[NFC][DebugInfo] Use iterator moveBefore at many call-sites (#123583)

As part of the "RemoveDIs" project, BasicBlock::iterator now carries a
debug-info bit that's needed when getFirstNonPHI and sim

[NFC][DebugInfo] Use iterator moveBefore at many call-sites (#123583)

As part of the "RemoveDIs" project, BasicBlock::iterator now carries a
debug-info bit that's needed when getFirstNonPHI and similar feed into
instruction insertion positions. Call-sites where that's necessary were
updated a year ago; but to ensure some type safety however, we'd like to
have all calls to moveBefore use iterators.

This patch adds a (guaranteed dereferenceable) iterator-taking
moveBefore, and changes a bunch of call-sites where it's obviously safe
to change to use it by just calling getIterator() on an instruction
pointer. A follow-up patch will contain less-obviously-safe changes.

We'll eventually deprecate and remove the instruction-pointer
insertBefore, but not before adding concise documentation of what
considerations are needed (very few).

show more ...

Revert "[GuardUtils] Add asserts about loop varying widenable conditions"

This reverts commit 5675757f5fc6e27ce01b3b12bdfd04044df53aa3.

Assert maybe too strict. revert and investigate why assert fi

Revert "[GuardUtils] Add asserts about loop varying widenable conditions"

This reverts commit 5675757f5fc6e27ce01b3b12bdfd04044df53aa3.

Assert maybe too strict. revert and investigate why assert fires.

show more ...

[GuardUtils] Add asserts about loop varying widenable conditions

We have now seen two miscompiles because of widening widenable
conditions at incorrect IR points and thereby changing a branch's loop

[GuardUtils] Add asserts about loop varying widenable conditions

We have now seen two miscompiles because of widening widenable
conditions at incorrect IR points and thereby changing a branch's loop
invariant condition to a loop-varying one (see PR60234 and PR61963).

This patch adds asserts in common guard utilities that we use for
widening to proactively catch these bugs in future.
Note that these asserts will not fire if we were to sink a widenable
condition from out of a loop into a loop (that's also incorrect for the
same reason as above).

Tested this without the fix for PR60234 (guard widening miscompile) and
confirmed the assert fires.

WARNING: Sometimes, the assert can fire if we failed to hoist the
invariant condition out of the loop. This is a pass-ordering issue or a
limitation in LICM, which would need an investigation. See details in
review.

Differential Revision: https://reviews.llvm.org/D147752

show more ...

[llvm][NFC] Inclusive language: Reword replace uses of sanity in llvm/lib/Transform comments and asserts

Reworded some comments and asserts to avoid usage of `sanity check/test`

Reviewed By: dblaik

[llvm][NFC] Inclusive language: Reword replace uses of sanity in llvm/lib/Transform comments and asserts

Reworded some comments and asserts to avoid usage of `sanity check/test`

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D114372

show more ...

[llvm] Construct SmallVector with iterator ranges (NFC)

Further cleanup manipulation of widenable branches [NFC]

This is a follow on to aaea24802bf5. In post commit discussion, Artur and I realized we could cleanup the code using Uses; this patch does s

Further cleanup manipulation of widenable branches [NFC]

This is a follow on to aaea24802bf5. In post commit discussion, Artur and I realized we could cleanup the code using Uses; this patch does so.

show more ...

Broaden the definition of a "widenable branch"

As a reminder, a "widenable branch" is the pattern "br i1 (and i1 X, WC()), label %taken, label %untaken" where "WC" is the widenable condition intrins

Broaden the definition of a "widenable branch"

As a reminder, a "widenable branch" is the pattern "br i1 (and i1 X, WC()), label %taken, label %untaken" where "WC" is the widenable condition intrinsics. The semantics of such a branch (derived from the semantics of WC) is that a new condition can be added into the condition arbitrarily without violating legality.

Broaden the definition in two ways:
Allow swapped operands to the br (and X, WC()) form
Allow widenable branch w/trivial condition (i.e. true) which takes form of br i1 WC()

The former is just general robustness (e.g. for X = non-instruction this is what instcombine produces). The later is specifically important as partial unswitching of a widenable range check produces exactly this form above the loop.

Differential Revision: https://reviews.llvm.org/D70502

show more ...

Move widenable branch formation into makeGuardControlFlowExplicit helper

This is mostly NFC, but I removed the setting of the guard's calling convention onto the WC call. Why? Because it was untes

Move widenable branch formation into makeGuardControlFlowExplicit helper

This is mostly NFC, but I removed the setting of the guard's calling convention onto the WC call. Why? Because it was untested, and was producing an ill defined output as the declaration's convention wasn't been changed leaving a mismatch which is UB.

show more ...

[NFC] Factor out utilities for manipulating widenable branches

With the widenable condition construct, we have the ability to reason about branches which can be 'widened' (i.e. made to fail more oft

[NFC] Factor out utilities for manipulating widenable branches

With the widenable condition construct, we have the ability to reason about branches which can be 'widened' (i.e. made to fail more often). We've got a couple o transforms which leverage this. This patch just cleans up the API a bit.

This is prep work for generalizing our definition of a widenable branch slightly. At the moment "br i1 (and A, wc()), ..." is considered widenable, but oddly, neither "br i1 (and wc(), B), ..." or "br i1 wc(), ..." is. That clearly needs addressed, so first, let's centralize the code in one place.

show more ...

Add missing includes needed to prune LLVMContext.h include, NFC

These are a pre-requisite to removing #include "llvm/Support/Options.h"
from LLVMContext.h: https://reviews.llvm.org/D70280

Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the ne

Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636

show more ...

Revert r340921 "[NFC] Unify guards detection"

This broke the build, see e.g.

http://lab.llvm.org:8011/builders/clang-cmake-armv8-lnt/builds/4626/
http://lab.llvm.org:8011/builders/clang-ppc64be-lin

Revert r340921 "[NFC] Unify guards detection"

This broke the build, see e.g.

http://lab.llvm.org:8011/builders/clang-cmake-armv8-lnt/builds/4626/
http://lab.llvm.org:8011/builders/clang-ppc64be-linux-lnt/builds/18647/
http://lab.llvm.org:8011/builders/clang-cmake-x86_64-avx2-linux/builds/5856/
http://lab.llvm.org:8011/builders/lld-x86_64-freebsd/builds/22800/

> We have multiple places in code where we try to identify whether or not
> some instruction is a guard. This patch factors out this logic into a separate
> utility function which works uniformly in all places.
>
> Differential Revision: https://reviews.llvm.org/D51152
> Reviewed By: fedor.sergeev

llvm-svn: 340923

show more ...

[NFC] Unify guards detection

We have multiple places in code where we try to identify whether or not
some instruction is a guard. This patch factors out this logic into a separate
utility function w

[NFC] Unify guards detection

We have multiple places in code where we try to identify whether or not
some instruction is a guard. This patch factors out this logic into a separate
utility function which works uniformly in all places.

Differential Revision: https://reviews.llvm.org/D51152
Reviewed By: fedor.sergeev

llvm-svn: 340921

show more ...

[NFC] Factor out guard utility methods into a separate file

This patch creates file GuardUtils which will contain logic for work with guards
that can be shared across different passes.

Differential

[NFC] Factor out guard utility methods into a separate file

This patch creates file GuardUtils which will contain logic for work with guards
that can be shared across different passes.

Differential Revision: https://reviews.llvm.org/D51151
Reviewed By: fedor.sergeev

llvm-svn: 340914

show more ...