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add TableGen support to create relationship maps between instructions

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Relationship maps are represented as InstrMapping records which are parsed by
TableGen and the information is used to construct mapping tables to represent
appropriate relations between instructions. These tables are emitted into
XXXGenInstrInfo.inc file along with the functions to query them.

Patch by Jyotsna Verma <jverma@codeaurora.org>.

llvm-svn: 166685
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Sebastian Pop 2012-10-25 15:54:06 +00:00
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179
docs/HowToUseInstrMappings.rst Executable file
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.. _how_to_use_instruction_mappings:
===============================
How To Use Instruction Mappings
===============================
.. sectionauthor:: Jyotsna Verma <jverma@codeaurora.org>
.. contents::
:local:
Introduction
============
This document contains information about adding instruction mapping support
for a target. The motivation behind this feature comes from the need to switch
between different instruction formats during various optimizations. One approach
could be to use switch cases which list all the instructions along with formats
they can transition to. However, it has large maintenance overhead
because of the hardcoded instruction names. Also, whenever a new instruction is
added in the .td files, all the relevant switch cases should be modified
accordingly. Instead, the same functionality could be achieved with TableGen and
some support from the .td files for a fraction of maintenance cost.
``InstrMapping`` Class Overview
===============================
TableGen uses relationship models to map instructions with each other. These
models are described using ``InstrMapping`` class as a base. Each model sets
various fields of the ``InstrMapping`` class such that they can uniquely
describe all the instructions using that model. TableGen parses all the relation
models and uses the information to construct relation tables which relate
instructions with each other. These tables are emitted in the
``XXXInstrInfo.inc`` file along with the functions to query them. Following
is the definition of ``InstrMapping`` class definied in Target.td file:
.. code-block:: llvm
class InstrMapping {
// Used to reduce search space only to the instructions using this
// relation model.
string FilterClass;
// List of fields/attributes that should be same for all the instructions in
// a row of the relation table. Think of this as a set of properties shared
// by all the instructions related by this relationship.
list<string> RowFields = [];
// List of fields/attributes that are same for all the instructions
// in a column of the relation table.
list<string> ColFields = [];
// Values for the fields/attributes listed in 'ColFields' corresponding to
// the key instruction. This is the instruction that will be transformed
// using this relation model.
list<string> KeyCol = [];
// List of values for the fields/attributes listed in 'ColFields', one for
// each column in the relation table. These are the instructions a key
// instruction will be transformed into.
list<list<string> > ValueCols = [];
}
Sample Example
--------------
Let's say that we want to have a function
``int getPredOpcode(uint16_t Opcode, enum PredSense inPredSense)`` which
takes a non-predicated instruction and returns its predicated true or false form
depending on some input flag, ``inPredSense``. The first step in the process is
to define a relationship model that relates predicated instructions to their
non-predicated form by assigning appropriate values to the ``InstrMapping``
fields. For this relationship, non-predicated instructions are treated as key
instruction since they are the one used to query the interface function.
.. code-block:: llvm
def getPredOpcode : InstrMapping {
// Choose a FilterClass that is used as a base class for all the
// instructions modeling this relationship. This is done to reduce the
// search space only to these set of instructions.
let FilterClass = "PredRel";
// Instructions with same values for all the fields in RowFields form a
// row in the resulting relation table.
// For example, if we want to relate 'ADD' (non-predicated) with 'Add_pt'
// (predicated true) and 'Add_pf' (predicated false), then all 3
// instructions need to have same value for BaseOpcode field. It can be any
// unique value (Ex: XYZ) and should not be shared with any other
// instruction not related to 'add'.
let RowFields = ["BaseOpcode"];
// List of attributes that can be used to define key and column instructions
// for a relation. Key instruction is passed as an argument
// to the function used for querying relation tables. Column instructions
// are the instructions they (key) can transform into.
//
// Here, we choose 'PredSense' as ColFields since this is the unique
// attribute of the key (non-predicated) and column (true/false)
// instructions involved in this relationship model.
let ColFields = ["PredSense"];
// The key column contains non-predicated instructions.
let KeyCol = ["none"];
// Two value columns - first column contains instructions with
// PredSense=true while second column has instructions with PredSense=false.
let ValueCols = [["true"], ["false"]];
}
TableGen uses the above relationship model to emit relation table that maps
non-predicated instructions with their predicated forms. It also outputs the
interface function
``int getPredOpcode(uint16_t Opcode, enum PredSense inPredSense)`` to query
the table. Here, Function ``getPredOpcode`` takes two arguments, opcode of the
current instruction and PredSense of the desired instruction, and returns
predicated form of the instruction, if found in the relation table.
In order for an instruction to be added into the relation table, it needs
to include relevant information in its definition. For example, consider
following to be the current definitions of ADD, ADD_pt (true) and ADD_pf (false)
instructions:
.. code-block::llvm
def ADD : ALU32_rr<(outs IntRegs:$dst), (ins IntRegs:$a, IntRegs:$b),
"$dst = add($a, $b)",
[(set (i32 IntRegs:$dst), (add (i32 IntRegs:$a),
(i32 IntRegs:$b)))]>;
def ADD_Pt : ALU32_rr<(outs IntRegs:$dst),
(ins PredRegs:$p, IntRegs:$a, IntRegs:$b),
"if ($p) $dst = add($a, $b)",
[]>;
def ADD_Pf : ALU32_rr<(outs IntRegs:$dst),
(ins PredRegs:$p, IntRegs:$a, IntRegs:$b),
"if (!$p) $dst = add($a, $b)",
[]>;
In this step, we modify these instructions to include the information
required by the relationship model, <tt>getPredOpcode</tt>, so that they can
be related.
.. code-block::llvm
def ADD : PredRel, ALU32_rr<(outs IntRegs:$dst), (ins IntRegs:$a, IntRegs:$b),
"$dst = add($a, $b)",
[(set (i32 IntRegs:$dst), (add (i32 IntRegs:$a),
(i32 IntRegs:$b)))]> {
let BaseOpcode = "ADD";
let PredSense = "none";
}
def ADD_Pt : PredRel, ALU32_rr<(outs IntRegs:$dst),
(ins PredRegs:$p, IntRegs:$a, IntRegs:$b),
"if ($p) $dst = add($a, $b)",
[]> {
let BaseOpcode = "ADD";
let PredSense = "true";
}
def ADD_Pf : PredRel, ALU32_rr<(outs IntRegs:$dst),
(ins PredRegs:$p, IntRegs:$a, IntRegs:$b),
"if (!$p) $dst = add($a, $b)",
[]> {
let BaseOpcode = "ADD";
let PredSense = "false";
}
Please note that all the above instructions use ``PredRel`` as a base class.
This is extremely important since TableGen uses it as a filter for selecting
instructions for ``getPredOpcode`` model. Any instruction not derived from
``PredRel`` is excluded from the analysis. ``BaseOpcode`` is another important
field. Since it's selected as a ``RowFields`` of the model, it is required
to have the same value for all 3 instructions in order to be related. Next,
``PredSense`` is used to determine their column positions by comparing its value
with ``KeyCol`` and ``ValueCols``. If an instruction sets its ``PredSense``
value to something not used in the relation model, it will not be assigned
a column in the relation table.

24
docs/WritingAnLLVMBackend.html
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@ -32,6 +32,7 @@
<li><a href="#InstructionSet">Instruction Set</a> <li><a href="#InstructionSet">Instruction Set</a>
<ul> <ul>
<li><a href="#operandMapping">Instruction Operand Mapping</a></li> <li><a href="#operandMapping">Instruction Operand Mapping</a></li>
<li><a href="#relationMapping">Instruction Relation Mapping</a></li>
<li><a href="#implementInstr">Implement a subclass of TargetInstrInfo</a></li> <li><a href="#implementInstr">Implement a subclass of TargetInstrInfo</a></li>
<li><a href="#branchFolding">Branch Folding and If Conversion</a></li> <li><a href="#branchFolding">Branch Folding and If Conversion</a></li>
</ul></li> </ul></li>
@ -1257,6 +1258,29 @@ the <tt>rd</tt>, <tt>rs1</tt>, and <tt>rs2</tt> fields respectively.
</div> </div>
<!-- ======================================================================= -->
<h3>
<a name="relationMapping">Instruction Relation Mapping</a>
</h3>
<div>
<p>
This TableGen feature is used to relate instructions with each other. It is
particularly useful when you have multiple instruction formats and need to
switch between them after instruction selection. This entire feature is driven
by relation models which can be defined in <tt>XXXInstrInfo.td</tt> files
according to the target-specific instruction set. Relation models are defined
using <tt>InstrMapping</tt> class as a base. TableGen parses all the models
and generates instruction relation maps using the specified information.
Relation maps are emitted as tables in the <tt>XXXGenInstrInfo.inc</tt> file
along with the functions to query them. For the detailed information on how to
use this feature, please refer to
<a href="HowToUseInstrMappings.html">How to add Instruction Mappings</a>
document.
</p>
</div>
<!-- ======================================================================= --> <!-- ======================================================================= -->
<h3> <h3>
<a name="implementInstr">Implement a subclass of </a> <a name="implementInstr">Implement a subclass of </a>

49
include/llvm/Target/Target.td
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@ -997,6 +997,55 @@ class ProcessorModel<string n, SchedMachineModel m, list<SubtargetFeature> f>
let SchedModel = m; let SchedModel = m;
} }
//===----------------------------------------------------------------------===//
// InstrMapping - This class is used to create mapping tables to relate
// instructions with each other based on the values specified in RowFields,
// ColFields, KeyCol and ValueCols.
//
class InstrMapping {
// FilterClass - Used to limit search space only to the instructions that
// define the relationship modeled by this InstrMapping record.
string FilterClass;
// RowFields - List of fields/attributes that should be same for all the
// instructions in a row of the relation table. Think of this as a set of
// properties shared by all the instructions related by this relationship
// model and is used to categorize instructions into subgroups. For instance,
// if we want to define a relation that maps 'Add' instruction to its
// predicated forms, we can define RowFields like this:
//
// let RowFields = BaseOp
// All add instruction predicated/non-predicated will have to set their BaseOp
// to the same value.
//
// def Add: { let BaseOp = 'ADD'; let predSense = 'nopred' }
// def Add_predtrue: { let BaseOp = 'ADD'; let predSense = 'true' }
// def Add_predfalse: { let BaseOp = 'ADD'; let predSense = 'false' }
list<string> RowFields = [];
// List of fields/attributes that are same for all the instructions
// in a column of the relation table.
// Ex: let ColFields = 'predSense' -- It means that the columns are arranged
// based on the 'predSense' values. All the instruction in a specific
// column have the same value and it is fixed for the column according
// to the values set in 'ValueCols'.
list<string> ColFields = [];
// Values for the fields/attributes listed in 'ColFields'.
// Ex: let KeyCol = 'nopred' -- It means that the key instruction (instruction
// that models this relation) should be non-predicated.
// In the example above, 'Add' is the key instruction.
list<string> KeyCol = [];
// List of values for the fields/attributes listed in 'ColFields', one for
// each column in the relation table.
//
// Ex: let ValueCols = [['true'],['false']] -- It adds two columns in the
// table. First column requires all the instructions to have predSense
// set to 'true' and second column requires it to be 'false'.
list<list<string> > ValueCols = [];
}
//===----------------------------------------------------------------------===// //===----------------------------------------------------------------------===//
// Pull in the common support for calling conventions. // Pull in the common support for calling conventions.
// //

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utils/TableGen/CodeGenMapTable.cpp Normal file
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@ -0,0 +1,609 @@
//===- CodeGenMapTable.cpp - Instruction Mapping Table Generator ----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// CodeGenMapTable provides functionality for the TabelGen to create
// relation mapping between instructions. Relation models are defined using
// InstrMapping as a base class. This file implements the functionality which
// parses these definitions and generates relation maps using the information
// specified there. These maps are emitted as tables in the XXXGenInstrInfo.inc
// file along with the functions to query them.
//
// A relationship model to relate non-predicate instructions with their
// predicated true/false forms can be defined as follows:
//
// def getPredOpcode : InstrMapping {
// let FilterClass = "PredRel";
// let RowFields = ["BaseOpcode"];
// let ColFields = ["PredSense"];
// let KeyCol = ["none"];
// let ValueCols = [["true"], ["false"]]; }
//
// CodeGenMapTable parses this map and generates a table in XXXGenInstrInfo.inc
// file that contains the instructions modeling this relationship. This table
// is defined in the function
// "int getPredOpcode(uint16_t Opcode, enum PredSense inPredSense)"
// that can be used to retrieve the predicated form of the instruction by
// passing its opcode value and the predicate sense (true/false) of the desired
// instruction as arguments.
//
// Short description of the algorithm:
//
// 1) Iterate through all the records that derive from "InstrMapping" class.
// 2) For each record, filter out instructions based on the FilterClass value.
// 3) Iterate through this set of instructions and insert them into
// RowInstrMap map based on their RowFields values. RowInstrMap is keyed by the
// vector of RowFields values and contains vectors of Records (instructions) as
// values. RowFields is a list of fields that are required to have the same
// values for all the instructions appearing in the same row of the relation
// table. All the instructions in a given row of the relation table have some
// sort of relationship with the key instruction defined by the corresponding
// relationship model.
//
// Ex: RowInstrMap(RowVal1, RowVal2, ...) -> [Instr1, Instr2, Instr3, ... ]
// Here Instr1, Instr2, Instr3 have same values (RowVal1, RowVal2) for
// RowFields. These groups of instructions are later matched against ValueCols
// to determine the column they belong to, if any.
//
// While building the RowInstrMap map, collect all the key instructions in
// KeyInstrVec. These are the instructions having the same values as KeyCol
// for all the fields listed in ColFields.
//
// For Example:
//
// Relate non-predicate instructions with their predicated true/false forms.
//
// def getPredOpcode : InstrMapping {
// let FilterClass = "PredRel";
// let RowFields = ["BaseOpcode"];
// let ColFields = ["PredSense"];
// let KeyCol = ["none"];
// let ValueCols = [["true"], ["false"]]; }
//
// Here, only instructions that have "none" as PredSense will be selected as key
// instructions.
//
// 4) For each key instruction, get the group of instructions that share the
// same key-value as the key instruction from RowInstrMap. Iterate over the list
// of columns in ValueCols (it is defined as a list<list<string> >. Therefore,
// it can specify multi-column relationships). For each column, find the
// instruction from the group that matches all the values for the column.
// Multiple matches are not allowed.
//
//===----------------------------------------------------------------------===//
#include "CodeGenTarget.h"
#include "llvm/Support/Format.h"
using namespace llvm;
typedef std::map<std::string, std::vector<Record*> > InstrRelMapTy;
typedef std::map<std::vector<Init*>, std::vector<Record*> > RowInstrMapTy;
namespace {
//===----------------------------------------------------------------------===//
// This class is used to represent InstrMapping class defined in Target.td file.
class InstrMap {
private:
std::string Name;
std::string FilterClass;
ListInit *RowFields;
ListInit *ColFields;
ListInit *KeyCol;
std::vector<ListInit*> ValueCols;
public:
InstrMap(Record* MapRec) {
Name = MapRec->getName();
// FilterClass - It's used to reduce the search space only to the
// instructions that define the kind of relationship modeled by
// this InstrMapping object/record.
const RecordVal *Filter = MapRec->getValue("FilterClass");
FilterClass = Filter->getValue()->getAsUnquotedString();
// List of fields/attributes that need to be same across all the
// instructions in a row of the relation table.
RowFields = MapRec->getValueAsListInit("RowFields");
// List of fields/attributes that are constant across all the instruction
// in a column of the relation table. Ex: ColFields = 'predSense'
ColFields = MapRec->getValueAsListInit("ColFields");
// Values for the fields/attributes listed in 'ColFields'.
// Ex: KeyCol = 'noPred' -- key instruction is non predicated
KeyCol = MapRec->getValueAsListInit("KeyCol");
// List of values for the fields/attributes listed in 'ColFields', one for
// each column in the relation table.
//
// Ex: ValueCols = [['true'],['false']] -- it results two columns in the
// table. First column requires all the instructions to have predSense
// set to 'true' and second column requires it to be 'false'.
ListInit *ColValList = MapRec->getValueAsListInit("ValueCols");
// Each instruction map must specify at least one column for it to be valid.
if (ColValList->getSize() == 0)
throw "InstrMapping record `" + MapRec->getName() + "' has empty " +
"`ValueCols' field!";
for (unsigned i = 0, e = ColValList->getSize(); i < e; i++) {
ListInit *ColI = dyn_cast<ListInit>(ColValList->getElement(i));
// Make sure that all the sub-lists in 'ValueCols' have same number of
// elements as the fields in 'ColFields'.
if (ColI->getSize() == ColFields->getSize())
ValueCols.push_back(ColI);
else {
throw "Record `" + MapRec->getName() + "', field `" + "ValueCols" +
"' entries don't match with the entries in 'ColFields'!";
}
}
}
std::string getName() const {
return Name;
}
std::string getFilterClass() {
return FilterClass;
}
ListInit *getRowFields() const {
return RowFields;
}
ListInit *getColFields() const {
return ColFields;
}
ListInit *getKeyCol() const {
return KeyCol;
}
const std::vector<ListInit*> &getValueCols() const {
return ValueCols;
}
};
} // End anonymous namespace.
//===----------------------------------------------------------------------===//
// class MapTableEmitter : It builds the instruction relation maps using
// the information provided in InstrMapping records. It outputs these
// relationship maps as tables into XXXGenInstrInfo.inc file along with the
// functions to query them.
namespace {
class MapTableEmitter {
private:
// std::string TargetName;
const CodeGenTarget &Target;
RecordKeeper &Records;
// InstrMapDesc - InstrMapping record to be processed.
InstrMap InstrMapDesc;
// InstrDefs - list of instructions filtered using FilterClass defined
// in InstrMapDesc.
std::vector<Record*> InstrDefs;
// RowInstrMap - maps RowFields values to the instructions. It's keyed by the
// values of the row fields and contains vector of records as values.
RowInstrMapTy RowInstrMap;
// KeyInstrVec - list of key instructions.
std::vector<Record*> KeyInstrVec;
DenseMap<Record*, std::vector<Record*> > MapTable;
public:
MapTableEmitter(CodeGenTarget &Target, RecordKeeper &Records, Record *IMRec):
Target(Target), Records(Records), InstrMapDesc(IMRec) {
const std::string FilterClass = InstrMapDesc.getFilterClass();
InstrDefs = Records.getAllDerivedDefinitions(FilterClass);
};
void buildRowInstrMap();
// Returns true if an instruction is a key instruction, i.e., its ColFields
// have same values as KeyCol.
bool isKeyColInstr(Record* CurInstr);
// Find column instruction corresponding to a key instruction based on the
// constraints for that column.
Record *getInstrForColumn(Record *KeyInstr, ListInit *CurValueCol);
// Find column instructions for each key instruction based
// on ValueCols and store them into MapTable.
void buildMapTable();
void emitBinSearch(raw_ostream &OS, unsigned TableSize);
void emitTablesWithFunc(raw_ostream &OS);
unsigned emitBinSearchTable(raw_ostream &OS);
// Lookup functions to query binary search tables.
void emitMapFuncBody(raw_ostream &OS, unsigned TableSize);
};
} // End anonymous namespace.
//===----------------------------------------------------------------------===//
// Process all the instructions that model this relation (alreday present in
// InstrDefs) and insert them into RowInstrMap which is keyed by the values of
// the fields listed as RowFields. It stores vectors of records as values.
// All the related instructions have the same values for the RowFields thus are
// part of the same key-value pair.
//===----------------------------------------------------------------------===//
void MapTableEmitter::buildRowInstrMap() {
for (unsigned i = 0, e = InstrDefs.size(); i < e; i++) {
std::vector<Record*> InstrList;
Record *CurInstr = InstrDefs[i];
std::vector<Init*> KeyValue;
ListInit *RowFields = InstrMapDesc.getRowFields();
for (unsigned j = 0, endRF = RowFields->getSize(); j < endRF; j++) {
Init *RowFieldsJ = RowFields->getElement(j);
Init *CurInstrVal = CurInstr->getValue(RowFieldsJ)->getValue();
KeyValue.push_back(CurInstrVal);
}
// Collect key instructions into KeyInstrVec. Later, these instructions are
// processed to assign column position to the instructions sharing
// their KeyValue in RowInstrMap.
if (isKeyColInstr(CurInstr))
KeyInstrVec.push_back(CurInstr);
RowInstrMap[KeyValue].push_back(CurInstr);
}
}
//===----------------------------------------------------------------------===//
// Return true if an instruction is a KeyCol instruction.
//===----------------------------------------------------------------------===//
bool MapTableEmitter::isKeyColInstr(Record* CurInstr) {
ListInit *ColFields = InstrMapDesc.getColFields();
ListInit *KeyCol = InstrMapDesc.getKeyCol();
// Check if the instruction is a KeyCol instruction.
bool MatchFound = true;
for (unsigned j = 0, endCF = ColFields->getSize();
(j < endCF) && MatchFound; j++) {
RecordVal *ColFieldName = CurInstr->getValue(ColFields->getElement(j));
std::string CurInstrVal = ColFieldName->getValue()->getAsUnquotedString();
std::string KeyColValue = KeyCol->getElement(j)->getAsUnquotedString();
MatchFound = (CurInstrVal == KeyColValue);
}
return MatchFound;
}
//===----------------------------------------------------------------------===//
// Build a map to link key instructions with the column instructions arranged
// according to their column positions.
//===----------------------------------------------------------------------===//
void MapTableEmitter::buildMapTable() {
// Find column instructions for a given key based on the ColField
// constraints.
const std::vector<ListInit*> &ValueCols = InstrMapDesc.getValueCols();
unsigned NumOfCols = ValueCols.size();
for (unsigned j = 0, endKI = KeyInstrVec.size(); j < endKI; j++) {
Record *CurKeyInstr = KeyInstrVec[j];
std::vector<Record*> ColInstrVec(NumOfCols);
// Find the column instruction based on the constraints for the column.
for (unsigned ColIdx = 0; ColIdx < NumOfCols; ColIdx++) {
ListInit *CurValueCol = ValueCols[ColIdx];
Record *ColInstr = getInstrForColumn(CurKeyInstr, CurValueCol);
ColInstrVec[ColIdx] = ColInstr;
}
MapTable[CurKeyInstr] = ColInstrVec;
}
}
//===----------------------------------------------------------------------===//
// Find column instruction based on the constraints for that column.
//===----------------------------------------------------------------------===//
Record *MapTableEmitter::getInstrForColumn(Record *KeyInstr,
ListInit *CurValueCol) {
ListInit *RowFields = InstrMapDesc.getRowFields();
std::vector<Init*> KeyValue;
// Construct KeyValue using KeyInstr's values for RowFields.
for (unsigned j = 0, endRF = RowFields->getSize(); j < endRF; j++) {
Init *RowFieldsJ = RowFields->getElement(j);
Init *KeyInstrVal = KeyInstr->getValue(RowFieldsJ)->getValue();
KeyValue.push_back(KeyInstrVal);
}
// Get all the instructions that share the same KeyValue as the KeyInstr
// in RowInstrMap. We search through these instructions to find a match
// for the current column, i.e., the instruction which has the same values
// as CurValueCol for all the fields in ColFields.
const std::vector<Record*> &RelatedInstrVec = RowInstrMap[KeyValue];
ListInit *ColFields = InstrMapDesc.getColFields();
Record *MatchInstr = NULL;
for (unsigned i = 0, e = RelatedInstrVec.size(); i < e; i++) {
bool MatchFound = true;
Record *CurInstr = RelatedInstrVec[i];
for (unsigned j = 0, endCF = ColFields->getSize();
(j < endCF) && MatchFound; j++) {
Init *ColFieldJ = ColFields->getElement(j);
Init *CurInstrInit = CurInstr->getValue(ColFieldJ)->getValue();
std::string CurInstrVal = CurInstrInit->getAsUnquotedString();
Init *ColFieldJVallue = CurValueCol->getElement(j);
MatchFound = (CurInstrVal == ColFieldJVallue->getAsUnquotedString());
}
if (MatchFound) {
if (MatchInstr) // Already had a match
// Error if multiple matches are found for a column.
throw "Multiple matches found for `" + KeyInstr->getName() +
"', for the relation `" + InstrMapDesc.getName();
else
MatchInstr = CurInstr;
}
}
return MatchInstr;
}
//===----------------------------------------------------------------------===//
// Emit one table per relation. Only instructions with a valid relation of a
// given type are included in the table sorted by their enum values (opcodes).
// Binary search is used for locating instructions in the table.
//===----------------------------------------------------------------------===//
unsigned MapTableEmitter::emitBinSearchTable(raw_ostream &OS) {
const std::vector<const CodeGenInstruction*> &NumberedInstructions =
Target.getInstructionsByEnumValue();
std::string TargetName = Target.getName();
const std::vector<ListInit*> &ValueCols = InstrMapDesc.getValueCols();
unsigned NumCol = ValueCols.size();
unsigned TotalNumInstr = NumberedInstructions.size();
unsigned TableSize = 0;
OS << "static const uint16_t "<<InstrMapDesc.getName();
// Number of columns in the table are NumCol+1 because key instructions are
// emitted as first column.
OS << "Table[]["<< NumCol+1 << "] = {\n";
for (unsigned i = 0; i < TotalNumInstr; i++) {
Record *CurInstr = NumberedInstructions[i]->TheDef;
std::vector<Record*> ColInstrs = MapTable[CurInstr];
std::string OutStr("");
unsigned RelExists = 0;
if (ColInstrs.size()) {
for (unsigned j = 0; j < NumCol; j++) {
if (ColInstrs[j] != NULL) {
RelExists = 1;
OutStr += ", ";
OutStr += TargetName;
OutStr += "::";
OutStr += ColInstrs[j]->getName();
} else { OutStr += ", -1";}
}
if (RelExists) {
OS << " { " << TargetName << "::" << CurInstr->getName();
OS << OutStr <<" },\n";
TableSize++;
}
}
}
if (!TableSize) {
OS << " { " << TargetName << "::" << "INSTRUCTION_LIST_END, ";
OS << TargetName << "::" << "INSTRUCTION_LIST_END }";
}
OS << "}; // End of " << InstrMapDesc.getName() << "Table\n\n";
return TableSize;
}
//===----------------------------------------------------------------------===//
// Emit binary search algorithm as part of the functions used to query
// relation tables.
//===----------------------------------------------------------------------===//
void MapTableEmitter::emitBinSearch(raw_ostream &OS, unsigned TableSize) {
OS << " unsigned mid;\n";
OS << " unsigned start = 0;\n";
OS << " unsigned end = " << TableSize << ";\n";
OS << " while (start < end) {\n";
OS << " mid = start + (end - start)/2;\n";
OS << " if (Opcode == " << InstrMapDesc.getName() << "Table[mid][0]) {\n";
OS << " break;\n";
OS << " }\n";
OS << " if (Opcode < " << InstrMapDesc.getName() << "Table[mid][0])\n";
OS << " end = mid;\n";
OS << " else\n";
OS << " start = mid + 1;\n";
OS << " }\n";
OS << " if (start == end)\n";
OS << " return -1; // Instruction doesn't exist in this table.\n\n";
}
//===----------------------------------------------------------------------===//
// Emit functions to query relation tables.
//===----------------------------------------------------------------------===//
void MapTableEmitter::emitMapFuncBody(raw_ostream &OS,
unsigned TableSize) {
ListInit *ColFields = InstrMapDesc.getColFields();
const std::vector<ListInit*> &ValueCols = InstrMapDesc.getValueCols();
// Emit binary search algorithm to locate instructions in the
// relation table. If found, return opcode value from the appropriate column
// of the table.
emitBinSearch(OS, TableSize);
if (ValueCols.size() > 1) {
for (unsigned i = 0, e = ValueCols.size(); i < e; i++) {
ListInit *ColumnI = ValueCols[i];
for (unsigned j = 0, ColSize = ColumnI->getSize(); j < ColSize; j++) {
std::string ColName = ColFields->getElement(j)->getAsUnquotedString();
OS << " if (in" << ColName;
OS << " == ";
OS << ColName << "_" << ColumnI->getElement(j)->getAsUnquotedString();
if (j < ColumnI->getSize() - 1) OS << " && ";
else OS << ")\n";
}
OS << " return " << InstrMapDesc.getName();
OS << "Table[mid]["<<i+1<<"];\n";
}
OS << " return -1;";
}
else
OS << " return " << InstrMapDesc.getName() << "Table[mid][1];\n";
OS <<"}\n\n";
}
//===----------------------------------------------------------------------===//
// Emit relation tables and the functions to query them.
//===----------------------------------------------------------------------===//
void MapTableEmitter::emitTablesWithFunc(raw_ostream &OS) {
// Emit function name and the input parameters : mostly opcode value of the
// current instruction. However, if a table has multiple columns (more than 2
// since first column is used for the key instructions), then we also need
// to pass another input to indicate the column to be selected.
ListInit *ColFields = InstrMapDesc.getColFields();
const std::vector<ListInit*> &ValueCols = InstrMapDesc.getValueCols();
OS << "// "<< InstrMapDesc.getName() << "\n";
OS << "int "<< InstrMapDesc.getName() << "(uint16_t Opcode";
if (ValueCols.size() > 1) {
for (unsigned i = 0, e = ColFields->getSize(); i < e; i++) {
std::string ColName = ColFields->getElement(i)->getAsUnquotedString();
OS << ", enum " << ColName << " in" << ColName << ") {\n";
}
} else { OS << ") {\n"; }
// Emit map table.
unsigned TableSize = emitBinSearchTable(OS);
// Emit rest of the function body.
emitMapFuncBody(OS, TableSize);
}
//===----------------------------------------------------------------------===//
// Emit enums for the column fields across all the instruction maps.
//===----------------------------------------------------------------------===//
static void emitEnums(raw_ostream &OS, RecordKeeper &Records) {
std::vector<Record*> InstrMapVec;
InstrMapVec = Records.getAllDerivedDefinitions("InstrMapping");
std::map<std::string, std::vector<Init*> > ColFieldValueMap;
// Iterate over all InstrMapping records and create a map between column
// fields and their possible values across all records.
for (unsigned i = 0, e = InstrMapVec.size(); i < e; i++) {
Record *CurMap = InstrMapVec[i];
ListInit *ColFields;
ColFields = CurMap->getValueAsListInit("ColFields");
ListInit *List = CurMap->getValueAsListInit("ValueCols");
std::vector<ListInit*> ValueCols;
unsigned ListSize = List->getSize();
for (unsigned j = 0; j < ListSize; j++) {
ListInit *ListJ = dyn_cast<ListInit>(List->getElement(j));
if (ListJ->getSize() != ColFields->getSize()) {
throw "Record `" + CurMap->getName() + "', field `" + "ValueCols" +
"' entries don't match with the entries in 'ColFields' !";
}
ValueCols.push_back(ListJ);
}
for (unsigned j = 0, endCF = ColFields->getSize(); j < endCF; j++) {
for (unsigned k = 0; k < ListSize; k++){
std::string ColName = ColFields->getElement(j)->getAsUnquotedString();
ColFieldValueMap[ColName].push_back((ValueCols[k])->getElement(j));
}
}
}
for (std::map<std::string, std::vector<Init*> >::iterator
II = ColFieldValueMap.begin(), IE = ColFieldValueMap.end();
II != IE; II++) {
std::vector<Init*> FieldValues = (*II).second;
unsigned FieldSize = FieldValues.size();
// Delete duplicate entries from ColFieldValueMap
for (unsigned i = 0; i < FieldSize - 1; i++) {
Init *CurVal = FieldValues[i];
for (unsigned j = i+1; j < FieldSize; j++) {
if (CurVal == FieldValues[j]) {
FieldValues.erase(FieldValues.begin()+j);
}
}
}
// Emit enumerated values for the column fields.
OS << "enum " << (*II).first << " {\n";
for (unsigned i = 0; i < FieldSize; i++) {
OS << "\t" << (*II).first << "_" << FieldValues[i]->getAsUnquotedString();
if (i != FieldValues.size() - 1)
OS << ",\n";
else
OS << "\n};\n\n";
}
}
}
namespace llvm {
//===----------------------------------------------------------------------===//
// Parse 'InstrMapping' records and use the information to form relationship
// between instructions. These relations are emitted as a tables along with the
// functions to query them.
//===----------------------------------------------------------------------===//
void EmitMapTable(RecordKeeper &Records, raw_ostream &OS) {
CodeGenTarget Target(Records);
std::string TargetName = Target.getName();
std::vector<Record*> InstrMapVec;
InstrMapVec = Records.getAllDerivedDefinitions("InstrMapping");
if (!InstrMapVec.size())
return;
OS << "#ifdef GET_INSTRMAP_INFO\n";
OS << "#undef GET_INSTRMAP_INFO\n";
OS << "namespace llvm {\n\n";
OS << "namespace " << TargetName << " {\n\n";
// Emit coulumn field names and their values as enums.
emitEnums(OS, Records);
// Iterate over all instruction mapping records and construct relationship
// maps based on the information specified there.
//
for (unsigned i = 0, e = InstrMapVec.size(); i < e; i++) {
MapTableEmitter IMap(Target, Records, InstrMapVec[i]);
// Build RowInstrMap to group instructions based on their values for
// RowFields. In the process, also collect key instructions into
// KeyInstrVec.
IMap.buildRowInstrMap();
// Build MapTable to map key instructions with the corresponding column
// instructions.
IMap.buildMapTable();
// Emit map tables and the functions to query them.
IMap.emitTablesWithFunc(OS);
}
OS << "} // End " << TargetName << " namespace\n";
OS << "} // End llvm namespace\n";
OS << "#endif // GET_INSTRMAP_INFO\n\n";
}
} // End llvm namespace

2
utils/TableGen/InstrInfoEmitter.cpp
View File

@ -16,6 +16,7 @@
#include "CodeGenDAGPatterns.h" #include "CodeGenDAGPatterns.h"
#include "CodeGenSchedule.h" #include "CodeGenSchedule.h"
#include "CodeGenTarget.h" #include "CodeGenTarget.h"
#include "TableGenBackends.h"
#include "SequenceToOffsetTable.h" #include "SequenceToOffsetTable.h"
#include "llvm/ADT/StringExtras.h" #include "llvm/ADT/StringExtras.h"
#include "llvm/TableGen/Record.h" #include "llvm/TableGen/Record.h"
@ -415,6 +416,7 @@ namespace llvm {
void EmitInstrInfo(RecordKeeper &RK, raw_ostream &OS) { void EmitInstrInfo(RecordKeeper &RK, raw_ostream &OS) {
InstrInfoEmitter(RK).run(OS); InstrInfoEmitter(RK).run(OS);
EmitMapTable(RK, OS);
} }
} // End llvm namespace } // End llvm namespace

1
utils/TableGen/TableGenBackends.h
View File

@ -74,5 +74,6 @@ void EmitInstrInfo(RecordKeeper &RK, raw_ostream &OS);
void EmitPseudoLowering(RecordKeeper &RK, raw_ostream &OS); void EmitPseudoLowering(RecordKeeper &RK, raw_ostream &OS);
void EmitRegisterInfo(RecordKeeper &RK, raw_ostream &OS); void EmitRegisterInfo(RecordKeeper &RK, raw_ostream &OS);
void EmitSubtarget(RecordKeeper &RK, raw_ostream &OS); void EmitSubtarget(RecordKeeper &RK, raw_ostream &OS);
void EmitMapTable(RecordKeeper &RK, raw_ostream &OS);
} // End llvm namespace } // End llvm namespace