Commit Graph

588 Commits

Author SHA1 Message Date
Teresa Johnson 17f8c800c4 [Inliner] Remove incorrect early exit during switch cost computation
Summary:
The CallAnalyzer::visitSwitchInst has an early exit when the estimated
lower bound of the switch cost will put the overall cost of the inline
above the threshold. However, this code is not correctly estimating the
lower bound for switches that can be transformed into bit tests, leading
to unnecessary lost inlines, and also differing behavior with
optimization remarks enabled.

First, the early exit is controlled by whether ComputeFullInlineCost is
enabled or not, and that in turn is disabled by default but enabled when
enabling -pass-remarks=missed. This by itself wouldn't lead to a
problem, except that as described below, the lower bound can be above
the real lower bound, so we can sometimes get different inline decisions
with inline remarks enabled, which is problematic.

The early exit was added in along with a new switch cost model in D31085.
The reason why this early exit was added is due to a concern one reviewer
raised about compile time for large switches:
https://reviews.llvm.org/D31085?id=94559#inline-276200

However, the code just below there calls
getEstimatedNumberOfCaseClusters, which in turn immediately calls
BasicTTIImpl getEstimatedNumberOfCaseClusters, which in the worst case
does a linear scan of the cases to get the high and low values. The
bit test handling in particular is guarded by whether the number of
cases fits into the max bit width. There is no suggestion that anyone
measured a compile time issue, it appears to be theoretical.

The problem is that the reviewer's comment about the lower bound
calculation is incorrect, specifically in the case of a switch that can
be lowered to a bit test. This isn't followed up on the comment
thread, but the author does add a FIXME to that effect above the early
exit added when they subsequently revised the patch.

As a result, we were incorrectly early exiting and not inlining
functions with switch statements that would be lowered to bit tests in
cases where we were nearing the threshold. Combined with the fact that
this early exit was skipped with opt remarks enabled, this caused
different inlining decisions to be made when -pass-remarks=missed is
enabled to debug the missing inline.

Remove the early exit for the above reasons.

I also copied over an existing AArch64 inlining test to X86, and
adjusted the threshold so that the bit test inline only occurs with the
fix in this patch.

Reviewers: davidxl

Subscribers: eraman, kristof.beyls, haicheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67716

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@372440 91177308-0d34-0410-b5e6-96231b3b80d8
2019-09-20 23:29:17 +00:00
Clement Courbet f24f9a875a [Inliner][NFC] Make test less brittle.
Summary:
This tests inlining size thresholds, but relies on the output of running
the full O2 pipeline, making it brittle against changes in unrelated
passes.

Only run the inlining pass and set thresholds on the test RUN line
instead.

Found while investigating D60318.

Reviewers: RKSimon, qcolombet

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67349

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@371397 91177308-0d34-0410-b5e6-96231b3b80d8
2019-09-09 13:08:16 +00:00
Hideto Ueno 204c769d62 [FunctionAttrs] Annotate "willreturn" for intrinsics
Summary:
In D62801, new function attribute `willreturn` was introduced. In short, a function with `willreturn` is guaranteed to come back to the call site(more precise definition is in LangRef).

In this patch, willreturn is annotated for LLVM intrinsics.

Reviewers: jdoerfert

Reviewed By: jdoerfert

Subscribers: jvesely, nhaehnle, sstefan1, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64904

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@367184 91177308-0d34-0410-b5e6-96231b3b80d8
2019-07-28 06:09:56 +00:00
Daniil Fukalov 7768f31c04 [AMDGPU] Tune inlining parameters for AMDGPU target
Summary:
Since the target has no significant advantage of vectorization,
vector instructions bous threshold bonus should be optional.

amdgpu-inline-arg-alloca-cost parameter default value and the target
InliningThresholdMultiplier value tuned then respectively.

Reviewers: arsenm, rampitec

Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, eraman, hiraditya, haicheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64642

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@366348 91177308-0d34-0410-b5e6-96231b3b80d8
2019-07-17 16:51:29 +00:00
Evgeniy Stepanov 8060f84343 ARM MTE stack sanitizer.
Add "memtag" sanitizer that detects and mitigates stack memory issues
using armv8.5 Memory Tagging Extension.

It is similar in principle to HWASan, which is a software implementation
of the same idea, but there are enough differencies to warrant a new
sanitizer type IMHO. It is also expected to have very different
performance properties.

The new sanitizer does not have a runtime library (it may grow one
later, along with a "debugging" mode). Similar to SafeStack and
StackProtector, the instrumentation pass (in a follow up change) will be
inserted in all cases, but will only affect functions marked with the
new sanitize_memtag attribute.

Reviewers: pcc, hctim, vitalybuka, ostannard

Subscribers: srhines, mehdi_amini, javed.absar, kristof.beyls, hiraditya, cryptoad, steven_wu, dexonsmith, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D64169

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@366123 91177308-0d34-0410-b5e6-96231b3b80d8
2019-07-15 20:02:23 +00:00
Jordan Rupprecht 25fd8235ff Revert [InlineCost] cleanup calculations of Cost and Threshold
This reverts r364422 (git commit 1a3dc761860d620ac8ed7e32a4285952142f780b)

The inlining cost calculation is incorrect, leading to stack overflow due to large stack frames from heavy inlining.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365000 91177308-0d34-0410-b5e6-96231b3b80d8
2019-07-03 04:01:51 +00:00
Fedor Sergeev 9c871764b9 [InlineCost] cleanup calculations of Cost and Threshold
Summary:
Doing better separation of Cost and Threshold.
Cost counts the abstract complexity of live instructions, while Threshold is an upper bound of complexity that inlining is comfortable to pay.
There are two parts:
     - huge 15K last-call-to-static bonus is no longer subtracted from Cost
       but rather is now added to Threshold.

       That makes much more sense, as the cost of inlining (Cost) is not changed by the fact
       that internal function is called once. It only changes the likelyhood of this inlining
       being profitable (Threshold).

     - bonus for calls proved-to-be-inlinable into callee is no longer subtracted from Cost
       but added to Threshold instead.

While calculations are somewhat different,  overall InlineResult should stay the same since Cost >= Threshold compares the same.

Reviewers: eraman, greened, chandlerc, yrouban, apilipenko
Reviewed By: apilipenko
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60740

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364422 91177308-0d34-0410-b5e6-96231b3b80d8
2019-06-26 13:24:24 +00:00
Fangrui Song 1002960b9d [lit] Delete empty lines at the end of lit.local.cfg NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363538 91177308-0d34-0410-b5e6-96231b3b80d8
2019-06-17 09:51:07 +00:00
David Bolvansky b6ab2ccd59 [NFC] Added test from PR42084 for D63058
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362906 91177308-0d34-0410-b5e6-96231b3b80d8
2019-06-09 14:56:46 +00:00
Craig Topper d55132f7cf [InlineCost] Add support for unary fneg.
This adds support for unary fneg based on the implementation of BinaryOperator without the soft float FP cost.

Previously we would just delegate to visitUnaryInstruction. I think the only real change is that we will pass the FastMath flags to SimplifyFNeg now.

Differential Revision: https://reviews.llvm.org/D62699

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362732 91177308-0d34-0410-b5e6-96231b3b80d8
2019-06-06 19:02:18 +00:00
Craig Topper 1f535d6428 [InlineCost] Don't add the soft float function call cost for the fneg idiom, fsub -0.0, %x
Summary: Fneg can be implemented with an xor rather than a function call so we don't need to add the function call overhead. This was pointed out in D62699

Reviewers: efriedma, cameron.mcinally

Reviewed By: efriedma

Subscribers: javed.absar, eraman, hiraditya, haicheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62747

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362304 91177308-0d34-0410-b5e6-96231b3b80d8
2019-06-01 19:40:07 +00:00
Stanislav Mekhanoshin 66f50791b8 [AMDGPU] Use InliningThresholdMultiplier for inline hint
AMDGPU uses multiplier 9 for the inline cost. It is taken into account
everywhere except for inline hint threshold. As a result we are penalizing
functions with the inline hint making them less probable to be inlined
than those without the hint. Defaults are 225 for a normal function and
325 for a function with an inline hint. Currently we have effective
threshold 225 * 9 = 2025 for normal functions and just 325 for those with
the hint. That is fixed by this patch.

Differential Revision: https://reviews.llvm.org/D62707

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362239 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-31 16:19:26 +00:00
Tim Northover a8aa168ce3 Reapply: IR: add optional type to 'byval' function parameters
When we switch to opaque pointer types we will need some way to describe
how many bytes a 'byval' parameter should occupy on the stack. This adds
a (for now) optional extra type parameter.

If present, the type must match the pointee type of the argument.

The original commit did not remap byval types when linking modules, which broke
LTO. This version fixes that.

Note to front-end maintainers: if this causes test failures, it's probably
because the "byval" attribute is printed after attributes without any parameter
after this change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362128 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-30 18:48:23 +00:00
Tim Northover 3d26f10b85 Revert "IR: add optional type to 'byval' function parameters"
The IRLinker doesn't delve into the new byval attribute when mapping types, and
this breaks LTO.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362029 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-29 20:46:38 +00:00
Tim Northover aef2b1ac1a IR: add optional type to 'byval' function parameters
When we switch to opaque pointer types we will need some way to describe
how many bytes a 'byval' parameter should occupy on the stack. This adds
a (for now) optional extra type parameter.

If present, the type must match the pointee type of the argument.

Note to front-end maintainers: if this causes test failures, it's probably
because the "byval" attribute is printed after attributes without any parameter
after this change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362012 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-29 19:12:48 +00:00
Simon Tatham 2edda5220d [ARM] Replace fp-only-sp and d16 with fp64 and d32.
Those two subtarget features were awkward because their semantics are
reversed: each one indicates the _lack_ of support for something in
the architecture, rather than the presence. As a consequence, you
don't get the behavior you want if you combine two sets of feature
bits.

Each SubtargetFeature for an FP architecture version now comes in four
versions, one for each combination of those options. So you can still
say (for example) '+vfp2' in a feature string and it will mean what
it's always meant, but there's a new string '+vfp2d16sp' meaning the
version without those extra options.

A lot of this change is just mechanically replacing positive checks
for the old features with negative checks for the new ones. But one
more interesting change is that I've rearranged getFPUFeatures() so
that the main FPU feature is appended to the output list *before*
rather than after the features derived from the Restriction field, so
that -fp64 and -d32 can override defaults added by the main feature.

Reviewers: dmgreen, samparker, SjoerdMeijer

Subscribers: srhines, javed.absar, eraman, kristof.beyls, hiraditya, zzheng, Petar.Avramovic, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D60691



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361845 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-28 16:13:20 +00:00
Matt Arsenault bbaa274fa9 AMDGPU: Boost inline threshold with addrspacecasted alloca arguments
This was skipping GetUnderlyingObject for nonprivate addresses, but an
alloca could also be found through an addrspacecast if it's flat.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361649 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-24 16:52:35 +00:00
Nick Desaulniers 8e4472e3d0 [INLINER] allow inlining of blockaddresses if sole uses are callbrs
Summary:
It was supposed that Ref LazyCallGraph::Edge's were being inserted by
inlining, but that doesn't seem to be the case.  Instead, it seems that
there was no test for a blockaddress Constant in an instruction that
referenced the function that contained the instruction. Ex:

```
define void @f() {
  %1 = alloca i8*, align 8
2:
  store i8* blockaddress(@f, %2), i8** %1, align 8
  ret void
}
```

When iterating blockaddresses, do not add the function they refer to
back to the worklist if the blockaddress is referring to the contained
function (as opposed to an external function).

Because blockaddress has sligtly different semantics than GNU C's
address of labels, there are 3 cases that can occur with blockaddress,
where only 1 can happen in GNU C due to C's scoping rules:
* blockaddress is within the function it refers to (possible in GNU C).
* blockaddress is within a different function than the one it refers to
(not possible in GNU C).
* blockaddress is used in to declare a global (not possible in GNU C).

The second case is tested in:

```
$ ./llvm/build/unittests/Analysis/AnalysisTests \
  --gtest_filter=LazyCallGraphTest.HandleBlockAddress
```

This patch adjusts the iteration of blockaddresses in
LazyCallGraph::visitReferences to not revisit the blockaddresses
function in the first case.

The Linux kernel contains code that's not semantically valid at -O0;
specifically code passed to asm goto. It requires that asm goto be
inline-able. This patch conservatively does not attempt to handle the
more general case of inlining blockaddresses that have non-callbr users
(pr/39560).

https://bugs.llvm.org/show_bug.cgi?id=39560
https://bugs.llvm.org/show_bug.cgi?id=40722
https://github.com/ClangBuiltLinux/linux/issues/6
https://reviews.llvm.org/rL212077

Reviewers: jyknight, eli.friedman, chandlerc

Reviewed By: chandlerc

Subscribers: george.burgess.iv, nathanchance, mgorny, craig.topper, mengxu.gatech, void, mehdi_amini, E5ten, chandlerc, efriedma, eraman, hiraditya, haicheng, pirama, llvm-commits, srhines

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58260

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361173 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-20 16:48:09 +00:00
Orlando Cazalet-Hyams 2d3f411b4a Resubmit "[DebugInfo] Update loop metadata for inlined loops"
This reverts commit 95805bc425b264805a472232a75ed2ffe58aceda.
I've squashed the test fix into this commit.

[DebugInfo] Update loop metadata for inlined loops

Currently, when a loop is cloned while inlining function (A) into function (B)
the loop metadata is copied and then not modified at all. The loop metadata can
encode the loop's start and end DILocations. Therefore, the new inlined loop in
function (B) may have loop metadata which shows start and end locations residing
in function (A).

This patch ensures loop metadata is updated while inlining so that the start and
end DILocations are given the "inlinedAt" operand. I've also added a regression
test for this.

This fix is required for D60831 because that patch uses loop metadata to
determine the DILocation for the branches of new loop preheaders.

Reviewers: aprantl, dblaikie, anemet

Reviewed By: aprantl

Subscribers: eraman, hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D61933

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361149 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-20 13:02:30 +00:00
Orlando Cazalet-Hyams 5eebfc3d0e Revert "[DebugInfo] Update loop metadata for inlined loops"
This reverts commit 6e8f1a80cd988db8870aff9c3bc2ca7a20e04104.
Reverting patch while investigating build bot failure.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361143 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-20 11:24:39 +00:00
Orlando Cazalet-Hyams 8d0ebfc10c [DebugInfo] Update loop metadata for inlined loops
Summary:
Currently, when a loop is cloned while inlining function (A) into function (B) the loop metadata is copied and then not modified at all. The loop metadata can encode the loop's start and end DILocations. Therefore, the new inlined loop in function (B) may have loop metadata which shows start and end locations residing in function (A).

This patch ensures loop metadata is updated while inlining so that the start and end DILocations are given the "inlinedAt" operand. I've also added a regression test for this.

This fix is required for D60831 because that patch uses loop metadata to determine the DILocation for the branches of new loop preheaders.

Reviewers: aprantl, dblaikie, anemet

Reviewed By: aprantl

Subscribers: eraman, hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D61933

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361132 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-20 09:40:44 +00:00
Matt Arsenault a3e4b69abb AMDGPU: Assume xnack is enabled by default
This is the conservatively correct default. It is always safe to
assume xnack is enabled, but not the converse.

Introduce a feature to blacklist targets where xnack can never be
meaningfully enabled. I'm not sure the targets this is applied to is
100% correct.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360903 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-16 14:48:34 +00:00
Eric Christopher 598198edbc Revert "Temporarily Revert "Add basic loop fusion pass.""
The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358552 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-17 04:52:47 +00:00
Eric Christopher 02cc44c1b9 Temporarily Revert "Add basic loop fusion pass."
As it's causing some bot failures (and per request from kbarton).

This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358546 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-17 02:12:23 +00:00
Matt Arsenault cd3a8dda10 AMDGPU: Assume ECC is enabled by default if supported
The test should really be checking for the property directly in the
code object headers, but there are problems with this. I don't see
this directly represented in the text form, and for the binary
emission this is depending on a function level subtarget feature to
emit a global flag.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357558 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-03 01:58:57 +00:00
Matt Arsenault 30c1233cb5 AMDGPU: Fix test filename
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357441 91177308-0d34-0410-b5e6-96231b3b80d8
2019-04-02 00:36:04 +00:00
Matt Arsenault 234b3a117e AMDGPU: Remove dx10-clamp from subtarget features
Since this can be set with s_setreg*, it should not be a subtarget
property. Set a default based on the calling convention, and Introduce
a new amdgpu-dx10-clamp attribute to override this if desired.

Also introduce a new amdgpu-ieee attribute to match.

The values need to match to allow inlining. I think it is OK for the
caller's dx10-clamp attribute to override the callee, but there
doesn't appear to be the infrastructure to do this currently without
definining the attribute in the generic Attributes.td.

Eventually the calling convention lowering will need to insert a mode
switch somewhere for these.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357302 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-29 19:14:54 +00:00
Chandler Carruth 1cb1b30368 [NewPM] Fix a nasty bug with analysis invalidation in the new PM.
The issue here is that we actually allow CGSCC passes to mutate IR (and
therefore invalidate analyses) outside of the current SCC. At a minimum,
we need to support mutating parent and ancestor SCCs to support the
ArgumentPromotion pass which rewrites all calls to a function.

However, the analysis invalidation infrastructure is heavily based
around not needing to invalidate the same IR-unit at multiple levels.
With Loop passes for example, they don't invalidate other Loops. So we
need to customize how we handle CGSCC invalidation. Doing this without
gratuitously re-running analyses is even harder. I've avoided most of
these by using an out-of-band preserved set to accumulate the cross-SCC
invalidation, but it still isn't perfect in the case of re-visiting the
same SCC repeatedly *but* it coming off the worklist. Unclear how
important this use case really is, but I wanted to call it out.

Another wrinkle is that in order for this to successfully propagate to
function analyses, we have to make sure we have a proxy from the SCC to
the Function level. That requires pre-creating the necessary proxy.

The motivating test case now works cleanly and is added for
ArgumentPromotion.

Thanks for the review from Philip and Wei!

Differential Revision: https://reviews.llvm.org/D59869

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357137 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-28 00:51:36 +00:00
Craig Topper 7300bbb814 [X86] Filter out tuning feature flags and a few ISA feature flags when checking for function inline compatibility.
Tuning flags don't have any effect on the available instructions so aren't a good reason to prevent inlining.

There are also some ISA flags that don't have any intrinsics our ABI requirements that we can exclude. I've put only the most basic ones like cmpxchg16b and lahfsahf. These are interesting because they aren't present in all 64-bit CPUs, but we have codegen workarounds when they aren't present.

Loosening these checks can help with scenarios where a caller has a more specific CPU than a callee. The default tuning flags on our generic 'x86-64' CPU can currently make it inline compatible with other CPUs. I've also added an example test for 'nocona' and 'prescott' where 'nocona' is just a 64-bit capable version of 'prescott' but in 32-bit mode they should be completely compatible.

I've based the implementation here of the similar code in AMDGPU.

Differential Revision: https://reviews.llvm.org/D58371

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354355 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-19 17:05:11 +00:00
Matt Arsenault b232056f5e AMDGPU: Ignore CodeObjectV3 when inlining
This was inhibiting inlining of library functions when clang was
invoking the inliner directly. This is covering a bit of a mess with
subtarget feature handling, and this shouldn't be a subtarget
feature. The behavior is different depending on whether you are using
a -mattr flag in clang, or llc, opt.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353899 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-12 23:30:11 +00:00
Yevgeny Rouban a53c9ac0aa Provide reason messages for unviable inlining
InlineCost's isInlineViable() is changed to return InlineResult
instead of bool. This provides messages for failure reasons and
allows to get more specific messages for cases where callsites
are not viable for inlining.

Reviewed By: xbolva00, anemet

Differential Revision: https://reviews.llvm.org/D57089

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@352849 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-01 10:44:43 +00:00
Easwaran Raman 9ea2e7f6a4 [Inliner] Assert that the computed inline threshold is non-negative.
Reviewers: chandlerc

Subscribers: haicheng, llvm-commits

Differential Revision: https://reviews.llvm.org/D56409

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350751 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-09 19:26:17 +00:00
Michael Kruse 42a382c204 Introduce llvm.loop.parallel_accesses and llvm.access.group metadata.
The current llvm.mem.parallel_loop_access metadata has a problem in that
it uses LoopIDs. LoopID unfortunately is not loop identifier. It is
neither unique (there's even a regression test assigning the some LoopID
to multiple loops; can otherwise happen if passes such as LoopVersioning
make copies of entire loops) nor persistent (every time a property is
removed/added from a LoopID's MDNode, it will also receive a new LoopID;
this happens e.g. when calling Loop::setLoopAlreadyUnrolled()).
Since most loop transformation passes change the loop attributes (even
if it just to mark that a loop should not be processed again as
llvm.loop.isvectorized does, for the versioned and unversioned loop),
the parallel access information is lost for any subsequent pass.

This patch unlinks LoopIDs and parallel accesses.
llvm.mem.parallel_loop_access metadata on instruction is replaced by
llvm.access.group metadata. llvm.access.group points to a distinct
MDNode with no operands (avoiding the problem to ever need to add/remove
operands), called "access group". Alternatively, it can point to a list
of access groups. The LoopID then has an attribute
llvm.loop.parallel_accesses with all the access groups that are parallel
(no dependencies carries by this loop).

This intentionally avoid any kind of "ID". Loops that are clones/have
their attributes modifies retain the llvm.loop.parallel_accesses
attribute. Access instructions that a cloned point to the same access
group. It is not necessary for each access to have it's own "ID" MDNode,
but those memory access instructions with the same behavior can be
grouped together.

The behavior of llvm.mem.parallel_loop_access is not changed by this
patch, but should be considered deprecated.

Differential Revision: https://reviews.llvm.org/D52116

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@349725 91177308-0d34-0410-b5e6-96231b3b80d8
2018-12-20 04:58:07 +00:00
Wei Mi acfb046e52 [SampleFDO] handle ProfileSampleAccurate when initializing function entry count
ProfileSampleAccurate is used to indicate the profile has exact match to the
code to be optimized.

Previously ProfileSampleAccurate is handled in ProfileSummaryInfo::isColdCallSite
and ProfileSummaryInfo::isColdBlock. A better solution is to initialize function
entry count to 0 when ProfileSampleAccurate is true, so we don't have to handle
ProfileSampleAccurate in multiple places.

Differential Revision: https://reviews.llvm.org/D55660


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@349088 91177308-0d34-0410-b5e6-96231b3b80d8
2018-12-13 21:51:42 +00:00
Craig Topper 75aaec5145 [Inliner] Modify the merging of min-legal-vector-width attribute to better handle when the caller or callee don't have the attribute.
Lack of an attribute means that the function hasn't been checked for what vector width it requires. So if the caller or the callee doesn't have the attribute we should make sure the combined function after inlining does not have the attribute.

If the caller already doesn't have the attribute we can just avoid adding it. Otherwise if the callee doesn't have the attribute just remove the caller's attribute.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@347841 91177308-0d34-0410-b5e6-96231b3b80d8
2018-11-29 07:27:38 +00:00
Craig Topper 5c4417bb46 [Inliner] Add test for merging of min-legal-vector-width function attribute.
This should have been added in r337844, but apparently was I failed to 'git add' the file.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@347840 91177308-0d34-0410-b5e6-96231b3b80d8
2018-11-29 07:02:47 +00:00
David Green 5cc99f0569 [Inliner] Penalise inlining of calls with loops at Oz
We currently seem to underestimate the size of functions with loops in them,
both in terms of absolute code size and in the difficulties of dealing with
such code. (Calls, for example, can be tail merged to further reduce
codesize). At -Oz, we can then increase code size by inlining small loops
multiple times.

This attempts to penalise functions with loops at -Oz by adding a CallPenalty
for each top level loop in the function. It uses LI (and hence DT) to calculate
the number of loops. As we are dealing with minsize, the inline threshold is
small and functions at this point should be relatively small, making the
construction of these cheap.

Differential Revision: https://reviews.llvm.org/D52716



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@346134 91177308-0d34-0410-b5e6-96231b3b80d8
2018-11-05 14:54:34 +00:00
Wei Mi a73d657b58 [PM] keeping history when original SCC split and then merge into itself
in the same round of SCC update.

In https://reviews.llvm.org/rL309784, inline history is added to prevent
infinite inlining across multiple run of inliner and SCC update, but the
history will only be kept when new SCC is actually generated during SCC update.

We found a case that SCC can be split and then merge into itself in the same
round of SCC update, so the same SCC will be pop out from UR.CWorklist and
then added back immediately, without any new SCC generated, that is why the
existing patch cannot catch the infinite inline case.

What the patch does is even if no new SCC is generated, if only the current
SCC appears in UR.CWorklist again, then keep the inline history.

Differential Revision: https://reviews.llvm.org/D52915



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@345103 91177308-0d34-0410-b5e6-96231b3b80d8
2018-10-23 23:29:45 +00:00
Zachary Turner d5e155bacd Make YAML quote forward slashes.
If you have the string /usr/bin, prior to this patch it would not
be quoted by our YAML serializer.  But a string like C:\src would
be, due to the presence of a backslash.  This makes the quoting
rules of basically every single file path different depending on
the path syntax (posix vs. Windows).

While technically not required by the YAML specification to quote
forward slashes, when the behavior of paths is inconsistent it
makes it difficult to portably write FileCheck lines that will
work with either kind of path.

Differential Revision: https://reviews.llvm.org/D53169

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@344359 91177308-0d34-0410-b5e6-96231b3b80d8
2018-10-12 16:31:20 +00:00
Zachary Turner 7b3c188641 Revert "Make YAML quote forward slashes."
This reverts commit b86c16ad8c97dadc1f529da72a5bb74e9eaed344.

This is being reverted because I forgot to write a useful
commit message, so I'm going to resubmit it with an actual
commit message.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@344358 91177308-0d34-0410-b5e6-96231b3b80d8
2018-10-12 16:31:08 +00:00
Zachary Turner 185de913d5 Make YAML quote forward slashes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@344357 91177308-0d34-0410-b5e6-96231b3b80d8
2018-10-12 16:24:09 +00:00
Robert Lougher 791162c487 [TailCallElim] Enable marking of calls with byval as tails
In r339636 the alias analysis rules were changed with regards to tail calls
and byval arguments. Previously, tail calls were assumed not to alias
allocas from the current frame. This has been updated, to not assume this
for arguments with the byval attribute.

This patch aligns TailCallElim with the new rule. Tail marking can now be
more aggressive and mark more calls as tails, e.g.:

define void @test() {
  %f = alloca %struct.foo
  call void @bar(%struct.foo* byval %f)
  ret void
}

define void @test2(%struct.foo* byval %f) {
  call void @bar(%struct.foo* byval %f)
  ret void
}

define void @test3(%struct.foo* byval %f) {
  %agg.tmp = alloca %struct.foo
  %0 = bitcast %struct.foo* %agg.tmp to i8*
  %1 = bitcast %struct.foo* %f to i8*
  call void @llvm.memcpy.p0i8.p0i8.i64(i8* %0, i8* %1, i64 40, i1 false)
  call void @bar(%struct.foo* byval %agg.tmp)
  ret void
}

The problematic case where a byval parameter is captured by a call is still
handled correctly, and will not be marked as a tail (see PR7272).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@343986 91177308-0d34-0410-b5e6-96231b3b80d8
2018-10-08 18:03:40 +00:00
Sameer AbuAsal e54994e9c0 [inline Cost] Don't mark functions accessing varargs as non-inlinable
Summary:
rL323619 marks functions that are calling va_end as not viable for
inlining. This patch reverses that since this va_end doesn't need
access to the vriadic arguments list that are saved on the stack, only
va_start does.

Reviewers: efriedma, fhahn

Reviewed By: fhahn

Subscribers: eraman, haicheng, llvm-commits

Differential Revision: https://reviews.llvm.org/D52067

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342675 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-20 18:39:34 +00:00
Fedor Sergeev e6959a6ecf [New PM] Introducing PassInstrumentation framework
Pass Execution Instrumentation interface enables customizable instrumentation
of pass execution, as per "RFC: Pass Execution Instrumentation interface"
posted 06/07/2018 on llvm-dev@

The intent is to provide a common machinery to implement all
the pass-execution-debugging features like print-before/after,
opt-bisect, time-passes etc.

Here we get a basic implementation consisting of:
* PassInstrumentationCallbacks class that handles registration of callbacks
  and access to them.

* PassInstrumentation class that handles instrumentation-point interfaces
  that call into PassInstrumentationCallbacks.

* Callbacks accept StringRef which is just a name of the Pass right now.
  There were some ideas to pass an opaque wrapper for the pointer to pass instance,
  however it appears that pointer does not actually identify the instance
  (adaptors and managers might have the same address with the pass they govern).
  Hence it was decided to go simple for now and then later decide on what the proper
  mental model of identifying a "pass in a phase of pipeline" is.

* Callbacks accept llvm::Any serving as a wrapper for const IRUnit*, to remove direct dependencies
  on different IRUnits (e.g. Analyses).

* PassInstrumentationAnalysis analysis is explicitly requested from PassManager through
  usual AnalysisManager::getResult. All pass managers were updated to run that
  to get PassInstrumentation object for instrumentation calls.

* Using tuples/index_sequence getAnalysisResult helper to extract generic AnalysisManager's extra
  args out of a generic PassManager's extra args. This is the only way I was able to explicitly
  run getResult for PassInstrumentationAnalysis out of a generic code like PassManager::run or
  RepeatedPass::run.
  TODO: Upon lengthy discussions we agreed to accept this as an initial implementation
  and then get rid of getAnalysisResult by improving RepeatedPass implementation.

* PassBuilder takes PassInstrumentationCallbacks object to pass it further into
  PassInstrumentationAnalysis. Callbacks registration should be performed directly
  through PassInstrumentationCallbacks.

* new-pm tests updated to account for PassInstrumentationAnalysis being run

* Added PassInstrumentation tests to PassBuilderCallbacks unit tests.
  Other unit tests updated with registration of the now-required PassInstrumentationAnalysis.

  Made getName helper to return std::string (instead of StringRef initially) to fix
  asan builtbot failures on CGSCC tests.

Reviewers: chandlerc, philip.pfaffe
Differential Revision: https://reviews.llvm.org/D47858

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342664 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-20 17:08:45 +00:00
Eric Christopher 85a14f0491 Temporarily Revert "[New PM] Introducing PassInstrumentation framework"
as it was causing failures in the asan buildbot.

This reverts commit r342597.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342616 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-20 05:16:29 +00:00
Fedor Sergeev 5ffd6db668 [New PM] Introducing PassInstrumentation framework
Pass Execution Instrumentation interface enables customizable instrumentation
of pass execution, as per "RFC: Pass Execution Instrumentation interface"
posted 06/07/2018 on llvm-dev@

The intent is to provide a common machinery to implement all
the pass-execution-debugging features like print-before/after,
opt-bisect, time-passes etc.

Here we get a basic implementation consisting of:
* PassInstrumentationCallbacks class that handles registration of callbacks
  and access to them.

* PassInstrumentation class that handles instrumentation-point interfaces
  that call into PassInstrumentationCallbacks.

* Callbacks accept StringRef which is just a name of the Pass right now.
  There were some ideas to pass an opaque wrapper for the pointer to pass instance,
  however it appears that pointer does not actually identify the instance
  (adaptors and managers might have the same address with the pass they govern).
  Hence it was decided to go simple for now and then later decide on what the proper
  mental model of identifying a "pass in a phase of pipeline" is.

* Callbacks accept llvm::Any serving as a wrapper for const IRUnit*, to remove direct dependencies
  on different IRUnits (e.g. Analyses).

* PassInstrumentationAnalysis analysis is explicitly requested from PassManager through
  usual AnalysisManager::getResult. All pass managers were updated to run that
  to get PassInstrumentation object for instrumentation calls.

* Using tuples/index_sequence getAnalysisResult helper to extract generic AnalysisManager's extra
  args out of a generic PassManager's extra args. This is the only way I was able to explicitly
  run getResult for PassInstrumentationAnalysis out of a generic code like PassManager::run or
  RepeatedPass::run.
  TODO: Upon lengthy discussions we agreed to accept this as an initial implementation
  and then get rid of getAnalysisResult by improving RepeatedPass implementation.

* PassBuilder takes PassInstrumentationCallbacks object to pass it further into
  PassInstrumentationAnalysis. Callbacks registration should be performed directly
  through PassInstrumentationCallbacks.

* new-pm tests updated to account for PassInstrumentationAnalysis being run

* Added PassInstrumentation tests to PassBuilderCallbacks unit tests.
  Other unit tests updated with registration of the now-required PassInstrumentationAnalysis.

Reviewers: chandlerc, philip.pfaffe
Differential Revision: https://reviews.llvm.org/D47858

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342597 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-19 22:42:57 +00:00
Fedor Sergeev 68fc66e3d3 Revert rL342544: [New PM] Introducing PassInstrumentation framework
A bunch of bots fail to compile unittests. Reverting.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342552 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-19 14:54:48 +00:00
Fedor Sergeev fa4dbf77f1 [New PM] Introducing PassInstrumentation framework
Summary:
Pass Execution Instrumentation interface enables customizable instrumentation
of pass execution, as per "RFC: Pass Execution Instrumentation interface"
posted 06/07/2018 on llvm-dev@

The intent is to provide a common machinery to implement all
the pass-execution-debugging features like print-before/after,
opt-bisect, time-passes etc.

Here we get a basic implementation consisting of:
* PassInstrumentationCallbacks class that handles registration of callbacks
  and access to them.

* PassInstrumentation class that handles instrumentation-point interfaces
  that call into PassInstrumentationCallbacks.

* Callbacks accept StringRef which is just a name of the Pass right now.
  There were some ideas to pass an opaque wrapper for the pointer to pass instance,
  however it appears that pointer does not actually identify the instance
  (adaptors and managers might have the same address with the pass they govern).
  Hence it was decided to go simple for now and then later decide on what the proper
  mental model of identifying a "pass in a phase of pipeline" is.

* Callbacks accept llvm::Any serving as a wrapper for const IRUnit*, to remove direct dependencies
  on different IRUnits (e.g. Analyses).

* PassInstrumentationAnalysis analysis is explicitly requested from PassManager through
  usual AnalysisManager::getResult. All pass managers were updated to run that
  to get PassInstrumentation object for instrumentation calls.

* Using tuples/index_sequence getAnalysisResult helper to extract generic AnalysisManager's extra
  args out of a generic PassManager's extra args. This is the only way I was able to explicitly
  run getResult for PassInstrumentationAnalysis out of a generic code like PassManager::run or
  RepeatedPass::run.
  TODO: Upon lengthy discussions we agreed to accept this as an initial implementation
  and then get rid of getAnalysisResult by improving RepeatedPass implementation.

* PassBuilder takes PassInstrumentationCallbacks object to pass it further into
  PassInstrumentationAnalysis. Callbacks registration should be performed directly
  through PassInstrumentationCallbacks.

* new-pm tests updated to account for PassInstrumentationAnalysis being run

* Added PassInstrumentation tests to PassBuilderCallbacks unit tests.
  Other unit tests updated with registration of the now-required PassInstrumentationAnalysis.

Reviewers: chandlerc, philip.pfaffe
Differential Revision: https://reviews.llvm.org/D47858

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342544 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-19 12:25:52 +00:00
Piotr Padlewski b9bd7dd812 Set cost of invariant group intrinsics to 0
Summary:
Like with other similar intrinsics, presense of strip or
launder.invariant.group should not change the result of inlining cost.
This is because they are just markers and do not perform any computation.

Reviewers: amharc, rsmith, reames, kuhar

Subscribers: eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D51814

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341725 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-07 22:29:48 +00:00
Chandler Carruth d2b1fb11d3 [x86/SLH] Add a real Clang flag and LLVM IR attribute for Speculative
Load Hardening.

Wires up the existing pass to work with a proper IR attribute rather
than just a hidden/internal flag. The internal flag continues to work
for now, but I'll likely remove it soon.

Most of the churn here is adding the IR attribute. I talked about this
Kristof Beyls and he seemed at least initially OK with this direction.
The idea of using a full attribute here is that we *do* expect at least
some forms of this for other architectures. There isn't anything
*inherently* x86-specific about this technique, just that we only have
an implementation for x86 at the moment.

While we could potentially expose this as a Clang-level attribute as
well, that seems like a good question to defer for the moment as it
isn't 100% clear whether that or some other programmer interface (or
both?) would be best. We'll defer the programmer interface side of this
for now, but at least get to the point where the feature can be enabled
without relying on implementation details.

This also allows us to do something that was really hard before: we can
enable *just* the indirect call retpolines when using SLH. For x86, we
don't have any other way to mitigate indirect calls. Other architectures
may take a different approach of course, and none of this is surfaced to
user-level flags.

Differential Revision: https://reviews.llvm.org/D51157

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341363 91177308-0d34-0410-b5e6-96231b3b80d8
2018-09-04 12:38:00 +00:00