Commit Graph

22 Commits

Author SHA1 Message Date
Francis Visoiu Mistrih 25528d6de7 [CodeGen] Unify MBB reference format in both MIR and debug output
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.

The MIR printer prints the IR name of a MBB only for block definitions.

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix

Differential Revision: https://reviews.llvm.org/D40422

llvm-svn: 319665
2017-12-04 17:18:51 +00:00
Evandro Menezes 0cd23f5642 [CodeGen] Rename DEBUG_TYPE to match passnames
Rename missing DEBUG_TYPE "machine-scheduler" from backend files, which were
absent from https://reviews.llvm.org/rL303921.

Differential revision: https://reviews.llvm.org/D35231

llvm-svn: 307719
2017-07-11 22:08:28 +00:00
Stanislav Mekhanoshin acca0f5c02 [AMDGPU] Use GCNRPTracker dumper methods in scheduler
Differential Revision: https://reviews.llvm.org/D33244

llvm-svn: 303186
2017-05-16 16:31:45 +00:00
Stanislav Mekhanoshin b10860788f [AMDGPU] Cache live-ins and register pressure in scheduler
Using LIS can be quite expensive, so caching of calculated region
live-ins and pressure is implemented. It does two things:

1. Caches the info for the second stage when we schedule with
   decreased target occupancy.
2. Tracks the basic block from top to bottom thus eliminating the
   need to scan whole register file liveness at every region split
   in the middle of the block.

The scheduling is now done in 3 stages instead of two, with the first
one being really a no-op and only used to collect scheduling regions
as sent by the scheduler driver.

There is no functional change to the current behavior, only compilation
speed is affected. In general computeBlockPressure() could be simplified
if we switch to backward RP tracker, because scheduler sends regions
within a block starting from the last upward. We could use a natural
order of upward tracker to seamlessly change between regions of the same
block, since live reg set of a previous tracked region would become a
live-out of the next region. That however requires fixing upward tracker
to properly account defs and uses of the same instruction as both are
contributing to the current pressure. When we converge on the produced
pressure we should be able to switch between them back and forth. In
addition, backward tracker is less expensive as it uses LIS in recede
less often than forward uses it in advance.

At the moment the worst known case compilation time has improved from 26
minutes to 8.5.

Differential Revision: https://reviews.llvm.org/D33117

llvm-svn: 303184
2017-05-16 16:11:26 +00:00
Stanislav Mekhanoshin 464cecf81e [AMDGPU] Turn register pressure estimation into forward tracker
This factors register pressure estimation mechanism from the
GCNSchedStrategy into the forward tracker to unify interface
with other strategies and expose it to other interested phases.

Differential Revision: https://reviews.llvm.org/D33105

llvm-svn: 303179
2017-05-16 15:43:52 +00:00
Stanislav Mekhanoshin 33a97ec4ed [AMDGPU] Fix incorrect register pressure calculation
Earlier fix D32572 introduced a bug where live-ins were calculated
for basic block instead of scheduling region. This change fixes it.

Differential Revision: https://reviews.llvm.org/D33086

llvm-svn: 302812
2017-05-11 17:16:55 +00:00
Konstantin Zhuravlyov 97a663b6a2 AMDGPU: Fix assert in scheduler
Assert is triggered if DBG_VALUE is first instruction in BB

Differential Revision: https://reviews.llvm.org/D32572

llvm-svn: 301511
2017-04-27 03:22:44 +00:00
Stanislav Mekhanoshin b933c3f554 [AMDGPU] Fix recorded region boundaries in max-occupancy scheduler
This is incorrect to record region boundaries before scheduling,
it may change after scheduling. As a result second pass may see less
instructions to schedule than it should.

Differential Revision: https://reviews.llvm.org/D31434

llvm-svn: 298945
2017-03-28 21:48:54 +00:00
Valery Pykhtin fd4c410f4d [AMDGPU] Iterative scheduling infrastructure + minimal registry scheduler
Differential revision: https://reviews.llvm.org/D31046

llvm-svn: 298368
2017-03-21 13:15:46 +00:00
Stanislav Mekhanoshin 79da2a7698 [AMDGPU] Remove getBidirectionalReasonRank
This method inverts the Reason field of a scheduling candidate.
It does right comparison between RegCritical and RegExcess, but
everything else is broken. In fact it can prefer less strong reason
such as Weak over RegCritical because Weak > -RegCritical.

The CandReason enum is properly sorted, so just remove artificial
ranking.

Differential Revision: https://reviews.llvm.org/D30557

llvm-svn: 297536
2017-03-11 00:29:27 +00:00
Stanislav Mekhanoshin 357d3db0a4 [AMDGPU] Add second pass of the scheduler
If during scheduling we have identified that we cannot keep optimistic
occupancy increase critical register pressure limit and try scheduling
of the whole function again. In this case blocks with smaller pressure
will have a chance for better scheduling.

Differential Revision: https://reviews.llvm.org/D30442

llvm-svn: 296506
2017-02-28 19:20:33 +00:00
Stanislav Mekhanoshin 282e8e4a72 [AMDGPU] New method to estimate register pressure
This change introduces new method to estimate register pressure in
GCNScheduler. Standard RPTracker gives huge error due to the following
reasons:

1. It does not account for live-ins or live-outs if value is not used
in the region itself. That creates a huge error in a very common case
if there are a lot of live-thu registers.
2. It does not properly count subregs.
3. It assumes a register used as an input operand can be reused as an
output. This is not always possible by itself, this is not what RA
will finally do in many cases for various reasons not limited to RA's
inability to do so, and this is not so if the value is actually a
live-thu.

In addition we can now see clear separation between live-in pressure
which we cannot change with the scheduling and tentative pressure
which we can change.

Differential Revision: https://reviews.llvm.org/D30439

llvm-svn: 296491
2017-02-28 17:22:39 +00:00
Stanislav Mekhanoshin 080889cad7 [AMDGPU] Fix read-undef flags when schedule is reverted
If two subregs of the same register are defined and we need to revert
schedule changing def order, we will end up with both instructions
having def,read-undef flags because adjustLaneLiveness() will only set
this flag but will not remove it.

Fix this by removing read-undef flags before calling adjustLaneLiveness.

Differential Revision: https://reviews.llvm.org/D30428

llvm-svn: 296484
2017-02-28 16:26:27 +00:00
Stanislav Mekhanoshin 582a5237f9 [AMDGPU] Revert failed scheduling
This patch reverts region's scheduling to the original untouched state
in case if we have have decreased occupancy.

In addition it switches to use TargetRegisterInfo occupancy callback
for pressure limits instead of gradually increasing limits which were
just passed by. We are going to stay with the best schedule so we do
not need to tolerate worsened scheduling anymore.

Differential Revision: https://reviews.llvm.org/D29971

llvm-svn: 295206
2017-02-15 17:19:50 +00:00
Konstantin Zhuravlyov e03b1d7b6a [AMDGPU] Move register related queries to subtarget class
Differential Revision: https://reviews.llvm.org/D29318

llvm-svn: 294440
2017-02-08 13:02:33 +00:00
Stanislav Mekhanoshin 99be1aff31 [AMDGPU] Fix GCNSchedStrategy.cpp debug output
There is typo in the debug output: top and bottom candidates are switched.

Differential Revision: https://reviews.llvm.org/D29608

llvm-svn: 294257
2017-02-06 23:16:51 +00:00
Stanislav Mekhanoshin 2b913b1f49 [AMDGPU] Account workgroup size in LDS occupancy limits
Functions matching LDS use to occupancy return results for a workgroup
of 64 workitems. The numbers has to be adjusted for bigger workgroups.
For example a workgroup of size 256 already occupies 4 waves just by
itself. Given that all numbers of LDS use in the compiler are per
workgroup, occupancy shall be multiplied by 4 in this case. Each 64
workitems still limited by the same number, but 4 subrgoups 64 workitems
each can afford 4 times more LDS to get the same occupancy.

In addition change initializes LDS size in the subtarget to a real value
for SI+ targets. This is required since LDS size is a variable in these
calculations.

Differential Revision: https://reviews.llvm.org/D29423

llvm-svn: 293837
2017-02-01 22:59:50 +00:00
Valery Pykhtin 75d1de903f [AMDGPU] Fix typo in GCNSchedStrategy
Differential revision: https://reviews.llvm.org/D28980

llvm-svn: 293171
2017-01-26 10:51:47 +00:00
Marek Olsak 91f22fbf4f AMDGPU/SI: Allow using SGPRs 96-101 on VI
Summary:
There is no point in setting SGPRS=104, because VI allocates SGPRs
in multiples of 16, so 104 -> 112. That enables us to use all 102 SGPRs
for general purposes.

Reviewers: tstellarAMD

Subscribers: qcolombet, arsenm, kzhuravl, wdng, nhaehnle, yaxunl, tony-tye

Differential Revision: https://reviews.llvm.org/D27149

llvm-svn: 289260
2016-12-09 19:49:40 +00:00
Matt Arsenault f3dd863031 AMDGPU: Whitespace fixes
llvm-svn: 285659
2016-11-01 00:55:14 +00:00
Konstantin Zhuravlyov 1d65026ca6 [AMDGPU] Wave and register controls
- Implemented amdgpu-flat-work-group-size attribute
- Implemented amdgpu-num-active-waves-per-eu attribute
- Implemented amdgpu-num-sgpr attribute
- Implemented amdgpu-num-vgpr attribute
- Dynamic LDS constraints are in a separate patch

Patch by Tom Stellard and Konstantin Zhuravlyov

Differential Revision: https://reviews.llvm.org/D21562

llvm-svn: 280747
2016-09-06 20:22:28 +00:00
Tom Stellard 0d23ebe888 AMDGPU/SI: Implement a custom MachineSchedStrategy
Summary:
GCNSchedStrategy re-uses most of GenericScheduler, it's just uses
a different method to compute the excess and critical register
pressure limits.

It's not enabled by default, to enable it you need to pass -misched=gcn
to llc.

Shader DB stats:

32464 shaders in 17874 tests
Totals:
SGPRS: 1542846 -> 1643125 (6.50 %)
VGPRS: 1005595 -> 904653 (-10.04 %)
Spilled SGPRs: 29929 -> 27745 (-7.30 %)
Spilled VGPRs: 334 -> 352 (5.39 %)
Scratch VGPRs: 1612 -> 1624 (0.74 %) dwords per thread
Code Size: 36688188 -> 37034900 (0.95 %) bytes
LDS: 1913 -> 1913 (0.00 %) blocks
Max Waves: 254101 -> 265125 (4.34 %)
Wait states: 0 -> 0 (0.00 %)

Totals from affected shaders:
SGPRS: 1338220 -> 1438499 (7.49 %)
VGPRS: 886221 -> 785279 (-11.39 %)
Spilled SGPRs: 29869 -> 27685 (-7.31 %)
Spilled VGPRs: 334 -> 352 (5.39 %)
Scratch VGPRs: 1612 -> 1624 (0.74 %) dwords per thread
Code Size: 34315716 -> 34662428 (1.01 %) bytes
LDS: 1551 -> 1551 (0.00 %) blocks
Max Waves: 188127 -> 199151 (5.86 %)
Wait states: 0 -> 0 (0.00 %)

Reviewers: arsenm, mareko, nhaehnle, MatzeB, atrick

Subscribers: arsenm, kzhuravl, llvm-commits

Differential Revision: https://reviews.llvm.org/D23688

llvm-svn: 279995
2016-08-29 19:42:52 +00:00