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The process of going from an instruction definition to an instruction to be returned by the decoder has been fleshed out more. The following steps describe how an instruction implementation becomes a StaticInst.

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1. Microops are created. These are StaticInsts use templates to provide a basic form of polymorphism without having to make the microassembler smarter.
2. An instruction class is created which has a "templated" microcode program as it's docstring. The template parameters are refernced with ^ following by a number.
3. An instruction in the decoder references an instruction template using it's mnemonic. The parameters to it's format end up replacing the placeholders. These parameters describe a source for an operand which could be memory, a register, or an immediate. It it's a register, the register index is used. If it's memory, eventually a load/store will be pre/postpended to the instruction template and it's destination register will be used in place of the ^. If it's an immediate, the immediate is used. Some operand types, specifically those that come from the ModRM byte, need to be decoded further into memory vs. register versions. This is accomplished by making the decode_block text for these instructions another case statement based off ModRM.
4. Once all of the template parameters have been handled, the instruction goes throw the microcode assembler which resolves labels and creates a list of python op objects. If an operand is a register, it uses a % prefix, an immediate uses $, and a label uses @. If the operand is just letters, numbers, and underscores, it can appear immediately after the prefix. If it's not, it can be encolsed in non nested {}s.
5. If there is a single "op" object (which corresponds to a single microop) the decoder is set up to return it directly. If not, a macroop wrapper is created around it.

In the future, I'm considering seperating the operand type specialization from the template substitution step. A problem this introduces is that either the template arguments need to be kept around for the specialization step, or they need to be re-extracted. Re-extraction might be the way to go so that the operand formats can be coded directly into the micro assembler template without having to pass them in as parameters. I don't know if that's actually useful, though.

src/arch/x86/isa/decoder/one_byte_opcodes.isa:
src/arch/x86/isa/microasm.isa:
src/arch/x86/isa/microops/microops.isa:
src/arch/x86/isa/operands.isa:
src/arch/x86/isa/microops/base.isa:
    Implemented polymorphic microops and changed around the microcode assembler syntax.

--HG--
extra : convert_revision : e341f7b8ea9350a31e586a3d33250137e5954f43
This commit is contained in:
Gabe Black 2007-04-04 23:35:20 +00:00
parent ab2bed349b
commit ff7b89beee
5 changed files with 216 additions and 28 deletions
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8
src/arch/x86/isa/decoder/one_byte_opcodes.isa
View file

@ -61,8 +61,8 @@
0x1: decode OPCODE_OP_TOP5 {
format WarnUnimpl {
0x00: decode OPCODE_OP_BOTTOM3 {
0x4: Inst::addI(rAl,Ib);
0x5: Inst::addI(rAx,Iz);
0x4: Inst::add(rAl,Ib);
0x5: Inst::add(rAx,Iz);
0x6: push_ES();
0x7: pop_ES();
default: MultiInst::add(OPCODE_OP_BOTTOM3,
@ -123,8 +123,8 @@
0x7: das();
}
0x06: decode OPCODE_OP_BOTTOM3 {
0x4: Inst::xorI(rAl,Ib);
0x5: Inst::xorI(rAx,Iz);
0x4: Inst::xor(rAl,Ib);
0x5: Inst::xor(rAx,Iz);
0x6: M5InternalError::error(
{{"Tried to execute the SS segment override prefix!"}});
0x7: aaa();

53
src/arch/x86/isa/microasm.isa
View file

@ -135,36 +135,35 @@ let {{
opNum = len(opTypes) - 1
# A regular expression to find the operand placeholders we're
# interested in.
opRe = re.compile("%%(?P<operandNum>%d)(?=[^0-9]|$)" % opNum)
opRe = re.compile("\\^(?P<operandNum>%d)(?=[^0-9]|$)" % opNum)
# Parse the operand type strign we're working with
print "About to parse tag %s" % opTypes[opNum]
opType = OpType(opTypes[opNum])
if opType.reg:
#Figure out what to do with fixed register operands
if opType.reg in ("Ax", "Bx", "Cx", "Dx"):
code = opRe.sub("{INTREG_R%s}" % opType.reg.upper(), code)
code = opRe.sub("%%{INTREG_R%s}" % opType.reg.upper(), code)
elif opType.reg == "Al":
# We need a way to specify register width
code = opRe.sub("{INTREG_RAX}", code)
code = opRe.sub("%{INTREG_RAX}", code)
else:
print "Didn't know how to encode fixed register %s!" % opType.reg
elif opType.tag == None or opType.size == None:
raise Exception, "Problem parsing operand tag: %s" % opType.tag
elif opType.tag in ("C", "D", "G", "P", "S", "T", "V"):
# Use the "reg" field of the ModRM byte to select the register
code = opRe.sub("{(uint8_t)MODRM_REG}", code)
code = opRe.sub("%{(uint8_t)MODRM_REG}", code)
elif opType.tag in ("E", "Q", "W"):
# This might refer to memory or to a register. We need to
# divide it up farther.
regCode = opRe.sub("{(uint8_t)MODRM_RM}", code)
regCode = opRe.sub("%{(uint8_t)MODRM_RM}", code)
regTypes = copy.copy(opTypes)
regTypes.pop(-1)
# This needs to refer to memory, but we'll fill in the details
# later. It needs to take into account unaligned memory
# addresses.
memCode = opRe.sub("0", code)
memCode = opRe.sub("%0", code)
memTypes = copy.copy(opTypes)
memTypes.pop(-1)
return doSplitDecode(name, Name, specializeInst, "MODRM_MOD",
@ -172,16 +171,16 @@ let {{
elif opType.tag in ("I", "J"):
# Immediates are already in the instruction, so don't leave in
# those parameters
code = opRe.sub("", code)
code = opRe.sub("${IMMEDIATE}", code)
elif opType.tag == "M":
# This needs to refer to memory, but we'll fill in the details
# later. It needs to take into account unaligned memory
# addresses.
code = opRe.sub("0", code)
code = opRe.sub("%0", code)
elif opType.tag in ("PR", "R", "VR"):
# There should probably be a check here to verify that mod
# is equal to 11b
code = opRe.sub("{(uint8_t)MODRM_RM}", code)
code = opRe.sub("%{(uint8_t)MODRM_RM}", code)
else:
raise Exception, "Unrecognized tag %s." % opType.tag
opTypes.pop(-1)
@ -223,16 +222,24 @@ let {{
def getAllocator(self, *microFlags):
args = ''
signature = "<"
emptySig = True
for arg in self.args:
if arg.has_key("operandConst"):
args += ", %s" % arg["operandConst"]
elif arg.has_key("operandCode"):
args += ", %s" % arg["operandCode"]
if not emptySig:
signature += ", "
emptySig = False
if arg.has_key("operandImm"):
args += ", %s" % arg["operandImm"]
signature += ImmOpType
elif arg.has_key("operandReg"):
args += ", %s" % arg["operandReg"]
signature += RegOpType
elif arg.has_key("operandLabel"):
raise Exception, "Found a label while creating allocator string."
else:
raise Exception, "Unrecognized operand type."
return 'new %s(machInst%s%s)' % (self.className, self.microFlagsText(microFlags), args)
signature += ">"
return 'new %s%s(machInst%s%s)' % (self.className, signature, self.microFlagsText(microFlags), args)
}};
let {{
@ -260,7 +267,7 @@ let{{
# time. Each expression expects the thing it's looking for to be at
# the beginning of the line, so the previous component is stripped
# before continuing.
labelRe = re.compile(r'^[ \t]*(?P<label>[a-zA-Z_]\w*)[ \t]:')
labelRe = re.compile(r'^[ \t]*(?P<label>\w\w*)[ \t]:')
lineRe = re.compile(r'^(?P<line>[^\n][^\n]*)$')
classRe = re.compile(r'^[ \t]*(?P<className>[a-zA-Z_]\w*)')
# This recognizes three different flavors of operands:
@ -271,7 +278,12 @@ let{{
# underscore, which is optionally followed by a sequence of
# capital or small letters, underscores, or digts between 0 and 9
opRe = re.compile( \
r'^[ \t]*((?P<operandLabel>[a-zA-Z_]\w*)|(?P<operandConst>[0-9][0-9]*)|(\{(?P<operandCode>[^}]*)\}))')
r'^[ \t]*((\@(?P<operandLabel0>\w\w*))|' +
r'(\@\{(?P<operandLabel1>[^}]*)\})|' +
r'(\%(?P<operandReg0>\w\w*))|' +
r'(\%\{(?P<operandReg1>[^}]*)\})|' +
r'(\$(?P<operandImm0>\w\w*))|' +
r'(\$\{(?P<operandImm1>[^}]*)\}))')
lineMatch = lineRe.search(code)
while lineMatch != None:
statement = MicroOpStatement()
@ -310,9 +322,10 @@ let{{
# representations of operand values. Different forms might be
# needed in different places, for instance to replace a label
# with an offset.
for opType in ("operandLabel", "operandConst", "operandCode"):
for opType in ("operandLabel0", "operandReg0", "operandImm0",
"operandLabel1", "operandReg1", "operandImm1"):
if opMatch.group(opType):
statement.args[-1][opType] = opMatch.group(opType)
statement.args[-1][opType[:-1]] = opMatch.group(opType)
if len(statement.args[-1]) == 0:
print "Problem parsing operand in statement: %s" \
% orig_line
@ -338,7 +351,7 @@ let{{
# This is assuming that intra microcode branches go to
# the next micropc + displacement, or
# micropc + 1 + displacement.
arg["operandConst"] = labels[arg["operandLabel"]] - micropc - 1
arg["operandImm"] = labels[arg["operandLabel"]] - micropc - 1
micropc += 1
return statements
}};

172
src/arch/x86/isa/microops/base.isa Normal file
View file

@ -0,0 +1,172 @@
// -*- mode:c++ -*-
// Copyright (c) 2007 The Hewlett-Packard Development Company
// All rights reserved.
//
// Redistribution and use of this software in source and binary forms,
// with or without modification, are permitted provided that the
// following conditions are met:
//
// The software must be used only for Non-Commercial Use which means any
// use which is NOT directed to receiving any direct monetary
// compensation for, or commercial advantage from such use. Illustrative
// examples of non-commercial use are academic research, personal study,
// teaching, education and corporate research & development.
// Illustrative examples of commercial use are distributing products for
// commercial advantage and providing services using the software for
// commercial advantage.
//
// If you wish to use this software or functionality therein that may be
// covered by patents for commercial use, please contact:
// Director of Intellectual Property Licensing
// Office of Strategy and Technology
// Hewlett-Packard Company
// 1501 Page Mill Road
// Palo Alto, California 94304
//
// 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 HOLDER(s), HEWLETT-PACKARD COMPANY, nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission. No right of
// sublicense is granted herewith. Derivatives of the software and
// output created using the software may be prepared, but only for
// Non-Commercial Uses. Derivatives of the software may be shared with
// others provided: (i) the others agree to abide by the list of
// conditions herein which includes the Non-Commercial Use restrictions;
// and (ii) such Derivatives of the software include the above copyright
// notice to acknowledge the contribution from this software where
// applicable, this list of conditions and the disclaimer below.
//
// 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
//The operand types a microop template can be specialized with
output header {{
enum OperandType {
RegisterOperand,
ImmediateOperand
};
}};
//A class which is the base of all x86 micro ops it provides a function to
//set necessary flags appropriately.
output header {{
class X86MicroOpBase : public X86StaticInst
{
protected:
X86MicroOpBase(bool isMicro, bool isDelayed,
bool isFirst, bool isLast,
const char *mnem, ExtMachInst _machInst,
OpClass __opClass) :
X86StaticInst(mnem, _machInst, __opClass)
{
flags[IsMicroOp] = isMicro;
flags[IsDelayedCommit] = isDelayed;
flags[IsFirstMicroOp] = isFirst;
flags[IsLastMicroOp] = isLast;
}
};
}};
// This sets up a class which is templated on the type of
// arguments a particular flavor of a microcode instruction
// can accept. It's parameters are specialized to create polymorphic
// behavior in microops.
def template BaseMicroOpTemplateDeclare {{
template%(signature)s
class %(class_name)s;
}};
let {{
def buildBaseMicroOpTemplate(Name, numParams):
signature = "<"
signature += "int SignatureOperandTypeSpecifier0"
for count in xrange(1,numParams):
signature += \
", int SingatureOperandTypeSpecifier%d" % count
signature += ">"
subs = {"signature" : signature, "class_name" : Name}
return BaseMicroOpTemplateDeclare.subst(subs)
RegOpType = "RegisterOperand"
ImmOpType = "ImmediateOperand"
def buildMicroOpTemplateDict(*params):
signature = "<"
if len(params):
signature += params[0]
if len(params) > 1:
for param in params[1:]:
signature += ", %s" % param
signature += ">"
subs = {"param_dec" : "", "param_arg_dec" : "",
"param_init" : "", "signature" : signature}
for count in xrange(len(params)):
subs["param_dec"] += "uint64_t param%d;\n" % count
subs["param_arg_dec"] += ", uint64_t _param%d" % count
subs["param_init"] += ", param%d(_param%d)" % (count, count)
return subs
}};
// A tmeplate for building a specialized version of the microcode
// instruction which knows specifies which arguments it wants
def template MicroOpDeclare {{
template<>
class %(class_name)s%(signature)s : public X86MicroOpBase
{
protected:
%(param_dec)s
void buildMe();
public:
%(class_name)s(bool isMicro, bool isDelayed,
bool isFirst, bool isLast,
ExtMachInst _machInst %(param_arg_dec)s);
%(class_name)s(ExtMachInst _machInst %(param_arg_dec)s);
%(BasicExecDeclare)s
};
}};
def template MicroOpConstructor {{
inline void %(class_name)s%(signature)s::buildMe()
{
%(constructor)s;
}
inline %(class_name)s%(signature)s::%(class_name)s(
ExtMachInst machInst %(param_arg_dec)s) :
%(base_class)s(false, false, false, false,
"%(mnemonic)s", machInst, %(op_class)s)
%(param_init)s
{
buildMe();
}
inline %(class_name)s%(signature)s::%(class_name)s(
bool isMicro, bool isDelayed, bool isFirst, bool isLast,
ExtMachInst machInst %(param_arg_dec)s)
: %(base_class)s(isMicro, isDelayed, isFirst, isLast,
"%(mnemonic)s", machInst, %(op_class)s)
%(param_init)s
{
buildMe();
}
}};

5
src/arch/x86/isa/microops/microops.isa
View file

@ -53,5 +53,8 @@
//
// Authors: Gabe Black
//Micro ops
//Common microop stuff
##include "base.isa"
//Integer microop definitions
##include "int.isa"

6
src/arch/x86/isa/operands.isa
View file

@ -96,7 +96,7 @@ def operand_types {{
}};
def operands {{
'IntRegOp0': ('IntReg', 'udw', 'regIndex0', 'IsInteger', 1),
'IntRegOp1': ('IntReg', 'udw', 'regIndex1', 'IsInteger', 2),
'IntRegOp2': ('IntReg', 'udw', 'regIndex2', 'IsInteger', 2),
'IntRegOp0': ('IntReg', 'udw', 'param0', 'IsInteger', 1),
'IntRegOp1': ('IntReg', 'udw', 'param1', 'IsInteger', 2),
'IntRegOp2': ('IntReg', 'udw', 'param2', 'IsInteger', 2),
}};