Rewrite LiveVariable liveness computation. The new implementation is much simplified. It eliminated the nasty recursive routines and removed the partial def / use bookkeeping. There is also potential for performance improvement by replacing the conservative handling of partial physical register definitions. The code is currently disabled until live interval analysis is taught of the name scheme.

This patch also fixed a couple of nasty corner cases.

llvm-svn: 49784

llvm-svn: 49783

llvm-svn: 49760

the scheduler has inserted no-ops. This fixes
the 2006-07-03-schedulers.ll regression on ppc32.

llvm-svn: 49747

llvm-svn: 49715

ScheduleDAG; they don't correspond to any actual instructions so they
don't need to be scheduled.

This fixes a bug where the EntryToken was being scheduled multiple
times in some cases, though it ended up not causing any trouble because 
EntryToken doesn't expand into anything. With this fixed the schedulers
reliably schedule the expected number of units, so we can check this
with an assertion.

This requires a tweak to test/CodeGen/X86/loop-hoist.ll because it
ends up getting scheduled differently in a trivial way, though it was
enough to fool the prcontext+grep that the test does.

llvm-svn: 49701

instead of blue to distinguish them from regular dependencies.

llvm-svn: 49696

llvm-svn: 49676

memory intrinsic expansion code.

llvm-svn: 49666

stack tracebacks on Darwin x86-64 won't work by default;
nevertheless, everybody but me thinks this is a good idea.

llvm-svn: 49663

llvm-svn: 49652

much simpler than in LegalizeDAG because calls are
not yet expanded into call sequences: that happens
after type legalization has finished.

llvm-svn: 49634

in its maps.  Add some sanity checks that catch
this kind of thing.  Hopefully these can be
removed one day (once all problems are fixed!)
but for the moment it seems wise to have them in.

llvm-svn: 49612

llvm-svn: 49611

the result IRBuilder.  Patch by Dominic Hamon.

llvm-svn: 49604

llvm-svn: 49583

on any current target and aren't optimized in DAGCombiner. Instead
of using intermediate nodes, expand the operations, choosing between
simple loads/stores, target-specific code, and library calls,
immediately.

Previously, the code to emit optimized code for these operations
was only used at initial SelectionDAG construction time; now it is
used at all times. This fixes some cases where rep;movs was being
used for small copies where simple loads/stores would be better.

This also cleans up code that checks for alignments less than 4;
let the targets make that decision instead of doing it in
target-independent code. This allows x86 to use rep;movs in
low-alignment cases.

Also, this fixes a bug that resulted in the use of rep;stos for
memsets of 0 with non-constant memory size when the alignment was
at least 4. It's better to use the library in this case, which
can be significantly faster when the size is large.

This also preserves more SourceValue information when memory
intrinsics are lowered into simple loads/stores.

llvm-svn: 49572

llvm-svn: 49544

llvm-svn: 49543

Use of implicit_def is not part of live interval. Create empty intervals for the uses when the live interval is being spilled.

llvm-svn: 49542

llvm-svn: 49524

llvm-svn: 49513

llvm-svn: 49512

llvm-svn: 49491

llvm-svn: 49469

Teach branch folding pass about implicit_def instructions. Unfortunately we can't just eliminate them since register scavenger expects every register use to be defined. However, we can delete them when there are no intra-block uses.  Carefully removing some implicit def's which enable more blocks to be optimized away.

llvm-svn: 49461

- Added insert_subreg coalescing support.

llvm-svn: 49448

llvm-svn: 49415

Corresponds to -fno-unwind-tables (usually default in gcc).

llvm-svn: 49361

review feedback from Chris quite a while ago. No functionality
change.

llvm-svn: 49348

by Dan Gohman is fixed.

llvm-svn: 49330

llvm-svn: 49284

If it cannot be expanded, it will keep the old behaviour and try to shrink the constant.
Part of enhancement for PR2191.

llvm-svn: 49280

Specifically, introduction of XXX::Create methods
for Users that have a potentially variable number of
Uses.

llvm-svn: 49277

2. Coalescer can now create an interesting situation where a register def can
   reaches itself without being killed.

llvm-svn: 49246

before an invoke.  Failure to do this causes references in
the landing pad to variables that were not set.  Fixes
g++.dg/eh/delayslot1.C
g++.dg/eh/fp-regs.C
g++.old-deja/g++.brendan/eh1.C

llvm-svn: 49243

llvm-svn: 49198

llvm-svn: 49197

if some functions don't have debug info, we were outputing the same label at the start of each of those functions.  This makes assemblers unhappy

llvm-svn: 49176

- Be smarter about coalescing copies from implicit_def.

llvm-svn: 49168