[IndVarSimplify] Drop samesign flags after narrowing compares (#116263)

Samesign flag cannot be preserved after narrowing the compare since the
position of the sign bit is changed.

Closes https:

[IndVarSimplify] Drop samesign flags after narrowing compares (#116263)

Samesign flag cannot be preserved after narrowing the compare since the
position of the sign bit is changed.

Closes https://github.com/llvm/llvm-project/issues/116249.

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[Scalar] Remove unused includes (NFC) (#114645)

Identified with misc-include-cleaner.

[LLVM] Add `Intrinsic::getDeclarationIfExists` (#112428)

Add `Intrinsic::getDeclarationIfExists` to lookup an existing
declaration of an intrinsic in a `Module`.

Fix LLVM_ENABLE_ABI_BREAKING_CHECKS macro check: use #if instead of #ifdef (#110938)

This macros is always defined: either 0 or 1. The correct pattern is to
use #if.

Re-apply #110185 with more f

Fix LLVM_ENABLE_ABI_BREAKING_CHECKS macro check: use #if instead of #ifdef (#110938)

This macros is always defined: either 0 or 1. The correct pattern is to
use #if.

Re-apply #110185 with more fixes for debug build with the ABI breaking
checks disabled.

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[IndVars] Fix strict weak ordering violation (#108947)

The sort used the block name as a tie-breaker, which will not work for
unnamed blocks and can result in a strict weak ordering violation.

F

[IndVars] Fix strict weak ordering violation (#108947)

The sort used the block name as a tie-breaker, which will not work for
unnamed blocks and can result in a strict weak ordering violation.

Fix this by checking that all exiting blocks dominate the latch first,
which means that we have a total dominance order. This makes the code
structure here align with what optimizeLoopExits() does.

Fixes https://github.com/llvm/llvm-project/issues/108618.

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[IndVars] Use getSigned() in FP transform

This transform is working on signed integer, so this is the
logically correct API.

Split off from https://github.com/llvm/llvm-project/pull/80309.

[SCEV] Use const SCEV * explicitly in more places.

Use const SCEV * explicitly in more places to prepare for
https://github.com/llvm/llvm-project/pull/91961. Split off as suggested.

[IR] Add getDataLayout() helpers to Function and GlobalValue (#96919)

Similar to https://github.com/llvm/llvm-project/pull/96902, this adds
`getDataLayout()` helpers to Function and GlobalValue, re

[IR] Add getDataLayout() helpers to Function and GlobalValue (#96919)

Similar to https://github.com/llvm/llvm-project/pull/96902, this adds
`getDataLayout()` helpers to Function and GlobalValue, replacing the
current `getParent()->getDataLayout()` pattern.

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[IR] Add getDataLayout() helpers to BasicBlock and Instruction (#96902)

This is a helper to avoid writing `getModule()->getDataLayout()`. I
regularly try to use this method only to remember it does

[IR] Add getDataLayout() helpers to BasicBlock and Instruction (#96902)

This is a helper to avoid writing `getModule()->getDataLayout()`. I
regularly try to use this method only to remember it doesn't exist...

`getModule()->getDataLayout()` is also a common (the most common?)
reason why code has to include the Module.h header.

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[DebugInfo][IndVarSimplify] Fix missing debug location updates (#91443)

Adds debug location updates for the newly created `phi`, `add`, `icmp` and `sitofp` instructions in `IndVarSimplify`.

Fixes

[DebugInfo][IndVarSimplify] Fix missing debug location updates (#91443)

Adds debug location updates for the newly created `phi`, `add`, `icmp` and `sitofp` instructions in `IndVarSimplify`.

Fixes #91436

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[Passes] Run SimpleLoopUnswitch after introducing invariant branches. (#81271)

IndVars may be able to replace a loop dependent condition with a loop
invariant one, but loop-unswitch runs before Ind

[Passes] Run SimpleLoopUnswitch after introducing invariant branches. (#81271)

IndVars may be able to replace a loop dependent condition with a loop
invariant one, but loop-unswitch runs before IndVars, so the invariant
check remains in the loop.

For an example, consider a read-only loop with a bounds check:
https://godbolt.org/z/8cdj4qhbG

This patch uses a approach similar to the way extra cleanup passes are
run on demand after vectorization (added in acea6e9cfa4c4a0e8678c7).

It introduces a new ShouldRunExtraSimpleLoopUnswitch analysis marker,
which IndVars can use to indicate that extra unswitching is beneficial.

ExtraSimpleLoopUnswitchPassManager uses this analysis to determine
whether to run its passes on a loop.

Compile-time impact (geomean) ranges from +0.0% to 0.02%
https://llvm-compile-time-tracker.com/compare.php?from=138c0beb109ffe47f75a0fe8c4dc2cdabe8a6532&to=19e6e99eeb280d426907ea73a21b139ba7225627&stat=instructions%3Au

Compile-time impact (geomean) of unconditionally running
SimpleLoopUnswitch ranges from +0.05% - +0.16%

https://llvm-compile-time-tracker.com/compare.php?from=138c0beb109ffe47f75a0fe8c4dc2cdabe8a6532&to=2930dfd5accdce2e6f8d5146ae4d626add2065a2&stat=instructions:u

Unconditionally running SimpleLoopUnswitch seems to indicate that there
are multiple other scenarios where we fail to run unswitching when
opportunities remain.


Fixes https://github.com/llvm/llvm-project/issues/85551.

PR: https://github.com/llvm/llvm-project/pull/81271

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[NFC][RemoveDIs] Insert instruction using iterators in Transforms/

As part of the RemoveDIs project we need LLVM to insert instructions using
iterators wherever possible, so that the iterators can c

[NFC][RemoveDIs] Insert instruction using iterators in Transforms/

As part of the RemoveDIs project we need LLVM to insert instructions using
iterators wherever possible, so that the iterators can carry a bit of
debug-info. This commit implements some of that by updating the contents of
llvm/lib/Transforms/Utils to always use iterator-versions of instruction
constructors.

There are two general flavours of update:
* Almost all call-sites just call getIterator on an instruction
* Several make use of an existing iterator (scenarios where the code is
actually significant for debug-info)
The underlying logic is that any call to getFirstInsertionPt or similar
APIs that identify the start of a block need to have that iterator passed
directly to the insertion function, without being converted to a bare
Instruction pointer along the way.

Noteworthy changes:
* FindInsertedValue now takes an optional iterator rather than an
instruction pointer, as we need to always insert with iterators,
* I've added a few iterator-taking versions of some value-tracking and
DomTree methods -- they just unwrap the iterator. These are purely
convenience methods to avoid extra syntax in some passes.
* A few calls to getNextNode become std::next instead (to keep in the
theme of using iterators for positions),
* SeparateConstOffsetFromGEP has it's insertion-position field changed.
Noteworthy because it's not a purely localised spelling change.

All this should be NFC.

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[IndVars] Check expansion safety during LFTR

Check isSafeToExpand() before expanding the exit count. Otherwise
we may incorrectly speculate a udiv.

Fixes https://github.com/llvm/llvm-project/issues

[IndVars] Check expansion safety during LFTR

Check isSafeToExpand() before expanding the exit count. Otherwise
we may incorrectly speculate a udiv.

Fixes https://github.com/llvm/llvm-project/issues/66986.

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Remove several no longer needed includes. NFCI

Mostly removing includes of InitializePasses.h and Pass.h in
passes that no longer has support for the legacy PM.

[Scalar] Use range-based for loops (NFC)

[LFTR] Simplify integer case for genLoopLimit [nfc-ish]

The integer case in genLoopLimit reduces down to a special case for narrowing the bitwidth of the limit, and then performing the same expansio

[LFTR] Simplify integer case for genLoopLimit [nfc-ish]

The integer case in genLoopLimit reduces down to a special case for narrowing the bitwidth of the limit, and then performing the same expansion we would for a pointer IV.

Differential Revision: https://reviews.llvm.org/D146638

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[LFTR] Minor style cleanup [nfc]

[LFTR] Use evaluateAtIteration in genLoopLimit [nfc]

Note that the comments being removed appear to be very out of sync with the actual code in question.

Differential Revision: https://reviews.llvm

[LFTR] Use evaluateAtIteration in genLoopLimit [nfc]

Note that the comments being removed appear to be very out of sync with the actual code in question.

Differential Revision: https://reviews.llvm.org/D146468

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[LFTR] Simplify another case under assumption exit counts are integers [nfc]

This invariant was introduced in 8f3d16905d75b07a933d01dc29677fe5867c1b3e.

[IndVarSimplify] Remove duplicate call to getSCEV. NFC

We already did this same call on the line before.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D146444

[LFTR] Assert and simplify under assumption exit counts are integers [nfc]

This invariant was introduced in 8f3d16905d75b07a933d01dc29677fe5867c1b3e.

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

[LFTR] Assert and simplify under assumption exit counts are integers [nfc]

This invariant was introduced in 8f3d16905d75b07a933d01dc29677fe5867c1b3e.

Differential Revision: https://reviews.llvm.org/D146470

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[LSR/LFTR] Move two utilities to common code for reuse [nfc]

We're working on a transform in LSR which is essentiall an inverse of LFTR (in certain sub-cases). Move utilties so that they can be reu

[LSR/LFTR] Move two utilities to common code for reuse [nfc]

We're working on a transform in LSR which is essentiall an inverse of LFTR (in certain sub-cases). Move utilties so that they can be reused.

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[NFC] Drop NDEBUG around MSSA verification

Proposed on review of https://reviews.llvm.org/D145894.

[IndVars] Option verify-indvars is broken (and always has been), delete it

This option is switched off by default, and it seems that it has never worked correctly.
What it basically does is: it reme

[IndVars] Option verify-indvars is broken (and always has been), delete it

This option is switched off by default, and it seems that it has never worked correctly.
What it basically does is: it remembers current BECount SCEV, and after all transforms
tries to validate some facts for it. However, between these two points this SCEV may
become invalid (e.g. because some SCEVUnknown it references may be deleted as dead
code). So basically it may work with broken pointers.

Besides, its implementation does strange things (e.g. forgetLoop) which are invasive and
may affect behavior in other parts of the system (specifically verification), concealing some
other problems. Another issue is that it may use SCEVCouldNotCompute object without
checking this.

The option is not used in any unit tests, and if switched on by default, the following tests
fail:
```
********************
Failed Tests (14):
LLVM :: Transforms/IndVarSimplify/2005-06-15-InstMoveCrash.ll
LLVM :: Transforms/IndVarSimplify/2007-06-06-DeleteDanglesPtr.ll
LLVM :: Transforms/IndVarSimplify/2008-10-03-CouldNotCompute.ll
LLVM :: Transforms/IndVarSimplify/2009-05-24-useafterfree.ll
LLVM :: Transforms/IndVarSimplify/2011-10-27-lftrnull.ll
LLVM :: Transforms/IndVarSimplify/ARM/code-size.ll
LLVM :: Transforms/IndVarSimplify/X86/deterministic-scev-verify.ll
LLVM :: Transforms/IndVarSimplify/X86/pr57187.ll
LLVM :: Transforms/IndVarSimplify/X86/verify-scev.ll
LLVM :: Transforms/IndVarSimplify/bbi-63564.ll
LLVM :: Transforms/IndVarSimplify/invalidate-modified-lcssa-phi.ll
LLVM :: Transforms/IndVarSimplify/loop-predication.ll
LLVM :: Transforms/IndVarSimplify/post-inc-range.ll
LLVM :: Transforms/IndVarSimplify/turn-to-invariant.ll

********************
Unexpectedly Passed Tests (1):
LLVM :: Transforms/IndVarSimplify/pr55689.ll
```

None of these looks like real problems found by verification, these are
bugs in the verifying code itself (such as use of deleted SCEVs and
SCEVCouldNotCompute's).

I think it all gives enough justification for its removal.

https://github.com/llvm/llvm-project/issues/61302

Differential Revision: https://reviews.llvm.org/D145894
Reviewed By: nikic

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[Passes] Remove some legacy passes

DFAJumpThreading
JumpThreading
LibCallsShrink
LoopVectorize
SLPVectorizer
DeadStoreElimination
AggressiveDCE
CorrelatedValuePropagation
IndVarSimplify

These are p

[Passes] Remove some legacy passes

DFAJumpThreading
JumpThreading
LibCallsShrink
LoopVectorize
SLPVectorizer
DeadStoreElimination
AggressiveDCE
CorrelatedValuePropagation
IndVarSimplify

These are part of the optimization pipeline, of which the legacy version is deprecated and being removed.

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