[tree-ssa] PATCH to &&/|| gimplification

[law@redhat.com]

In message <10305301356.AA20869@vlsi1.ultra.nyu.edu>, Richard Kenner writes:
 >    Well, the mental model
 >    Richard and I hashed through a while back was that we'd do most loop
 >    optimizations at the tree level, but that we'd need a simplified loop
 >    optimizer to run on RTL as well.  Once we lower to RTL there's going
 >    to be some stuff exposed for LICM and possibly some strength
 >    reductions.
 >
 >I don't follow.  Most strength reduction opportunities are in addressing
 >calculations and those you don't see until RTL.
There will be a point at which we lower ARRAY_REF and friends down to 
address calculations.
jeff