diff options
Diffstat (limited to 'src/arch/arm/isa')
| -rw-r--r-- | src/arch/arm/isa/decoder/arm.isa | 8 | ||||
| -rw-r--r-- | src/arch/arm/isa/insts/branch.isa | 175 | ||||
| -rw-r--r-- | src/arch/arm/isa/insts/insts.isa | 3 | ||||
| -rw-r--r-- | src/arch/arm/isa/operands.isa | 3 |
4 files changed, 185 insertions, 4 deletions
diff --git a/src/arch/arm/isa/decoder/arm.isa b/src/arch/arm/isa/decoder/arm.isa index 8a5ba3e43..717bd1857 100644 --- a/src/arch/arm/isa/decoder/arm.isa +++ b/src/arch/arm/isa/decoder/arm.isa @@ -129,7 +129,7 @@ format DataOp { } } 0x1: decode OPCODE { - 0x9: BranchExchange::bx({{ }}); + 0x9: BranchExchange::oldbx({{ }}); 0xb: PredOp::clz({{ Rd = ((Rm == 0) ? 32 : (31 - findMsbSet(Rm))); }}); @@ -138,7 +138,7 @@ format DataOp { 0x9: WarnUnimpl::bxj(); } 0x3: decode OPCODE { - 0x9: BranchExchange::blx({{ }}, Link); + 0x9: BranchExchange::oldblx({{ }}, Link); } 0x5: decode OPCODE { 0x8: WarnUnimpl::qadd(); @@ -265,8 +265,8 @@ format DataOp { 0x4: ArmMacroMem::armMacroMem(); 0x5: decode OPCODE_24 { // Branch (and Link) Instructions - 0: Branch::b({{ }}); - 1: Branch::bl({{ }}, Link); + 0: Branch::oldb({{ }}); + 1: Branch::oldbl({{ }}, Link); } 0x6: decode CPNUM { 0xb: decode LOADOP { diff --git a/src/arch/arm/isa/insts/branch.isa b/src/arch/arm/isa/insts/branch.isa new file mode 100644 index 000000000..71a98053e --- /dev/null +++ b/src/arch/arm/isa/insts/branch.isa @@ -0,0 +1,175 @@ +// -*- mode:c++ -*- + +// 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. +// +// 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 + +let {{ + + header_output = "" + decoder_output = "" + exec_output = "" + + # B, BL + for (mnem, link) in (("b", False), ("bl", True)): + bCode = ''' + Addr PC = readPC(xc); + NPC = ((PC + imm) & mask(32)) | (PC & ~mask(32)); + ''' + if (link): + bCode += ''' + Addr tBit = PC & (ULL(1) << PcTBitShift); + if (!tBit) + LR = PC - 4; + else + LR = PC | 1; + ''' + + bIop = InstObjParams(mnem, mnem.capitalize(), "BranchImmCond", + {"code": bCode, + "predicate_test": predicateTest}) + header_output += BranchImmCondDeclare.subst(bIop) + decoder_output += BranchImmCondConstructor.subst(bIop) + exec_output += PredOpExecute.subst(bIop) + + # BX, BLX + blxCode = ''' + Addr PC = readPC(xc); + Addr tBit = PC & (ULL(1) << PcTBitShift); + // Other than the assert below, jBit isn't used. +#if !defined(NDEBUG) + Addr jBit = PC & (ULL(1) << PcJBitShift); +#endif + // X isn't permitted in ThumbEE mode. We shouldn't be in jazzelle mode? + assert(!jBit); + bool arm = !tBit; + arm = arm; // In case it's not used otherwise. + Addr tempPc = ((%(newPC)s) & mask(32)) | (PC & ~mask(32)); + %(link)s + // Switch modes + %(branch)s + ''' + + blxList = (("blx", True, True), + ("blx", False, True), + ("bx", False, False)) + + for (mnem, imm, link) in blxList: + Name = mnem.capitalize() + if imm and link: #blx with imm + branchStr = "FNPC = tempPc ^ (ULL(1) << PcTBitShift);" + else: + branchStr = "IWNPC = tempPc ^ (ULL(1) << PcTBitShift);" + + if imm: + Name += "Imm" + # Since we're switching ISAs, the target ISA will be the opposite + # of the current ISA. !arm is whether the target is ARM. + newPC = '(!arm ? (roundDown(PC, 4) + imm) : (PC + imm))' + base = "BranchImm" + declare = BranchImmDeclare + constructor = BranchImmConstructor + else: + Name += "Reg" + newPC = '(PC & PcModeMask) | Op1' + base = "BranchRegCond" + declare = BranchRegCondDeclare + constructor = BranchRegCondConstructor + if link and imm: + linkStr = ''' + // The immediate version of the blx thumb instruction + // is 32 bits wide, but "next pc" doesn't reflect that + // so we don't want to substract 2 from it at this point + if (arm) + LR = PC - 4; + else + LR = PC | 1; + ''' + elif link: + linkStr = ''' + if (arm) + LR = PC - 4; + else + LR = (PC - 2) | 1; + ''' + else: + linkStr = "" + code = blxCode % {"link": linkStr, + "newPC": newPC, + "branch": branchStr} + blxIop = InstObjParams(mnem, Name, base, + {"code": code, + "predicate_test": predicateTest}) + header_output += declare.subst(blxIop) + decoder_output += constructor.subst(blxIop) + exec_output += PredOpExecute.subst(blxIop) + + #Ignore BXJ for now + + #CBNZ, CBZ. These are always unconditional as far as predicates + for (mnem, test) in (("cbz", "=="), ("cbnz", "!=")): + code = ''' + Addr PC = readPC(xc); + NPC = ((PC + imm) & mask(32)) | (PC & ~mask(32)); + ''' + predTest = "Op1 %(test)s 0" % {"test": test} + iop = InstObjParams(mnem, mnem.capitalize(), "BranchImmReg", + {"code": code, "predicate_test": predTest}) + header_output += BranchImmRegDeclare.subst(iop) + decoder_output += BranchImmRegConstructor.subst(iop) + exec_output += PredOpExecute.subst(iop) + + #TBB, TBH + for isTbh in (0, 1): + if isTbh: + eaCode = "EA = Op1 + Op2 * 2" + accCode = "NPC = readPC(xc) + 2 * (Mem.uh);" + mnem = "tbh" + else: + eaCode = "EA = Op1 + Op2" + accCode = "NPC = readPC(xc) + 2 * (Mem.ub);" + mnem = "tbb" + eaCode = "unsigned memAccessFlags = 0;\n" + eaCode + iop = InstObjParams(mnem, mnem.capitalize(), "BranchRegReg", + {'ea_code': eaCode, + 'memacc_code': accCode, + 'predicate_test': predicateTest}) + header_output += BranchTableDeclare.subst(iop) + decoder_output += BranchRegRegConstructor.subst(iop) + exec_output += LoadExecute.subst(iop) + \ + LoadInitiateAcc.subst(iop) + \ + LoadCompleteAcc.subst(iop) +}}; diff --git a/src/arch/arm/isa/insts/insts.isa b/src/arch/arm/isa/insts/insts.isa index 4168d39b5..a7a96a51c 100644 --- a/src/arch/arm/isa/insts/insts.isa +++ b/src/arch/arm/isa/insts/insts.isa @@ -54,3 +54,6 @@ //Data processing instructions ##include "data.isa" + +//Branches +##include "branch.isa" diff --git a/src/arch/arm/isa/operands.isa b/src/arch/arm/isa/operands.isa index 3f331832c..ab4d95d47 100644 --- a/src/arch/arm/isa/operands.isa +++ b/src/arch/arm/isa/operands.isa @@ -68,6 +68,7 @@ let {{ readNPC = 'xc->readNextPC() & ~PcModeMask' writeNPC = 'setNextPC(xc, %(final_val)s)' writeIWNPC = 'setIWNextPC(xc, %(final_val)s)' + forceNPC = 'xc->setNextPC(%(final_val)s)' }}; def operands {{ @@ -125,6 +126,8 @@ def operands {{ 'Fpexc': ('ControlReg', 'uw', 'MISCREG_FPEXC', None, 45), 'NPC': ('NPC', 'ud', None, (None, None, 'IsControl'), 51, readNPC, writeNPC), + 'FNPC': ('NPC', 'ud', None, (None, None, 'IsControl'), 51, + readNPC, forceNPC), 'IWNPC': ('NPC', 'ud', None, (None, None, 'IsControl'), 51, readNPC, writeIWNPC), }}; |