def vnot : PatFrag<(ops node:$in), (xor node:$in, immAllOnesV)>;
def ineg : PatFrag<(ops node:$in), (sub 0, node:$in)>;
+// null_frag - The null pattern operator is used in multiclass instantiations
+// which accept an SDPatternOperator for use in matching patterns for internal
+// definitions. When expanding a pattern, if the null fragment is referenced
+// in the expansion, the pattern is discarded and it is as-if '[]' had been
+// specified. This allows multiclasses to have the isel patterns be optional.
+def null_frag : SDPatternOperator;
+
// load fragments.
def unindexedload : PatFrag<(ops node:$ptr), (ld node:$ptr), [{
return cast<LoadSDNode>(N)->getAddressingMode() == ISD::UNINDEXED;
IsVariadic = true; // Can warn if we want.
}
+/// hasNullFragReference - Return true if the DAG has any reference to the
+/// null_frag operator.
+static bool hasNullFragReference(DagInit *DI) {
+ DefInit *OpDef = dynamic_cast<DefInit*>(DI->getOperator());
+ if (!OpDef) return false;
+ Record *Operator = OpDef->getDef();
+
+ // If this is the null fragment, return true.
+ if (Operator->getName() == "null_frag") return true;
+ // If any of the arguments reference the null fragment, return true.
+ for (unsigned i = 0, e = DI->getNumArgs(); i != e; ++i) {
+ DagInit *Arg = dynamic_cast<DagInit*>(DI->getArg(i));
+ if (Arg && hasNullFragReference(Arg))
+ return true;
+ }
+
+ return false;
+}
+
+/// hasNullFragReference - Return true if any DAG in the list references
+/// the null_frag operator.
+static bool hasNullFragReference(ListInit *LI) {
+ for (unsigned i = 0, e = LI->getSize(); i != e; ++i) {
+ DagInit *DI = dynamic_cast<DagInit*>(LI->getElement(i));
+ assert(DI && "non-dag in an instruction Pattern list?!");
+ if (hasNullFragReference(DI))
+ return true;
+ }
+ return false;
+}
+
/// ParseInstructions - Parse all of the instructions, inlining and resolving
/// any fragments involved. This populates the Instructions list with fully
/// resolved instructions.
// If there is no pattern, only collect minimal information about the
// instruction for its operand list. We have to assume that there is one
- // result, as we have no detailed info.
- if (!LI || LI->getSize() == 0) {
+ // result, as we have no detailed info. A pattern which references the
+ // null_frag operator is as-if no pattern were specified. Normally this
+ // is from a multiclass expansion w/ a SDPatternOperator passed in as
+ // null_frag.
+ if (!LI || LI->getSize() == 0 || hasNullFragReference(LI)) {
std::vector<Record*> Results;
std::vector<Record*> Operands;