148 Commits

Author SHA1 Message Date
Dan Gohman
77e3f07d4b Factor out the code for verifying the work of the scheduler,
extend it a bit, and make use of it in all schedulers, to
ensure consistent checking.

llvm-svn: 59689
2008-11-20 01:26:25 +00:00
Dan Gohman
f4b2751ee6 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.

llvm-svn: 59676
2008-11-19 23:18:57 +00:00
Dan Gohman
32a8ee5c90 Move the code for printing a graph node label for an SUnit into
a virtual method of SelectionDAG.

llvm-svn: 59667
2008-11-19 22:09:45 +00:00
Dan Gohman
b5ce3ebed1 Convert SUnit's dump method into a print method and implement
dump in terms of it.

llvm-svn: 59665
2008-11-19 21:32:03 +00:00
Dan Gohman
bc8cfae5c3 Change SUnit's dump method to take a ScheduleDAG* instead of
a SelectionDAG*.

llvm-svn: 59488
2008-11-18 02:06:40 +00:00
Dan Gohman
5283c5dc53 There is no InstrStage class.
llvm-svn: 59480
2008-11-18 01:05:04 +00:00
Dan Gohman
521cee6a9c Add support for building a ScheduleDAG from MachineInstrs. This is currently
fairly conservative; it doesn't do alias-analysis queries and it doesn't
attempt to break anti-dependencies.

llvm-svn: 59324
2008-11-14 21:47:58 +00:00
Dan Gohman
3abe79e3e9 Add a version of NewSUnit for creating units with MachineInstrs.
llvm-svn: 59282
2008-11-14 00:41:36 +00:00
Dan Gohman
f92f2d0c97 Initial support for carrying MachineInstrs in SUnits.
llvm-svn: 59278
2008-11-14 00:06:09 +00:00
Dan Gohman
24b2c89cdf Clarify the comment about NumPreds and NumSuccs to reflect that they only
count non-control preds and succs.

llvm-svn: 59276
2008-11-13 23:41:41 +00:00
Dan Gohman
0a3ae5c0f2 Remove the FlaggedNodes member from SUnit. Instead of requiring each SUnit
to carry a SmallVector of flagged nodes, just calculate the flagged nodes
dynamically when they are needed.

The local-liveness change is due to a trivial scheduling change where
the scheduler arbitrary decision differently.

llvm-svn: 59273
2008-11-13 23:24:17 +00:00
Dan Gohman
0cefa8f2ff Make the Node member of SUnit private, and add accessors.
llvm-svn: 59264
2008-11-13 21:36:12 +00:00
Dan Gohman
df9f75e981 Change ScheduleDAG's DAG member from a reference to a pointer, to prepare
for the possibility of scheduling without a SelectionDAG being present.

llvm-svn: 59263
2008-11-13 21:21:28 +00:00
Dan Gohman
ec3b31e7eb 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.

llvm-svn: 59055
2008-11-11 17:50:47 +00:00
Dale Johannesen
bc29bec7f8 Next round of earlyclobber handling. Approach the
RA problem by expanding the live interval of an
earlyclobber def back one slot.  Remove
overlap-earlyclobber throughout.  Remove 
earlyclobber bits and their handling from
live internals.

llvm-svn: 56539
2008-09-24 01:07:17 +00:00
Dan Gohman
b7c5b0f44b 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.

llvm-svn: 56307
2008-09-18 16:26:26 +00:00
Dale Johannesen
99091ed94f Add a bit to mark operands of asm's that conflict
with an earlyclobber operand elsewhere.  Propagate
this bit and the earlyclobber bit through SDISel.
Change linear-scan RA not to allocate regs in a way 
that conflicts with an earlyclobber.  See also comments.

llvm-svn: 56290
2008-09-17 21:13:11 +00:00
Bill Wendling
932818c75a Reverting r56249. On further investigation, this functionality isn't needed.
Apologies for the thrashing.

llvm-svn: 56251
2008-09-16 21:48:12 +00:00
Bill Wendling
1a240c8033 - Change "ExternalSymbolSDNode" to "SymbolSDNode".
- Add linkage to SymbolSDNode (default to external).
- Change ISD::ExternalSymbol to ISD::Symbol.
- Change ISD::TargetExternalSymbol to ISD::TargetSymbol

These changes pave the way to allowing SymbolSDNodes with non-external linkage.

llvm-svn: 56249
2008-09-16 21:12:30 +00:00
Dan Gohman
9742f7772d Rename SDOperand to SDValue.
llvm-svn: 54128
2008-07-27 21:46:04 +00:00
Dan Gohman
e76fd33ee5 Reapply 53476 and 53480, with a fix so that it properly updates
the BB member to the current basic block after emitting
instructions.

llvm-svn: 53567
2008-07-14 18:19:29 +00:00
Evan Cheng
67ce381ffe Do not use computationally expensive scheduling heuristics with -fast.
llvm-svn: 52971
2008-07-01 18:05:03 +00:00
Dan Gohman
13e2ffe637 Comment fixes, and make Schedule() pure virtual.
llvm-svn: 52658
2008-06-24 00:02:44 +00:00
Dan Gohman
015a5ca374 Remove ScheduleDAG's SUnitMap altogether. Instead, use SDNode's NodeId
field, which is otherwise unused after instruction selection, as an index
into the SUnit array.

llvm-svn: 52583
2008-06-21 19:18:17 +00:00
Dan Gohman
4099d0bf27 Add a priority queue class, which is a wrapper around std::priority_queue
and provides fairly efficient removal of arbitrary elements. Switch
ScheduleDAGRRList from std::set to this new priority queue.

llvm-svn: 52582
2008-06-21 18:35:25 +00:00
Dan Gohman
3a5a96e045 Change ScheduleDAG's SUnitMap from DenseMap<SDNode*, vector<SUnit*> >
to DenseMap<SDNode*, SUnit*>, and adjust the way cloned SUnit nodes are
handled so that only the original node needs to be in the map.
This speeds up llc on 447.dealII.llvm.bc by about 2%.

llvm-svn: 52576
2008-06-21 15:52:51 +00:00
Bill Wendling
1866fa680f Remove warnings about unused parameters and shadowed variables.
llvm-svn: 51266
2008-05-19 20:15:12 +00:00
Evan Cheng
d9353009b7 Fix more -Wshorten-64-to-32 warnings.
llvm-svn: 50659
2008-05-05 18:30:58 +00:00
Roman Levenstein
35f24acb46 Use std::set instead of std::priority_queue for the RegReductionPriorityQueue.
This removes the existing bottleneck related to the removal of elements from 
the middle of the queue.

Also fixes a subtle bug in ScheduleDAGRRList::CapturePred:
It was updating the state of the SUnit before removing it. As a result, the
comparison operators were working incorrectly and this SUnit could not be removed 
from the queue properly.

Reviewed by Evan and Dan. Approved by Dan.

llvm-svn: 50412
2008-04-29 09:07:59 +00:00
Roman Levenstein
728d59166f Ongoing work on improving the instruction selection infrastructure:
Rename SDOperandImpl back to SDOperand.
Introduce the SDUse class that represents a use of the SDNode referred by
an SDOperand. Now it is more similar to Use/Value classes.

Patch is approved by Dan Gohman.

llvm-svn: 49795
2008-04-16 16:15:27 +00:00
Dan Gohman
3b99b3c807 Treat EntryToken nodes as "passive" so that they aren't added to the
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
2008-04-15 01:22:18 +00:00
Dan Gohman
dfa422fe9e In -view-sunit-dags, display "special" chain dependencies as cyan
instead of blue to distinguish them from regular dependencies.

llvm-svn: 49696
2008-04-14 23:15:07 +00:00
Dan Gohman
aa52f1c5b0 Fix a typo in a comment.
llvm-svn: 49502
2008-04-10 22:27:06 +00:00
Dan Gohman
d7301ea935 Rename MemOperand to MachineMemOperand. This was suggested by
review feedback from Chris quite a while ago. No functionality
change.

llvm-svn: 49348
2008-04-07 19:35:22 +00:00
Roman Levenstein
b40d332929 Re-commit of the r48822, where the infinite looping problem discovered
by Dan Gohman is fixed.

llvm-svn: 49330
2008-04-07 10:06:32 +00:00
Evan Cheng
53c8db51dd Start of a series of patches related to implicit_def.
There is no point in creating a long live range defined by an implicit_def. Scheduler now duplicates implicit_def instruction for each of its uses. Therefore, if an implicit_def node has multiple uses, it will become a number of very short live ranges, rather than a long one. This will make coalescer's job easier.

llvm-svn: 49164
2008-04-03 16:36:07 +00:00
Evan Cheng
497c607fae Backing out 48222 temporarily.
llvm-svn: 49124
2008-04-03 03:13:16 +00:00
Roman Levenstein
55b8822511 Use a linked data structure for the uses lists of an SDNode, just like
LLVM Value/Use does and MachineRegisterInfo/MachineOperand does.
This allows constant time for all uses list maintenance operations.

The idea was suggested by Chris. Reviewed by Evan and Dan.
Patch is tested and approved by Dan.

On normal use-cases compilation speed is not affected. On very big basic
blocks there are compilation speedups in the range of 15-20% or even better. 

llvm-svn: 48822
2008-03-26 12:39:26 +00:00
Evan Cheng
d466e7a521 Forgot this.
llvm-svn: 48349
2008-03-14 00:17:29 +00:00
Evan Cheng
620fd19798 Experimental scheduler change to schedule / coalesce the copies added for function livein's. Take 2008-03-10-RegAllocInfLoop.ll, the schedule looks like this after these copies are inserted:
entry: 0x12049d0, LLVM BB @0x1201fd0, ID#0:
Live Ins: %EAX %EDX %ECX
        %reg1031<def> = MOVPC32r 0
        %reg1032<def> = ADD32ri %reg1031, <es:_GLOBAL_OFFSET_TABLE_>, %EFLAGS<imp-def>
        %reg1028<def> = MOV32rr %EAX
        %reg1029<def> = MOV32rr %EDX
        %reg1030<def> = MOV32rr %ECX
        %reg1027<def> = MOV8rm %reg0, 1, %reg0, 0, Mem:LD(1,1) [0x1201910 + 0]
        %reg1025<def> = MOV32rr %reg1029
        %reg1026<def> = MOV32rr %reg1030
        %reg1024<def> = MOV32rr %reg1028

The copies unnecessarily increase register pressure and it will end up requiring a physical register to be spilled.

With -schedule-livein-copies:
entry: 0x12049d0, LLVM BB @0x1201fa0, ID#0:
Live Ins: %EAX %EDX %ECX
        %reg1031<def> = MOVPC32r 0
        %reg1032<def> = ADD32ri %reg1031, <es:_GLOBAL_OFFSET_TABLE_>, %EFLAGS<imp-def>
        %reg1024<def> = MOV32rr %EAX
        %reg1025<def> = MOV32rr %EDX
        %reg1026<def> = MOV32rr %ECX
        %reg1027<def> = MOV8rm %reg0, 1, %reg0, 0, Mem:LD(1,1) [0x12018e0 + 0]

Much better!

llvm-svn: 48307
2008-03-12 22:19:41 +00:00
Dan Gohman
a9386d8501 Rename CountMemOperands to ComputeMemOperandsEnd to reflect what
it actually does. Simplify CountOperands a little by reusing
ComputeMemOperandsEnd. And reword some comments for both.

llvm-svn: 47198
2008-02-16 00:36:48 +00:00
Nate Begeman
1ef1013b6c Change how FP immediates are handled.
1) ConstantFP is now expand by default
2) ConstantFP is not turned into TargetConstantFP during Legalize
   if it is legal.

This allows ConstantFP to be handled like Constant, allowing for 
targets that can encode FP immediates as MachineOperands.

As a bonus, fix up Itanium FP constants, which now correctly match,
and match more constants!  Hooray.

llvm-svn: 47121
2008-02-14 08:57:00 +00:00
Dan Gohman
cabaec582f Rename MRegisterInfo to TargetRegisterInfo.
llvm-svn: 46930
2008-02-10 18:45:23 +00:00
Dan Gohman
f00842e086 Re-apply the memory operand changes, with a fix for the static
initializer problem, a minor tweak to the way the
DAGISelEmitter finds load/store nodes, and a renaming of the
new PseudoSourceValue objects.

llvm-svn: 46827
2008-02-06 22:27:42 +00:00
Evan Cheng
2a533e6894 Revert 46556 and 46585. Dan please fix the PseudoSourceValue problem and re-commit.
llvm-svn: 46623
2008-01-31 21:00:00 +00:00
Dan Gohman
4326d513ab Create a new class, MemOperand, for describing memory references
in the backend. Introduce a new SDNode type, MemOperandSDNode, for
holding a MemOperand in the SelectionDAG IR, and add a MemOperand
list to MachineInstr, and code to manage them. Remove the offset
field from SrcValueSDNode; uses of SrcValueSDNode that were using
it are all all using MemOperandSDNode now.

Also, begin updating some getLoad and getStore calls to use the
PseudoSourceValue objects.

Most of this was written by Florian Brander, some
reorganization and updating to TOT by me.

llvm-svn: 46585
2008-01-31 00:25:39 +00:00
Evan Cheng
07f3cd3242 A semi-gross fix for a debug info issue. When inserting the "function start" label (i.e. first label in the entry block) take care to insert it at the beginning of the block.
llvm-svn: 46568
2008-01-30 19:35:32 +00:00
Chris Lattner
f83aae613c rename TargetInstrDescriptor -> TargetInstrDesc.
Make MachineInstr::getDesc return a reference instead
of a pointer, since it can never be null.

llvm-svn: 45695
2008-01-07 07:27:27 +00:00
Chris Lattner
96167aa93c Rename SSARegMap -> MachineRegisterInfo in keeping with the idea
that "machine" classes are used to represent the current state of
the code being compiled.  Given this expanded name, we can start 
moving other stuff into it.  For now, move the UsedPhysRegs and
LiveIn/LoveOuts vectors from MachineFunction into it.

Update all the clients to match.

This also reduces some needless #includes, such as MachineModuleInfo
from MachineFunction.

llvm-svn: 45467
2007-12-31 04:13:23 +00:00
Chris Lattner
e0b1ee937a Don't attribute in file headers anymore. See llvmdev for the
discussion of this change.  Boy are my fingers tired. ;-)

llvm-svn: 45411
2007-12-29 19:59:42 +00:00