ b/src/arch/arm/predecoder.hh @@ -46,7 +46,7 @@ #define __ARCH_ARM_PREDECODER_HH__ #include "arch/arm/types.hh" -#include "base/misc.hh" +#include "arch/arm/miscregs.hh" #include "base/types.hh" class ThreadContext; @@ -83,119 +83,18 @@ namespace ArmISA return tc; } - void setTC(ThreadContext * _tc) + void + setTC(ThreadContext * _tc) { tc = _tc; } - void advanceThumbCond() - { - uint8_t condMask = itstate.mask; - uint8_t thumbCond = itstate.cond; - DPRINTF(Predecoder, "Advancing ITSTATE from %#x, %#x.\n", - thumbCond, condMask); - condMask = condMask << 1; - uint8_t newBit = bits(condMask, 4); - condMask &= mask(4); - if (condMask == 0) { - thumbCond = 0; - } else { - replaceBits(thumbCond, 0, newBit); - } - DPRINTF(Predecoder, "Advancing ITSTATE to %#x, %#x.\n", - thumbCond, condMask); - itstate.mask = condMask; - itstate.cond = thumbCond; - } - - void process() - { - if (!emi.thumb) { - emi.instBits = data; - emi.sevenAndFour = bits(data, 7) && bits(data, 4); - emi.isMisc = (bits(data, 24, 23) == 0x2 && - bits(data, 20) == 0); - DPRINTF(Predecoder, "Arm inst: %#x.\n", (uint64_t)emi); - } else { - uint16_t word = (data >> (offset * 8)); - if (bigThumb) { - // A 32 bit thumb inst is half collected. - emi.instBits = emi.instBits | word; - bigThumb = false; - offset += 2; - DPRINTF(Predecoder, "Second half of 32 bit Thumb: %#x.\n", - emi.instBits); - if (itstate.mask) { - emi.itstate = itstate; - advanceThumbCond(); - emi.newItstate = itstate; - } - } else { - uint16_t highBits = word & 0xF800; - if (highBits == 0xE800 || highBits == 0xF000 || - highBits == 0xF800) { - // The start of a 32 bit thumb inst. - emi.bigThumb = 1; - if (offset == 0) { - // We've got the whole thing. - emi.instBits = (data >> 16) | (data << 16); - DPRINTF(Predecoder, "All of 32 bit Thumb: %#x.\n", - emi.instBits); - offset += 4; - if (itstate.mask) { - emi.itstate = itstate; - advanceThumbCond(); - emi.newItstate = itstate; - } - } else { - // We only have the first half word. - DPRINTF(Predecoder, - "First half of 32 bit Thumb.\n"); - emi.instBits = (uint32_t)word << 16; - bigThumb = true; - offset += 2; - } - } else { - // A 16 bit thumb inst. - offset += 2; - emi.instBits = word; - // Set the condition code field artificially. - emi.condCode = COND_UC; - DPRINTF(Predecoder, "16 bit Thumb: %#x.\n", - emi.instBits); - if (bits(word, 15, 8) == 0xbf && - bits(word, 3, 0) != 0x0) { - emi.itstate = itstate; - itstate = bits(word, 7, 0); - emi.newItstate = itstate; - DPRINTF(Predecoder, - "IT detected, cond = %#x, mask = %#x\n", - itstate.cond, itstate.mask); - } else if (itstate.mask) { - emi.itstate = itstate; - advanceThumbCond(); - emi.newItstate = itstate; - } - } - } - } - } + void advanceThumbCond(); + void process(); //Use this to give data to the predecoder. This should be used //when there is control flow. - void moreBytes(Addr pc, Addr fetchPC, MachInst inst) - { - data = inst; - offset = (fetchPC >= pc) ? 0 : pc - fetchPC; - emi.thumb = (pc & (ULL(1) << PcTBitShift)) ? 1 : 0; - FPSCR fpscr = tc->readMiscReg(MISCREG_FPSCR); - emi.fpscrLen = fpscr.len; - emi.fpscrStride = fpscr.stride; - CPSR cpsr = tc->readMiscReg(MISCREG_CPSR); - itstate.top6 = cpsr.it2; - itstate.bottom2 = cpsr.it1; - process(); - } + void moreBytes(Addr pc, Addr fetchPC, MachInst inst); //Use this to give data to the predecoder. This should be used //when instructions are executed in order. |