Cleanup codegen includes

after: 1061034926
before: 1063332844

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

Reduce dependencies on llvm/BinaryFormat/Dwarf.h

This header is very large (3M Lines once expended) and was included in location
where dwarf-specific information were not needed.

More specifically,

Reduce dependencies on llvm/BinaryFormat/Dwarf.h

This header is very large (3M Lines once expended) and was included in location
where dwarf-specific information were not needed.

More specifically, this commit suppresses the dependencies on
llvm/BinaryFormat/Dwarf.h in two headers: llvm/IR/IRBuilder.h and
llvm/IR/DebugInfoMetadata.h. As these headers (esp. the former) are widely used,
this has a decent impact on number of preprocessed lines generated during
compilation of LLVM, as showcased below.

This is achieved by moving some definitions back to the .cpp file, no
performance impact implied[0].

As a consequence of that patch, downstream user may need to manually some extra
files:

llvm/IR/IRBuilder.h no longer includes llvm/BinaryFormat/Dwarf.h
llvm/IR/DebugInfoMetadata.h no longer includes llvm/BinaryFormat/Dwarf.h

In some situations, codes maybe relying on the fact that
llvm/BinaryFormat/Dwarf.h was including llvm/ADT/Triple.h, this hidden
dependency now needs to be explicit.

$ clang++ -E -Iinclude -I../llvm/include ../llvm/lib/Transforms/Scalar/*.cpp -std=c++14 -fno-rtti -fno-exceptions | wc -l
after: 10978519
before: 11245451

Related Discourse thread: https://llvm.discourse.group/t/include-what-you-use-include-cleanup
[0] https://llvm-compile-time-tracker.com/compare.php?from=fa7145dfbf94cb93b1c3e610582c495cb806569b&to=995d3e326ee1d9489145e20762c65465a9caeab4&stat=instructions

Differential Revision: https://reviews.llvm.org/D118781

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[llvm] Use true/false instead of 1/0 (NFC)

Identified with modernize-use-bool-literals.

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

[DebugInfo][InstrRef] Avoid some quadratic behaviour in LiveDebugVariables

This is a performance patch -- LiveDebugVariables can behave quadratically
if a lot of debug instructions are inserted back

[DebugInfo][InstrRef] Avoid some quadratic behaviour in LiveDebugVariables

This is a performance patch -- LiveDebugVariables can behave quadratically
if a lot of debug instructions are inserted back into the same place, and
we have to repeatedly step-over hte ones we've already inserted.

To get around it, whenever we insert a debug instruction at a slot index,
check whether there are more debug instructions to insert at this point,
and insert them too. That avoids the repeated lookup and stepping through.
It relies on the container for unlinked debug instructions being recorded
in-order, which is how LiveDebugVariables currently does it.

Differential Revision: https://reviews.llvm.org/D114587

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[CodeGen] Use make_early_inc_range (NFC)

[CodeGen] LiveDebug - Use const-ref iterator in for-range loop. NFCI.

Avoid unnecessary copies, reported by MSVC static analyzer.

[DebugInfo][InstrRef] Don't use instr-ref for unoptimised functions

InstrRefBasedLDV is marginally slower than VarlocBasedLDV when analysing
optimised code -- however, it's much slower when analysin

[DebugInfo][InstrRef] Don't use instr-ref for unoptimised functions

InstrRefBasedLDV is marginally slower than VarlocBasedLDV when analysing
optimised code -- however, it's much slower when analysing code compiled
-O0.

To avoid this: don't use instruction referencing for -O0 functions. In the
"pure" case of unoptimised code, this won't really harm the debugging
experience because most variables won't have been promoted off the stack,
so can't go missing. It becomes more complicated when optimised code is
inlined into functions marked optnone; however these are rare, and as -O0
doesn't run many optimisations there should be little damage to the debug
experience as a result.

I've taken the opportunity to refactor testing for instruction-referencing
into a MachineFunction method, which seems the most appropriate place to
put it.

Differential Revision: https://reviews.llvm.org/D108585

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[DebugInfo][InstrRef][4/4] Support DBG_INSTR_REF through all backend passes

This is a cleanup patch -- we're now able to support all flavours of
variable location in instruction referencing mode. Th

[DebugInfo][InstrRef][4/4] Support DBG_INSTR_REF through all backend passes

This is a cleanup patch -- we're now able to support all flavours of
variable location in instruction referencing mode. This patch updates
various tests for debug instructions to be broader: numerous code paths
try to ignore debug isntructions, and they now have to ignore the
additional DBG_PHI and DBG_INSTR_REFs that we can generate.

A small amount of rework happens for LiveDebugVariables: as we don't need
to track live intervals through regalloc any more, we can get away with
unlinking debug instructions before regalloc, then re-inserting them after.
Note that this isn't (yet) true of DBG_VALUE_LISTs, they still have to go
through live interval tracking.

In SelectionDAG, add a helper lambda that emits half-formed DBG_INSTR_REFs
for arguments in instr-ref mode, DBG_VALUE otherwise. This is one of the
final locations where DBG_VALUEs are emitted for vreg arguments.

X86InstrInfo now un-sets the debug instr number on SUB instructions that
get mutated into CMP instructions. As the instruction no longer computes a
subtraction, we can't use it for variable locations.

Differential Revision: https://reviews.llvm.org/D88898

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[LiveDebugVariables] Stop trimming locations of non-inlined vars

The D35953, D62650 and D73691 introduced trimming of variables locations
in LiveDebugVariables pass, since there are some cases where

[LiveDebugVariables] Stop trimming locations of non-inlined vars

The D35953, D62650 and D73691 introduced trimming of variables locations
in LiveDebugVariables pass, since there are some cases where after
the virtregrewrite we have exploded number of DBG_VALUEs created for some
inlined variables. As it looks, all problematic cases were regarding
inlined variables, so it seems reasonable to stop trimming the location
ranges for non-inlined variables.
It has very good impact on the llvm-locstats report.

Differential Revision: https://reviews.llvm.org/D102917

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[DebugInstrRef][1/3] Track PHI values through register allocation

This patch introduces "DBG_PHI" instructions, a marker of where a PHI
instruction used to be, before PHI elimination. Under the inst

[DebugInstrRef][1/3] Track PHI values through register allocation

This patch introduces "DBG_PHI" instructions, a marker of where a PHI
instruction used to be, before PHI elimination. Under the instruction
referencing model, we want to know where every value in the function is
defined -- and a PHI, even if implicit, is such a place.

Just like instruction numbers, we can use this to identify a value to be
used as a variable value, but we don't need to know what instruction
defines that value, for example:

bb1:
DBG_PHI $rax, 1
[... more insts ... ]
bb2:
DBG_INSTR_REF 1, 0, !1234, !DIExpression()

This specifies that on entry to bb1, whatever value is in $rax is known
as value number one -- and the later DBG_INSTR_REF marks the position
where variable !1234 should take on value number one.

PHI locations are stored in MachineFunction for the duration of the
regalloc phase in the DebugPHIPositions map. The map is populated by
PHIElimination, and then flushed back into the instruction stream by
virtregrewriter. A small amount of maintenence is needed in
LiveDebugVariables to account for registers being split, but only for
individual positions, not for entire ranges of blocks.

Differential Revision: https://reviews.llvm.org/D86812

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Reapply "[DebugInfo] Drop DBG_VALUE_LISTs with an excessive number of debug operands"

Reapply b623df3c, which was reverted while reverting a different patch
with a breaking change. There are no unde

Reapply "[DebugInfo] Drop DBG_VALUE_LISTs with an excessive number of debug operands"

Reapply b623df3c, which was reverted while reverting a different patch
with a breaking change. There are no underlying issues with this patch,
so no changes have been made to the original patch.

This reverts commit b11e4c990771541e440861f017afea7b4ba162f4.

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[CodeGen] Ensure UserValue::getDebugLoc() and UserLabel::getDebugLoc() consistently return a const reference NFCI.

Avoids a lot of unnecessary tracking increments/decrements of the underlying Tracki

[CodeGen] Ensure UserValue::getDebugLoc() and UserLabel::getDebugLoc() consistently return a const reference NFCI.

Avoids a lot of unnecessary tracking increments/decrements of the underlying TrackingMDNodeRef.

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Revert "[DebugInfo] Drop DBG_VALUE_LISTs with an excessive number of debug operands"

This reverts commit b623df3c93983c4512aa54f2c706716bdf865a90, as per
https://llvm.org/docs/DeveloperPolicy.html#p

Revert "[DebugInfo] Drop DBG_VALUE_LISTs with an excessive number of debug operands"

This reverts commit b623df3c93983c4512aa54f2c706716bdf865a90, as per
https://llvm.org/docs/DeveloperPolicy.html#patch-reversion-policy.

Breakages observed downstream reported in:
https://reviews.llvm.org/D91722#2724321

Fixes exist in:
https://reviews.llvm.org/D101523
https://reviews.llvm.org/D101540

but haven't landed yet going into the weekend.

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[DebugInfo] Drop DBG_VALUE_LISTs with an excessive number of debug operands

This patch fixes a crash in LiveDebugVariables for inputs where a
DBG_VALUE_LIST had 64 or more debug operands. This was t

[DebugInfo] Drop DBG_VALUE_LISTs with an excessive number of debug operands

This patch fixes a crash in LiveDebugVariables for inputs where a
DBG_VALUE_LIST had 64 or more debug operands. This was triggering an
assert, which was added under the assumption that only bad CodeGen would
result in such a limit being hit, but relatively simple source files
that result in these incredibly long debug values have been found, so
this assert has been changed to a condition that drops the debug value
if it is not met.

Differential Revision: https://reviews.llvm.org/D101373

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[CSSPGO] Exclude pseudo probes from slot index

Pseudo probe are currently given a slot index like other regular instructions. This affects register pressure and lifetime weight computation because o

[CSSPGO] Exclude pseudo probes from slot index

Pseudo probe are currently given a slot index like other regular instructions. This affects register pressure and lifetime weight computation because of enlarged lifetime length with pseudo probe instructions. As a consequence, program could get different code generated w/ and w/o pseudo probes. I'm closing the gap by excluding pseudo probes from stack index and downstream register allocation related passes.

Reviewed By: wmi

Differential Revision: https://reviews.llvm.org/D100334

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[DebugInfo] Process DBG_VALUE_LIST in LiveDebugVariables

This patch adds support for DBG_VALUE_LIST in the LiveDebugVariables pass. The
changes are mostly in computeIntervals, extendDef, and addDefs

[DebugInfo] Process DBG_VALUE_LIST in LiveDebugVariables

This patch adds support for DBG_VALUE_LIST in the LiveDebugVariables pass. The
changes are mostly in computeIntervals, extendDef, and addDefsFromCopies; when
extending the def of a DBG_VALUE_LIST the live ranges of every used register
must be considered, and when such a def is killed by more than one of its used
registers being killed at the same time it is necessary to find valid copies of
all of those registers to create a new def with.

The DebugVariableValue class has also been changed to reference multiple
location numbers instead of just one. This has been accomplished by using a
C-style array with a unique_ptr and an array length packed into 6 bits, to
minimize the size of the class (which must be kept low to be used with
IntervalMap). This may not be the most efficient solution possible, and should
be looked at if performance issues arise.

Differential Revision: https://reviews.llvm.org/D83895

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

[LiveDebugVariables] Add cache for SkipPHIsLabelsAndDebug to prevent
iterating the same PHI/LABEL/Debug instructions repeatedly.

We run into a compiling timeout problem when building a target after

[LiveDebugVariables] Add cache for SkipPHIsLabelsAndDebug to prevent
iterating the same PHI/LABEL/Debug instructions repeatedly.

We run into a compiling timeout problem when building a target after its
SampleFDO profile is updated. It is because some very large blocks with
a bunch of PHIs at the beginning. LiveDebugVariables::emitDebugValues
called during VirtRegRewriter phase searchs the insertion point for those
large BBs repeatedly in SkipPHIsLabelsAndDebug, and each time
SkipPHIsLabelsAndDebug needs to go through the same set of PHIs before it
can find the first non PHI/Label/Debug instruction. This patch adds a cache
to save the last position for the sequence which has been checked in the
previous call of SkipPHIsLabelsAndDebug.

Differential Revision: https://reviews.llvm.org/D94981

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[LiveDebugVariables] Strip all debug instructions from nodebug functions

A crash/assertion failure in the greedy register allocator was tracked
down to a debug instr being passed to LiveIntervals::g

[LiveDebugVariables] Strip all debug instructions from nodebug functions

A crash/assertion failure in the greedy register allocator was tracked
down to a debug instr being passed to LiveIntervals::getInstructionIndex.
Normally this should not occur as debug instructions are collected and
removed by LiveDebugVariables before RA, and reinserted afterwards.
However, when a function has no debug info, LiveDebugVariables simply
strips any debug values that are present as they're not needed (this
situation will occur when a function with debug info is inlined into a
nodebug function). The problem is, it only removes DBG_VALUE instructions,
leaving DBG_LABELs (the cause of the crash).

This patch updates the LiveDebugVariables nodebug path to remove all debug
instructions. The test case verifies that DBG_VALUE/DBG_LABEL instructions
are present, and that they are stripped.

When -experimental-debug-variable-locations is enabled, certain variable
locations are represented by DBG_INSTR_REF instead of DBG_VALUE. The test
case verifies that a DBG_INSTR_REF is emitted by the option, and that it
is also stripped.

Differential Revision: https://reviews.llvm.org/D92127

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[DebugInstrRef] Pass DBG_INSTR_REFs through register allocation

Both FastRegAlloc and LiveDebugVariables/greedy need to cope with
DBG_INSTR_REFs. None of them actually need to take any action, other

[DebugInstrRef] Pass DBG_INSTR_REFs through register allocation

Both FastRegAlloc and LiveDebugVariables/greedy need to cope with
DBG_INSTR_REFs. None of them actually need to take any action, other than
passing DBG_INSTR_REFs through: variable location information doesn't refer
to any registers at this stage.

LiveDebugVariables stashes the instruction information in a tuple, then
re-creates it later. This is only necessary as the register allocator
doesn't expect to see any debug instructions while it's working. No
equivalence classes or interval splitting is required at all!

No changes are needed for the fast register allocator, as it just ignores
debug instructions. The test added checks that both of them preserve
DBG_INSTR_REFs.

This also expands ScheduleDAGInstrs.cpp to treat DBG_INSTR_REFs the same as
DBG_VALUEs when rescheduling instructions around. The current movement of
DBG_VALUEs around is less than ideal, but it's not a regression to make
DBG_INSTR_REFs subject to the same movement.

Differential Revision: https://reviews.llvm.org/D85757

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LiveDebugVariables.cpp - remove unnecessary Compiler.h include. NFCI.

Already included in LiveDebugVariables.h

[NFC][Regalloc] accessors for 'reg' and 'weight'

Also renamed the fields to follow style guidelines.

Accessors help with readability - weight mutation, in particular,
is easier to follow this way.

[NFC][Regalloc] accessors for 'reg' and 'weight'

Also renamed the fields to follow style guidelines.

Accessors help with readability - weight mutation, in particular,
is easier to follow this way.

Differential Revision: https://reviews.llvm.org/D87725

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[LiveDebugVariables] Delete unneeded doInitialization