15326 Commits

Author SHA1 Message Date
Roman Lebedev
2655a70a04
[InstCombine] After merging store into successor, queue prev. store to be visited (PR46661)
We can happen to have a situation with many stores eligible for transform,
but due to our visitation order (top to bottom), when we have processed
the first eligible instruction, we would not try to reprocess the previous
instructions that are now also eligible.

So after we've successfully merged a store that was second-to-last instruction
into successor, if the now-second-to-last instruction is also a such store
that is eligible, add it to worklist to be revisited.

Fixes https://bugs.llvm.org/show_bug.cgi?id=46661
2020-07-10 17:49:16 +03:00
Roman Lebedev
ef0ecb7b03
[NFCI][InstCombine] PR46661: multiple stores eligible for merging into successor - worklist issue
The testcase should pass with a single instcombine iteration.
2020-07-10 17:49:16 +03:00
Florian Hahn
264ab1e2c8 [LV] Pick vector loop body as insert point for SCEV expansion.
Currently the DomTree is not kept up to date for additional blocks
generated in the vector loop, for example when vectorizing with
predication. SCEVExpander relies on dominance checks when looking for
existing instructions to re-use and in some cases that can lead to the
expander picking instructions that do not actually dominate their insert
point (e.g. as in PR46525).

Unfortunately keeping the DT up-to-date is a bit tricky, because the CFG
is only patched up after generating code for a block. For now, we can
just use the vector loop header, as this ensures the inserted
instructions dominate all uses in the vector loop. There should be no
noticeable impact on the generated code, as other passes should sink
those instructions, if profitable.

Fixes PR46525.

Reviewers: Ayal, gilr, mkazantsev, dmgreen

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D83288
2020-07-10 10:37:12 +01:00
Diogo Sampaio
7bf168390f [BDCE] SExt -> ZExt when no sign bits is used and instruction has multiple uses
Summary: This allows to convert any SExt to a ZExt when we know none of the extended bits are used, specially in cases where there are multiple uses of the value.

Reviewers: dmgreen, eli.friedman, spatel, lebedev.ri, nikic

Reviewed By: lebedev.ri, nikic

Subscribers: hiraditya, dmgreen, craig.topper, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60413
2020-07-10 08:34:53 +01:00
Chen Zheng
f1efb8bb4b [SCEV][IndVarSimplify] insert point should not be block front.
The block front may be a PHI node, inserting a cast instructions like
BitCast, PtrToInt, IntToPtr among PHIs is not right.

Reviewed By: lebedev.ri

Differential Revision:  https://reviews.llvm.org/D80975
2020-07-09 21:56:57 -04:00
Nikita Popov
c0308fd154 [PredicateInfo] Print RenamedOp (NFC)
Make it easier to debug renaming issues.
2020-07-09 23:14:24 +02:00
Craig Topper
469da663f2 [InstSimplify] Re-enable select ?, undef, X -> X transform when X is provably not poison
Follow up from the transform being removed in D83360. If X is probably not poison, then the transform is safe.

Still plan to remove or adjust the code from ConstantFolding after this.

Differential Revision: https://reviews.llvm.org/D83440
2020-07-09 12:21:03 -07:00
Craig Topper
122b0640fc [InstSimplify] Don't fold vectors of partial undef in SimplifySelectInst if the non-undef element value might produce poison
We can't fold to the non-undef value unless we know it isn't poison. So check each element with isGuaranteedNotToBeUndefOrPoison. This currently rules out all constant expressions.

Differential Revision: https://reviews.llvm.org/D83442
2020-07-09 11:01:12 -07:00
Florian Hahn
9477d39e61 [SCCP] Move tests using only ipsccp from IPConstantProp to SCCP (NFC).
Some of the tests in the llvm/test/Transforms/IPConstantProp directory
actually only use -ipsccp. Those tests belong to the other (IP)SCCP
tests in llvm/test/Transforms/SCCP/ and this commits moves them there to
avoid confusion with IPConstantProp.
2020-07-09 17:16:15 +01:00
Diogo Sampaio
a0e981c190 [NFC] Add SExt multiuses test 2020-07-09 15:31:16 +01:00
dfukalov
167767a775 SpeculativeExecution: Fix for logic change introduced in D81730.
Summary:
The test case started to hoist bitcasts to upper BB after D81730.
Reverted unintentional logic change. Some instructions may have zero cost but
will not be hoisted by different limitation so should be counted for threshold.

Reviewers: aprantl, arsenm, nhaehnle

Reviewed By: aprantl

Subscribers: wdng, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D82761
2020-07-09 15:45:23 +03:00
Florian Hahn
a86ce06faf [SCCP] Use conditional info with AND/OR branch conditions.
Currently SCCP does not combine the information of conditions joined by
AND in the true branch or OR in the false branch.

For branches on AND, 2 copies will be inserted for the true branch, with
one being the operand of the other as in the code below. We can combine
the information using intersection. Note that for the OR case, the
copies are inserted in the false branch, where using intersection is
safe as well.

    define void @foo(i32 %a) {
    entry:
      %lt = icmp ult i32 %a, 100
      %gt = icmp ugt i32 %a, 20
      %and = and i1 %lt, %gt
    ; Has predicate info
    ; branch predicate info { TrueEdge: 1 Comparison:  %lt = icmp ult i32 %a, 100 Edge: [label %entry,label %true] }
      %a.0 = call i32 @llvm.ssa.copy.140247425954880(i32 %a)
    ; Has predicate info
    ; branch predicate info { TrueEdge: 1 Comparison:  %gt = icmp ugt i32 %a, 20 Edge: [label %entry,label %false] }
      %a.1 = call i32 @llvm.ssa.copy.140247425954880(i32 %a.0)
      br i1 %and, label %true, label %false

    true:                                             ; preds = %entry
      call void @use(i32 %a.1)
      %true.1 = icmp ne i32 %a.1, 20
      call void @use.i1(i1 %true.1)
      ret void

    false:                                            ; preds = %entry
      call void @use(i32 %a.1)
      ret void
    }

Reviewers: efriedma, davide, mssimpso, nikic

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D77808
2020-07-09 12:59:24 +01:00
Paul Walker
6b403319f8 [SVE] Scalarize fixed length masked loads and stores.
When adding support for scalable vector masked loads and stores we
accidently opened up likewise for fixed length vectors. This patch
restricts support to scalable vectors only, thus ensuring fixed
length vectors are treated the same regardless of SVE support.

Differential Revision: https://reviews.llvm.org/D83341
2020-07-09 10:47:04 +00:00
Jun Ma
f0bfad2ed9 [Coroutines] Refactor sinkLifetimeStartMarkers
Differential Revision: https://reviews.llvm.org/D83379
2020-07-09 18:23:28 +08:00
Dmitry Polukhin
9e7fddbd36 [yaml][clang-tidy] Fix multiline YAML serialization
Summary:
New line duplication logic introduced in https://reviews.llvm.org/D63482
has two issues: (1) there is no logic that removes duplicate newlines
when clang-apply-replacment reads YAML and (2) in general such logic
should be applied to all strings and should happen on string
serialization level instead in YAML parser.

This diff changes multiline strings quotation from single quote `'` to
double `"`. It solves problems with internal newlines because now they are
escaped. Also double quotation solves the problem with leading whitespace after
newline. In case of single quotation YAML parsers should remove leading
whitespace according to specification. In case of double quotation these
leading are internal space and they are preserved. There is no way to
instruct YAML parsers to preserve leading whitespaces after newline so
double quotation is the only viable option that solves all problems at
once.

Test Plan: check-all

Reviewers: gribozavr, mgehre, yvvan

Subscribers: xazax.hun, hiraditya, cfe-commits, llvm-commits

Tags: #clang-tools-extra, #clang, #llvm

Differential Revision: https://reviews.llvm.org/D80301
2020-07-09 02:41:58 -07:00
Craig Topper
ac0af12ed2 [InstSimplify] Add test cases for opportunities to fold select ?, X, undef -> X when we can prove X isn't poison
Part of addressing post-commit feedback from D83360
2020-07-08 15:24:55 -07:00
Craig Topper
9b1e95329a [InstSimplify] Remove select ?, undef, X -> X and select ?, X, undef -> X transforms
As noted here https://lists.llvm.org/pipermail/llvm-dev/2016-October/106182.html and by alive2, this transform isn't valid. If X is poison this potentially propagates poison when it shouldn't.

This same transform still exists in DAGCombiner.

Differential Revision: https://reviews.llvm.org/D83360
2020-07-08 12:53:05 -07:00
Nikita Popov
a48cf72238 [InstSimplify] Handle not inserted instruction gracefully (PR46638)
When simplifying comparisons using a dominating assume, bail out
if the context instruction is not inserted.
2020-07-08 21:43:32 +02:00
Wei Mi
e32469a140 [SampleFDO] Enable sample-profile-top-down-load and sample-profile-merge-inlinee
by default.

sample-profile-top-down-load is an internal option which can enable top-down
order of inlining and profile annotation in sample profile load pass. It was
found to be beneficial for better profile annotation.

Recently we found it could also solve some build time issue. Suppose function
A has many callsites in function B. In the last release binary where sample
profile was collected, the outline copy of A is large because there are many
other functions inlined into A. However although all the callsites calling A
in B are inlined, but every inlined body is small (A was inlined into B
before other functions are inlined into A), there is no build time issue in
last release.

In an optimized build using the sample profile collected from last release,
without top-down inlining, we saw a case that A got very large because of
inlining, and then multiple callsites of A got inlined into B, and that led
to a huge B which caused significant build time issue besides profile
annotation issue.

To solve that problem, the patch enables the flag
sample-profile-top-down-load by default. sample-profile-top-down-load can
have better performance when it is enabled together with
sample-profile-merge-inlinee so in this patch we also enable
sample-profile-merge-inlinee by default.

Differential Revision: https://reviews.llvm.org/D82919
2020-07-08 09:23:18 -07:00
Arthur Eubanks
481709e831 [NewPM][opt] Share -disable-loop-unrolling between pass managers
There's no reason to introduce a new option for the NPM.
The various PGO options are shared in this manner.

Reviewed By: echristo

Differential Revision: https://reviews.llvm.org/D83368
2020-07-08 08:50:56 -07:00
Stanislav Mekhanoshin
64030099c3 SLP: honor requested max vector size merging PHIs
At the moment this place does not check maximum size set
by TTI and just creates a maximum possible vectors.

Differential Revision: https://reviews.llvm.org/D82227
2020-07-08 08:06:15 -07:00
Florian Hahn
80970ac875 [DSE,MSSA] Eliminate stores by terminators (free,lifetime.end).
This patch adds support for eliminating stores by free & lifetime.end
calls. We can remove stores that are not read before calling a memory
terminator and we can eliminate all stores after a memory terminator
until we see a new lifetime.start. The second case seems to not really
trigger much in practice though.

Reviewers: dmgreen, rnk, efriedma, bryant, asbirlea, Tyker

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D72410
2020-07-08 08:59:46 +01:00
Florian Hahn
04b85e2bcb Revert "[SLP] Make sure instructions are ordered when computing spill cost."
This seems to break http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win/builds/24371

This reverts commit eb46137daa92723b75d828f2db959f2061612622.
2020-07-07 23:15:01 +01:00
Christopher Tetreault
021d56abb9 [SVE] Make Constant::getSplatValue work for scalable vector splats
Summary:
Make Constant::getSplatValue recognize scalable vector splats of the
form created by ConstantVector::getSplat. Add unit test to verify that
C == ConstantVector::getSplat(C)->getSplatValue() for fixed width and
scalable vector splats

Reviewers: efriedma, spatel, fpetrogalli, c-rhodes

Reviewed By: efriedma

Subscribers: sdesmalen, tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D82416
2020-07-07 13:45:51 -07:00
Arthur Eubanks
2279380eab [Inliner] Don't skip inlining alwaysinline in optnone functions
Previously the NPM inliner would skip all potential inlines in an
optnone function, but alwaysinline callees should be inlined regardless
of optnone.

Fixes inline-optnone.ll under NPM.

Reviewed By: kazu

Differential Revision: https://reviews.llvm.org/D83021
2020-07-07 12:54:55 -07:00
Nikita Popov
8691544a27 [SCCP] Use range metadata for loads and calls
When all else fails, use range metadata to constrain the result
of loads and calls. It should also be possible to use !nonnull,
but that would require some general support for inequalities in
SCCP first.

Differential Revision: https://reviews.llvm.org/D83179
2020-07-07 21:09:21 +02:00
Nikita Popov
9dfea03517 [SCCP] Handle assume predicates
Take assume predicates into account when visiting ssa.copy. The
handling is the same as for branch predicates, with the difference
that we're always on the true edge.

Differential Revision: https://reviews.llvm.org/D83257
2020-07-07 20:22:52 +02:00
Hans Wennborg
7fc279ca3d [GlobalOpt] Don't remove inalloca from musttail-called functions
Otherwise the verifier complains about the mismatching function ABIs.

Differential revision: https://reviews.llvm.org/D83300
2020-07-07 19:02:46 +02:00
Roman Lebedev
16266e6396
[Scalarizer] When gathering scattered scalar, don't replace it with itself
The (previously-crashing) test-case would cause us to seemingly-harmlessly
replace some use with something else, but we can't replace it with itself,
so we would crash.
2020-07-07 17:03:53 +03:00
Ayal Zaks
7bf299c8d8 [LV] Vectorize without versioning-for-unit-stride under -Os/-Oz
If a loop is in a function marked OptSize, Loop Access Analysis should refrain
from generating runtime checks for unit strides that will version the loop.

If a loop is in a function marked OptSize and its vectorization is enabled, it
should be vectorized w/o any versioning.

Fixes PR46228.

Differential Revision: https://reviews.llvm.org/D81345
2020-07-07 15:04:21 +03:00
Max Kazantsev
094e99d264 [Test] Add one more missing optimization opportunity test 2020-07-07 13:04:15 +07:00
Jordan Rupprecht
10c82eecbc Revert "[LV] Enable the LoopVectorizer to create pointer inductions"
This reverts commit a8fe12065ec8137e55a6a8b35dd5355477c2ac16.

It causes a crash when building gzip. Will post the detailed reduced test case to D81267.
2020-07-06 17:50:38 -07:00
Roman Lebedev
db05f2e34a
[Scalarizer] Centralize instruction DCE
As reported in https://reviews.llvm.org/D83101#2133062
the new visitInsertElementInst()/visitExtractElementInst() functionality
is causing miscompiles (previously-crashing test added)

It is due to the fact how the infra of Scalarizer is dealing with DCE,
it was not updated or was it ready for such scalar value forwarding.
It always assumed that the moment we "scalarized" something,
it can go away, and did so with prejudice.

But that is no longer safe/okay to do.

Instead, let's prevent it from ever shooting itself into foot,
and let's just accumulate the instructions-to-be-deleted
in a vector, and collectively cleanup (those that are *actually* dead)
them all at the end.

All existing tests are not reporting any new garbage leftovers,
but maybe it's test coverage issue.
2020-07-07 01:12:51 +03:00
David Green
146dad0077 [ARM] MVE FP16 cost adjustments
This adjusts the MVE fp16 cost model, similar to how we already do for
integer casts. It uses the base cost of 1 per cvt for most fp extend /
truncates, but adjusts it for loads and stores where we know that a
extending load has been used to get the load into the correct lane, and
only an MVE VCVTB is then needed.

Differential Revision: https://reviews.llvm.org/D81813
2020-07-06 15:57:51 +01:00
Roman Lebedev
51f9310ff2
[Scalarizer] ExtractElement handling w/ variable insert index (PR46524)
Summary:
Similar to D82961.

Reviewers: bjope, cameron.mcinally, arsenm, jdoerfert

Reviewed By: jdoerfert

Subscribers: arphaman, wdng, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D82970
2020-07-06 13:19:33 +03:00
Roman Lebedev
6e50474581
[Scalarizer] InsertElement handling w/ variable insert index (PR46524)
Summary:
I'm interested in taking the original C++ input,
for which we currently are stuck with an alloca
and producing roughly the lower IR,
with neither an alloca nor a vector ops:
https://godbolt.org/z/cRRWaJ

For that, as intermediate step, i'd to somehow perform scalarization.
As per @arsenmn suggestion, i'm trying to see if scalarizer can help me
avoid writing a bicycle.

I'm not sure if it's really intentional that variable insert is not handled currently.
If it really is, and is supposed to stay that way (?), i guess i could guard it..

See [[ https://bugs.llvm.org/show_bug.cgi?id=46524 | PR46524 ]].

Reviewers: bjope, cameron.mcinally, arsenm, jdoerfert

Reviewed By: jdoerfert

Subscribers: arphaman, uabelho, wdng, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D82961
2020-07-06 13:19:32 +03:00
Roman Lebedev
28b7816b78
[Scalarizer] ExtractElement handling w/ constant extract index
Summary:
It appears to be better IR-wise to aggressively scalarize it,
rather than relying on gathering it, and leaving it as-is.

Reviewers: jdoerfert, bjope, arsenm, cameron.mcinally

Reviewed By: jdoerfert

Subscribers: arphaman, wdng, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D83101
2020-07-06 13:19:32 +03:00
Roman Lebedev
f62c8dbc99
[Scalarizer] InsertElement handling w/ constant insert index
Summary: As it can be clearly seen from the diff, this results in nicer IR.

Reviewers: jdoerfert, arsenm, bjope, cameron.mcinally

Reviewed By: jdoerfert

Subscribers: arphaman, wdng, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D83102
2020-07-06 13:19:32 +03:00
David Green
55227f85d0 [ARM] Use BaseT::getMemoryOpCost for getMemoryOpCost
This alters getMemoryOpCost to use the Base TargetTransformInfo version
that includes some additional checks for whether extending loads are
legal. This will generally have the effect of making <2 x ..> and some
<4 x ..> loads/stores more expensive, which in turn should help favour
larger vector factors.

Notably it alters the cost of a <4 x half>, which with the current
codegen will be expensive if it is not extended.

Differential Revision: https://reviews.llvm.org/D82456
2020-07-06 10:58:40 +01:00
Nikita Popov
516ff1d4ba [SCCP] Add test for range metadata (NFC) 2020-07-05 21:41:04 +02:00
sstefan1
6c4a5e9257 [OpenMPOpt] ICV Tracking
This is the first and most basic ICV Tracking implementation. For this
first version, we only support deduplication within the same BB.

Reviewers: jdoerfert, JonChesterfield, hamax97, jhuber6, uenoku,
baziotis

Differential Revision: https://reviews.llvm.org/D81788
2020-07-04 23:31:50 +02:00
Roman Lebedev
7ea46aee36
Revert "[AssumeBundles] Use operand bundles to encode alignment assumptions"
Assume bundle can have more than one entry with the same name,
but at least AlignmentFromAssumptionsPass::extractAlignmentInfo() uses
getOperandBundle("align"), which internally assumes that it isn't the
case, and happily crashes otherwise.

Minimal reduced reproducer: run `opt -alignment-from-assumptions` on

target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

%0 = type { i64, %1*, i8*, i64, %2, i32, %3*, i8* }
%1 = type opaque
%2 = type { i8, i8, i16 }
%3 = type { i32, i32, i32, i32 }

; Function Attrs: nounwind
define i32 @f(%0* noalias nocapture readonly %arg, %0* noalias %arg1) local_unnamed_addr #0 {
bb:
  call void @llvm.assume(i1 true) [ "align"(%0* %arg, i64 8), "align"(%0* %arg1, i64 8) ]
  ret i32 0
}

; Function Attrs: nounwind willreturn
declare void @llvm.assume(i1) #1

attributes #0 = { nounwind "reciprocal-estimates"="none" }
attributes #1 = { nounwind willreturn }


This is what we'd have with -mllvm -enable-knowledge-retention

This reverts commit c95ffadb2474a4d8c4f598d94d35a9f31d9606cb.
2020-07-04 23:49:23 +03:00
Roman Lebedev
11a3f040c7
[Utils] Make -assume-builder/-assume-simplify actually work on Old-PM
clang w/ old-pm currently would simply crash
when -mllvm  -enable-knowledge-retention=true is specified.

Clearly, these two passes had no Old-PM test coverage,
which would have shown the problem - not requiring AssumptionCacheTracker,
but then trying to always get it.

Also, why try to get domtree only if it's cached,
but at the same time marking it as required?
2020-07-04 21:06:36 +03:00
Sanjay Patel
3b8ae1001f [InstCombine] fix miscompile from umul_with_overflow matching
As noted in PR46561:
https://bugs.llvm.org/show_bug.cgi?id=46561
...it takes something beyond a minimal IR example to trigger
this bug because it relies on matching non-canonical IR.

There are no tests that show the need for matching this
pattern, so I'm just deleting it to fix the miscompile.
2020-07-04 11:16:23 -04:00
Roman Lebedev
c3b8bd1eea
[InstCombine] Always try to invert non-canonical predicate of an icmp
Summary:
The actual transform i was going after was:
https://rise4fun.com/Alive/Tp9H
```
Name: zz
Pre: isPowerOf2(C0) && isPowerOf2(C1) && C1 == C0
%t0 = and i8 %x, C0
%r = icmp eq i8 %t0, C1
  =>
%t = icmp eq i8 %t0, 0
%r = xor i1 %t, -1

Name: zz
Pre: isPowerOf2(C0)
%t0 = and i8 %x, C0
%r = icmp ne i8 %t0, 0
  =>
%t = icmp eq i8 %t0, 0
%r = xor i1 %t, -1
```
but as it can be seen from the current tests, we already canonicalize most of it,
and we are only missing handling multi-use non-canonical icmp predicates.

If we have both `!=0` and `==0`, even though we can CSE them,
we end up being stuck with them. We should canonicalize to the `==0`.

I believe this is one of the cleanup steps i'll need after `-scalarizer`
if i end up proceeding with my WIP alloca promotion helper pass.

Reviewers: spatel, jdoerfert, nikic

Reviewed By: nikic

Subscribers: zzheng, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D83139
2020-07-04 18:12:04 +03:00
Sanjay Patel
ef70cc9d1a [InstCombine] improve debug value names; NFC
The use of 'tmp' can trigger warnings from the update_test_checks.py
script. That's evidence of a flaw in the script's logic, but we
can always do better than naming variables 'tmp' in LLVM too.

The phi test file should be updated with auto-generated regex CHECK
lines, so it isn't affected by cosmetic diffs, but I don't have
time to do that right now.
2020-07-04 11:06:30 -04:00
Sanjay Patel
14936e01e2 [InstCombine] add test for miscompile (PR46561); NFC 2020-07-04 11:06:30 -04:00
Nikita Popov
3b671022e4 [InstSimplify] Simplify comparison between zext(x) and sext(x)
This is picking up a loose thread from D69006: We can simplify
(zext x) ule (sext x) and (zext x) sge (sext x) to true, with
various permutations. Oddly, SCEV knows about this identity,
but nothing on the IR level does.

Differential Revision: https://reviews.llvm.org/D83081
2020-07-04 11:03:00 +02:00
Nikita Popov
93ccb8eb52 [InstSimplify] Add additional zext/sext comparison tests (NFC)
Add vector variants, and negative tests where the operand does
not match.
2020-07-04 11:03:00 +02:00
Francis Visoiu Mistrih
aa5ec34e31 [LoopDeletion] Emit a remark when a dead loop is deleted
This emits a remark when LoopDeletion deletes a dead loop, using the
source location of the loop's header. There are currently two reasons
for removing the loop: invariant loop or loop that never executes.

Differential Revision: https://reviews.llvm.org/D83113
2020-07-03 15:20:23 -07:00