Commit Graph

84 Commits

Author SHA1 Message Date
Andrew Trick
4bbf4678e3 Improve pre-RA-sched register pressure tracking for duplicate operands.
This helps cases like 2008-07-19-movups-spills.ll, but doesn't have an obvious impact on benchmarks


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127347 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-09 19:12:43 +00:00
Eric Christopher
29449448b0 Fix some latent bugs if the nodes are unschedulable. We'd gotten away
with this before since none of the register tracking or nightly tests
had unschedulable nodes.

This should probably be refixed with a special default Node that just
returns some "don't touch me" values.

Fixes PR9427


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127263 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-08 19:35:47 +00:00
Andrew Trick
5e84e3ccaa Fix for -sched-high-latency-cycles in sched=list-ilp mode.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127071 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-05 09:18:16 +00:00
Andrew Trick
e0ef509aeb Increased the register pressure limit on x86_64 from 8 to 12
regs. This is the only change in this checkin that may affects the
default scheduler. With better register tracking and heuristics, it
doesn't make sense to artificially lower the register limit so much.

Added -sched-high-latency-cycles and X86InstrInfo::isHighLatencyDef to
give the scheduler a way to account for div and sqrt on targets that
don't have an itinerary. It is currently defaults to 10 (the actual
number doesn't matter much), but only takes effect on non-default
schedulers: list-hybrid and list-ilp.

Added several heuristics that can be individually disabled for the
non-default sched=list-ilp mode. This helps us determine how much
better we can do on a given benchmark than the default
scheduler. Certain compute intensive loops run much faster in this
mode with the right set of heuristics, and it doesn't seem to have
much negative impact elsewhere. Not all of the heuristics are needed,
but we still need to experiment to decide which should be disabled by
default for sched=list-ilp.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127067 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-05 08:00:22 +00:00
Andrew Trick
92e946630d Introducing a new method of tracking register pressure. We can't
precisely track pressure on a selection DAG, but we can at least keep
it balanced. This design accounts for various interesting aspects of
selection DAGS: register and subregister copies, glued nodes, dead
nodes, unused registers, etc.

Added SUnit::NumRegDefsLeft and ScheduleDAGSDNodes::RegDefIter.

Note: I disabled PrescheduleNodesWithMultipleUses when register
pressure is enabled, based on no evidence other than I don't think it
makes sense to have both enabled.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124853 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-04 03:18:17 +00:00
Andrew Trick
cd5af07c45 whitespace
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124827 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-03 23:00:17 +00:00
Devang Patel
39078a8bde Reapply 124301
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124339 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-27 00:13:27 +00:00
Devang Patel
4a95c19977 Revert 124301.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124327 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-26 21:41:22 +00:00
Devang Patel
6f121fdede Process valid SDDbgValues even if the node does not have any order assigned.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124301 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-26 18:42:32 +00:00
Devang Patel
55d20e8ff1 Refactor.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124300 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-26 18:20:04 +00:00
Devang Patel
3a00ffacdc This assertion is too restrictive, it does not apply for dangling dbg value nodes (nodes where dbg.value intrinsic preceds use of the value).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124202 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-25 18:09:33 +00:00
Chris Lattner
29d8f0cae4 flags -> glue for selectiondag
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122509 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-23 17:24:32 +00:00
Chris Lattner
f1b4eafbfe rename MVT::Flag to MVT::Glue. "Flag" is a terrible name for
something that just glues two nodes together, even if it is
sometimes used for flags.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122310 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-21 02:38:05 +00:00
Evan Cheng
8239daf7c8 Two sets of changes. Sorry they are intermingled.
1. Fix pre-ra scheduler so it doesn't try to push instructions above calls to
   "optimize for latency". Call instructions don't have the right latency and
   this is more likely to use introduce spills.
2. Fix if-converter cost function. For ARM, it should use instruction latencies,
   not # of micro-ops since multi-latency instructions is completely executed
   even when the predicate is false. Also, some instruction will be "slower"
   when they are predicated due to the register def becoming implicit input.
   rdar://8598427


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118135 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-03 00:45:17 +00:00
Evan Cheng
089751535d Avoiding overly aggressive latency scheduling. If the two nodes share an
operand and one of them has a single use that is a live out copy, favor the
one that is live out. Otherwise it will be difficult to eliminate the copy
if the instruction is a loop induction variable update. e.g.

BB:
sub r1, r3, #1
str r0, [r2, r3]
mov r3, r1
cmp
bne BB

=>

BB:
str r0, [r2, r3]
sub r3, r3, #1
cmp
bne BB

This fixed the recent 256.bzip2 regression.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117675 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-29 18:09:28 +00:00
Evan Cheng
7e2fe9150f Re-commit 117518 and 117519 now that ARM MC test failures are out of the way.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117531 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-28 06:47:08 +00:00
Evan Cheng
9e08ee5d16 Revert 117518 and 117519 for now. They changed scheduling and cause MC tests to fail. Ugh.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117520 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-28 02:00:25 +00:00
Evan Cheng
7c88cdcc3b Fix a major bug in operand latency computation. The use index must be adjusted
by the number of defs first for it to match the instruction itinerary.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117518 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-28 01:46:29 +00:00
Evan Cheng
a0792de66c - Add TargetInstrInfo::getOperandLatency() to compute operand latencies. This
allow target to correctly compute latency for cases where static scheduling
  itineraries isn't sufficient. e.g. variable_ops instructions such as
  ARM::ldm.
  This also allows target without scheduling itineraries to compute operand
  latencies. e.g. X86 can return (approximated) latencies for high latency
  instructions such as division.
- Compute operand latencies for those defined by load multiple instructions,
  e.g. ldm and those used by store multiple instructions, e.g. stm.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115755 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-06 06:27:31 +00:00
Evan Cheng
3881cb7a5d Model Cortex-a9 load to SUB, RSB, ADD, ADC, SBC, RSC, CMN, MVN, or CMP
pipeline forwarding path.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115098 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-29 22:42:35 +00:00
Evan Cheng
3ef1c8759a Teach if-converter to be more careful with predicating instructions that would
take multiple cycles to decode.
For the current if-converter clients (actually only ARM), the instructions that
are predicated on false are not nops. They would still take machine cycles to
decode. Micro-coded instructions such as LDM / STM can potentially take multiple
cycles to decode. If-converter should take treat them as non-micro-coded
simple instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113570 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-10 01:29:16 +00:00
Evan Cheng
c120af4567 Add missing null check reported by Amaury Pouly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110649 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-10 02:39:45 +00:00
Dan Gohman
a8dab36f3d Fix a bug in the code which re-inserts DBG_VALUE nodes after scheduling;
if a block is split (by a custom inserter), the insert point may be in a
different block than it was originally. This fixes 32-bit llvm-gcc
bootstrap builds, and I haven't been able to reproduce it otherwise.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108060 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-10 22:42:31 +00:00
Dan Gohman
84023e0fbe Reapply bottom-up fast-isel, with several fixes for x86-32:
- Check getBytesToPopOnReturn().
 - Eschew ST0 and ST1 for return values.
 - Fix the PIC base register initialization so that it doesn't ever
   fail to end up the top of the entry block.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108039 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-10 09:00:22 +00:00
Bob Wilson
02266e29f9 --- Reverse-merging r107947 into '.':
U    utils/TableGen/FastISelEmitter.cpp
--- Reverse-merging r107943 into '.':
U    test/CodeGen/X86/fast-isel.ll
U    test/CodeGen/X86/fast-isel-loads.ll
U    include/llvm/Target/TargetLowering.h
U    include/llvm/Support/PassNameParser.h
U    include/llvm/CodeGen/FunctionLoweringInfo.h
U    include/llvm/CodeGen/CallingConvLower.h
U    include/llvm/CodeGen/FastISel.h
U    include/llvm/CodeGen/SelectionDAGISel.h
U    lib/CodeGen/LLVMTargetMachine.cpp
U    lib/CodeGen/CallingConvLower.cpp
U    lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
U    lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
U    lib/CodeGen/SelectionDAG/FastISel.cpp
U    lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
U    lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
U    lib/CodeGen/SelectionDAG/InstrEmitter.cpp
U    lib/CodeGen/SelectionDAG/TargetLowering.cpp
U    lib/Target/XCore/XCoreISelLowering.cpp
U    lib/Target/XCore/XCoreISelLowering.h
U    lib/Target/X86/X86ISelLowering.cpp
U    lib/Target/X86/X86FastISel.cpp
U    lib/Target/X86/X86ISelLowering.h


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107987 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-09 16:37:18 +00:00
Dan Gohman
bf87e24917 Re-apply bottom-up fast-isel, with fixes. Be very careful to avoid emitting
a DBG_VALUE after a terminator, or emitting any instructions before an EH_LABEL.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107943 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-09 00:39:23 +00:00
Jim Grosbach
d27946d1d4 grammar tweak in comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107321 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-30 21:27:56 +00:00
Rafael Espindola
d31f972bd3 Add a VT argument to getMinimalPhysRegClass and replace the copy related uses
of getPhysicalRegisterRegClass with it.

If we want to make a copy (or estimate its cost), it is better to use the
smallest class as more efficient operations might be possible.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107140 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-29 14:02:34 +00:00
Duncan Sands
b447c4e65b Remove variables which are assigned to but for which the value
is not used.  Spotted by gcc-4.6.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106854 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-25 14:48:39 +00:00
Bill Wendling
10707f3b44 It's possible that a flag is added to the SDNode that points back to the
original SDNode. This is badness. Also, this function allows one SDNode to point
multiple flags to another SDNode. Badness as well.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106793 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-24 22:00:37 +00:00
Bill Wendling
151d26d15d MorphNodeTo doesn't preserve the memory operands. Because we're morphing a node
into the same node, but with different non-memory operands, we need to replace
the memory operands after it's finished morphing.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106643 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-23 18:16:24 +00:00
Dan Gohman
403a8cdda5 Use A.append(...) instead of A.insert(A.end(), ...) when A is a
SmallVector, and other SmallVector simplifications.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106452 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-21 19:47:52 +00:00
Evan Cheng
302ef834e0 Code refactoring, no functionality changes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105775 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-10 02:09:31 +00:00
Evan Cheng
046fa3f90a Fix some latency computation bugs: if the use is not a machine opcode do not just return zero.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105061 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-28 23:26:21 +00:00
Evan Cheng
1cc3984148 Allow targets more controls on what nodes are scheduled by reg pressure, what for latency in hybrid mode.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104293 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-20 23:26:43 +00:00
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
Evan Cheng
e163168aab Code clean up.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104173 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-19 22:42:23 +00:00
Dan Gohman
af1d8ca44a Get rid of the EdgeMapping map. Instead, just check for BasicBlock
changes before doing phi lowering for switches.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102809 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-01 00:01:06 +00:00
Dan Gohman
891ff8fbd6 EmitDbgValue doesn't need its EdgeMapping argument.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102742 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-30 19:35:33 +00:00
Dale Johannesen
fdb42fa5fe Add DBG_VALUE handling for byval parameters; this
produces a comment on targets that support it, but
the Dwarf writer is not hooked up yet.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102372 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-26 20:06:49 +00:00
Evan Cheng
962021bc7f - Move TargetLowering::EmitTargetCodeForFrameDebugValue to TargetInstrInfo and rename it to emitFrameIndexDebugValue.
- Teach spiller to modify DBG_VALUE instructions to reference spill slots.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102323 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-26 07:38:55 +00:00
Dan Gohman
3fb150a902 Fix -Wcast-qual warnings.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101655 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-17 17:42:52 +00:00
Evan Cheng
4ec9bd9a6f Scheduler assumes SDDbgValue nodes are in source order. That's true currently. But add an assertion to verify it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99501 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-25 07:16:57 +00:00
Evan Cheng
167bda4baa Remove a fixme that doesn't make sense any more.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99489 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-25 06:02:53 +00:00
Evan Cheng
bfcb305189 Change how dbg_value sdnodes are converted into machine instructions. Their placement should be determined by the relative order of incoming llvm instructions. The scheduler will now use the SDNode ordering information to determine where to insert them. A dbg_value instruction is inserted after the instruction with the last highest source order and before the instruction with the next highest source order. It will optimize the placement by inserting right after the instruction that produces the value if they have consecutive order numbers.
Here is a theoretical example that illustrates why the placement is important.

tmp1 = 
store tmp1 -> x
...
tmp2 = add ...
...
call
...
store tmp2 -> x

Now mem2reg comes along:

tmp1 = 
dbg_value (tmp1 -> x)
...
tmp2 = add ...
...
call
...
dbg_value (tmp2 -> x)

When the debugger examine the value of x after the add instruction but before the call, it should have the value of tmp1.

Furthermore, for dbg_value's that reference constants, they should not be emitted at the beginning of the block (since they do not have "producers").

This patch also cleans up how SDISel manages DbgValue nodes. It allow a SDNode to be referenced by multiple SDDbgValue nodes. When a SDNode is deleted, it uses the information to find the SDDbgValues and invalidate them. They are not deleted until the corresponding SelectionDAG is destroyed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99469 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-25 01:38:16 +00:00
Evan Cheng
a8efe28a44 Rename SDDbgValue.h to SDNodeDbgValue.h for consistency.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98513 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-14 19:56:39 +00:00
Dale Johannesen
bfdf7f3852 Progress towards shepherding debug info through SelectionDAG.
No functional effect yet.  This is still evolving and should
not be viewed as final.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98195 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-10 22:13:47 +00:00
Chris Lattner
736a6ea3a2 Change the scheduler from adding nodes in allnodes order
to adding them in a determinstic order (bottom up from 
the root) based on the structure of the graph itself.

This updates tests for some random changes, interesting
bits: CodeGen/Blackfin/promote-logic.ll no longer crashes.
I have no idea why, but that's good right?

CodeGen/X86/2009-07-16-LoadFoldingBug.ll also fails, but
now compiles to have one fewer constant pool entry, making
the expected load that was being folded disappear.  Since it
is an unreduced mass of gnast, I just removed it.

This fixes PR6370


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97023 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-24 06:11:37 +00:00
Evan Cheng
42dae2d5ba Enable pre-regalloc scheduling load clustering by default.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94255 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-22 23:49:45 +00:00
Evan Cheng
c589e03865 Teach pre-regalloc scheduler to schedule loads from nearby addresses. It may improve cache locality. This is controlled by -cluster-loads for now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94148 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-22 03:36:51 +00:00