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[TableGen] CodeGenDAGPatterns::GenerateVariants - full caching of matching predicates

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Further extension to D51035, this patch avoids all repeated predicates[] matching by caching as it collects the patterns that have multiple variants.

Saves around 25secs in debug builds of x86 -gen-dag-isel.

Differential Revision: https://reviews.llvm.org/D51839

llvm-svn: 342467
This commit is contained in:
Simon Pilgrim 2018-09-18 11:30:30 +00:00
parent 937f3fedec
commit 0621f56c84
1 changed files with 49 additions and 11 deletions
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60
llvm/utils/TableGen/CodeGenDAGPatterns.cpp
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@ -4461,8 +4461,18 @@ void CodeGenDAGPatterns::GenerateVariants() {
// intentionally do not reconsider these. Any variants of added patterns have
// already been added.
//
for (unsigned i = 0, e = PatternsToMatch.size(); i != e; ++i) {
MultipleUseVarSet DepVars;
const unsigned NumOriginalPatterns = PatternsToMatch.size();
BitVector MatchedPatterns(NumOriginalPatterns);
std::vector<BitVector> MatchedPredicates(NumOriginalPatterns,
BitVector(NumOriginalPatterns));
typedef std::pair<MultipleUseVarSet, std::vector<TreePatternNodePtr>>
DepsAndVariants;
std::map<unsigned, DepsAndVariants> PatternsWithVariants;
// Collect patterns with more than one variant.
for (unsigned i = 0; i != NumOriginalPatterns; ++i) {
MultipleUseVarSet DepVars;
std::vector<TreePatternNodePtr> Variants;
FindDepVars(PatternsToMatch[i].getSrcPattern(), DepVars);
LLVM_DEBUG(errs() << "Dependent/multiply used variables: ");
@ -4472,21 +4482,46 @@ void CodeGenDAGPatterns::GenerateVariants() {
*this, DepVars);
assert(!Variants.empty() && "Must create at least original variant!");
if (Variants.size() == 1) // No additional variants for this pattern.
if (Variants.size() == 1) // No additional variants for this pattern.
continue;
LLVM_DEBUG(errs() << "FOUND VARIANTS OF: ";
PatternsToMatch[i].getSrcPattern()->dump(); errs() << "\n");
PatternsWithVariants[i] = std::make_pair(DepVars, Variants);
// Cache matching predicates.
// TODO: Is it performant to pull this out of the loop entirely?
BitVector MatchedPredicates(PatternsToMatch.size(), false);
for (unsigned p = 0, e = PatternsToMatch.size(); p != e; ++p)
MatchedPredicates[p] = (i == p) || (PatternsToMatch[i].getPredicates() ==
PatternsToMatch[p].getPredicates());
if (MatchedPatterns[i])
continue;
const std::vector<Predicate> &Predicates =
PatternsToMatch[i].getPredicates();
BitVector &Matches = MatchedPredicates[i];
MatchedPatterns[i] = true;
Matches[i] = true;
// Don't test patterns that have already been cached - it won't match.
for (unsigned p = 0; p != NumOriginalPatterns; ++p)
if (!MatchedPatterns[p])
Matches[p] = (Predicates == PatternsToMatch[p].getPredicates());
// Copy this to all the matching patterns.
for (int p = Matches.find_first(); p != -1; p = Matches.find_next(p))
if (p != i) {
MatchedPatterns[p] = true;
MatchedPredicates[p] = Matches;
}
}
for (auto it : PatternsWithVariants) {
unsigned i = it.first;
const MultipleUseVarSet &DepVars = it.second.first;
const std::vector<TreePatternNodePtr> &Variants = it.second.second;
for (unsigned v = 0, e = Variants.size(); v != e; ++v) {
TreePatternNodePtr Variant = Variants[v];
BitVector &Matches = MatchedPredicates[i];
LLVM_DEBUG(errs() << " VAR#" << v << ": "; Variant->dump();
errs() << "\n");
@ -4495,7 +4530,7 @@ void CodeGenDAGPatterns::GenerateVariants() {
bool AlreadyExists = false;
for (unsigned p = 0, e = PatternsToMatch.size(); p != e; ++p) {
// Skip if the top level predicates do not match.
if (!MatchedPredicates[p])
if (!Matches[p])
continue;
// Check to see if this variant already exists.
if (Variant->isIsomorphicTo(PatternsToMatch[p].getSrcPattern(),
@ -4514,8 +4549,11 @@ void CodeGenDAGPatterns::GenerateVariants() {
Variant, PatternsToMatch[i].getDstPatternShared(),
PatternsToMatch[i].getDstRegs(),
PatternsToMatch[i].getAddedComplexity(), Record::getNewUID()));
MatchedPredicates.resize(PatternsToMatch.size());
MatchedPredicates[PatternsToMatch.size() - 1] = true;
MatchedPredicates.push_back(Matches);
unsigned NumPatterns = PatternsToMatch.size();
for (unsigned p = 0; p != NumPatterns; ++p)
MatchedPredicates[p].resize(NumPatterns, MatchedPredicates[p][i]);
}
LLVM_DEBUG(errs() << "\n");