print the complexity of the pattern being matched in the
comment in the generated table.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99794 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/CodeGenDAGPatterns.cpp b/utils/TableGen/CodeGenDAGPatterns.cpp
index 84a041b..d2c0195 100644
--- a/utils/TableGen/CodeGenDAGPatterns.cpp
+++ b/utils/TableGen/CodeGenDAGPatterns.cpp
@@ -491,6 +491,59 @@
// PatternToMatch implementation
//
+
+/// getPatternSize - Return the 'size' of this pattern. We want to match large
+/// patterns before small ones. This is used to determine the size of a
+/// pattern.
+static unsigned getPatternSize(const TreePatternNode *P,
+ const CodeGenDAGPatterns &CGP) {
+ unsigned Size = 3; // The node itself.
+ // If the root node is a ConstantSDNode, increases its size.
+ // e.g. (set R32:$dst, 0).
+ if (P->isLeaf() && dynamic_cast<IntInit*>(P->getLeafValue()))
+ Size += 2;
+
+ // FIXME: This is a hack to statically increase the priority of patterns
+ // which maps a sub-dag to a complex pattern. e.g. favors LEA over ADD.
+ // Later we can allow complexity / cost for each pattern to be (optionally)
+ // specified. To get best possible pattern match we'll need to dynamically
+ // calculate the complexity of all patterns a dag can potentially map to.
+ const ComplexPattern *AM = P->getComplexPatternInfo(CGP);
+ if (AM)
+ Size += AM->getNumOperands() * 3;
+
+ // If this node has some predicate function that must match, it adds to the
+ // complexity of this node.
+ if (!P->getPredicateFns().empty())
+ ++Size;
+
+ // Count children in the count if they are also nodes.
+ for (unsigned i = 0, e = P->getNumChildren(); i != e; ++i) {
+ TreePatternNode *Child = P->getChild(i);
+ if (!Child->isLeaf() && Child->getNumTypes() &&
+ Child->getType(0) != MVT::Other)
+ Size += getPatternSize(Child, CGP);
+ else if (Child->isLeaf()) {
+ if (dynamic_cast<IntInit*>(Child->getLeafValue()))
+ Size += 5; // Matches a ConstantSDNode (+3) and a specific value (+2).
+ else if (Child->getComplexPatternInfo(CGP))
+ Size += getPatternSize(Child, CGP);
+ else if (!Child->getPredicateFns().empty())
+ ++Size;
+ }
+ }
+
+ return Size;
+}
+
+/// Compute the complexity metric for the input pattern. This roughly
+/// corresponds to the number of nodes that are covered.
+unsigned PatternToMatch::
+getPatternComplexity(const CodeGenDAGPatterns &CGP) const {
+ return getPatternSize(getSrcPattern(), CGP) + getAddedComplexity();
+}
+
+
/// getPredicateCheck - Return a single string containing all of this
/// pattern's predicates concatenated with "&&" operators.
///