[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)

[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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[clang] Use i64 for the !srcloc metadata on asm IR nodes.

This is part of a patch series working towards the ability to make
SourceLocation into a 64-bit type to handle larger translation units.

!s

[clang] Use i64 for the !srcloc metadata on asm IR nodes.

This is part of a patch series working towards the ability to make
SourceLocation into a 64-bit type to handle larger translation units.

!srcloc is generated in clang codegen, and pulled back out by llvm
functions like AsmPrinter::emitInlineAsm that need to report errors in
the inline asm. From there it goes to LLVMContext::emitError, is
stored in DiagnosticInfoInlineAsm, and ends up back in clang, at
BackendConsumer::InlineAsmDiagHandler(), which reconstitutes a true
clang::SourceLocation from the integer cookie.

Throughout this code path, it's now 64-bit rather than 32, which means
that if SourceLocation is expanded to a 64-bit type, this error report
won't lose half of the data.

The compiler will tolerate both of i32 and i64 !srcloc metadata in
input IR without faulting. Test added in llvm/MC. (The semantic
accuracy of the metadata is another matter, but I don't know of any
situation where that matters: if you're reading an IR file written by
a previous run of clang, you don't have the SourceManager that can
relate those source locations back to the original source files.)

Original version of the patch by Mikhail Maltsev.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D105491

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[DebugInfo][InstrRef][1/4] Support transformations that widen values

Very late in compilation, backends like X86 will perform optimisations like
this:

$cx = MOV16rm $rax, ...
->
$rcx =

[DebugInfo][InstrRef][1/4] Support transformations that widen values

Very late in compilation, backends like X86 will perform optimisations like
this:

$cx = MOV16rm $rax, ...
->
$rcx = MOV64rm $rax, ...

Widening the load from 16 bits to 64 bits. SEeing how the lower 16 bits
remain the same, this doesn't affect execution. However, any debug
instruction reference to the defined operand now refers to a 64 bit value,
nto a 16 bit one, which might be unexpected. Elsewhere in codegen, there's
often this pattern:

CALL64pcrel32 @foo, implicit-def $rax
%0:gr64 = COPY $rax
%1:gr32 = COPY %0.sub_32bit

Where we want to refer to the definition of $eax by the call, but don't
want to refer the copies (they don't define values in the way
LiveDebugValues sees it). To solve this, add a subregister field to the
existing "substitutions" facility, so that we can describe a field within
a larger value definition. I would imagine that this would be used most
often when a value is widened, and we need to refer to the original,
narrower definition.

Differential Revision: https://reviews.llvm.org/D88891

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[NFC][AA] Prepare to convert AliasResult to class with PartialAlias offset.

Main reason is preparation to transform AliasResult to class that contains
offset for PartialAlias case.

Reviewed By: asb

[NFC][AA] Prepare to convert AliasResult to class with PartialAlias offset.

Main reason is preparation to transform AliasResult to class that contains
offset for PartialAlias case.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D98027

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[DebugInfo] Handle DBG_VALUES with multiple variable location operands in MIR

This patch adds handling for DBG_VALUE_LIST in the MIR-passes (after
finalize-isel), excluding the debug liveness passes

[DebugInfo] Handle DBG_VALUES with multiple variable location operands in MIR

This patch adds handling for DBG_VALUE_LIST in the MIR-passes (after
finalize-isel), excluding the debug liveness passes and DWARF emission. This
most significantly affects MachineSink, which now needs to consider all used
registers of a debug value when sinking, but for most passes this change is
simply replacing getDebugOperand(0) with an iteration over all debug operands.

Differential Revision: https://reviews.llvm.org/D92578

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Reapply "[DebugInfo] Add new instruction and DIExpression operator for variadic debug values"

Rewrites test to use correct architecture triple; fixes incorrect
reference in SourceLevelDebugging doc

Reapply "[DebugInfo] Add new instruction and DIExpression operator for variadic debug values"

Rewrites test to use correct architecture triple; fixes incorrect
reference in SourceLevelDebugging doc; simplifies `spillReg` behaviour
so as to not be dependent on changes elsewhere in the patch stack.

This reverts commit d2000b45d033c06dc7973f59909a0ad12887ff51.

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Revert "[DebugInfo] Add new instruction and DIExpression operator for variadic debug values"

This reverts commit d07f106f4a48b6e941266525b6f7177834d7b74e.

[DebugInfo] Add new instruction and DIExpression operator for variadic debug values

This patch adds a new instruction that can represent variadic debug values,
DBG_VALUE_VAR. This patch alone covers

[DebugInfo] Add new instruction and DIExpression operator for variadic debug values

This patch adds a new instruction that can represent variadic debug values,
DBG_VALUE_VAR. This patch alone covers the addition of the instruction and a set
of basic code changes in MachineInstr and a few adjacent areas, but does not
correctly handle variadic debug values outside of these areas, nor does it
generate them at any point.

The new instruction is similar to the existing DBG_VALUE instruction, with the
following differences: the operands are in a different order, any number of
values may be used in the instruction following the Variable and Expression
operands (these are referred to in code as “debug operands”) and are indexed
from 0 so that getDebugOperand(X) == getOperand(X+2), and the Expression in a
DBG_VALUE_VAR must use the DW_OP_LLVM_arg operator to pass arguments into the
expression.

The new DW_OP_LLVM_arg operator is only valid in expressions appearing in a
DBG_VALUE_VAR; it takes a single argument and pushes the debug operand at the
index given by the argument onto the Expression stack. For example the
sub-expression `DW_OP_LLVM_arg, 0` has the meaning “Push the debug operand at
index 0 onto the expression stack.”

Differential Revision: https://reviews.llvm.org/D82363

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

[CSSPGO] Unblock optimizations with pseudo probe instrumentation.

The IR/MIR pseudo probe intrinsics don't get materialized into real machine instructions and therefore they don't incur runtime cost

[CSSPGO] Unblock optimizations with pseudo probe instrumentation.

The IR/MIR pseudo probe intrinsics don't get materialized into real machine instructions and therefore they don't incur runtime cost directly. However, they come with indirect cost by blocking certain optimizations. Some of the blocking are intentional (such as blocking code merge) for better counts quality while the others are accidental. This change unblocks perf-critical optimizations that do not affect counts quality. They include:

1. IR InstCombine, sinking load operation to shorten lifetimes.
2. MIR LiveRangeShrink, similar to #1
3. MIR TwoAddressInstructionPass, i.e, opeq transform
4. MIR function argument copy elision
5. IR stack protection. (though not perf-critical but nice to have).

Reviewed By: wmi

Differential Revision: https://reviews.llvm.org/D95982

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[XRay] Support DW_TAG_call_site and delete unneeded PATCHABLE_EVENT_CALL/PATCHABLE_TYPED_EVENT_CALL lowering

[NFC] Don't copy MachineFrameInfo on each invocation of HasAlias

Also fix a typo in a comment. This fixes a compile time issue in XLA
(https://www.tensorflow.org/xla).

Differential Revision: https

[NFC] Don't copy MachineFrameInfo on each invocation of HasAlias

Also fix a typo in a comment. This fixes a compile time issue in XLA
(https://www.tensorflow.org/xla).

Differential Revision: https://reviews.llvm.org/D94182

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Prevent FENTRY_CALL reordering

FEntryInserter prepends FENTRY_CALL to the first basic block. In case
there are other instructions, PostRA Machine Instruction Scheduler can
move FENTRY_CALL call arou

Prevent FENTRY_CALL reordering

FEntryInserter prepends FENTRY_CALL to the first basic block. In case
there are other instructions, PostRA Machine Instruction Scheduler can
move FENTRY_CALL call around. This actually occurs on SystemZ (see the
testcase). This is bad for the following reasons:

* FENTRY_CALL clobbers registers.
* Linux Kernel depends on whatever FENTRY_CALL expands to to be the very
first instruction in the function.

Fix by adding isCall attribute to FENTRY_CALL, which prevents reordering
by making it a scheduling boundary for PostRA Machine Instruction
Scheduler.

Reviewed By: niravd

Differential Revision: https://reviews.llvm.org/D91218

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[MachineInstr] Add support for instructions with multiple memory operands.

- Basically iterate each pair of memory operands from both instructions
and return true if any of them may alias.
- The e

[MachineInstr] Add support for instructions with multiple memory operands.

- Basically iterate each pair of memory operands from both instructions
and return true if any of them may alias.
- The exception are memory instructions without any memory operand. They
may touch everything and could alias to any memory instruction.

Differential Revision: https://reviews.llvm.org/D89447

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[Statepoints] Unlimited tied operands.

Current limit on amount of tied operands (15) sometimes is too low
for statepoint. We may get couple dozens of gc pointer operands on
statepoint.
Review D87154

[Statepoints] Unlimited tied operands.

Current limit on amount of tied operands (15) sometimes is too low
for statepoint. We may get couple dozens of gc pointer operands on
statepoint.
Review D87154 changed format of statepoint to list every gc pointer
only once, which makes it trivial to find tiedness relation between
statepoint operands: defs are mapped 1-1 to gc pointer operands passed
on registers.

Reviewed By: skatkov

Differential Revision: https://reviews.llvm.org/D87915

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[MachineInstr] exclude call instruction in mayAlias

we now get noAlias result for a call instruction and other
load/store/call instructions if we query mayAlias.
This is not right as call instructio

[MachineInstr] exclude call instruction in mayAlias

we now get noAlias result for a call instruction and other
load/store/call instructions if we query mayAlias.
This is not right as call instruction is not with mayloadorstore,
but it may alter the memory.

This patch fixes this wrong alias query.

Differential Revision: https://reviews.llvm.org/D87490

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[DebugInstrRef][1/9] Add fields for instr-ref variable locations

Add a DBG_INSTR_REF instruction and a "debug instruction number" field to
MachineInstr. The two allow variable values to be specified

[DebugInstrRef][1/9] Add fields for instr-ref variable locations

Add a DBG_INSTR_REF instruction and a "debug instruction number" field to
MachineInstr. The two allow variable values to be specified by
identifying where the value is computed, rather than the register it lies
in, like so:

%0 = fooinst, debug-instr-number 1
[...]
DBG_INSTR_REF 1, 0

See the original RFC for motivation:
http://lists.llvm.org/pipermail/llvm-dev/2020-February/139440.html

This patch is NFCI; it only adds fields and other boiler plate.

Differential Revision: https://reviews.llvm.org/D85741

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Fix a couple of typos. NFC

[ScheduleDAG] Move DBG_VALUEs after first term forward.

MBBs are not allowed to have non-terminator instructions after the first
terminator. Currently in some cases (see the modified test),
EmitSche

[ScheduleDAG] Move DBG_VALUEs after first term forward.

MBBs are not allowed to have non-terminator instructions after the first
terminator. Currently in some cases (see the modified test),
EmitSchedule can add DBG_VALUEs after the last terminator, for example
when referring a debug value that gets folded into a TCRETURN
instruction on ARM.

This patch updates EmitSchedule to move inserted DBG_VALUEs just before
the first terminator. I am not sure if there are terminators produce
values that can in turn be used by a DBG_VALUE. In that case, moving the
DBG_VALUE might result in referencing an undefined register. But in any
case, it seems like currently there is no way to insert a proper DBG_VALUEs
for such registers anyways.

Alternatively it might make sense to just remove those extra DBG_VALUES.

I am not too familiar with the details of debug info in the backend and
would appreciate any suggestions on how to address the issue in the best
possible way.

Reviewers: vsk, aprantl, jpaquette, efriedma, paquette

Reviewed By: aprantl

Differential Revision: https://reviews.llvm.org/D83561

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[DebugInfo] Update MachineInstr to help support variadic DBG_VALUE instructions

Following on from this RFC[0] from a while back, this is the first patch towards
implementing variadic debug values.

[DebugInfo] Update MachineInstr to help support variadic DBG_VALUE instructions

Following on from this RFC[0] from a while back, this is the first patch towards
implementing variadic debug values.

This patch specifically adds a set of functions to MachineInstr for performing
operations specific to debug values, and replacing uses of the more general
functions where appropriate. The most prevalent of these is replacing
getOperand(0) with getDebugOperand(0) for debug-value-specific code, as the
operands corresponding to values will no longer be at index 0, but index 2 and
upwards: getDebugOperand(x) == getOperand(x+2). Similar replacements have been
added for the other operands, along with some helper functions to replace
oft-repeated code and operate on a variable number of value operands.

[0] http://lists.llvm.org/pipermail/llvm-dev/2020-February/139376.html<Paste>

Differential Revision: https://reviews.llvm.org/D81852

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Add NoMerge MIFlag to avoid MIR branch folding

Let the codegen recognized the nomerge attribute and disable branch folding when the attribute is given

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

Add NoMerge MIFlag to avoid MIR branch folding

Let the codegen recognized the nomerge attribute and disable branch folding when the attribute is given

Differential Revision: https://reviews.llvm.org/D79537

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Revert "[CodeGen] Add support for multiple memory operands in MachineInstr::mayAlias"

This temporarily reverts commit 7019cea26dfef5882c96f278c32d0f9c49a5e516.

It seems that, for some targets, ther

Revert "[CodeGen] Add support for multiple memory operands in MachineInstr::mayAlias"

This temporarily reverts commit 7019cea26dfef5882c96f278c32d0f9c49a5e516.

It seems that, for some targets, there are instructions with a lot of memory operands (probably more than would be expected). This causes a lot of buildbots to timeout and notify failed builds. While investigations are ongoing to find out why this happens, revert the changes.

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[CodeGen] Add support for multiple memory operands in MachineInstr::mayAlias

Summary:
To support all targets, the mayAlias member function needs to support instructions with multiple operands.

This

[CodeGen] Add support for multiple memory operands in MachineInstr::mayAlias

Summary:
To support all targets, the mayAlias member function needs to support instructions with multiple operands.

This revision also changes the order of the emitted instructions in some test cases.

Reviewers: efriedma, hfinkel, craig.topper, dmgreen

Reviewed By: efriedma

Subscribers: MatzeB, dmgreen, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80161

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