[SCEV] Extend type hint in analysis output to all backedge kinds

This extends the work from 7755c26 to all of the different backend
taken count kinds that we print for the scev analysis printer. As

[SCEV] Extend type hint in analysis output to all backedge kinds

This extends the work from 7755c26 to all of the different backend
taken count kinds that we print for the scev analysis printer. As
before, the goal is to cut down on confusion as i4 -1 is a very
different (unsigned) value from i32 -1.

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[SCEV] Print predicate backedge count only if new information available

When printing the result of SCEV's analysis, we can avoid printing
the predicated backedge taken count and the predicates if t

[SCEV] Print predicate backedge count only if new information available

When printing the result of SCEV's analysis, we can avoid printing
the predicated backedge taken count and the predicates if the predicates
are empty and no new information is provided. This helps to reduce the
verbosity of the output.

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[SCEV] Include type when printing constant max backedge taken count

When printing the result of the analysis, i8 -1 and i64 -1 are quite
different in terms of analysis quality. In a recent conversi

[SCEV] Include type when printing constant max backedge taken count

When printing the result of the analysis, i8 -1 and i64 -1 are quite
different in terms of analysis quality. In a recent conversion with
a new contributor, we ran into exactly this confusion.

Adding the type for constant scevs more globally seems worthwhile, but
introduces a much larger test diff. I'm splitting this off first since
it addresses the immediate need, and then going to do some further
changes to clarify a few related bits of analysis result output.

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[SCEV] Regenerate test checks (NFC)

There have been some minor but pervasive changes to the generated
CHECK lines, so regenerate all of them, to minimize future diffs.

[SCEV] Strengthen nowrap flags via ranges for ARs on construction.

At the moment, proveNoWrapViaConstantRanges is only used when creating
SCEV[Zero,Sign]ExtendExprs. We can get significant improveme

[SCEV] Strengthen nowrap flags via ranges for ARs on construction.

At the moment, proveNoWrapViaConstantRanges is only used when creating
SCEV[Zero,Sign]ExtendExprs. We can get significant improvements by
strengthening flags after creating the AddRec.

I'll also share a follow-up patch that removes the code to strengthen
flags when creating SCEV[Zero,Sign]ExtendExprs. Modifying AddRecs while
creating those can lead to surprising changes.

Compile-time looks neutral:
https://llvm-compile-time-tracker.com/compare.php?from=94676cf8a13c511a9acfc24ed53c98964a87bde3&to=aced434e8b103109104882776824c4136c90030d&stat=instructions:u

Reviewed By: mkazantsev, nikic

Differential Revision: https://reviews.llvm.org/D144050

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[SCEV] Convert some tests to opaque pointers (NFC)

[SCEV] Add printout of symbolic max backedge-taken and block exit count

We do compute it and use in optimizations, but never print it out. We need
to do it in order to be able to track improvements

[SCEV] Add printout of symbolic max backedge-taken and block exit count

We do compute it and use in optimizations, but never print it out. We need
to do it in order to be able to track improvements in its computation.

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[SCEV] Rename max backedge-taken count -> constant max backedge taken-count in printout

This is a preparatory step for introducing symbolic max backedge-taken count.

Recommit "[SCEV] Look through single value PHIs." (take 3)

This reverts commit 1fbdbb559569641f6d509b569966901c8fb02b63.

All known issues surfaced by this patch should have been fixed now.

The fix

Recommit "[SCEV] Look through single value PHIs." (take 3)

This reverts commit 1fbdbb559569641f6d509b569966901c8fb02b63.

All known issues surfaced by this patch should have been fixed now.

The fixes included fixing issues with SCEV expansion in LV and DA's
reliance on LCSSA phis.

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Revert "Recommit "[SCEV] Look through single value PHIs." (take 2)"

This reverts commit 764d9aa97905f202385b4f25f8d234630b4feef3.

This patch exposed a few additional cases where SCEV expressions ar

Revert "Recommit "[SCEV] Look through single value PHIs." (take 2)"

This reverts commit 764d9aa97905f202385b4f25f8d234630b4feef3.

This patch exposed a few additional cases where SCEV expressions are not
properly invalidated.

See PR52024, PR52023.

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Recommit "[SCEV] Look through single value PHIs." (take 2)

This reverts commit 8fdac7cb7abbeeaed016ef9eb7a087458e41e33f.

The issue causing the revert has been fixed a while ago in 60b852092c98.

Or

Recommit "[SCEV] Look through single value PHIs." (take 2)

This reverts commit 8fdac7cb7abbeeaed016ef9eb7a087458e41e33f.

The issue causing the revert has been fixed a while ago in 60b852092c98.

Original message:

Now that SCEVExpander can preserve LCSSA form,
we do not have to worry about LCSSA form when
trying to look through PHIs. SCEVExpander will take
care of inserting LCSSA PHI nodes as required.

This increases precision of the analysis in some cases.

Reviewed By: mkazantsev, bmahjour

Differential Revision: https://reviews.llvm.org/D71539

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[test][NewPM] Remove RUN lines using -analyze

Only tests in llvm/test/Analysis.

-analyze is legacy PM-specific.

This only touches files with `-passes`.

I looked through everything and made sure t

[test][NewPM] Remove RUN lines using -analyze

Only tests in llvm/test/Analysis.

-analyze is legacy PM-specific.

This only touches files with `-passes`.

I looked through everything and made sure that everything had a new PM equivalent.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D109040

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Revert D71539 "Recommit "[SCEV] Look through single value PHIs.""

This reverts commit 11dccf8d3aa5d55210f8b886fb21926c7a8353ca.

A bootstrapped clang crashes (due to ArrayRef::front called on an emp

Revert D71539 "Recommit "[SCEV] Look through single value PHIs.""

This reverts commit 11dccf8d3aa5d55210f8b886fb21926c7a8353ca.

A bootstrapped clang crashes (due to ArrayRef::front called on an empty
ArrayRef) when compiling some files. Very strangely, this only reproduces with
modules.

```
13 0x0000564d3349e968 llvm::ArrayRef<llvm::BasicBlock*>::front() const /proc/self/cwd/llvm/include/llvm/ADT/ArrayRef.h:160:7
14 0x0000564d3349e896 llvm::LoopBase<llvm::BasicBlock, llvm::Loop>::getHeader() const /proc/self/cwd/llvm/include/llvm/Analysis/LoopInfo.h:104:50
15 0x0000564d3349fd9d llvm::LoopBase<llvm::BasicBlock, llvm::Loop>::getLoopLatch() const /proc/self/cwd/llvm/include/llvm/Analysis/LoopInfoImpl.h:210:11
16 0x0000564d33593c8a llvm::ScalarEvolution::computeBackedgeTakenCount(llvm::Loop const*, bool) /proc/self/cwd/llvm/lib/Analysis/ScalarEvolution.cpp:6933:15
17 0x0000564d33592ebc llvm::ScalarEvolution::getBackedgeTakenInfo(llvm::Loop const*) /proc/self/cwd/llvm/lib/Analysis/ScalarEvolution.cpp:0:30
18 0x0000564d33593a54 llvm::ScalarEvolution::getBackedgeTakenCount(llvm::Loop const*, llvm::ScalarEvolution::ExitCountKind) /proc/self/cwd/llvm/lib/Analysis/ScalarEvolution.cpp:6487:36
19 0x0000564d32be2402 llvm::ScalarEvolution::getConstantMaxBackedgeTakenCount(llvm::Loop const*) /proc/self/cwd/llvm/include/llvm/Analysis/ScalarEvolution.h:768:5
20 0x0000564d33590807 llvm::ScalarEvolution::getRangeRef(llvm::SCEV const*, llvm::ScalarEvolution::RangeSignHint) /proc/self/cwd/llvm/lib/Analysis/ScalarEvolution.cpp:5495:19
21 0x0000564d320abab7 llvm::ScalarEvolution::getSignedRange(llvm::SCEV const*) /proc/self/cwd/llvm/include/llvm/Analysis/ScalarEvolution.h:840:12
22 0x0000564d335a03aa llvm::ScalarEvolution::isKnownPredicateViaConstantRanges(llvm::CmpInst::Predicate, llvm::SCEV const*, llvm::SCEV const*) /proc/self/cwd/llvm/lib/Analysis/ScalarEvolution.cpp:9239:60
23 0x0000564d33586a80 llvm::ScalarEvolution::isKnownViaNonRecursiveReasoning(llvm::CmpInst::Predicate, llvm::SCEV const*, llvm::SCEV const*) /proc/self/cwd/llvm/lib/Analysis/ScalarEvolution.cpp:10284:60
```

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Recommit "[SCEV] Look through single value PHIs."

This commit was originally because it was suspected to cause a crash,
but a reproducer did not surface.

A crash that was exposed by this change was

Recommit "[SCEV] Look through single value PHIs."

This commit was originally because it was suspected to cause a crash,
but a reproducer did not surface.

A crash that was exposed by this change was fixed in 1d8f2e52925b.

This reverts the revert commit 0581c0b0eeba03da590d1176a4580cf9b9e8d1e3.

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Revert "[SCEV] Look through single value PHIs."

This reverts commit e441b7a7a0a72c28daf5a8e594559c667e5b4534.

This patch causes a compile error in tensorflow opensource project. The stack trace loo

Revert "[SCEV] Look through single value PHIs."

This reverts commit e441b7a7a0a72c28daf5a8e594559c667e5b4534.

This patch causes a compile error in tensorflow opensource project. The stack trace looks like:

Point of crash:
llvm/include/llvm/Analysis/LoopInfoImpl.h : line 35

(gdb) ptype *this
type = const class llvm::LoopBase<llvm::BasicBlock, llvm::Loop> [with BlockT = llvm::BasicBlock, LoopT = llvm::Loop]

(gdb) p *this
$1 = {ParentLoop = 0x0, SubLoops = std::vector of length 0, capacity 0, Blocks = std::vector of length 0, capacity 1,
DenseBlockSet = {<llvm::SmallPtrSetImpl<llvm::BasicBlock const*>> = {<llvm::SmallPtrSetImplBase> = {<llvm::DebugEpochBase> = {Epoch = 3}, SmallArray = 0x1b2bf6c8, CurArray = 0x1b2bf6c8,
CurArraySize = 8, NumNonEmpty = 0, NumTombstones = 0}, <No data fields>}, SmallStorage = {0xfffffffffffffffe, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}}, IsInvalid = true}

(gdb) p *this->DenseBlockSet->CurArray
$2 = (const void *) 0xfffffffffffffffe

I will try to get a case from tensorflow or use creduce to get a small case.

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[SCEV] Look through single value PHIs.

Now that SCEVExpander can preserve LCSSA form,
we do not have to worry about LCSSA form when
trying to look through PHIs. SCEVExpander will take
care of insert

[SCEV] Look through single value PHIs.

Now that SCEVExpander can preserve LCSSA form,
we do not have to worry about LCSSA form when
trying to look through PHIs. SCEVExpander will take
care of inserting LCSSA PHI nodes as required.

This increases precision of the analysis in some cases.

Reviewed By: mkazantsev, bmahjour

Differential Revision: https://reviews.llvm.org/D71539

show more ...

[SCEV] Fix ScalarEvolution tests under NPM

Many tests use opt's -analyze feature, which does not translate well to
NPM and has better alternatives. The alternative here is to explicitly
add a pass t

[SCEV] Fix ScalarEvolution tests under NPM

Many tests use opt's -analyze feature, which does not translate well to
NPM and has better alternatives. The alternative here is to explicitly
add a pass that calls ScalarEvolution::print().

The legacy pass manager RUNs aren't changing, but they are now pinned to
the legacy pass manager. For each legacy pass manager RUN, I added a
corresponding NPM RUN using the 'print<scalar-evolution>' pass. For
compatibility with update_analyze_test_checks.py and existing test
CHECKs, 'print<scalar-evolution>' now prints what -analyze prints per
function.

This was generated by the following Python script and failures were
manually fixed up:

import sys
for i in sys.argv:
with open(i, 'r') as f:
s = f.read()
with open(i, 'w') as f:
for l in s.splitlines():
if "RUN:" in l and ' -analyze ' in l and '\\' not in l:
f.write(l.replace(' -analyze ', ' -analyze -enable-new-pm=0 '))
f.write('\n')
f.write(l.replace(' -analyze ', ' -disable-output ').replace(' -scalar-evolution ', ' "-passes=print<scalar-evolution>" ').replace(" | ", " 2>&1 | "))
f.write('\n')
else:
f.write(l)

There are a couple failures still in ScalarEvolution under NPM, but
those are due to other unrelated naming conflicts.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D83798

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[SCEV] Properly solve quadratic equations

Differential Revision: https://reviews.llvm.org/D48283

llvm-svn: 338758