forked from OSchip/llvm-project
175 lines
6.1 KiB
C++
175 lines
6.1 KiB
C++
//===- DAGISelEmitter.cpp - Generate an instruction selector --------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This tablegen backend emits a DAG instruction selector.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "CodeGenDAGPatterns.h"
|
|
#include "DAGISelMatcher.h"
|
|
#include "llvm/Support/Debug.h"
|
|
#include "llvm/TableGen/Record.h"
|
|
#include "llvm/TableGen/TableGenBackend.h"
|
|
using namespace llvm;
|
|
|
|
#define DEBUG_TYPE "dag-isel-emitter"
|
|
|
|
namespace {
|
|
/// DAGISelEmitter - The top-level class which coordinates construction
|
|
/// and emission of the instruction selector.
|
|
class DAGISelEmitter {
|
|
CodeGenDAGPatterns CGP;
|
|
public:
|
|
explicit DAGISelEmitter(RecordKeeper &R) : CGP(R) {}
|
|
void run(raw_ostream &OS);
|
|
};
|
|
} // End anonymous namespace
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// DAGISelEmitter Helper methods
|
|
//
|
|
|
|
/// getResultPatternCost - Compute the number of instructions for this pattern.
|
|
/// This is a temporary hack. We should really include the instruction
|
|
/// latencies in this calculation.
|
|
static unsigned getResultPatternCost(TreePatternNode *P,
|
|
CodeGenDAGPatterns &CGP) {
|
|
if (P->isLeaf()) return 0;
|
|
|
|
unsigned Cost = 0;
|
|
Record *Op = P->getOperator();
|
|
if (Op->isSubClassOf("Instruction")) {
|
|
Cost++;
|
|
CodeGenInstruction &II = CGP.getTargetInfo().getInstruction(Op);
|
|
if (II.usesCustomInserter)
|
|
Cost += 10;
|
|
}
|
|
for (unsigned i = 0, e = P->getNumChildren(); i != e; ++i)
|
|
Cost += getResultPatternCost(P->getChild(i), CGP);
|
|
return Cost;
|
|
}
|
|
|
|
/// getResultPatternCodeSize - Compute the code size of instructions for this
|
|
/// pattern.
|
|
static unsigned getResultPatternSize(TreePatternNode *P,
|
|
CodeGenDAGPatterns &CGP) {
|
|
if (P->isLeaf()) return 0;
|
|
|
|
unsigned Cost = 0;
|
|
Record *Op = P->getOperator();
|
|
if (Op->isSubClassOf("Instruction")) {
|
|
Cost += Op->getValueAsInt("CodeSize");
|
|
}
|
|
for (unsigned i = 0, e = P->getNumChildren(); i != e; ++i)
|
|
Cost += getResultPatternSize(P->getChild(i), CGP);
|
|
return Cost;
|
|
}
|
|
|
|
namespace {
|
|
// PatternSortingPredicate - return true if we prefer to match LHS before RHS.
|
|
// In particular, we want to match maximal patterns first and lowest cost within
|
|
// a particular complexity first.
|
|
struct PatternSortingPredicate {
|
|
PatternSortingPredicate(CodeGenDAGPatterns &cgp) : CGP(cgp) {}
|
|
CodeGenDAGPatterns &CGP;
|
|
|
|
bool operator()(const PatternToMatch *LHS, const PatternToMatch *RHS) {
|
|
const TreePatternNode *LHSSrc = LHS->getSrcPattern();
|
|
const TreePatternNode *RHSSrc = RHS->getSrcPattern();
|
|
|
|
MVT LHSVT = (LHSSrc->getNumTypes() != 0 ? LHSSrc->getType(0) : MVT::Other);
|
|
MVT RHSVT = (RHSSrc->getNumTypes() != 0 ? RHSSrc->getType(0) : MVT::Other);
|
|
if (LHSVT.isVector() != RHSVT.isVector())
|
|
return RHSVT.isVector();
|
|
|
|
if (LHSVT.isFloatingPoint() != RHSVT.isFloatingPoint())
|
|
return RHSVT.isFloatingPoint();
|
|
|
|
// Otherwise, if the patterns might both match, sort based on complexity,
|
|
// which means that we prefer to match patterns that cover more nodes in the
|
|
// input over nodes that cover fewer.
|
|
int LHSSize = LHS->getPatternComplexity(CGP);
|
|
int RHSSize = RHS->getPatternComplexity(CGP);
|
|
if (LHSSize > RHSSize) return true; // LHS -> bigger -> less cost
|
|
if (LHSSize < RHSSize) return false;
|
|
|
|
// If the patterns have equal complexity, compare generated instruction cost
|
|
unsigned LHSCost = getResultPatternCost(LHS->getDstPattern(), CGP);
|
|
unsigned RHSCost = getResultPatternCost(RHS->getDstPattern(), CGP);
|
|
if (LHSCost < RHSCost) return true;
|
|
if (LHSCost > RHSCost) return false;
|
|
|
|
unsigned LHSPatSize = getResultPatternSize(LHS->getDstPattern(), CGP);
|
|
unsigned RHSPatSize = getResultPatternSize(RHS->getDstPattern(), CGP);
|
|
if (LHSPatSize < RHSPatSize) return true;
|
|
if (LHSPatSize > RHSPatSize) return false;
|
|
|
|
// Sort based on the UID of the pattern, giving us a deterministic ordering
|
|
// if all other sorting conditions fail.
|
|
assert(LHS == RHS || LHS->ID != RHS->ID);
|
|
return LHS->ID < RHS->ID;
|
|
}
|
|
};
|
|
} // End anonymous namespace
|
|
|
|
|
|
void DAGISelEmitter::run(raw_ostream &OS) {
|
|
emitSourceFileHeader("DAG Instruction Selector for the " +
|
|
CGP.getTargetInfo().getName() + " target", OS);
|
|
|
|
OS << "// *** NOTE: This file is #included into the middle of the target\n"
|
|
<< "// *** instruction selector class. These functions are really "
|
|
<< "methods.\n\n";
|
|
|
|
DEBUG(errs() << "\n\nALL PATTERNS TO MATCH:\n\n";
|
|
for (CodeGenDAGPatterns::ptm_iterator I = CGP.ptm_begin(),
|
|
E = CGP.ptm_end(); I != E; ++I) {
|
|
errs() << "PATTERN: "; I->getSrcPattern()->dump();
|
|
errs() << "\nRESULT: "; I->getDstPattern()->dump();
|
|
errs() << "\n";
|
|
});
|
|
|
|
// Add all the patterns to a temporary list so we can sort them.
|
|
std::vector<const PatternToMatch*> Patterns;
|
|
for (CodeGenDAGPatterns::ptm_iterator I = CGP.ptm_begin(), E = CGP.ptm_end();
|
|
I != E; ++I)
|
|
Patterns.push_back(&*I);
|
|
|
|
// We want to process the matches in order of minimal cost. Sort the patterns
|
|
// so the least cost one is at the start.
|
|
std::sort(Patterns.begin(), Patterns.end(), PatternSortingPredicate(CGP));
|
|
|
|
|
|
// Convert each variant of each pattern into a Matcher.
|
|
std::vector<Matcher*> PatternMatchers;
|
|
for (unsigned i = 0, e = Patterns.size(); i != e; ++i) {
|
|
for (unsigned Variant = 0; ; ++Variant) {
|
|
if (Matcher *M = ConvertPatternToMatcher(*Patterns[i], Variant, CGP))
|
|
PatternMatchers.push_back(M);
|
|
else
|
|
break;
|
|
}
|
|
}
|
|
|
|
Matcher *TheMatcher = new ScopeMatcher(PatternMatchers);
|
|
|
|
TheMatcher = OptimizeMatcher(TheMatcher, CGP);
|
|
//Matcher->dump();
|
|
EmitMatcherTable(TheMatcher, CGP, OS);
|
|
delete TheMatcher;
|
|
}
|
|
|
|
namespace llvm {
|
|
|
|
void EmitDAGISel(RecordKeeper &RK, raw_ostream &OS) {
|
|
DAGISelEmitter(RK).run(OS);
|
|
}
|
|
|
|
} // End llvm namespace
|