llvm-project/llvm/utils/TableGen/DAGISelMatcherOpt.cpp

49 lines
1.6 KiB
C++

//===- DAGISelMatcherOpt.cpp - Optimize a DAG Matcher ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the DAG Matcher optimizer.
//
//===----------------------------------------------------------------------===//
#include "DAGISelMatcher.h"
using namespace llvm;
static void FormRecordChildNodes(OwningPtr<MatcherNode> &Matcher) {
// If we reached the end of the chain, we're done.
MatcherNode *N = Matcher.get();
if (N == 0) return;
// If we have a push node, walk down both edges.
if (PushMatcherNode *Push = dyn_cast<PushMatcherNode>(N))
FormRecordChildNodes(Push->getFailurePtr());
// If we found a movechild node, check to see if our pattern matches.
if (MoveChildMatcherNode *MC = dyn_cast<MoveChildMatcherNode>(N)) {
if (RecordMatcherNode *RM = dyn_cast<RecordMatcherNode>(MC->getNext()))
if (MoveParentMatcherNode *MP =
dyn_cast<MoveParentMatcherNode>(RM->getNext())) {
MatcherNode *New
= new RecordChildMatcherNode(MC->getChildNo(), RM->getWhatFor());
New->setNext(MP->takeNext());
Matcher.reset(New);
return FormRecordChildNodes(Matcher);
}
}
FormRecordChildNodes(N->getNextPtr());
}
MatcherNode *llvm::OptimizeMatcher(MatcherNode *Matcher) {
OwningPtr<MatcherNode> MatcherPtr(Matcher);
FormRecordChildNodes(MatcherPtr);
return MatcherPtr.take();
}