opportunities that only present themselves after late optimizations
such as tail duplication .e.g.
## BB#1:
        movl    %eax, %ecx
        movl    %ecx, %eax
        ret

The register allocator also leaves some of them around (due to false
dep between copies from phi-elimination, etc.)

This required some changes in codegen passes. Post-ra scheduler and the
pseudo-instruction expansion passes have been moved after branch folding
and tail merging. They were before branch folding before because it did
not always update block livein's. That's fixed now. The pass change makes
independently since we want to properly schedule instructions after
branch folding / tail duplication.

rdar://10428165
rdar://10640363

llvm-svn: 147716

generator to it. For non-bundle instructions, these behave exactly the same
as the MC layer API.

For properties like mayLoad / mayStore, look into the bundle and if any of the
bundled instructions has the property it would return true.
For properties like isPredicable, only return true if *all* of the bundled
instructions have the property.
For properties like canFoldAsLoad, isCompare, conservatively return false for
bundles.

llvm-svn: 146026

llvm-svn: 134259

llvm-svn: 133944

No functional change was intended.

llvm-svn: 133202

llvm-svn: 132487

Luis Felipe Strano Moraes!

llvm-svn: 129558

llvm-svn: 121805

llvm-svn: 112832

make sure to allocate enough space in the std::vector.

llvm-svn: 108449

llvm-svn: 108448

llvm-svn: 108440

llvm-svn: 108419

llvm-svn: 108413

get *very* large, but we only need it to be the size of the number of pregs.

llvm-svn: 108412

AggressiveAntiDepBreaker should not be using getPhysicalRegisterRegClass. An
instruction might be using a register that can only be replaced with one from
a subclass of getPhysicalRegisterRegClass.

With this patch we use getMinimalPhysRegClass. This is correct, but
conservative. We should check the uses of the register and select the
largest register class that can be used in all of them.

llvm-svn: 108122

Make post-ra scheduling, anti-dep breaking, and register scavenger (conservatively) aware of predicated instructions. This enables ARM to move if-conversion before post-ra scheduler.

llvm-svn: 106091

for debug information.

llvm-svn: 105324

llvm-svn: 105300

and End arguments by-value rather than by-reference.

llvm-svn: 101830

llvm-svn: 100904

into TargetOpcodes.h.  #include the new TargetOpcodes.h
into MachineInstr.  Add new inline accessors (like isPHI())
to MachineInstr, and start using them throughout the 
codebase.

llvm-svn: 95687

llvm-svn: 92837

Change errs() to dbgs().

llvm-svn: 92093

llvm-svn: 90970

<rdar://problem/6721894>. Allow multiple registers to be renamed together (super and sub) if necessary to break an anti-dependence.

llvm-svn: 89722

llvm-svn: 89511

Remove some old experimental code that is no longer needed. Remove additional, speculative scheduling pass as its cost did not translate into significant performance improvement. Minor tweaks.

llvm-svn: 89471

llvm-svn: 89404

llvm-svn: 88682

llvm-svn: 87015

Allow targets to specify register classes whose member registers should not be renamed to break anti-dependencies. 

llvm-svn: 86628

Fix bug in aggressive antidep breaking; liveness was not updated correctly for regions that do not have antidep candidates.

llvm-svn: 86172

llvm-svn: 86102

Break anti-dependencies using free registers in a round-robin manner to avoid introducing new anti-dependencies.

llvm-svn: 86098

Do a scheduling pass ignoring anti-dependencies to identify candidate registers that should be renamed.

llvm-svn: 85939

Between scheduling regions, correctly maintain anti-dep breaking state so that we don't incorrectly rename registers that span these regions.

llvm-svn: 85537

llvm-svn: 85522

Allow the aggressive anti-dep breaker to process the same region multiple times. This is necessary because new anti-dependencies are exposed when "current" ones are broken.

llvm-svn: 85166

Add aggressive anti-dependence breaker. Currently it is not the default for any target. Enable with -break-anti-dependencies=all.

llvm-svn: 85145