[MachineVerifier] Try harder to verify LiveStacks

Verify the LiveStacks analysis after a pass that claims to preserve it,
even if there are no further passes (apart from the verifier itself)
that wo

[MachineVerifier] Try harder to verify LiveStacks

Verify the LiveStacks analysis after a pass that claims to preserve it,
even if there are no further passes (apart from the verifier itself)
that would use the analysis.

Differential Revision: https://reviews.llvm.org/D129200

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Fix interaction of CFI instructions with MachineOutliner.

1. When checking if a candidate contains a CFI instruction, actually
iterate over all of the instructions, instead of stopping halfway
throu

Fix interaction of CFI instructions with MachineOutliner.

1. When checking if a candidate contains a CFI instruction, actually
iterate over all of the instructions, instead of stopping halfway
through.
2. Make sure copied CFI directives refer to the correct instruction.

Fixes https://github.com/llvm/llvm-project/issues/55842

Differential Revision: https://reviews.llvm.org/D126930

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[GlobalISel] Add G_IS_FPCLASS

Add a generic opcode to represent `llvm.is_fpclass` intrinsic.

Differential Revision: https://reviews.llvm.org/D121454

GlobalISel: Relax handling of G_ASSERT_* with source register classes

The most common situation where G_ASSERT_ZEXT appears for AMDGPU is a
copy from a physical register, which happens to use set th

GlobalISel: Relax handling of G_ASSERT_* with source register classes

The most common situation where G_ASSERT_ZEXT appears for AMDGPU is a
copy from a physical register, which happens to use set the actual
register class on the virtual register. After copy coalescing, the
assert's source operand had a vreg with a set class. The verifier was
strictly rejecting cases where the set class/bank weren't an exact
match. Additionally, RegBankSelect was also expecting a register bank
to be set on the register, not a class.

This is much stricter than regular copies so relax this behavior. This
now allows these 2 cases:

1. Source register has either class or bank, and the result does not
2. Source register has a register class, and the result is a register
with a matching bank.

This should avoid needing some kind of special handling to avoid
violating this constraint when folding copies.

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GlobalISel: Verify atomic load/store ordering restriction

Reject acquire stores and release loads. This matches the restriction
imposed by the LLParser and IR verifier.

MachineVerifier: Diagnose undef set on full register defs

An undef def of a full register would assert in LiveIntervalCalc.

[NFC][CodeGen] Rename some functions in MachineInstr.h and remove duplicated comments

Cleanup codegen includes

This is a (fixed) recommit of https://reviews.llvm.org/D121169

after: 1061034926
before: 1063332844

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-in

Cleanup codegen includes

This is a (fixed) recommit of https://reviews.llvm.org/D121169

after: 1061034926
before: 1063332844

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D121681

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Revert "Cleanup codegen includes"

This reverts commit 7f230feeeac8a67b335f52bd2e900a05c6098f20.
Breaks CodeGenCUDA/link-device-bitcode.cu in check-clang,
and many LLVM tests, see comments on https:/

Revert "Cleanup codegen includes"

This reverts commit 7f230feeeac8a67b335f52bd2e900a05c6098f20.
Breaks CodeGenCUDA/link-device-bitcode.cu in check-clang,
and many LLVM tests, see comments on https://reviews.llvm.org/D121169

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Cleanup codegen includes

after: 1061034926
before: 1063332844

Differential Revision: https://reviews.llvm.org/D121169

[nfc][codegen] Move RegisterBank[Info].h under CodeGen

This wraps up from D119053. The 2 headers are moved as described,
fixed file headers and include guards, updated all files where the old
paths

[nfc][codegen] Move RegisterBank[Info].h under CodeGen

This wraps up from D119053. The 2 headers are moved as described,
fixed file headers and include guards, updated all files where the old
paths were detected (simple grep through the repo), and `clang-format`-ed it all.

Differential Revision: https://reviews.llvm.org/D119876

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[NFC] Remove unnecessary "#include"s from header files

[MVerifier] Don't check liveness of any debug instruction operands

Shiny new DBG_PHI instruction usually have physical registers as operands
-- however, the machine verifier checks to see whether th

[MVerifier] Don't check liveness of any debug instruction operands

Shiny new DBG_PHI instruction usually have physical registers as operands
-- however, the machine verifier checks to see whether they're live, and
occasionally this fails. There's a filter for DBG_VALUE instructions to not
get verified in this way: expand it to exempt all debug instructions from
liveness checking, which means DBG_PHIs get treated like DBG_VALUEs.

This also future proofs against us adding new debug instructions.

Differential Revision: https://reviews.llvm.org/D117891

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[GlobalISel] Verify operand types for G_SHL, G_LSHR, G_ASHR

Differential Revision: https://reviews.llvm.org/D115868

[MachineVerifier] Undef subreg operands do not require subranges

D112556 added verification that the live interval for a subreg operand
must have subranges. This patch fixes a corner case, where if

[MachineVerifier] Undef subreg operands do not require subranges

D112556 added verification that the live interval for a subreg operand
must have subranges. This patch fixes a corner case, where if all subreg
operands for a particular register are undef uses then no subranges
are required. This matches how LiveIntervalCalc would build the live
intervals in the first place, since an undef use is not considered
to read the register.

Before this patch, CodeGen/AMDGPU/no-remat-indirect-mov.mir would fail
with -early-live-intervals:

# After Live Interval Analysis
...
*** Bad machine code: Live interval for subreg operand has no subranges ***
- function: index_vgpr_waterfall_loop
- basic block: %bb.1 (0x6a9a968) [352B;496B)
- instruction: 432B %24:vgpr_32 = V_MOV_B32_e32 undef %18.sub0:vreg_512, implicit $exec, implicit %18:vreg_512, implicit $m0
- operand 1: undef %18.sub0:vreg_512

Differential Revision: https://reviews.llvm.org/D115360

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[GlobalISel] Allow DBG_VALUE to use undefined vregs before LiveDebugValues.

Expanding on D109750.

Since `DBG_VALUE` instructions have final register validity determined in
`LDVImpl::handleDebugValu

[GlobalISel] Allow DBG_VALUE to use undefined vregs before LiveDebugValues.

Expanding on D109750.

Since `DBG_VALUE` instructions have final register validity determined in
`LDVImpl::handleDebugValue`, there is no apparent reason to immediately prune
unused register operands as their defs are erased. Consequently, this renders
`MachineInstr::eraseFromParentAndMarkDBGValuesForRemoval` moot; gaining a
substantial performance improvement.

The only necessary changes involve making relevant passes consider invalid
DBG_VALUE vregs uses as valid.

Reviewed By: MatzeB

Differential Revision: https://reviews.llvm.org/D112852

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

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

[MachineVerifier] Live interval for a subreg must have subranges

MachineVerifier verified the subranges of a live interval if
they existed, but did not complain if they did not exist.

This patch ch

[MachineVerifier] Live interval for a subreg must have subranges

MachineVerifier verified the subranges of a live interval if
they existed, but did not complain if they did not exist.

This patch changes the verifier to complain if there are no
subranges in the live interval for a subreg operand (so long
as MachineRegisterInfo says we should be tracking subreg
liveness for that register). This matches the conditions for
LiveIntervalCalc to create subranges in the first place.

Differential Revision: https://reviews.llvm.org/D112556

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Add new MachineFunction property FailsVerification

TargetPassConfig::addPass takes a "bool verifyAfter" argument which lets
you skip machine verification after a particular pass. Unfortunately
this

Add new MachineFunction property FailsVerification

TargetPassConfig::addPass takes a "bool verifyAfter" argument which lets
you skip machine verification after a particular pass. Unfortunately
this is used in generic code in TargetPassConfig itself to skip
verification after a generic pass, only because some previous target-
specific pass damaged the MIR on that specific target. This is bad
because problems in one target cause lack of verification for all
targets.

This patch replaces that mechanism with a new MachineFunction property
called "FailsVerification" which can be set by (usually target-specific)
passes that are known to introduce problems. Later passes can reset it
again if they are known to clean up the previous problems.

Differential Revision: https://reviews.llvm.org/D111397

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[MachineInstr] Move MIParser's DBG_VALUE RegState::Debug invariant into MachineInstr::addOperand

Based on the reasoning of D53903, register operands of DBG_VALUE are
invariably treated as RegState::

[MachineInstr] Move MIParser's DBG_VALUE RegState::Debug invariant into MachineInstr::addOperand

Based on the reasoning of D53903, register operands of DBG_VALUE are
invariably treated as RegState::Debug operands. This change enforces
this invariant as part of MachineInstr::addOperand so that all passes
emit this flag consistently.

RegState::Debug is inconsistently set on DBG_VALUE registers throughout
LLVM. This runs the risk of a filtering iterator like
MachineRegisterInfo::reg_nodbg_iterator to process these operands
erroneously when not parsed from MIR sources.

This issue was observed in the development of the llvm-mos fork which
adds a backend that relies on physical register operands much more than
existing targets. Physical RegUnit 0 has the same numeric encoding as
$noreg (indicating an undef for DBG_VALUE). Allowing debug operands into
the machine scheduler correlates $noreg with RegUnit 0 (i.e. a collision
of register numbers with different zero semantics). Eventually, this
causes an assert where DBG_VALUE instructions are prohibited from
participating in live register ranges.

Reviewed By: MatzeB, StephenTozer

Differential Revision: https://reviews.llvm.org/D110105

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[LiveIntervals] Fix verification of early-clobbered segments

Enable verification of live intervals immediately after computing them
(when -early-live-intervals is used) and fix a problem that that
p

[LiveIntervals] Fix verification of early-clobbered segments

Enable verification of live intervals immediately after computing them
(when -early-live-intervals is used) and fix a problem that that
provokes: currently the verifier insists that a segment that ends at an
early-clobber slot must be followed by another segment starting at the
same slot. But before TwoAddressInstruction runs, the equivalent
condition is: a segment that ends at an early-clobber slot must have its
last use tied to an early-clobber def. That condition is harder to check
here, so for now just disable this check until tied operands have been
rewritten.

Differential Revision: https://reviews.llvm.org/D111065

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[LiveVariables] Skip verification of kills inside bundles

LiveVariables does not examine the contents of bundles, so
MachineVerifier should not expect it to know about kill flags on
operands of inst

[LiveVariables] Skip verification of kills inside bundles

LiveVariables does not examine the contents of bundles, so
MachineVerifier should not expect it to know about kill flags on
operands of instructions inside a bundle.

With this fix we can enable machine verification after running the
LiveVariables analysis. Doing this does not show any problems in
check-llvm in an LLVM_ENABLE_EXPENSIVE_CHECKS build.

Differential Revision: https://reviews.llvm.org/D110700

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[ARM] Add a tail-predication loop predicate register

The semantics of tail predication loops means that the value of LR as an
instruction is executed determines the predicate. In other words:

mov r

[ARM] Add a tail-predication loop predicate register

The semantics of tail predication loops means that the value of LR as an
instruction is executed determines the predicate. In other words:

mov r3, #3
DLSTP lr, r3 // Start tail predication, lr==3
VADD.s32 q0, q1, q2 // Lanes 0,1 and 2 are updated in q0.
mov lr, #1
VADD.s32 q0, q1, q2 // Only first lane is updated.

This means that the value of lr cannot be spilled and re-used in tail
predication regions without potentially altering the behaviour of the
program. More lanes than required could be stored, for example, and in
the case of a gather those lanes might not have been setup, leading to
alignment exceptions.

This patch adds a new lr predicate operand to MVE instructions in order
to keep a reference to the lr that they use as a tail predicate. It will
usually hold the zeroreg meaning not predicated, being set to the LR phi
value in the MVETPAndVPTOptimisationsPass. This will prevent it from
being spilled anywhere that it needs to be used.

A lot of tests needed updating.

Differential Revision: https://reviews.llvm.org/D107638

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Revert @llvm.isnan intrinsic patchset.

Please refer to
https://lists.llvm.org/pipermail/llvm-dev/2021-September/152440.html
(and that whole thread.)

TLDR: the original patch had no prior RFC, yet i

Revert @llvm.isnan intrinsic patchset.

Please refer to
https://lists.llvm.org/pipermail/llvm-dev/2021-September/152440.html
(and that whole thread.)

TLDR: the original patch had no prior RFC, yet it had some changes that
really need a proper RFC discussion. It won't be productive to discuss
such an RFC, once it's actually posted, while said patch is already
committed, because that introduces bias towards already-committed stuff,
and the tree is potentially in broken state meanwhile.

While the end result of discussion may lead back to the current design,
it may also not lead to the current design.

Therefore i take it upon myself
to revert the tree back to last known good state.

This reverts commit 4c4093e6e39fe6601f9c95a95a6bc242ef648cd5.
This reverts commit 0a2b1ba33ae6dcaedb81417f7c4cc714f72a5968.
This reverts commit d9873711cb03ac7aedcaadcba42f82c66e962e6e.
This reverts commit 791006fb8c6fff4f33c33cb513a96b1d3f94c767.
This reverts commit c22b64ef66f7518abb6f022fcdfd86d16c764caf.
This reverts commit 72ebcd3198327da12804305bda13d9b7088772a8.
This reverts commit 5fa6039a5fc1b6392a3c9a3326a76604e0cb1001.
This reverts commit 9efda541bfbd145de90f7db38d935db6246dc45a.
This reverts commit 94d3ff09cfa8d7aecf480e54da9a5334e262e76b.

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