CodeGenDAGPatterns, where it can be used in other tablegen backends.
This allows the inference to be done for DAGISelEmitter so that it
gets accurate mayLoad/mayStore/isSimpleLoad flags.
This brings MemOperand functionality back to where it was before
48329. However, it doesn't solve the problem of anonymous patterns
which expand to code that does loads or stores.
llvm-svn: 49123
were being pruned in patterns where a variable was used more than once, e.g.:
(or (and R32C:$rA, R32C:$rC), (and R32C:$rB, (not R32C:$rC)))
In this example, $rC is used more than once and is actually significant to
instruction selection pattern matching when commuted variants are produced.
This patch scans the pattern's clauses and collects the variables, creating
a set of variables that are used more than once. TreePatternNode::isIsomorphicTo()
also understands that multiply-used variables are significant.
llvm-svn: 47950
Dan Gohman