I'd like to eventually rip it out, but for now producing the
same selections as the old matcher is more important.

llvm-svn: 96458

resolving a fixme.

llvm-svn: 96457

'ischaincompatible' when a pattern has more than one input chain.  Need
to do some commenting and cleanup now that I understand how this works.

llvm-svn: 96443

llvm-svn: 96437

variables.  Use the fancy OpNo variable instead of i,
which has the right index including chains.

llvm-svn: 96436

llvm-svn: 96433

for evaluating complex patterns.  Some cleanup has to happen before
this can be used though.

llvm-svn: 96419

llvm-svn: 96416

record all their results.

llvm-svn: 96412

into a roundss intrinsic, producing a cyclic dag.  The root cause
of this is badness handling ComplexPattern nodes in the old dagisel
that I noticed through inspection.  Eliminate a copy of the of the
code that handled ComplexPatterns by making EmitChildMatchCode call
into EmitMatchCode.

llvm-svn: 96408

need to scan the entire subtree of the pattern anymore.

llvm-svn: 96369

use and only call IsProfitableToFold/IsLegalToFold on the load
being folded, like the old dagiselemitter does.  This 
substantially simplifies the code and improves opportunities for
sharing.

llvm-svn: 96368

llvm-svn: 96333

(isprofitable|islegal)tofold checks.

llvm-svn: 96331

produce a table based matcher instead of gobs of C++ Code.

Though it's not done yet, the shrinkage seems promising,
the table for the X86 ISel is 75K and still has a lot of 
optimization to come (compare to the ~1.5M of .o generated
the old way, much of which will go away).

The code is currently disabled by default (the #if 0 in
DAGISelEmitter.cpp).  When enabled it generates a dead
SelectCode2 function in the DAGISel Header which will
eventually replace SelectCode.

There is still a lot of stuff left to do, which are
documented with a trail of FIXMEs.

llvm-svn: 96215