[NFC] Modernize misc. uses of Align/MaybeAlign APIs.

Use the current getAlign() APIs where it makes sense, and use Align
instead of MaybeAlign when we know the value is non-zero.

[NFC] Split Knowledge retention and place it more appropriatly

Summary:
Splitting Knowledge retention into Queries in Analysis and Builder into Transform/Utils
allows Queries and Transform/Utils to

[NFC] Split Knowledge retention and place it more appropriatly

Summary:
Splitting Knowledge retention into Queries in Analysis and Builder into Transform/Utils
allows Queries and Transform/Utils to use Analysis.

Reviewers: jdoerfert, sstefan1

Reviewed By: jdoerfert

Subscribers: mgorny, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77171

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Introduce unify-loop-exits pass.

For each natural loop with multiple exit blocks, this pass creates a
new block N such that all exiting blocks now branch to N, and then
control flow is redistributed

Introduce unify-loop-exits pass.

For each natural loop with multiple exit blocks, this pass creates a
new block N such that all exiting blocks now branch to N, and then
control flow is redistributed to all the original exit blocks.

The bulk of the tranformation is a new function introduced in
BasicBlockUtils that an redirect control flow from a set of incoming
blocks to a set of outgoing blocks via a common "hub".

This is a useful workaround for a limitation in the structurizer which
incorrectly orders blocks when processing a nest of loops. This pass
bypasses that issue by ensuring that each natural loop is recognized
as a separate region. Since the structurizer is a region pass, it no
longer sees a nest of loops in a single region, and instead processes
each "level" in the nesting as a separate region.

The AMDGPU backend provides a new option to enable this pass before
the structurizer, which may eventually be enabled by default.

Reviewers: madhur13490, arsenm, nhaehnle

Reviewed By: nhaehnle

Differential Revision: https://reviews.llvm.org/D75865

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Allow replacing intrinsic operands with variables

Since intrinsics can now specify when an argument is required to be
constant, it is now OK to replace arguments with variables if they
aren't. This

Allow replacing intrinsic operands with variables

Since intrinsics can now specify when an argument is required to be
constant, it is now OK to replace arguments with variables if they
aren't. This means intrinsics must now be accurately marked with
immarg.

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[AssumeBundles] Detection of Empty bundles

Summary: Prevent InstCombine from removing llvm.assume for which the arguement is true when they have operand bundles with usefull information.

Reviewers:

[AssumeBundles] Detection of Empty bundles

Summary: Prevent InstCombine from removing llvm.assume for which the arguement is true when they have operand bundles with usefull information.

Reviewers: jdoerfert, nikic, lebedev.ri

Reviewed By: jdoerfert

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D76147

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[Coroutines] Use dbg.declare for frame variables

Summary:
https://gist.github.com/modocache/ed7c62f6e570766c0f39b35dad675c2f
is an example of a small C++ program that uses C++20 coroutines that
is d

[Coroutines] Use dbg.declare for frame variables

Summary:
https://gist.github.com/modocache/ed7c62f6e570766c0f39b35dad675c2f
is an example of a small C++ program that uses C++20 coroutines that
is difficult to debug, due to the loss of debug info for variables that
"spill" across coroutine suspension boundaries. This patch addresses
that issue by inserting 'llvm.dbg.declare' intrinsics that point the
debugger to the variables' location at an offset to the coroutine frame.

With this patch, I confirmed that running the 'frame variable' commands in
https://gist.github.com/modocache/ed7c62f6e570766c0f39b35dad675c2f at
the specified breakpoints results in the correct values being printed
for coroutine frame variables 'i' and 'j' when using an lldb built from
trunk, as well as with gdb 8.3 (lldb 9.0.1, however, could not print the
values). The added test case also verifies this improved behavior.

The existing coro-debug.ll test case is also modified to reflect the
locations at which Clang actually places calls to 'dbg.declare', and
additional checks are added to ensure this patch works as intended in that
example as well.

Reviewers: vsk, jmorse, GorNishanov, lewissbaker, wenlei

Subscribers: EricWF, aprantl, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75338

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[DebugInfo] Avoid generating duplicate llvm.dbg.value

Summary:
This is to avoid generating duplicate llvm.dbg.value instrinsic if it already exists after the Instruction.

Before inserting llvm.dbg.

[DebugInfo] Avoid generating duplicate llvm.dbg.value

Summary:
This is to avoid generating duplicate llvm.dbg.value instrinsic if it already exists after the Instruction.

Before inserting llvm.dbg.value instruction, LLVM checks if the same instruction is already present before the instruction to avoid duplicates.
Currently it misses to check if it already exists after the instruction.
flang generates IR like this.

%4 = load i32, i32* %i1_311, align 4, !dbg !42
call void @llvm.dbg.value(metadata i32 %4, metadata !35, metadata !DIExpression()), !dbg !33
When this IR is processed in llvm, it ends up inserting duplicates.
%4 = load i32, i32* %i1_311, align 4, !dbg !42
call void @llvm.dbg.value(metadata i32 %4, metadata !35, metadata !DIExpression()), !dbg !33
call void @llvm.dbg.value(metadata i32 %4, metadata !35, metadata !DIExpression()), !dbg !33
We have now updated LdStHasDebugValue to include the cases when instruction is already
followed by same dbg.value instruction we intend to insert.

Now,

Definition and usage of function LdStHasDebugValue are deleted.
RemoveRedundantDbgInstrs is called for the cleanup of duplicate dbg.value's

Testing:
Added unit test for validation
check-llvm
check-debuginfo (the debug info integration tests)

Reviewers: aprantl, probinson, dblaikie, jmorse, jini.susan.george
SouraVX, awpandey, dstenb, vsk

Reviewed By: aprantl, jmorse, dstenb, vsk

Differential Revision: https://reviews.llvm.org/D74030

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[Local] Do not move around dbg.declares during replaceDbgDeclare

replaceDbgDeclare is used to update the descriptions of stack variables
when they are moved (e.g. by ASan or SafeStack). A side effec

[Local] Do not move around dbg.declares during replaceDbgDeclare

replaceDbgDeclare is used to update the descriptions of stack variables
when they are moved (e.g. by ASan or SafeStack). A side effect of
replaceDbgDeclare is that it moves dbg.declares around in the
instruction stream (typically by hoisting them into the entry block).
This behavior was introduced in llvm/r227544 to fix an assertion failure
(llvm.org/PR22386), but no longer appears to be necessary.

Hoisting a dbg.declare generally does not create problems. Usually,
dbg.declare either describes an argument or an alloca in the entry
block, and backends have special handling to emit locations for these.
In optimized builds, LowerDbgDeclare places dbg.values in the right
spots regardless of where the dbg.declare is. And no one uses
replaceDbgDeclare to handle things like VLAs.

However, there doesn't seem to be a positive case for moving
dbg.declares around anymore, and this reordering can get in the way of
understanding other bugs. I propose getting rid of it.

Testing: stage2 RelWithDebInfo sanitized build, check-llvm

rdar://59397340

Differential Revision: https://reviews.llvm.org/D74517

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Re-revert: Recover debug intrinsics when killing duplicated/empty blocks

This reverts commit 61b35e4111160fe834a00c33d040e01150b576ac.

This commit causes a timeout in chromium builds; likely to hav

Re-revert: Recover debug intrinsics when killing duplicated/empty blocks

This reverts commit 61b35e4111160fe834a00c33d040e01150b576ac.

This commit causes a timeout in chromium builds; likely to have a
similar cause to the previous timeout issue caused by this commit (see
6ded69f294a9 for more details). It is possible that there is no way to
fix this bug that will not cause this issue; further investigations as
to the efficiency of handling large amounts of debug info will be
necessary.

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Re-reapply: Recover debug intrinsics when killing duplicated/empty blocks

This reverts commit 636c93ed11a5f98b5c3ff88241460d61cb7785bb.

The original patch caused build failures on TSan buildbots. C

Re-reapply: Recover debug intrinsics when killing duplicated/empty blocks

This reverts commit 636c93ed11a5f98b5c3ff88241460d61cb7785bb.

The original patch caused build failures on TSan buildbots. Commit 6ded69f294a9
fixes this issue by reducing the rate at which empty debug intrinsics
propagate, reducing the memory footprint and preventing a fatal spike.

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[LoopStrengthReduce] Reuse utility method to clean dead instructions. [NFCI]

Create a utility wrapper for the RecursivelyDeleteTriviallyDeadInstructions utility
method, which sets to nullptr the ins

[LoopStrengthReduce] Reuse utility method to clean dead instructions. [NFCI]

Create a utility wrapper for the RecursivelyDeleteTriviallyDeadInstructions utility
method, which sets to nullptr the instructions that are not trivially
dead. Use the new method in LoopStrengthReduce.
Alternative: add a bool to the same method; this option adds a marginal
amount of overhead to the other callers, and the method needs to be
updated to return a bool status when it removes/doesn't remove
instructions.

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[Utils] Use WeakTrackingVH in vector used as scratch storage.

The utility method RecursivelyDeleteTriviallyDeadInstructions receives
as input a vector of Instructions, where all inputs are valid
ins

[Utils] Use WeakTrackingVH in vector used as scratch storage.

The utility method RecursivelyDeleteTriviallyDeadInstructions receives
as input a vector of Instructions, where all inputs are valid
instructions. This same vector is used as a scratch storage (per the
header comment) to recursively delete instructions. If an instruction is
added as an operand of multiple other instructions, it may be added twice,
then deleted once, then the second reference in the vector is invalid.
Switch to using a Vector<WeakTrackingVH>.
This change facilitates a clean-up in LoopStrengthReduction.

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[IndVarSimplify] Fix for MemorySSA preserve.

Reapply: [DebugInfo] Correctly handle salvaged casts and split fragments at ISel

This reverts commit 1f3dd83cc1f2b8f72b9d59e2b4221b12fb7f9a95, reapplying
commit bb1b0bc4e57428ce364d3d6c075ff03cb8973

Reapply: [DebugInfo] Correctly handle salvaged casts and split fragments at ISel

This reverts commit 1f3dd83cc1f2b8f72b9d59e2b4221b12fb7f9a95, reapplying
commit bb1b0bc4e57428ce364d3d6c075ff03cb8973462.

The original commit failed on some builds seemingly due to the use of a
bracketed constructor with an std::array, i.e. `std::array<> arr({...})`.

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Revert "[DebugInfo] Correctly handle salvaged casts and split fragments at ISel"

Reverted due to build failure on windows bots.

This reverts commit bb1b0bc4e57428ce364d3d6c075ff03cb8973462.

[DebugInfo] Correctly handle salvaged casts and split fragments at ISel

Previously, LLVM had no functional way of performing casts inside of a
DIExpression(), which made salvaging cast instructions

[DebugInfo] Correctly handle salvaged casts and split fragments at ISel

Previously, LLVM had no functional way of performing casts inside of a
DIExpression(), which made salvaging cast instructions other than Noop
casts impossible. This patch enables the salvaging of casts by using the
DW_OP_LLVM_convert operator for SExt and Trunc instructions.

There is another issue which is exposed by this fix, in which fragment
DIExpressions (which are preserved more readily by this patch) for
values that must be split across registers in ISel trigger an assertion,
as the 'split' fragments extend beyond the bounds of the fragment
DIExpression causing an error. This patch also fixes this issue by
checking the fragment status of DIExpressions which are to be split, and
dropping fragments that are invalid.

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Reland [DataLayout] Fix occurrences that size and range of pointers are assumed to be the same.

GEP index size can be specified in the DataLayout, introduced in D42123. However, there were still pla

Reland [DataLayout] Fix occurrences that size and range of pointers are assumed to be the same.

GEP index size can be specified in the DataLayout, introduced in D42123. However, there were still places
in which getIndexSizeInBits was used interchangeably with getPointerSizeInBits. This notably caused issues
with Instcombine's visitPtrToInt; but the unit tests was incorrect, so this remained undiscovered.

This fixes the buildbot failures.

Differential Revision: https://reviews.llvm.org/D68328

Patch by Joseph Faulls!

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Temporarily Revert "[DataLayout] Fix occurrences that size and range of pointers are assumed to be the same."

This reverts commit 5f6208778ff92567c57d7c1e2e740c284d7e69a5.

This caused failures in T

Temporarily Revert "[DataLayout] Fix occurrences that size and range of pointers are assumed to be the same."

This reverts commit 5f6208778ff92567c57d7c1e2e740c284d7e69a5.

This caused failures in Transforms/PhaseOrdering/scev-custom-dl.ll
const: Assertion `getBitWidth() == CR.getBitWidth() && "ConstantRange types don't agree!"' failed.

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[DataLayout] Fix occurrences that size and range of pointers are assumed to be the same.

GEP index size can be specified in the DataLayout, introduced in D42123. However, there were still places
in

[DataLayout] Fix occurrences that size and range of pointers are assumed to be the same.

GEP index size can be specified in the DataLayout, introduced in D42123. However, there were still places
in which getIndexSizeInBits was used interchangeably with getPointerSizeInBits. This notably caused issues
with Instcombine's visitPtrToInt; but the unit tests was incorrect, so this remained undiscovered.

Differential Revision: https://reviews.llvm.org/D68328

Patch by Joseph Faulls!

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Revert "Reapply: [DebugInfo] Recover debug intrinsics when killing duplicated/empty..."

This reverts commit f2ba93971ccc236c0eef5323704d31f48107e04f, it was
causing build timeouts on sanitizer-x86_6

Revert "Reapply: [DebugInfo] Recover debug intrinsics when killing duplicated/empty..."

This reverts commit f2ba93971ccc236c0eef5323704d31f48107e04f, it was
causing build timeouts on sanitizer-x86_64-linux-autoconf such as
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-autoconf/builds/44917

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Reapply: [DebugInfo] Recover debug intrinsics when killing duplicated/empty...

basic blocks

Originally applied in 72ce759928e6dfee6a9efa310b966c19722352ba.

Fixed a build failure caused by incorrec

Reapply: [DebugInfo] Recover debug intrinsics when killing duplicated/empty...

basic blocks

Originally applied in 72ce759928e6dfee6a9efa310b966c19722352ba.

Fixed a build failure caused by incorrect use of cast instead of
dyn_cast.

This reverts commit 8b0780f795eb58fca0a2456e308adaaa1a0b5013.

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LowerDbgDeclare: look through bitcasts.

Summary:
Emit a value debug intrinsic (with OP_deref) when an alloca address is
passed to a function call after going through a bitcast.

This generates an FP

LowerDbgDeclare: look through bitcasts.

Summary:
Emit a value debug intrinsic (with OP_deref) when an alloca address is
passed to a function call after going through a bitcast.

This generates an FP or SP-relative location for the local variable in
the following case:
int x;
use((void *)&x;

Reviewers: aprantl, vsk, pcc

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70752

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Revert "[DebugInfo] Recover debug intrinsics when killing duplicated/empty basic blocks"

This reverts commit 72ce759928e6dfee6a9efa310b966c19722352ba.

Reverted due to build failure.

[DebugInfo] Recover debug intrinsics when killing duplicated/empty basic blocks

When basic blocks are killed, either due to being empty or to being an if.then
or if.else block whose complement conta

[DebugInfo] Recover debug intrinsics when killing duplicated/empty basic blocks

When basic blocks are killed, either due to being empty or to being an if.then
or if.else block whose complement contains identical instructions, some of the
debug intrinsics in that block are lost. This patch sinks those intrinsics
into the single successor block, setting them Undef if necessary to
prevent debug info from falling out-of-date.

Differential Revision: https://reviews.llvm.org/D70318

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[DebugInfo@O2][Utils] Undef instead of delete dbg.values in helper func

Summary:
Related bug: https://bugs.llvm.org/show_bug.cgi?id=40648

Static helper function rewriteDebugUsers in Local.cpp delet

[DebugInfo@O2][Utils] Undef instead of delete dbg.values in helper func

Summary:
Related bug: https://bugs.llvm.org/show_bug.cgi?id=40648

Static helper function rewriteDebugUsers in Local.cpp deletes dbg.value
intrinsics when it cannot move or rewrite them, or salvage the deleted
instruction's value. It should instead undef them in this case.

This patch fixes that and I've added a test which covers the failing test
case in bz40648. I've updated the unit test Local.ReplaceAllDbgUsesWith
to check for this behaviour (and fixed a typo in the test which would
cause the old test to always pass).

Reviewers: aprantl, vsk, djtodoro, probinson

Reviewed By: vsk

Subscribers: hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D70604

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