Commit Graph

34 Commits

Author SHA1 Message Date
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 872c57c90a [NewPM] Change tests to run them without PreserveCFGChecker. NFC
Change several pass sequence sensitive tests to be indifferent
to the PreserveCFGChecker by explicitly settting the option
-verify-cfg-preserved=0. It is a preparation step that allows
a redesign of PreserveCFGChecker.

Reviewed By: skatkov

Differential Revision: https://reviews.llvm.org/D99878
2021-04-06 11:33:07 +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
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
Arthur Eubanks be611431cd [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

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D95117
2021-01-21 19:46:38 -08:00
Mircea Trofin e8049dc3c8 [NewPM][Inliner] Move the 'always inliner' case in the same CGSCC pass as 'regular' inliner
Expanding from D94808 - we ensure the same InlineAdvisor is used by both
InlinerPass instances. The notion of mandatory inlining is moved into
the core InlineAdvisor: advisors anyway have to handle that case, so
this change also factors out that a bit better.

Differential Revision: https://reviews.llvm.org/D94825
2021-01-15 17:59:38 -08:00
Mircea Trofin 5fe10263ab [llvm][inliner] Reuse the inliner pass to implement 'always inliner'
Enable performing mandatory inlinings upfront, by reusing the same logic
as the full inliner, instead of the AlwaysInliner. This has the
following benefits:
- reduce code duplication - one inliner codebase
- open the opportunity to help the full inliner by performing additional
function passes after the mandatory inlinings, but before th full
inliner. Performing the mandatory inlinings first simplifies the problem
the full inliner needs to solve: less call sites, more contextualization, and,
depending on the additional function optimization passes run between the
2 inliners, higher accuracy of cost models / decision policies.

Note that this patch does not yet enable much in terms of post-always
inline function optimization.

Differential Revision: https://reviews.llvm.org/D91567
2020-11-30 12:03:39 -08:00
Roman Lebedev a8d74517dc
[PassManager] Run Induction Variable Simplification pass *after* Recognize loop idioms pass, not before
Currently, `-indvars` runs first, and then immediately after `-loop-idiom` does.
I'm not really sure if `-loop-idiom` requires `-indvars` to run beforehand,
but i'm *very* sure that `-indvars` requires `-loop-idiom` to run afterwards,
as it can be seen in the phase-ordering test.

LoopIdiom runs on two types of loops: countable ones, and uncountable ones.
For uncountable ones, IndVars obviously didn't make any change to them,
since they are uncountable, so for them the order should be irrelevant.
For countable ones, well, they should have been countable before IndVars
for IndVars to make any change to them, and since SCEV is used on them,
it shouldn't matter if IndVars have already canonicalized them.
So i don't really see why we'd want the current ordering.

Should this cause issues, it will give us a reproducer test case
that shows flaws in this logic, and we then could adjust accordingly.

While this is quite likely beneficial in-the-wild already,
it's a required part for the full motivational pattern
behind `left-shift-until-bittest` loop idiom (D91038).

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D91800
2020-11-25 19:20:07 +03:00
Arthur Eubanks 72badbcdcc [NPM] Move more O0 pass building into PassBuilder
This moves handling of alwaysinline, coroutines, matrix lowering, PGO,
and LTO-required passes into PassBuilder. Much of this is replicated
between Clang and opt. Other out-of-tree users also replicate some of
this, such as Rust [1] replicating the alwaysinline, LTO, and PGO
passes.

The LTO passes are also now run in
build(Thin)LTOPreLinkDefaultPipeline() since they are semantically
required for (Thin)LTO.

[1]: f5230fbf76/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp (L896)

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D91585
2020-11-19 11:22:23 -08:00
Florian Hahn 8dbe44cb29 Add pass to add !annotate metadata from @llvm.global.annotations.
This patch adds a new pass to add !annotation metadata for entries in
@llvm.global.anotations, which is generated  using
__attribute__((annotate("_name"))) on functions in Clang.

This has been discussed on llvm-dev as part of
    RFC: Combining Annotation Metadata and Remarks
    http://lists.llvm.org/pipermail/llvm-dev/2020-November/146393.html

Reviewed By: thegameg

Differential Revision: https://reviews.llvm.org/D91195
2020-11-16 14:57:11 +00:00
Florian Hahn 8bb6347939
Add !annotation metadata and remarks pass.
This patch adds a new !annotation metadata kind which can be used to
attach annotation strings to instructions.

It also adds a new pass that emits summary remarks per function with the
counts for each annotation kind.

The intended uses cases for this new metadata is annotating
'interesting' instructions and the remarks should provide additional
insight into transformations applied to a program.

To motivate this, consider these specific questions we would like to get answered:

* How many stores added for automatic variable initialization remain after optimizations? Where are they?
* How many runtime checks inserted by a frontend could be eliminated? Where are the ones that did not get eliminated?

Discussed on llvm-dev as part of 'RFC: Combining Annotation Metadata and Remarks'
(http://lists.llvm.org/pipermail/llvm-dev/2020-November/146393.html)

Reviewed By: thegameg, jdoerfert

Differential Revision: https://reviews.llvm.org/D91188
2020-11-13 13:24:10 +00:00
Fangrui Song 19dc6ec957 [test] Fix unused check prefixes in test/Linker/ and test/Other/ 2020-10-29 21:54:56 -07:00
Arthur Eubanks 0291e2c933 [Inliner] Run always-inliner in inliner-wrapper
An alwaysinline function may not get inlined in inliner-wrapper due to
the inlining order.

Previously for the following, the inliner would first inline @a() into @b(),

```
define void @a() {
entry:
  call void @b()
  ret void
}

define void @b() alwaysinline {
entry:
  br label %for.cond

for.cond:
  call void @a()
  br label %for.cond
}
```

making @b() recursive and unable to be inlined into @a(), ending at

```
define void @a() {
entry:
  call void @b()
  ret void
}

define void @b() alwaysinline {
entry:
  br label %for.cond

for.cond:
  call void @b()
  br label %for.cond
}
```

Running always-inliner first makes sure that we respect alwaysinline in more cases.

Fixes https://bugs.llvm.org/show_bug.cgi?id=46945.

Reviewed By: davidxl, rnk

Differential Revision: https://reviews.llvm.org/D86988
2020-10-22 19:16:25 -07:00
Florian Hahn 88241ffb56 [Passes] Move ADCE before DSE & LICM.
The adjustment seems to have very little impact on optimizations.
The only binary change with -O3 MultiSource/SPEC2000/SPEC2006 on X86 is
in consumer-typeset and the size there actually decreases by -0.1%, with
not significant changes in the stats.

On its own, it is mildly positive in terms of compile-time, most likely
due to LICM & DSE having to process slightly less instructions. It
should also be unlikely that DSE/LICM make much new code dead.

http://llvm-compile-time-tracker.com/compare.php?from=df63eedef64d715ce1f31843f7de9c11fe1e597f&to=e3bdfcf94a9eeae6e006d010464f0c1b3550577d&stat=instructions

With DSE & MemorySSA, it gives some nice compile-time improvements, due
to the fact that DSE can re-use the PDT from ADCE, if it does not make
any changes:

http://llvm-compile-time-tracker.com/compare.php?from=15fdd6cd7c24c745df1bb419e72ff66fd138aa7e&to=481f494515fc89cb7caea8d862e40f2c910dc994&stat=instructions

Reviewed By: xbolva00

Differential Revision: https://reviews.llvm.org/D87322
2020-10-21 10:30:56 +01:00
Yuanfang Chen 2c94d88e07 [NewPM] collapsing nested pass mangers of the same type
This is one of the reason for extra invalidations in D84959. In
practice, I don't think we have use cases needing this. This simplifies
the pipeline a bit and prune corner cases when considering
invalidations.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D85676
2020-10-04 15:57:13 -07:00
Nikita Popov 25af353b0e [NewPM][LVI] Abandon LVI after CVP
As mentioned on D70376, LVI can currently cause performance issues
when running under NewPM. The problem is that, unlike the legacy
pass manager, NewPM will not immediately discard the LVI analysis
if the following pass does not need it. This is a problem, because
LVI has a high memory requirement, and mass invalidation of LVI
values is very inefficient. LVI should only be alive during passes
that actively interact with it.

This patch addresses the issue by explicitly abandoning LVI after CVP,
which gets us back to the LegacyPM behavior.

Differential Revision: https://reviews.llvm.org/D84959
2020-08-01 23:47:46 +02:00
Yuanfang Chen 555cf42f38 [NewPM][PassInstrument] Add PrintPass callback to StandardInstrumentations
Problem:
Right now, our "Running pass" is not accurate when passes are wrapped in adaptor because adaptor is never skipped and a pass could be skipped. The other problem is that "Running pass" for a adaptor is before any "Running pass" of passes/analyses it depends on. (for example, FunctionToLoopPassAdaptor). So the order of printing is not the actual order.

Solution:
Doing things like PassManager::Debuglogging is very intrusive because we need to specify Debuglogging whenever adaptor is created. (Actually, right now we're not specifying Debuglogging for some sub-PassManagers. Check PassBuilder)

This patch move debug logging for pass as a PassInstrument callback. We could be sure that all running passes are logged and in the correct order.

This could also be used to implement hierarchy pass logging in legacy PM. We could also move logging of pass manager to this if we want.

The test fixes looks messy. It includes changes:
- Remove PassInstrumentationAnalysis
- Remove PassAdaptor
- If a PassAdaptor is for a real pass, the pass is added
- Pass reorder (to the correct order), related to PassAdaptor
- Add missing passes (due to Debuglogging not passed down)

Reviewed By: asbirlea, aeubanks

Differential Revision: https://reviews.llvm.org/D84774
2020-07-30 10:07:57 -07:00
Mircea Trofin d6695e1876 [llvm] Add interface to drive inlining decision using ML model
Summary:

This change introduces InliningAdvisor (and related APIs), the interface
that abstracts decision making away from the inlining pass. We will use
this interface to delegate decision making to a trained ML model,
subsequently (see referenced RFC).

RFC: http://lists.llvm.org/pipermail/llvm-dev/2020-April/140763.html

Reviewers: davidxl, eraman, dblaikie

Subscribers: mgorny, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79042
2020-05-13 13:27:29 -07:00
Whitney Tsang 5c10c6e012 [PassBuilder] Moved ProfileSummaryAnalysis in buildInlinerPipeline.
Summary:
As commented in the code, ProfileSummaryAnalysis is required for inliner
pass to query, so this patch moved
RequireAnalysisPass<ProfileSummaryAnalysis> in the recently created
buildInlinerPipeline.
Reviewer: mtrofin, davidxl, tejohnson, dblaikie, jdoerfert, sstefan1
Reviewed By: mtrofin, davidxl, jdoerfert
Subscribers: hiraditya, steven_wu, dexonsmith, wuzish, llvm-commits,
jsji
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D79696
2020-05-12 16:00:40 +00:00
Evgeniy Brevnov 3e68a66704 [BPI][NFC] Reuse post dominantor tree from analysis manager when available
Summary: Currenlty BPI unconditionally creates post dominator tree each time. While this is not incorrect we can save compile time by reusing existing post dominator tree (when it's valid) provided by analysis manager.

Reviewers: skatkov, taewookoh, yrouban

Reviewed By: skatkov

Subscribers: hiraditya, steven_wu, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78987
2020-04-30 11:31:03 +07:00
Mircea Trofin c3770c5d6d [llvm][NFC] Factor out inlining pipeline as a module pipeline.
Summary:
This simplifies testing in scenarios where we want to set up module-wide
analyses for inlining. The patch enables treating inlining and its
function cleanups, as a module pass. The alternative would be for tests
to describe the pipeline, which is tedious and adds maintenance
overhead.

Reviewers: davidxl, dblaikie, jdoerfert, sstefan1

Subscribers: hiraditya, steven_wu, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78512
2020-04-24 09:24:12 -07:00
Tarindu Jayatilaka b43b59fcc0 Expose `attributor-disable` to the new and old pass managers
The new and old pass managers (PassManagerBuilder.cpp and
PassBuilder.cpp) are exposed to an `extern` declaration of
`attributor-disable` option which will guard the addition of the
attributor passes to the pass pipelines.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D76871
2020-04-05 22:29:34 -05:00
Alina Sbirlea 4f33a68973 Compute ORE, BPI, BFI in Loop passes.
Summary:
Passes ORE, BPI, BFI are not being preserved by Loop passes, hence it
is incorrect to retrieve these passes as cached.
This patch makes the loop passes in question compute a new instance.

In some of these cases, however, it may be beneficial to change the Loop pass to
a Function pass instead, similar to the change for LoopUnrollAndJam.

Reviewers: chandlerc, dmgreen, jdoerfert, reames

Subscribers: mehdi_amini, hiraditya, zzheng, steven_wu, dexonsmith, Whitney, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72891
2020-02-12 09:15:18 -08:00
Johannes Doerfert b0c77c36d2 [Attributor] Add an Attributor CGSCC pass and run it
In addition to the module pass, this patch introduces a CGSCC pass that
runs the Attributor on a strongly connected component of the call graph
(both old and new PM). The Attributor was always design to be used on a
subset of functions which makes this patch mostly mechanical.

The one change is that we give up `norecurse` deduction in the module
pass in favor of doing it during the CGSCC pass. This makes the
interfaces simpler but can be revisited if needed.

Reviewed By: hfinkel

Differential Revision: https://reviews.llvm.org/D70767
2020-02-08 21:27:34 -06:00
Johannes Doerfert 98e8eb8be0 [FIX] Update PM tests after D69930 landed 2020-02-08 15:22:40 -06:00
Teresa Johnson 24a00ef240 Restore "[ThinLTO] Add additional ThinLTO pipeline testing with new PM"
This restores 2af97be802 (reverted at
6288f86e87), with all the fixes I had
applied at the time, along with a new fix for non-determinism in the
ordering of a couple of passes due to being accessed as parameters on
the same call.

I've also added --dump-input=fail to the new tests so I can more
thoroughly fix any additional failures.
2020-01-15 07:33:08 -08:00
Teresa Johnson 6288f86e87 Revert "[ThinLTO] Add additional ThinLTO pipeline testing with new PM"
This reverts commit 2af97be802.

After attempting to fix bot failures from matching issues (mostly due to
inconsistent printing of "llvm::" prefixes on objects, and
AnalysisManager objects being printed differntly, I am now seeing some
differences I don't understand (real differences in the passes being
printed). Giving up at this point to allow the bots to recover. Will
revisit later.
2020-01-13 11:01:48 -08:00
Teresa Johnson 7aed43b607 Hopefully last fix for bot failures
Hopefully final bot fix for last few failures from
2af97be802.

Looks like sometimes the "llvm::" preceeding objects get printed in the
debug pass manager output and sometimes they don't. Replace with
wildcard matching.
2020-01-13 10:34:54 -08:00
Teresa Johnson 292562c004 Try number 2 for fixing bot failures
Additional fixes for bot failures from 2af97be802.
Remove more exact matching on AnalyisManagers, as they can vary.
Also allow different orders between LoopAnalysis and
BranchProbabilityAnalysis as that can vary due to both being accessed in
the parameter list of a call.
2020-01-13 10:12:35 -08:00
Teresa Johnson bb2e5f5e45 Fix tests for builtbot failures
Should fix most of the buildbot failures from
2af97be802, by loosening up the matching
on the AnalysisProxy output.

Added in --dump-input=fail on the one test that appears to be something
different, so I can hopefully debug it better.
2020-01-13 09:28:13 -08:00
Teresa Johnson 2af97be802 [ThinLTO] Add additional ThinLTO pipeline testing with new PM
Summary:
I've added some more extensive ThinLTO pipeline testing with the new PM,
motivated by the bug fixed in D72386.

I beefed up llvm/test/Other/new-pm-pgo.ll a little so that it tests
ThinLTO pre and post link with PGO, similar to the testing for the
default pipelines with PGO.

Added new pre and post link PGO tests for both instrumentation and
sample PGO that exhaustively test the pipelines at different
optimization levels via opt.

Added a clang test to exhaustively test the post link pipeline invoked for
distributed builds. I am currently only testing O2 and O3 since these
are the most important for performance.

It would be nice to add similar exhaustive testing for full LTO, and for
the old PM, but I don't have the bandwidth now and this is a start to
cover some of the situations that are not currently default and were
under tested.

Reviewers: wmi

Subscribers: mehdi_amini, inglorion, hiraditya, steven_wu, dexonsmith, jfb, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D72538
2020-01-13 08:29:56 -08:00