do not double-count the duplicate instructions by counting once from the
beginning and again from the end. Keep track of where the duplicates from
the beginning ended and don't go past that point when counting duplicates
at the end. Radar 8589805.
This change causes one of the MC/ARM/simple-fp-encoding tests to produce
different (better!) code without the vmovne instruction being tested.
I changed the test to produce vmovne and vmoveq instructions but moving
between register files in the opposite direction. That's not quite the same
but predicated versions of those instructions weren't being tested before,
so at least the test coverage is not any worse, just different.
llvm-svn: 117333
instructions separately from the count of non-predicated instructions. The
instruction count is used in places to determine how many instructions to
copy, predicate, etc. and things get confused if that count includes the
extra cost for microcoded ops.
llvm-svn: 117332
2) live-outs.
Previously the post-RA schedulers completely ignore these dependencies since
returns, branches, etc. are all scheduling barriers. This patch model the
latencies between instructions being scheduled and the barriers. It also
handle calls by marking their register uses.
llvm-svn: 117193
framework. It's purpose is not to improve register allocation per se,
but to make it easier to develop powerful live range splitting. I call
it the basic allocator because it is as simple as a global allocator
can be but provides the building blocks for sophisticated register
allocation with live range splitting.
A minimal implementation is provided that trivially spills whenever it
runs out of registers. I'm checking in now to get high-level design
and style feedback. I've only done minimal testing. The next step is
implementing a "greedy" allocation algorithm that does some register
reassignment and makes better splitting decisions.
llvm-svn: 117174
When a block has exactly two uses and the register is both live-in and live-out,
don't isolate the block. We would be inserting two copies, so we haven't really
made any progress.
If the live-in and live-out values separate into disconnected components after
splitting, we would be making progress. We can't detect that for now.
llvm-svn: 117169
An exit block with a critical edge must only have predecessors in the loop, or
just before the loop. This guarantees that the inserted copies in the loop
predecessors dominate the exit block.
llvm-svn: 117144
- 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
operand, also check if subregisters are killed.
Add <imp-def> operands for subregisters that remain alive after a super register
is killed.
I don't have a testcase for this that reproduces on trunk. <rdar://problem/8441758>
llvm-svn: 116940
Pull an unsigned out of the Contents union such that it has the same size as two
pointers and no padding.
Arrange members such that the Contents union and all pointers can be 8-byte
aligned without padding.
This speeds up code generation by 0.8% on a 64-bit host. 32-bit hosts should be
unaffected.
llvm-svn: 116857
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
"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
does normal initialization and normal chaining. Change the default
AliasAnalysis implementation to NoAlias.
Update StandardCompileOpts.h and friends to explicitly request
BasicAliasAnalysis.
Update tests to explicitly request -basicaa.
llvm-svn: 116720
