[llvm-commits] [llvm] r96747 - /llvm/trunk/utils/TableGen/DAGISelEmitter.cpp
Chris Lattner
sabre at nondot.org
Sun Feb 21 11:22:06 PST 2010
Author: lattner
Date: Sun Feb 21 13:22:06 2010
New Revision: 96747
URL: http://llvm.org/viewvc/llvm-project?rev=96747&view=rev
Log:
Sort the patterns before adding them to the FA so that we get the
least cost matches. This gets us from 195 -> 208 passes on the ppc codegen tests.
Modified:
llvm/trunk/utils/TableGen/DAGISelEmitter.cpp
Modified: llvm/trunk/utils/TableGen/DAGISelEmitter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/DAGISelEmitter.cpp?rev=96747&r1=96746&r2=96747&view=diff
==============================================================================
--- llvm/trunk/utils/TableGen/DAGISelEmitter.cpp (original)
+++ llvm/trunk/utils/TableGen/DAGISelEmitter.cpp Sun Feb 21 13:22:06 2010
@@ -141,7 +141,6 @@
typedef std::pair<unsigned, std::string> CodeLine;
typedef std::vector<CodeLine> CodeList;
- typedef std::vector<std::pair<const PatternToMatch*, CodeList> > PatternList;
bool operator()(const std::pair<const PatternToMatch*, CodeList> &LHSPair,
const std::pair<const PatternToMatch*, CodeList> &RHSPair) {
@@ -1889,6 +1888,36 @@
<< "}\n\n";
}
+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 PatternSortingPredicate2 {
+ PatternSortingPredicate2(CodeGenDAGPatterns &cgp) : CGP(cgp) {}
+ CodeGenDAGPatterns &CGP;
+
+ bool operator()(const PatternToMatch *LHS,
+ const PatternToMatch *RHS) {
+ unsigned LHSSize = getPatternSize(LHS->getSrcPattern(), CGP);
+ unsigned RHSSize = getPatternSize(RHS->getSrcPattern(), CGP);
+ LHSSize += LHS->getAddedComplexity();
+ RHSSize += RHS->getAddedComplexity();
+ 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;
+
+ return getResultPatternSize(LHS->getDstPattern(), CGP) <
+ getResultPatternSize(RHS->getDstPattern(), CGP);
+ }
+};
+}
+
+
void DAGISelEmitter::run(raw_ostream &OS) {
EmitSourceFileHeader("DAG Instruction Selector for the " +
CGP.getTargetInfo().getName() + " target", OS);
@@ -1919,11 +1948,27 @@
#if 0
MatcherNode *Matcher = 0;
- // Walk the patterns backwards, building a matcher for each and adding it to
- // the matcher for the whole target.
- for (CodeGenDAGPatterns::ptm_iterator I = CGP.ptm_begin(),
- E = CGP.ptm_end(); I != E;) {
- const PatternToMatch &Pattern = *--E;
+
+ // 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.
+ // FIXME: Eliminate "PatternSortingPredicate" and rename.
+ std::stable_sort(Patterns.begin(), Patterns.end(),
+ PatternSortingPredicate2(CGP));
+
+
+ // Walk the patterns backwards (since we append to the front of the generated
+ // code), building a matcher for each and adding it to the matcher for the
+ // whole target.
+ while (!Patterns.empty()) {
+ const PatternToMatch &Pattern = *Patterns.back();
+ Patterns.pop_back();
+
MatcherNode *N = ConvertPatternToMatcher(Pattern, CGP);
if (Matcher == 0)
@@ -1933,8 +1978,8 @@
}
// OptimizeMatcher(Matcher);
- EmitMatcherTable(Matcher, OS);
//Matcher->dump();
+ EmitMatcherTable(Matcher, OS);
delete Matcher;
#endif
}
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