Chris claims we should never have visibility_hidden inside any .cpp file but
that's still not true even after this commit.

llvm-svn: 85042

is trivially rematerializable and integrate it into
TargetInstrInfo::isTriviallyReMaterializable. This way, all places that
need to know whether an instruction is rematerializable will get the
same answer.

This enables the useful parts of the aggressive-remat option by
default -- using AliasAnalysis to determine whether a memory location
is invariant, and removes the questionable parts -- rematting operations
with virtual register inputs that may not be live everywhere.

llvm-svn: 83687

llvm-svn: 79748

llvm-svn: 78663

llvm-svn: 57618

computation. A def of a register doesn't necessarily kill
live super-registers.

llvm-svn: 57614

isReg, etc., from isRegister, etc.

llvm-svn: 57006

llvm-svn: 56602

separate method.

llvm-svn: 56531

dead loads.

llvm-svn: 56529

correctly, it's not necessary to explicitly remove registers
from their use-def lists.

llvm-svn: 56509

efficient implementation possible, but it's pretty simple and
good enough for the time being.

llvm-svn: 56504

defs to be necessarily live.

llvm-svn: 56310

be used with fast-isel.

llvm-svn: 56268