Commit Graph

32 Commits

Author SHA1 Message Date
Evan Cheng
15a16def6e Add a hybrid bottom up scheduler that reduce register usage while avoiding
pipeline stall. It's useful for targets like ARM cortex-a8. NEON has a lot
of long latency instructions so a strict register pressure reduction
scheduler does not work well.
Early experiments show this speeds up some NEON loops by over 30%.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104216 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-20 06:13:19 +00:00
Jakob Stoklund Olesen
00207237dd Add fast register allocator, enabled with -regalloc=fast.
So far this is just a clone of -regalloc=local that has been lobotomized to run
25% faster. It drops the least-recently-used calculations, and is just plain
stupid when it runs out of registers.

The plan is to make this go even faster for -O0 by taking advantage of the short
live intervals in unoptimized code. It should not be necessary to calculate
liveness when most virtual registers are killed 2-3 instructions after they are
born.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102006 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-21 18:02:42 +00:00
Bill Wendling
187361b056 Remove the '-disable-scheduling' flag and replace it with the 'source' option of
the '-pre-RA-sched' flag. It actually makes more sense to do it this way. Also,
keep track of the SDNode ordering by default. Eventually, we would like to make
this ordering a way to break a "tie" in the scheduler. However, doing that now
breaks the "CodeGen/X86/abi-isel.ll" test for 32-bit Linux.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94308 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-23 10:26:57 +00:00
Chris Lattner
7896c9f436 improve portability to avoid conflicting with std::next in c++'0x.
Patch by Howard Hinnant!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90365 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-03 00:50:42 +00:00
Evan Cheng
f436463dbd Remove simple regalloc. It has bit rotted.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82127 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-17 05:48:07 +00:00
Lang Hames
2f75c727f2 Removed the BigBlock register allocator.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77640 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-30 23:18:43 +00:00
Bill Wendling
98a366d547 Instead of passing in an unsigned value for the optimization level, use an enum,
which better identifies what the optimization is doing. And is more flexible for
future uses.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70440 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-29 23:29:43 +00:00
Bill Wendling
be8cc2a3de Second attempt:
Massive check in. This changes the "-fast" flag to "-O#" in llc. If you want to
use the old behavior, the flag is -O0. This change allows for finer-grained
control over which optimizations are run at different -O levels.

Most of this work was pretty mechanical. The majority of the fixes came from
verifying that a "fast" variable wasn't used anymore. The JIT still uses a
"Fast" flag. I'll change the JIT with a follow-up patch.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70343 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-29 00:15:41 +00:00
Bill Wendling
c69d56f115 r70270 isn't ready yet. Back this out. Sorry for the noise.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70275 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-28 01:04:53 +00:00
Bill Wendling
2e9d5f912a Massive check in. This changes the "-fast" flag to "-O#" in llc. If you want to
use the old behavior, the flag is -O0. This change allows for finer-grained
control over which optimizations are run at different -O levels.

Most of this work was pretty mechanical. The majority of the fixes came from
verifying that a "fast" variable wasn't used anymore. The JIT still uses a
"Fast" flag. I'm not 100% sure if it's necessary to change it there...


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70270 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-28 00:21:31 +00:00
Dan Gohman
79ce276083 Move a few containers out of ScheduleDAGInstrs::BuildSchedGraph
and into the ScheduleDAGInstrs class, so that they don't get
destructed and re-constructed for each block. This fixes a
compile-time hot spot in the post-pass scheduler.

To help facilitate this, tidy and do some minor reorganization
in the scheduler constructor functions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62275 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-15 19:20:50 +00:00
Dan Gohman
ad38b6e4e5 Move the scheduler constructor functions to SchedulerRegistry.h, to
simplify header dependencies for front-ends that just want to choose
a scheduler and don't need all the scheduling machinery declarations.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59978 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-24 19:53:21 +00:00
Dan Gohman
343f0c0467 Experimental post-pass scheduling support. Post-pass scheduling
is currently off by default, and can be enabled with
-disable-post-RA-scheduler=false.

This doesn't have a significant impact on most code yet because it doesn't
yet do anything to address anti-dependencies and it doesn't attempt to
disambiguate memory references. Also, several popular targets
don't have pipeline descriptions yet.

The majority of the changes here are splitting the SelectionDAG-specific
code out of ScheduleDAG, so that ScheduleDAG can be moved to
libLLVMCodeGen.a. The interface between ScheduleDAG-using code and
the rest of the scheduling code is somewhat rough and will evolve.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59676 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-19 23:18:57 +00:00
Dan Gohman
9b75b37375 Change the scheduler accessor methods to accept an explicit TargetMachine
argument instead of taking the SelectionDAG's TargetMachine. This is
needed for some upcoming scheduler changes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59055 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-11 17:50:47 +00:00
Evan Cheng
b1290a6cc4 A Partitioned Boolean Quadratic Programming (PBQP) based register allocator.
Contributed by Lang Hames.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56959 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-02 18:29:27 +00:00
Dan Gohman
ee2e403545 Add a new "fast" scheduler. This is currently basically just a
copy of the BURRList scheduler, but with several parts ripped
out, such as backtracking, online topological sort maintenance
(needed by backtracking), the priority queue, and Sethi-Ullman
number computation and maintenance (needed by the priority
queue). As a result of all this, it generates somewhat lower
quality code, but that's its tradeoff for running about 30%
faster than list-burr in -fast mode in many cases.

This is somewhat experimental. Moving forward, major pieces of
this can be refactored with pieces in common with
ScheduleDAGRRList.cpp.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56307 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-18 16:26:26 +00:00
Dan Gohman
d3ead4329e Add a new MachineInstr-level DCE pass. It is very simple, and is intended to
be used with fast-isel.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56268 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-17 00:43:24 +00:00
Gordon Henriksen
5eca075b74 Rename some GC classes so that their roll will hopefully be clearer.
In particular, Collector was confusing to implementors. Several
thought that this compile-time class was the place to implement
their runtime GC heap. Of course, it doesn't even exist at runtime.
Specifically, the renames are:

  Collector               -> GCStrategy
  CollectorMetadata       -> GCFunctionInfo
  CollectorModuleMetadata -> GCModuleInfo
  CollectorRegistry       -> GCRegistry
  Function::getCollector  -> getGC (setGC, hasGC, clearGC)

Several accessors and nested types have also been renamed to be
consistent. These changes should be obvious.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54899 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-17 18:44:35 +00:00
Anton Korobeynikov
4a8978b61c Fix merge error
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54891 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-17 13:56:03 +00:00
Gordon Henriksen
5a29c9eed1 Factor GC metadata table assembly generation out of Collector in preparation for splitting AsmPrinter into its own library.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54881 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-17 12:56:54 +00:00
Evan Cheng
4576f6d7a9 Do not use computationally expensive scheduling heuristics with -fast.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52971 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-01 18:05:03 +00:00
Gordon Henriksen
572742e876 Setting GlobalDirective in TargetAsmInfo by default rather than
providing a misleading facility. It's used once in the MIPS backend
and hardcoded as "\t.globl\t" everywhere else.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45676 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-07 02:31:11 +00:00
Gordon Henriksen
8fa8929177 With this patch, the LowerGC transformation becomes the
ShadowStackCollector, which additionally has reduced overhead with
no sacrifice in portability.

Considering a function @fun with 8 loop-local roots,
ShadowStackCollector introduces the following overhead
(x86):

; shadowstack prologue
        movl    L_llvm_gc_root_chain$non_lazy_ptr, %eax
        movl    (%eax), %ecx
        movl    $___gc_fun, 20(%esp)
        movl    $0, 24(%esp)
        movl    $0, 28(%esp)
        movl    $0, 32(%esp)
        movl    $0, 36(%esp)
        movl    $0, 40(%esp)
        movl    $0, 44(%esp)
        movl    $0, 48(%esp)
        movl    $0, 52(%esp)
        movl    %ecx, 16(%esp)
        leal    16(%esp), %ecx
        movl    %ecx, (%eax)

; shadowstack loop overhead
        (none)

; shadowstack epilogue
        movl    48(%esp), %edx
        movl    %edx, (%ecx)

; shadowstack metadata
        .align  3
___gc_fun:                              # __gc_fun
        .long   8
        .space  4

In comparison to LowerGC:

; lowergc prologue
        movl    L_llvm_gc_root_chain$non_lazy_ptr, %eax
        movl    (%eax), %ecx
        movl    %ecx, 48(%esp)
        movl    $8, 52(%esp)
        movl    $0, 60(%esp)
        movl    $0, 56(%esp)
        movl    $0, 68(%esp)
        movl    $0, 64(%esp)
        movl    $0, 76(%esp)
        movl    $0, 72(%esp)
        movl    $0, 84(%esp)
        movl    $0, 80(%esp)
        movl    $0, 92(%esp)
        movl    $0, 88(%esp)
        movl    $0, 100(%esp)
        movl    $0, 96(%esp)
        movl    $0, 108(%esp)
        movl    $0, 104(%esp)
        movl    $0, 116(%esp)
        movl    $0, 112(%esp)

; lowergc loop overhead
        leal    44(%esp), %eax
        movl    %eax, 56(%esp)
        leal    40(%esp), %eax
        movl    %eax, 64(%esp)
        leal    36(%esp), %eax
        movl    %eax, 72(%esp)
        leal    32(%esp), %eax
        movl    %eax, 80(%esp)
        leal    28(%esp), %eax
        movl    %eax, 88(%esp)
        leal    24(%esp), %eax
        movl    %eax, 96(%esp)
        leal    20(%esp), %eax
        movl    %eax, 104(%esp)
        leal    16(%esp), %eax
        movl    %eax, 112(%esp)

; lowergc epilogue
        movl    48(%esp), %edx
        movl    %edx, (%ecx)

; lowergc metadata
        (none)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45670 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-07 01:30:53 +00:00
Chris Lattner
7ed47a1335 Don't attribute in file headers anymore. See llvmdev for the
discussion of this change.  Boy are my fingers tired. ;-)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45411 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-29 19:59:42 +00:00
Evan Cheng
450ff01faf Remove simple scheduler.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42499 91177308-0d34-0410-b5e6-96231b3b80d8
2007-10-01 20:44:07 +00:00
David Greene
2c17c4d8d9 Pluggable coalescers inplementation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41743 91177308-0d34-0410-b5e6-96231b3b80d8
2007-09-06 16:18:45 +00:00
Duraid Madina
a8c7682939 check in the BigBlock local register allocator
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37703 91177308-0d34-0410-b5e6-96231b3b80d8
2007-06-22 08:27:12 +00:00
Bill Wendling
fee18ae074 Accidental submission.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32639 91177308-0d34-0410-b5e6-96231b3b80d8
2006-12-17 11:13:13 +00:00
Bill Wendling
5c7e326585 Added an automatic cast to "std::ostream*" etc. from OStream. We then can
rework the hacks that had us passing OStream in. We pass in std::ostream*
instead, check for null, and then dispatch to the correct print() method.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32636 91177308-0d34-0410-b5e6-96231b3b80d8
2006-12-17 05:15:13 +00:00
Jim Laskey
9373beba60 Now that the ISel is available, it's possible to create a default instruction
scheduler creator.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29452 91177308-0d34-0410-b5e6-96231b3b80d8
2006-08-01 19:14:14 +00:00
Jim Laskey
9ff542f2cc 1. Change use of "Cache" to "Default".
2. Added argument to instruction scheduler creators so the creators can do
special things.
3. Repaired target hazard code.
4. Misc.

More to follow.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29450 91177308-0d34-0410-b5e6-96231b3b80d8
2006-08-01 18:29:48 +00:00
Jim Laskey
c6a0a117a6 Forgot the added files for plugable machine passes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29436 91177308-0d34-0410-b5e6-96231b3b80d8
2006-08-01 16:31:08 +00:00