TableGen: Allow AddedComplexity values to be negative

This is useful for cases when stand-alone patterns are preferred to the
patterns included in the instruction definitions.  Instead of requiring
that stand-alone patterns set a larger AddedComplexity value, which
can be confusing to new developers, the allows us to reduce the
complexity of the included patterns to achieve the same result.

There will be test cases for this added to the R600 backend in a
future commit.

llvm-svn: 214466
This commit is contained in:
Tom Stellard 2014-08-01 00:32:36 +00:00
parent 0e975cf6e5
commit 6655dd699f
3 changed files with 7 additions and 7 deletions

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@ -771,7 +771,7 @@ static unsigned getPatternSize(const TreePatternNode *P,
/// Compute the complexity metric for the input pattern. This roughly
/// corresponds to the number of nodes that are covered.
unsigned PatternToMatch::
int PatternToMatch::
getPatternComplexity(const CodeGenDAGPatterns &CGP) const {
return getPatternSize(getSrcPattern(), CGP) + getAddedComplexity();
}

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@ -667,7 +667,7 @@ public:
PatternToMatch(Record *srcrecord, ListInit *preds,
TreePatternNode *src, TreePatternNode *dst,
const std::vector<Record*> &dstregs,
unsigned complexity, unsigned uid)
int complexity, unsigned uid)
: SrcRecord(srcrecord), Predicates(preds), SrcPattern(src), DstPattern(dst),
Dstregs(dstregs), AddedComplexity(complexity), ID(uid) {}
@ -676,7 +676,7 @@ public:
TreePatternNode *SrcPattern; // Source pattern to match.
TreePatternNode *DstPattern; // Resulting pattern.
std::vector<Record*> Dstregs; // Physical register defs being matched.
unsigned AddedComplexity; // Add to matching pattern complexity.
int AddedComplexity; // Add to matching pattern complexity.
unsigned ID; // Unique ID for the record.
Record *getSrcRecord() const { return SrcRecord; }
@ -684,13 +684,13 @@ public:
TreePatternNode *getSrcPattern() const { return SrcPattern; }
TreePatternNode *getDstPattern() const { return DstPattern; }
const std::vector<Record*> &getDstRegs() const { return Dstregs; }
unsigned getAddedComplexity() const { return AddedComplexity; }
int getAddedComplexity() const { return AddedComplexity; }
std::string getPredicateCheck() const;
/// Compute the complexity metric for the input pattern. This roughly
/// corresponds to the number of nodes that are covered.
unsigned getPatternComplexity(const CodeGenDAGPatterns &CGP) const;
int getPatternComplexity(const CodeGenDAGPatterns &CGP) const;
};
class CodeGenDAGPatterns {

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@ -94,8 +94,8 @@ struct PatternSortingPredicate {
// 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.
unsigned LHSSize = LHS->getPatternComplexity(CGP);
unsigned RHSSize = RHS->getPatternComplexity(CGP);
int LHSSize = LHS->getPatternComplexity(CGP);
int RHSSize = RHS->getPatternComplexity(CGP);
if (LHSSize > RHSSize) return true; // LHS -> bigger -> less cost
if (LHSSize < RHSSize) return false;