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

llvm-svn: 46901

intrinsic that writes to memory.

llvm-svn: 45650

llvm-svn: 45646

llvm-svn: 45641

The only difference in output is that we now print them in alphabetical 
order instead of reverse alphabetical order.

llvm-svn: 45635

llvm-svn: 45634

llvm-svn: 45633

Split the pattern parsing code out from the dag isel emitter into it's own file.

No functionality change.

llvm-svn: 45632