Also teach MachineLICM to avoid "speculation" when register pressure is high.

llvm-svn: 141744

The blocks with invokes have branches to the dispatch block, because that more
correctly models the behavior of the CFG. The dispatch of course has edges to
the landing pads. Those landing pads could contain invokes, which then have
branches back to the dispatch. This creates a loop. The machine LICM pass looks
at this loop and thinks it can hoist elements out of it. But because the
dispatch is an alternate entry point into the program, the hoisted instructions
won't be executed.

I wasn't able to get a testcase which was small and could reproduce all of the
time. The function_try_block.cpp in llvm-test was where this showed up.

llvm-svn: 141726

For example, MachineLICM should not hoist a load that is not guaranteed to be executed.
Radar 10254254.

llvm-svn: 141689

llvm-svn: 141594

llvm-svn: 141576

For example, MachineLICM should not hoist a load that is not guaranteed to be executed.
Radar 10254254.

llvm-svn: 141569

Teach MachineLICM reg pressure tracking code to deal with MVT::untyped. Sorry, I can't come up with a small test case. rdar://10043690

llvm-svn: 138934

llvm-svn: 134049

sink them into MC layer.
- Added MCInstrInfo, which captures the tablegen generated static data. Chang
TargetInstrInfo so it's based off MCInstrInfo.

llvm-svn: 134021

llvm-svn: 133944

Look pass copies when determining whether hoisting would end up inserting more copies. rdar://9266679

llvm-svn: 129297

llvm-svn: 127175

TargetInstrInfo:
Change produceSameValue() to take MachineRegisterInfo as an optional argument.
When in SSA form, targets can use it to make more aggressive equality analysis.

Machine LICM:
1. Eliminate isLoadFromConstantMemory, use MI.isInvariantLoad instead.
2. Fix a bug which prevent CSE of instructions which are not re-materializable.
3. Use improved form of produceSameValue.

ARM:
1. Teach ARM produceSameValue to look pass some PIC labels.
2. Look for operands from different loads of different constant pool entries
   which have same values.
3. Re-implement PIC GA materialization using movw + movt. Combine the pair with
   a "add pc" or "ldr [pc]" to form pseudo instructions. This makes it possible
   to re-materialize the instruction, allow machine LICM to hoist the set of
   instructions out of the loop and make it possible to CSE them. It's a bit
   hacky, but it significantly improve code quality.
4. Some minor bug fixes as well.

With the fixes, using movw + movt to materialize GAs significantly outperform the
load from constantpool method. 186.crafty and 255.vortex improved > 20%, 254.gap
and 176.gcc ~10%.

llvm-svn: 123905

These functions not longer assert when passed 0, but simply return false instead.

No functional change intended.

llvm-svn: 123155

llvm-svn: 118803

edges on demand.

llvm-svn: 117982

llvm-svn: 117348

- Initial register pressure in the loop should be all the live defs into the
  loop. Not just those from loop preheader which is often empty.
- When an instruction is hoisted, update register pressure from loop preheader
  to the original BB.
- Treat only use of a virtual register as kill since the code is still SSA.

llvm-svn: 116956

llvm-svn: 116890

erased the instruction during LICM so UpdateRegPressureAfter() should not
reference it afterwards.

llvm-svn: 116845

Get rid of static constructors for pass registration.  Instead, every pass exposes an initializeMyPassFunction(), which
must be called in the pass's constructor.  This function uses static dependency declarations to recursively initialize
the pass's dependencies.

Clients that only create passes through the createFooPass() APIs will require no changes.  Clients that want to use the
CommandLine options for passes will need to manually call the appropriate initialization functions in PassInitialization.h
before parsing commandline arguments.

I have tested this with all standard configurations of clang and llvm-gcc on Darwin.  It is possible that there are problems
with the static dependencies that will only be visible with non-standard options.  If you encounter any crash in pass
registration/creation, please send the testcase to me directly.

llvm-svn: 116820

is", which breaks some nightly tests.

llvm-svn: 116816

in MultiSource/Benchmarks/VersaBench/beamformer/beamformer.
SmallSet.insert returns true if the element is inserted.

llvm-svn: 116790

  "long latency" enough to hoist even if it may increase spilling. Reloading
  a value from spill slot is often cheaper than performing an expensive
  computation in the loop. For X86, that means machine LICM will hoist
  SQRT, DIV, etc. ARM will be somewhat aggressive with VFP and NEON
  instructions.
- Enable register pressure aware machine LICM by default.

llvm-svn: 116781

More machine LICM work. It now tracks register pressure for path from preheader to current BB and use the information determine whether hoisting is worthwhile.

llvm-svn: 116654

llvm-svn: 116465

perform initialization without static constructors AND without explicit initialization
by the client.  For the moment, passes are required to initialize both their
(potential) dependencies and any passes they preserve.  I hope to be able to relax
the latter requirement in the future.

llvm-svn: 116334

llvm-svn: 116081

llvm-svn: 115996

llvm-svn: 110460

llvm-svn: 110410

ID member as the sole unique type identifier.  Clean up APIs related to this change.

llvm-svn: 110396

llvm-svn: 109765

llvm-svn: 109045

threshold a bit per experimentation.

llvm-svn: 108935

loop, for the reasons in the comments.  This is a
major win on 253.perlbmk on ARM Darwin.  I expect it
to be a good heuristic in general, but it's possible
some things will regress; I'll be watching.
7940152.

llvm-svn: 108792

Teach ProcessImplicitDefs to transform more COPY instructions into IMPLICIT_DEF (and subsequently eliminate them). This allows machine LICM to hoist IMPLICIT_DEF's. PR7620.

llvm-svn: 108304

intended functionality change.

The avoidance of hoistiing implicitdef seems wrong though.

llvm-svn: 108109

llvm-svn: 108001

into a utility routine, teach it how to update MachineLoopInfo, and
make use of it in MachineLICM to split critical edges on demand.

llvm-svn: 106555