Commit Graph

164 Commits

Author SHA1 Message Date
Florian Hahn 7c0ff64b0f
[LAA] Change to function analysis for new PM.
At the moment, LoopAccessAnalysis is a loop analysis for the new pass
manager. The issue with that is that LAI caches SCEV expressions and
modifications in a loop may impact SCEV expressions in other loops, but
we do not have a convenient way to invalidate LAI for other loops
withing a loop pipeline.

To avoid this issue, turn it into a function analysis which returns a
manager object that keeps track of the individual LAI objects per loop.

Fixes #50940.

Fixes #51669.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D134606
2022-10-01 15:44:27 +01:00
Pavel Samolysov 1c530500ab [Pipelines] Introduce DAE after ArgumentPromotion
The ArgumentPromotion pass uses Mem2Reg promotion at the end to cutting
down generated `alloca` instructions as well as meaningless `store`s and
this behavior can leave unused (dead) arguments. To eliminate the dead
arguments and therefore let the DeadCodeElimination remove becoming dead
inserted `GEP`s as well as `load`s and `cast`s in the callers, the
DeadArgumentElimination pass should be run after the ArgumentPromotion
one.

Differential Revision: https://reviews.llvm.org/D128830
2022-09-22 15:33:46 -07:00
Arthur Eubanks 9599393eeb Revert "[Pipelines] Introduce DAE after ArgumentPromotion"
This reverts commit b10a341aa5.

This commit exposes the pre-existing https://github.com/llvm/llvm-project/issues/56503 in some edge cases. Will fix that and then reland this.
2022-09-01 08:52:19 -07:00
Pavel Samolysov b10a341aa5 [Pipelines] Introduce DAE after ArgumentPromotion
The ArgumentPromotion pass uses Mem2Reg promotion at the end to cutting
down generated `alloca` instructions as well as meaningless `store`s and
this behavior can leave unused (dead) arguments. To eliminate the dead
arguments and therefore let the DeadCodeElimination remove becoming dead
inserted `GEP`s as well as `load`s and `cast`s in the callers, the
DeadArgumentElimination pass should be run after the ArgumentPromotion
one.

Differential Revision: https://reviews.llvm.org/D128830
2022-08-28 10:47:03 +03:00
Pavel Samolysov f964417c32 Revert "[Pipelines] Introduce DAE after ArgumentPromotion"
The commit breaks the compiler when a function is used as a function
parameter (hm... for a function from the standard C library?):

```
static float strtof(char *, char *) {}
void a() { strtof(a, 0); }
```

This reverts commit 879f5118fc.
2022-08-26 13:43:09 +03:00
Pavel Samolysov 879f5118fc [Pipelines] Introduce DAE after ArgumentPromotion
The ArgumentPromotion pass uses Mem2Reg promotion at the end to cutting
down generated `alloca` instructions as well as meaningless `store`s and
this behavior can leave unused (dead) arguments. To eliminate the dead
arguments and therefore let the DeadCodeElimination remove becoming dead
inserted `GEP`s as well as `load`s and `cast`s in the callers, the
DeadArgumentElimination pass should be run after the ArgumentPromotion
one.

Differential Revision: https://reviews.llvm.org/D128830
2022-08-25 10:55:47 +03:00
Pavel Samolysov 6703ad1e0c Revert "[Pipelines] Introduce DAE after ArgumentPromotion"
This reverts commit 3f20dcbf70.
2022-08-24 12:44:13 +03:00
Pavel Samolysov 3f20dcbf70 [Pipelines] Introduce DAE after ArgumentPromotion
The ArgumentPromotion pass uses Mem2Reg promotion at the end to cutting
down generated `alloca` instructions as well as meaningless `store`s and
this behavior can leave unused (dead) arguments. To eliminate the dead
arguments and therefore let the DeadCodeElimination remove becoming dead
inserted `GEP`s as well as `load`s and `cast`s in the callers, the
DeadArgumentElimination pass should be run after the ArgumentPromotion
one.

Differential Revision: https://reviews.llvm.org/D128830
2022-08-24 10:36:12 +03:00
Ruobing Han f756f06cc4 [SimpleLoopUnswitch] Skip non-trivial unswitching of cold loops
With profile data, non-trivial LoopUnswitch will only apply on non-cold loops, as unswitching cold loops may not gain much benefit but significantly increase the code size.

Reviewed By: aeubanks, asbirlea

Differential Revision: https://reviews.llvm.org/D129599
2022-08-08 18:12:04 +00:00
Sanjay Patel bfb9b8e075 [Passes] add a tail-call-elim pass near the end of the opt pipeline
We call tail-call-elim near the beginning of the pipeline,
but that is too early to annotate calls that get added later.

In the motivating case from issue #47852, the missing 'tail'
on memset leads to sub-optimal codegen.

I experimented with removing the early instance of
tail-call-elim instead of just adding another pass, but that
appears to be slightly worse for compile-time:
+0.15% vs. +0.08% time.
"tailcall" shows adding the pass; "tailcall2" shows moving
the pass to later, then adding the original early pass back
(so 1596886802 is functionally equivalent to 180b0439dc ):
https://llvm-compile-time-tracker.com/index.php?config=NewPM-O3&stat=instructions&remote=rotateright

Note that there was an effort to split the tail call functionality
into 2 passes - that could help reduce compile-time if we find
that this change costs more in compile-time than expected based
on the preliminary testing:
D60031

Differential Revision: https://reviews.llvm.org/D130374
2022-07-25 15:25:47 -04:00
Alina Sbirlea 846d10f16a Turn on flag to not re-run simplification pipeline.
This patch turns on the flag `-enable-no-rerun-simplification-pipeline`, which means the simplification pipeline will not be rerun on unchanged functions in the CGSCCPass Manager.

Compile time improvement:
https://llvm-compile-time-tracker.com/compare.php?from=17457be1c393ff691cca032b04ea1698fedf0301&to=882301ebb893c8ef9f09fe1ea871f7995426fa07&stat=instructions

No meaningful run time regressions observed in the llvm test suite and
in additional internal workloads at this time.

The example test in `test/Other/no-rerun-function-simplification-pipeline.ll` is a good means to understand the effect of this change:
```
define void @f1(void()* %p) alwaysinline {
  call void %p()
  ret void
}

define void @f2() #0 {
  call void @f1(void()* @f2)
  call void @f3()
  ret void
}

define void @f3() #0 {
  call void @f2()
  ret void
}
```

There are two SCCs formed by the ModuleToPostOrderCGSCCAdaptor: (f1) and (f2, f3).

The pass manager runs on the first SCC, leading to running the simplification pipeline (function and loop passes) on f1. With the flag on, after this, the output will have `Running analysis: ShouldNotRunFunctionPassesAnalysis on f1`.

Next, the pass manager runs on the second SCC: (f2, f3). Since f1() was inlined, f2() now calls itself, and also calls f3(), while f3() only calls f2().
So the pass manager for the SCC first runs the Inliner on (f2, f3), then the simplification pipeline on f2.
With the flag on, the output will have `Running analysis: ShouldNotRunFunctionPassesAnalysis on f2`; unless the inliner makes a change, this analysis remains preserved which means there's no reason to rerun the simplification pipeline. With the flag off, there is a second run of the simplification pipeline run on f2.

Next, the same flow occurs for f3. The simplification pipeline is run on f3 a single time with the flag on, along with `ShouldNotRunFunctionPassesAnalysis on f3`, and twice with the flag off.
The reruns occur only on f2 and f3 due to the additional ref edges.
2022-07-14 06:23:55 -07:00
Ben Dunbobbin 325e7e8b87 [LLVM][LTO][LLD] Enable Profile Guided Layout (--call-graph-profile-sort) for FullLTO
The CGProfilePass needs to be run during FullLTO compilation at link
time to emit the .llvm.call-graph-profile section to the compiled LTO
object file. Currently, it is being run only during the initial
LTO-prelink compilation stage (to produce the bitcode files to be
consumed by the linker) and so the section is not produced.

ThinLTO is not affected because:
- For ThinLTO-prelink compilation the CGProfilePass pass is not run
  because ThinLTO-prelink passes are added via
  buildThinLTOPreLinkDefaultPipeline. Normal and FullLTO-prelink
  passes are both added via buildPerModuleDefaultPipeline which uses
  the LTOPreLink parameter to customize its behavior for the
  FullLTO-prelink pass differences.
- ThinLTO backend compilation phase adds the CGProfilePass (see:
  buildModuleOptimizationPipeline).

Adjust when the pass is run so that the .llvm.call-graph-profile
section is produced correctly for FullLTO.

Fixes #56185 (https://github.com/llvm/llvm-project/issues/56185)
2022-07-01 13:57:36 +01:00
Chuanqi Xu 7d40f562e7 [Pipelines] Hoist CoroCleanup to avoid blocking optimizations
CoroCleanup is designed to lowering all the remaining coroutine
intrinsics. It is required to run after CoroSplit only. However, the
position of CoroCleanup now is far too late. The downside here is that
the unlowered coroutine instrincs might blocking other optimizations
too. So it should be a pure win to hoist the position of CoroCleanup.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D124360
2022-05-05 15:13:27 +08:00
Chuanqi Xu f9bee35689 [Pipelines] Hoist CoroEarly as a module pass
This change could reduce the time we call `declaresCoroEarlyIntrinsics`.
And it is helpful for future changes.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D123925
2022-04-19 11:04:24 +08:00
Wenju He 0bda12b5bc [NewPM] Add OptimizerEarly module extension point
VectorizerStart extension is module callback in old PM, but is function
callback in new PM. We lack a module extension point between end of
buildModuleSimplificationPipeline and the function optimization
(including vectorizer) pipeline. So this patch adds a new module
extension point before the function optimization pipeline.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D122296
2022-03-31 08:22:27 -07:00
Arthur Eubanks df1a216a62 [test] Set -verify-cfg-preserved=0 in new-pm-defaults.ll
Matches other similar tests.
2022-03-23 11:09:41 -07:00
Nikita Popov 07d5339819 [Tests] Update pipeline tests
After 20531b3a6b, we now use a cached
TTI instance, so the TargetIRAnalysis analysis run goes away.
2022-03-16 10:56:44 +01:00
Arthur Eubanks 4fc7c55fff [NewPM] Actually recompute GlobalsAA before module optimization pipeline
RequireAnalysis<GlobalsAA> doesn't actually recompute GlobalsAA.
GlobalsAA isn't invalidated (unless specifically invalidated) because
it's self-updating via ValueHandles, but can be imprecise during the
self-updates.

Rather than invalidating GlobalsAA, which would invalidate AAManager and
any analyses that use AAManager, create a new pass that recomputes
GlobalsAA.

Fixes #53131.

Differential Revision: https://reviews.llvm.org/D121167
2022-03-14 09:42:34 -07:00
Elia Geretto 5e4b68cc3b [NewPM] Fix tests for OptimizerLast extension point
This PR fixes the tests for the `OptimizerLast` extension point in the new pass manager. The extension point uses module passes, but it was being tested with a function pass.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D120581
2022-02-25 14:49:19 -08:00
Nikita Popov 8bd62119f9 [NewPM] Test more options in pipeline test (NFC)
As suggested on D115098, this tests the positioning of
HotColdSplitting, IROutliner and MergeFunctions in the optimization
pipeline.
2021-12-04 17:30:30 +01:00
Anton Afanasyev c34d157fc7 [Passes] Move AggressiveInstCombine after InstCombine
Swap AIC and IC neighbouring in pipeline. This looks more natural and even
almost has no effect for now (three slightly touched tests of test-suite). Also
this could be the first step towards merging AIC (or its part) to -O2 pipeline.

After several changes in AIC (like D108091, D108201, D107766, D109515, D109236)
there've been observed several regressions (like PR52078, PR52253, PR52289)
that were fixed in different passes (see D111330, D112721) by extending their
functionality, but these regressions were exposed since changed AIC prevents IC
from making some of early optimizations.

This is common problem and it should be fixed by just moving AIC after IC
which looks more logically by itself: make aggressive instruction combining
only after failed ordinary one.

Fixes PR52289

Reviewed By: spatel, RKSimon

Differential Revision: https://reviews.llvm.org/D113179
2021-12-04 14:22:43 +03:00
Arthur Eubanks 19867de9e7 [NewPM] Only invalidate modified functions' analyses in CGSCC passes + turn on eagerly invalidate analyses
Previously, any change in any function in an SCC would cause all
analyses for all functions in the SCC to be invalidated. With this
change, we now manually invalidate analyses for functions we modify,
then let the pass manager know that all function analyses should be
preserved since we've already handled function analysis invalidation.

So far this only touches the inliner, argpromotion, function-attrs, and
updateCGAndAnalysisManager(), since they are the most used.

This is part of an effort to investigate running the function
simplification pipeline less on functions we visit multiple times in the
inliner pipeline.

However, this causes major memory regressions especially on larger IR.
To counteract this, turn on the option to eagerly invalidate function
analyses. This invalidates analyses on functions immediately after
they're processed in a module or scc to function adaptor for specific
parts of the pipeline.

Within an SCC, if a pass only modifies one function, other functions in
the SCC do not have their analyses invalidated, so in later function
passes in the SCC pass manager the analyses may still be cached. It is
only after the function passes that the eager invalidation takes effect.
For the default pipelines this makes sense because the inliner pipeline
runs the function simplification pipeline after all other SCC passes
(except CoroSplit which doesn't request any analyses).

Overall this has mostly positive effects on compile time and positive effects on memory usage.
https://llvm-compile-time-tracker.com/compare.php?from=7f627596977624730f9298a1b69883af1555765e&to=39e824e0d3ca8a517502f13032dfa67304841c90&stat=instructions
https://llvm-compile-time-tracker.com/compare.php?from=7f627596977624730f9298a1b69883af1555765e&to=39e824e0d3ca8a517502f13032dfa67304841c90&stat=max-rss

D113196 shows that we slightly regressed compile times in exchange for
some memory improvements when turning on eager invalidation.  D100917
shows that we slightly improved compile times in exchange for major
memory regressions in some cases when invalidating less in SCC passes.
Turning these on at the same time keeps the memory improvements while
keeping compile times neutral/slightly positive.

Reviewed By: asbirlea, nikic

Differential Revision: https://reviews.llvm.org/D113304
2021-11-15 14:44:53 -08:00
Arthur Eubanks 1d8750c3da [NFC] Rename GVN -> GVNPass and SROA -> SROAPass
To be more consistent with other pass struct names.

There are still more passes that don't end with "Pass", but these are the important ones.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D112935
2021-11-09 10:35:58 -08:00
Roman Lebedev 9c2469c1dd
[PassManager] `buildModuleOptimizationPipeline()`: schedule `LoopDeletion` pass run before vectorization passes
Test thanks to Michael Kuklinski from `#llvm`: https://godbolt.org/z/bdrah5Goo
originally inspired by Daniel Lemire's https://lemire.me/blog/2021/10/26/in-c-is-empty-faster-than-comparing-the-size-with-zero/

We manage to deduce that the answer does not require looping,
but we do that after the last `LoopDeletion` pass run,
so we end up being stuck with a dead loop.

Now, as with all things SCEV, this has
a very expected ~`+0.12%` compile time performance regression:
https://llvm-compile-time-tracker.com/compare.php?from=0ae7bf124a9bca76dd9a91b2f7379168ff13f562&to=c2ae57c9b961aeb4a28c747266949340613a6d84&stat=instructions
(for comparison, doing that in function simplification pipeline
would have been ~`+0.5` compile time performance regression, D112840)

Looking at the transformation stats over vanilla test-suite, i think it's rather expected:
```
| statistic name                                   |  baseline |  proposed |     Δ |      % |    |%| |
|--------------------------------------------------|----------:|----------:|------:|-------:|-------:|
| scalar-evolution.NumBruteForceTripCountsComputed |       789 |       888 |    99 | 12.55% | 12.55% |
| scalar-evolution.NumTripCountsNotComputed        |    105592 |    117900 | 12308 | 11.66% | 11.66% |
| loop-delete.NumBackedgesBroken                   |       542 |       559 |    17 |  3.14% |  3.14% |
| regalloc.numExtends                              |        81 |        79 |    -2 | -2.47% |  2.47% |
| indvars.NumFoldedUser                            |       408 |       400 |    -8 | -1.96% |  1.96% |
| indvars.NumElimCmp                               |      3831 |      3758 |   -73 | -1.91% |  1.91% |
| scalar-evolution.NumTripCountsComputed           |    299759 |    304278 |  4519 |  1.51% |  1.51% |
| loop-delete.NumDeleted                           |      8055 |      8128 |    73 |  0.91% |  0.91% |
| machine-cse.NumCommutes                          |       111 |       110 |    -1 | -0.90% |  0.90% |
| globaldce.NumFunctions                           |      1187 |      1192 |     5 |  0.42% |  0.42% |
| codegenprepare.NumSelectsExpanded                |       277 |       278 |     1 |  0.36% |  0.36% |
| loop-unroll.NumRuntimeUnrolled                   |     13841 |     13791 |   -50 | -0.36% |  0.36% |
| machinelicm.NumPostRAHoisted                     |      1168 |      1172 |     4 |  0.34% |  0.34% |
| phi-node-elimination.NumCriticalEdgesSplit       |     83054 |     82879 |  -175 | -0.21% |  0.21% |
| machine-cse.NumPREs                              |      3085 |      3079 |    -6 | -0.19% |  0.19% |
| branch-folder.NumBranchOpts                      |    108122 |    107942 |  -180 | -0.17% |  0.17% |
| loop-unroll.NumUnrolled                          |     40136 |     40067 |   -69 | -0.17% |  0.17% |
| branch-folder.NumDeadBlocks                      |    130818 |    130607 |  -211 | -0.16% |  0.16% |
| codegenprepare.NumBlocksElim                     |     92856 |     92714 |  -142 | -0.15% |  0.15% |
| instsimplify.NumSimplified                       |    103263 |    103129 |  -134 | -0.13% |  0.13% |
| instcombine.NumConstProp                         |     26070 |     26102 |    32 |  0.12% |  0.12% |
| instsimplify.NumExpand                           |      1716 |      1718 |     2 |  0.12% |  0.12% |
| loop-unroll.NumCompletelyUnrolled                |      9236 |      9225 |   -11 | -0.12% |  0.12% |
| branch-folder.NumHoist                           |      2773 |      2770 |    -3 | -0.11% |  0.11% |
| regalloc.NumReloadsRemoved                       |     10822 |     10834 |    12 |  0.11% |  0.11% |
| regalloc.NumSnippets                             |     11394 |     11406 |    12 |  0.11% |  0.11% |
| machine-cse.NumCrossBBCSEs                       |      1052 |      1053 |     1 |  0.10% |  0.10% |
| machinelicm.NumCSEed                             |     99887 |     99784 |  -103 | -0.10% |  0.10% |
| branch-folder.NumTailMerge                       |     72501 |     72435 |   -66 | -0.09% |  0.09% |
| codegenprepare.NumExtUses                        |     22007 |     21987 |   -20 | -0.09% |  0.09% |
| local.NumRemoved                                 |     68232 |     68294 |    62 |  0.09% |  0.09% |
| loop-vectorize.LoopsAnalyzed                     |     75483 |     75413 |   -70 | -0.09% |  0.09% |
```

Note that i'm only changing current PM, and not touching obsolete PM.

This is an alternative to the function simplification pipeline variant
of the same change, D112840. It has both less compile time impact
(since the additional number of SCEV trip count calculations
is way lass less than with the D112840), and it is
much more powerful/impactful (almost 2x more loops deleted).

I have checked, and doing this after loop rotation
is favorable (more loops deleted).

Reviewed By: mkazantsev

Differential Revision: https://reviews.llvm.org/D112851
2021-11-03 19:24:49 +03:00
Arthur Eubanks 9fb0257b85 [test] Add missing pass name to new-pm-defaults.ll 2021-11-01 09:48:20 -07:00
Mircea Trofin ea4a6c8426 [Inline] Make sure the InlineAdvisor is correctly cleared.
If another inlining session came after a ModuleInlinerWrapperPass, the
advisor alanysis would still be cached, but its Result would be cleared.
We need to clear both.

This addresses PR52118

Differential Revision: https://reviews.llvm.org/D111586
2021-10-12 10:42:41 -07:00
Florian Hahn a7c6471a85
[Passes] Run vector-combine early with -fenable-matrix.
IR with matrix intrinsics is likely to also contain large vector
operations, which can benefit from early simplifications.

This is the last step in a series of changes to improve code-gen for
code using matrix subscript operators with the C/C++ matrix extension in
CLang, like

    using matrix_t = double __attribute__((matrix_type(15, 15)));

    void foo(unsigned i, matrix_t &A, matrix_t &B) {
      for (unsigned j = 0; j < 4; ++j)
        for (unsigned k = 0; k < i; k++)
          B[k][j] -= A[k][j] * B[i][j];
    }

https://clang.godbolt.org/z/6dKxK1Ed7

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D102496
2021-09-22 12:48:32 +01:00
Chuanqi Xu 8a1727ba51 [Coroutines] Run coroutine passes by default
This patch make coroutine passes run by default in LLVM pipeline. Now
the clang and opt could handle IR inputs containing coroutine intrinsics
without special options.
It should be fine. On the one hand, the coroutine passes seems to be stable
since there are already many projects using coroutine feature.
On the other hand, the coroutine passes should do nothing for IR who doesn't
contain coroutine intrinsic.

Test Plan: check-llvm

Reviewed by: lxfind, aeubanks

Differential Revision: https://reviews.llvm.org/D105877
2021-07-15 14:33:40 +08:00
Joseph Huber aaad46e6f5 [OpenMP] Run the OpenMPOpt module pass at O1
Now that the OpenMPOpt module pass include important optimizations for removing
globalization from offloading regions it should be run at a lower optimization
level.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D105056
2021-06-28 18:47:41 -04:00
Roman Lebedev e52364532a
[NewPM] Remove SpeculateAroundPHIs pass
Addition of this pass has been botched.
There is no particular reason why it had to be sold as an inseparable part
of new-pm transition. It was added when old-pm was still the default,
and very *very* few users were actually tracking new-pm,
so it's effects weren't measured.

Which means, some of the turnoil of the new-pm transition
are actually likely regressions due to this pass.

Likewise, there has been a number of post-commit feedback
(post new-pm switch), namely
* https://reviews.llvm.org/D37467#2787157 (regresses HW-loops)
* https://reviews.llvm.org/D37467#2787259 (should not be in middle-end, should run after LSR, not before)
* https://reviews.llvm.org/D95789 (an attempt to fix bad loop backedge metadata)
and in the half year past, the pass authors (google) still haven't found time to respond to any of that.

Hereby it is proposed to backout the pass from the pipeline,
until someone who cares about it can address the issues reported,
and properly start the process of adding a new pass into the pipeline,
with proper performance evaluation.

Furthermore, neither google nor facebook reports any perf changes
from this change, so i'm dropping the pass completely.
It can always be re-reverted should/if anyone want to pick it up again.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D104099
2021-06-15 20:35:55 +03:00
Florian Hahn 9a4506e759
[Matrix] Include matrix pipeline for new PM in new-pm-defaults.ll.
-enable-matrix just adds a single pass, so it's easier to just check in
new-pm-default.ll rather than duplicating the full checks for -O3 with
the new pass manager.

Suggested post-commit by @aeubanks.
2021-05-27 10:57:39 +01:00
Arthur Eubanks 34a8a437bf [NewPM] Hide pass manager debug logging behind -debug-pass-manager-verbose
Printing pass manager invocations is fairly verbose and not super
useful.

This allows us to remove DebugLogging from pass managers and PassBuilder
since all logging (aside from analysis managers) goes through
instrumentation now.

This has the downside of never being able to print the top level pass
manager via instrumentation, but that seems like a minor downside.

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D101797
2021-05-07 21:51:47 -07:00
Arthur Eubanks 2df3426fd1 [NewPM] Invalidate AAManager after populating GlobalsAA
GlobalsAA is only created at the beginning of the inliner pipeline.  If
an AAManager is cached from previous passes, it won't get rebuilt to
include the newly created GlobalsAA.

Reviewed By: mtrofin

Differential Revision: https://reviews.llvm.org/D101379
2021-05-03 16:37:32 -07:00
Gulfem Savrun Yeniceri 4423a7a09b [NewPM] Disable RelLookupTableConverter pass in LTO
Relative look table converter pass caused an issue when full lto
is enabled (reported in https://reviews.llvm.org/D94355).
This patch disables that pass from full lto pre-link phase optimization
pipeline until the issue is fixed.

Differential Revision: https://reviews.llvm.org/D101664
2021-04-30 21:23:40 +00:00
Joseph Huber b2ad63d3cf [OpenMP] Add OpenMPOpt as a Module pass
Summary:
This patch registers OpenMPOpt as a Module pass in addition to a CGSCC
pass. This is so certain optimzations that are sensitive to intact
call-sites can happen before inlining. The old `openmpopt` pass name is
changed to `openmp-opt-cgscc` and `openmp-opt` calls the Module pass.
The current module pass only runs a single check but will be expanded in
the future.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D99202
2021-04-20 12:28:58 -04:00
Gulfem Savrun Yeniceri e96df3e531 [Passes] Add relative lookup table converter pass
Lookup tables generate non PIC-friendly code, which requires dynamic relocation as described in:
https://bugs.llvm.org/show_bug.cgi?id=45244

This patch adds a new pass that converts lookup tables to relative lookup tables to make them PIC-friendly.

Differential Revision: https://reviews.llvm.org/D94355
2021-04-13 01:29:41 +00:00
Sanjay Patel 661cc71a1c [PassManager][PhaseOrdering] lower expects before running simplifyCFG
Retry of 330619a3a6 that includes a clang test update.

Original commit message:

If we run passes before lowering llvm.expect intrinsics to metadata,
then those passes have no way to act on the hints provided by llvm.expect.
SimplifyCFG is the known offender, and we made it smarter about profile
metadata in D98898 <https://reviews.llvm.org/D98898>.

In the motivating example from https://llvm.org/PR49336 , this means we
were ignoring the recommended method for a programmer to tell the compiler
that a compare+branch is expensive. This change appears to solve that case -
the metadata survives to the backend, the compare order is as expected in IR,
and the backend does not do anything to reverse it.

We make the same change to the old pass manager to keep things synchronized.

Differential Revision: https://reviews.llvm.org/D100213
2021-04-12 15:07:53 -04:00
Sanjay Patel 23ac9d1e6e Revert "[PassManager][PhaseOrdering] lower expects before running simplifyCFG"
This reverts commit 330619a3a6.
There are clang tests that also need to be updated.
2021-04-12 13:58:54 -04:00
Sanjay Patel 330619a3a6 [PassManager][PhaseOrdering] lower expects before running simplifyCFG
If we run passes before lowering llvm.expect intrinsics to metadata,
then those passes have no way to act on the hints provided by llvm.expect.
SimplifyCFG is the known offender, and we made it smarter about profile
metadata in D98898.

In the motivating example from https://llvm.org/PR49336 , this means we
were ignoring the recommended method for a programmer to tell the compiler
that a compare+branch is expensive. This change appears to solve that case -
the metadata survives to the backend, the compare order is as expected in IR,
and the backend does not do anything to reverse it.

We make the same change to the old pass manager to keep things synchronized.

Differential Revision: https://reviews.llvm.org/D100213
2021-04-12 12:23:31 -04:00
Yevgeny Rouban 39e3e3aa51 [NewPM] Redesign of PreserveCFG Checker
The reason for the NewPM redesign is described in the commit
  cba3e783389a: [NewPM] Disable PreservedCFGChecker ...

The checker introduces an internal custom CFG analysis that tracks
current up-to date CFG snapshot. The analysis is invalidated along
any other CFG related analysis (the key is CFGAnalyses). If the CFG
analysis is not invalidated at a functional pass exit then the checker
asserts that the CFG snapshot taken from this analysis is equals to
a snapshot of the current CFG.

Along the way:
- the function CFG::printDiff() is simplified by removing function
  name calculation. The name is printed by the caller;
- fixed CFG invalidated condition (see CFG::invalidate());
- StandardInstrumentations::registerCallbacks() gets additional
  optional parameter of type FunctionAnalysisManager*, which is
  needed by the checker to get the custom CFG analysis;
- several PM related tests updated to explicitly set
  -verify-cfg-preserved=1 as they need.

This patch is safe to land as the CFGChecker is left switched off
(the options -verify-cfg-preserved is false by default). It will be
switched on by a separate patch to minimize possible reverts.

Reviewed By: skatkov, kuhar

Differential Revision: https://reviews.llvm.org/D91327
2021-04-06 12:35:49 +07:00
Roman Lebedev a26f1bf67e
[PassManager] Run additional LICM before LoopRotate
Loop rotation often has to perform code duplication
from header into preheader, which introduces PHI nodes.

>>! In D99204, @thopre wrote:
>
> With loop peeling, it is important that unnecessary PHIs be avoided or
> it will leads to spurious peeling. One source of such PHIs is loop
> rotation which creates PHIs for invariant loads. Those PHIs are
> particularly problematic since loop peeling is now run as part of simple
> loop unrolling before GVN is run, and are thus a source of spurious
> peeling.
>
> Note that while some of the load can be hoisted and eventually
> eliminated by instruction combine, this is not always possible due to
> alignment issue. In particular, the motivating example [1] was a load
> inside a class instance which cannot be hoisted because the `this'
> pointer has an alignment of 1.
>
> [1] http://lists.llvm.org/pipermail/llvm-dev/attachments/20210312/4ce73c47/attachment.cpp

Now, we could enhance LoopRotate to avoid duplicating code when not needed,
but instead hoist loop-invariant code, but isn't that a code duplication? (*sic*)
We have LICM, and in fact we already run it right after LoopRotation.

We could try to move it to before LoopRotation,
that is basically free from compile-time perspective:
https://llvm-compile-time-tracker.com/compare.php?from=6c93eb4477d88af046b915bc955c03693b2cbb58&to=a4bee6d07732b1184c436da489040b912f0dc271&stat=instructions
But, looking at stats, i think it isn't great that we would no longer do LICM after LoopRotation, in particular:
| statistic name                                   | LoopRotate-LICM | LICM-LoopRotate |     Δ |       % | abs(%) |
| asm-printer.EmittedInsts                         | 9015930         | 9015799         |  -131 |   0.00% |  0.00% |
| indvars.NumElimCmp                               | 3536            | 3544            |     8 |   0.23% |  0.23% |
| indvars.NumElimExt                               | 36725           | 36580           |  -145 |  -0.39% |  0.39% |
| indvars.NumElimIV                                | 1197            | 1187            |   -10 |  -0.84% |  0.84% |
| indvars.NumElimIdentity                          | 143             | 136             |    -7 |  -4.90% |  4.90% |
| indvars.NumElimRem                               | 4               | 5               |     1 |  25.00% | 25.00% |
| indvars.NumLFTR                                  | 29842           | 29890           |    48 |   0.16% |  0.16% |
| indvars.NumReplaced                              | 2293            | 2227            |   -66 |  -2.88% |  2.88% |
| indvars.NumSimplifiedSDiv                        | 6               | 8               |     2 |  33.33% | 33.33% |
| indvars.NumWidened                               | 26438           | 26329           |  -109 |  -0.41% |  0.41% |
| instcount.TotalBlocks                            | 1178338         | 1173840         | -4498 |  -0.38% |  0.38% |
| instcount.TotalFuncs                             | 111825          | 111829          |     4 |   0.00% |  0.00% |
| instcount.TotalInsts                             | 9905442         | 9896139         | -9303 |  -0.09% |  0.09% |
| lcssa.NumLCSSA                                   | 425871          | 423961          | -1910 |  -0.45% |  0.45% |
| licm.NumHoisted                                  | 378357          | 378753          |   396 |   0.10% |  0.10% |
| licm.NumMovedCalls                               | 2193            | 2208            |    15 |   0.68% |  0.68% |
| licm.NumMovedLoads                               | 35899           | 31821           | -4078 | -11.36% | 11.36% |
| licm.NumPromoted                                 | 11178           | 11154           |   -24 |  -0.21% |  0.21% |
| licm.NumSunk                                     | 13359           | 13587           |   228 |   1.71% |  1.71% |
| loop-delete.NumDeleted                           | 8547            | 8402            |  -145 |  -1.70% |  1.70% |
| loop-instsimplify.NumSimplified                  | 12876           | 11890           |  -986 |  -7.66% |  7.66% |
| loop-peel.NumPeeled                              | 1008            | 925             |   -83 |  -8.23% |  8.23% |
| loop-rotate.NumNotRotatedDueToHeaderSize         | 368             | 365             |    -3 |  -0.82% |  0.82% |
| loop-rotate.NumRotated                           | 42015           | 42003           |   -12 |  -0.03% |  0.03% |
| loop-simplifycfg.NumLoopBlocksDeleted            | 240             | 242             |     2 |   0.83% |  0.83% |
| loop-simplifycfg.NumLoopExitsDeleted             | 497             | 20              |  -477 | -95.98% | 95.98% |
| loop-simplifycfg.NumTerminatorsFolded            | 618             | 336             |  -282 | -45.63% | 45.63% |
| loop-unroll.NumCompletelyUnrolled                | 11028           | 11032           |     4 |   0.04% |  0.04% |
| loop-unroll.NumUnrolled                          | 12608           | 12529           |   -79 |  -0.63% |  0.63% |
| mem2reg.NumDeadAlloca                            | 10222           | 10221           |    -1 |  -0.01% |  0.01% |
| mem2reg.NumPHIInsert                             | 192110          | 192106          |    -4 |   0.00% |  0.00% |
| mem2reg.NumSingleStore                           | 637650          | 637643          |    -7 |   0.00% |  0.00% |
| scalar-evolution.NumBruteForceTripCountsComputed | 814             | 812             |    -2 |  -0.25% |  0.25% |
| scalar-evolution.NumTripCountsComputed           | 283108          | 282934          |  -174 |  -0.06% |  0.06% |
| scalar-evolution.NumTripCountsNotComputed        | 106712          | 106718          |     6 |   0.01% |  0.01% |
| simple-loop-unswitch.NumBranches                 | 5178            | 4752            |  -426 |  -8.23% |  8.23% |
| simple-loop-unswitch.NumCostMultiplierSkipped    | 914             | 503             |  -411 | -44.97% | 44.97% |
| simple-loop-unswitch.NumSwitches                 | 20              | 18              |    -2 | -10.00% | 10.00% |
| simple-loop-unswitch.NumTrivial                  | 183             | 95              |   -88 | -48.09% | 48.09% |

... but that actually regresses LICM (-12% `licm.NumMovedLoads`),
loop-simplifycfg (`NumLoopExitsDeleted`, `NumTerminatorsFolded`),
simple-loop-unswitch (`NumTrivial`).

What if we instead have LICM both before and after LoopRotate?
| statistic name                                | LoopRotate-LICM | LICM-LoopRotate-LICM |     Δ |       % | abs(%) |
| asm-printer.EmittedInsts                      | 9015930         | 9014474              | -1456 |  -0.02% |  0.02% |
| indvars.NumElimCmp                            | 3536            | 3546                 |    10 |   0.28% |  0.28% |
| indvars.NumElimExt                            | 36725           | 36681                |   -44 |  -0.12% |  0.12% |
| indvars.NumElimIV                             | 1197            | 1185                 |   -12 |  -1.00% |  1.00% |
| indvars.NumElimIdentity                       | 143             | 146                  |     3 |   2.10% |  2.10% |
| indvars.NumElimRem                            | 4               | 5                    |     1 |  25.00% | 25.00% |
| indvars.NumLFTR                               | 29842           | 29899                |    57 |   0.19% |  0.19% |
| indvars.NumReplaced                           | 2293            | 2299                 |     6 |   0.26% |  0.26% |
| indvars.NumSimplifiedSDiv                     | 6               | 8                    |     2 |  33.33% | 33.33% |
| indvars.NumWidened                            | 26438           | 26404                |   -34 |  -0.13% |  0.13% |
| instcount.TotalBlocks                         | 1178338         | 1173652              | -4686 |  -0.40% |  0.40% |
| instcount.TotalFuncs                          | 111825          | 111829               |     4 |   0.00% |  0.00% |
| instcount.TotalInsts                          | 9905442         | 9895452              | -9990 |  -0.10% |  0.10% |
| lcssa.NumLCSSA                                | 425871          | 425373               |  -498 |  -0.12% |  0.12% |
| licm.NumHoisted                               | 378357          | 383352               |  4995 |   1.32% |  1.32% |
| licm.NumMovedCalls                            | 2193            | 2204                 |    11 |   0.50% |  0.50% |
| licm.NumMovedLoads                            | 35899           | 35755                |  -144 |  -0.40% |  0.40% |
| licm.NumPromoted                              | 11178           | 11163                |   -15 |  -0.13% |  0.13% |
| licm.NumSunk                                  | 13359           | 14321                |   962 |   7.20% |  7.20% |
| loop-delete.NumDeleted                        | 8547            | 8538                 |    -9 |  -0.11% |  0.11% |
| loop-instsimplify.NumSimplified               | 12876           | 12041                |  -835 |  -6.48% |  6.48% |
| loop-peel.NumPeeled                           | 1008            | 924                  |   -84 |  -8.33% |  8.33% |
| loop-rotate.NumNotRotatedDueToHeaderSize      | 368             | 365                  |    -3 |  -0.82% |  0.82% |
| loop-rotate.NumRotated                        | 42015           | 42005                |   -10 |  -0.02% |  0.02% |
| loop-simplifycfg.NumLoopBlocksDeleted         | 240             | 241                  |     1 |   0.42% |  0.42% |
| loop-simplifycfg.NumTerminatorsFolded         | 618             | 619                  |     1 |   0.16% |  0.16% |
| loop-unroll.NumCompletelyUnrolled             | 11028           | 11029                |     1 |   0.01% |  0.01% |
| loop-unroll.NumUnrolled                       | 12608           | 12525                |   -83 |  -0.66% |  0.66% |
| mem2reg.NumPHIInsert                          | 192110          | 192073               |   -37 |  -0.02% |  0.02% |
| mem2reg.NumSingleStore                        | 637650          | 637652               |     2 |   0.00% |  0.00% |
| scalar-evolution.NumTripCountsComputed        | 283108          | 282998               |  -110 |  -0.04% |  0.04% |
| scalar-evolution.NumTripCountsNotComputed     | 106712          | 106691               |   -21 |  -0.02% |  0.02% |
| simple-loop-unswitch.NumBranches              | 5178            | 5185                 |     7 |   0.14% |  0.14% |
| simple-loop-unswitch.NumCostMultiplierSkipped | 914             | 925                  |    11 |   1.20% |  1.20% |
| simple-loop-unswitch.NumTrivial               | 183             | 179                  |    -4 |  -2.19% |  2.19% |
| simple-loop-unswitch.NumBranches              | 5178            | 4752                 |  -426 |  -8.23% |  8.23% |
| simple-loop-unswitch.NumCostMultiplierSkipped | 914             | 503                  |  -411 | -44.97% | 44.97% |
| simple-loop-unswitch.NumSwitches              | 20              | 18                   |    -2 | -10.00% | 10.00% |
| simple-loop-unswitch.NumTrivial               | 183             | 95                   |   -88 | -48.09% | 48.09% |

I.e. we end up with less instructions, less peeling, more LICM activity,
also note how none of those 4 regressions are here. Namely:

| statistic name                                   | LICM-LoopRotate | LICM-LoopRotate-LICM |     Δ |        % |   abs(%) |
| asm-printer.EmittedInsts                         | 9015799         | 9014474              | -1325 |   -0.01% |    0.01% |
| indvars.NumElimCmp                               | 3544            | 3546                 |     2 |    0.06% |    0.06% |
| indvars.NumElimExt                               | 36580           | 36681                |   101 |    0.28% |    0.28% |
| indvars.NumElimIV                                | 1187            | 1185                 |    -2 |   -0.17% |    0.17% |
| indvars.NumElimIdentity                          | 136             | 146                  |    10 |    7.35% |    7.35% |
| indvars.NumLFTR                                  | 29890           | 29899                |     9 |    0.03% |    0.03% |
| indvars.NumReplaced                              | 2227            | 2299                 |    72 |    3.23% |    3.23% |
| indvars.NumWidened                               | 26329           | 26404                |    75 |    0.28% |    0.28% |
| instcount.TotalBlocks                            | 1173840         | 1173652              |  -188 |   -0.02% |    0.02% |
| instcount.TotalInsts                             | 9896139         | 9895452              |  -687 |   -0.01% |    0.01% |
| lcssa.NumLCSSA                                   | 423961          | 425373               |  1412 |    0.33% |    0.33% |
| licm.NumHoisted                                  | 378753          | 383352               |  4599 |    1.21% |    1.21% |
| licm.NumMovedCalls                               | 2208            | 2204                 |    -4 |   -0.18% |    0.18% |
| licm.NumMovedLoads                               | 31821           | 35755                |  3934 |   12.36% |   12.36% |
| licm.NumPromoted                                 | 11154           | 11163                |     9 |    0.08% |    0.08% |
| licm.NumSunk                                     | 13587           | 14321                |   734 |    5.40% |    5.40% |
| loop-delete.NumDeleted                           | 8402            | 8538                 |   136 |    1.62% |    1.62% |
| loop-instsimplify.NumSimplified                  | 11890           | 12041                |   151 |    1.27% |    1.27% |
| loop-peel.NumPeeled                              | 925             | 924                  |    -1 |   -0.11% |    0.11% |
| loop-rotate.NumRotated                           | 42003           | 42005                |     2 |    0.00% |    0.00% |
| loop-simplifycfg.NumLoopBlocksDeleted            | 242             | 241                  |    -1 |   -0.41% |    0.41% |
| loop-simplifycfg.NumLoopExitsDeleted             | 20              | 497                  |   477 | 2385.00% | 2385.00% |
| loop-simplifycfg.NumTerminatorsFolded            | 336             | 619                  |   283 |   84.23% |   84.23% |
| loop-unroll.NumCompletelyUnrolled                | 11032           | 11029                |    -3 |   -0.03% |    0.03% |
| loop-unroll.NumUnrolled                          | 12529           | 12525                |    -4 |   -0.03% |    0.03% |
| mem2reg.NumDeadAlloca                            | 10221           | 10222                |     1 |    0.01% |    0.01% |
| mem2reg.NumPHIInsert                             | 192106          | 192073               |   -33 |   -0.02% |    0.02% |
| mem2reg.NumSingleStore                           | 637643          | 637652               |     9 |    0.00% |    0.00% |
| scalar-evolution.NumBruteForceTripCountsComputed | 812             | 814                  |     2 |    0.25% |    0.25% |
| scalar-evolution.NumTripCountsComputed           | 282934          | 282998               |    64 |    0.02% |    0.02% |
| scalar-evolution.NumTripCountsNotComputed        | 106718          | 106691               |   -27 |   -0.03% |    0.03% |
| simple-loop-unswitch.NumBranches                 | 4752            | 5185                 |   433 |    9.11% |    9.11% |
| simple-loop-unswitch.NumCostMultiplierSkipped    | 503             | 925                  |   422 |   83.90% |   83.90% |
| simple-loop-unswitch.NumSwitches                 | 18              | 20                   |     2 |   11.11% |   11.11% |
| simple-loop-unswitch.NumTrivial                  | 95              | 179                  |    84 |   88.42% |   88.42% |

{F15983613} {F15983615} {F15983616}
(this is vanilla llvm testsuite + rawspeed + darktable)

As an example of the code where early LICM only is bad, see:
https://godbolt.org/z/GzEbacs4K

This does have an observable compile-time regression of +~0.5% geomean
https://llvm-compile-time-tracker.com/compare.php?from=7c5222e4d1a3a14f029e5f614c9aefd0fa505f1e&to=5d81826c3411982ca26e46b9d0aff34c80577664&stat=instructions
but i think that's basically nothing, and there's potential that it might
be avoidable in the future by fixing clang to produce alignment information
on function arguments, thus making the second run unneeded.

Differential Revision: https://reviews.llvm.org/D99249
2021-04-02 11:11:42 +03:00
Krasimir Georgiev c51e91e046 Revert "[Passes] Add relative lookup table converter pass"
This reverts commit 5178ffc7cf.

Compiling `llvm-profdata` with a compiler build from this produces a
crashing binary.
2021-03-30 14:13:37 +02:00
Gulfem Savrun Yeniceri 5178ffc7cf [Passes] Add relative lookup table converter pass
Lookup tables generate non PIC-friendly code, which requires dynamic relocation as described in:
https://bugs.llvm.org/show_bug.cgi?id=45244

This patch adds a new pass that converts lookup tables to relative lookup tables to make them PIC-friendly.

Differential Revision: https://reviews.llvm.org/D94355
2021-03-29 21:53:32 +00:00
Gulfem Savrun Yeniceri 5fbe1fdf17 Revert "[Passes] Add relative lookup table converter pass"
This reverts commit 5fd001a5ff
because it broke clang-with-thin-lto-ubuntu bot.
2021-03-24 18:59:33 +00:00
Gulfem Savrun Yeniceri 5fd001a5ff [Passes] Add relative lookup table converter pass
Lookup tables generate non PIC-friendly code, which requires dynamic relocation as described in:
https://bugs.llvm.org/show_bug.cgi?id=45244

This patch adds a new pass that converts lookup tables to relative lookup tables to make them PIC-friendly.

Differential Revision: https://reviews.llvm.org/D94355
2021-03-24 17:31:18 +00:00
Gulfem Savrun Yeniceri e3a6d70c68 Revert "[Passes] Add relative lookup table converter pass"
This reverts commit 78a65cd945 which
caused buildbot failures.
2021-03-23 00:43:16 +00:00
Gulfem Savrun Yeniceri 78a65cd945 [Passes] Add relative lookup table converter pass
Lookup tables generate non PIC-friendly code, which requires dynamic relocation as described in:
https://bugs.llvm.org/show_bug.cgi?id=45244

This patch adds a new pass that converts lookup tables to relative lookup tables to make them PIC-friendly.

Differential Revision: https://reviews.llvm.org/D94355
2021-03-22 22:09:02 +00:00
Nikita Popov 71a8e4e7d6 [MemCopyOpt] Enable MemorySSA by default
This enables use of MemorySSA instead of MemDep in MemCpyOpt. To
allow this without significant compile-time impact, the MemCpyOpt
pass is moved directly before DSE (in the cases where this was not
already the case), which allows us to reuse the existing MemorySSA
analysis.

Unlike the MemDep-based implementation, the MemorySSA-based MemCpyOpt
can also perform simple optimizations across basic blocks.

Differential Revision: https://reviews.llvm.org/D94376
2021-02-19 18:06:25 +01:00
Arthur Eubanks 6699029b67 [NewPM][opt] Run the "default" AA pipeline by default
We tend to assume that the AA pipeline is by default the default AA
pipeline and it's confusing when it's empty instead.

PR48779

Initially reverted due to BasicAA running analyses in an unspecified
order (multiple function calls as parameters), fixed by fetching
analyses before the call to construct BasicAA.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D95117
2021-01-21 21:08:54 -08:00
Arthur Eubanks ba9b4ea4ee Revert "[NewPM][opt] Run the "default" AA pipeline by default"
This reverts commit be611431cd.

Other/new-pm-lto-defaults.ll failing
2021-01-21 20:16:34 -08:00