[AMDGPU][SIPreEmitPeephole] mustRetainExeczBranch: use BranchProbability and TargetSchedmodel (#109818)

Remove s_cbranch_execnz branches if the transformation is
profitable according to `BranchProb

[AMDGPU][SIPreEmitPeephole] mustRetainExeczBranch: use BranchProbability and TargetSchedmodel (#109818)

Remove s_cbranch_execnz branches if the transformation is
profitable according to `BranchProbability` and `TargetSchedmodel`.

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[LowerSwitch] Don't let pass manager handle the dependency (#68662)

Some passes has limitation that only support simple terminators:
branch/unreachable/return. Right now, they ask the pass manager

[LowerSwitch] Don't let pass manager handle the dependency (#68662)

Some passes has limitation that only support simple terminators:
branch/unreachable/return. Right now, they ask the pass manager to add
LowerSwitch pass to eliminate `switch`. Let's manage such kind of pass
dependency by ourselves. Also add the assertion in the related passes.

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Revert "[CodeGen] Really renumber slot indexes before register allocation (#67038)"

This reverts commit 2501ae58e3bb9a70d279a56d7b3a0ed70a8a852c.

Reverted due to various buildbot failures.

[CodeGen] Really renumber slot indexes before register allocation (#67038)

PR #66334 tried to renumber slot indexes before register allocation, but
the numbering was still affected by list entries

[CodeGen] Really renumber slot indexes before register allocation (#67038)

PR #66334 tried to renumber slot indexes before register allocation, but
the numbering was still affected by list entries for instructions which
had been erased. Fix this to make the register allocator's live range
length heuristics even less dependent on the history of how instructions
have been added to and removed from SlotIndexes's maps.

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Reapply "[CodeGen] Add new pass for late cleanup of redundant definitions."

This reverts commit 122efef8ee9be57055d204d52c38700fe933c033.

- Patch fixed to not reuse definitions from predecessors in

Reapply "[CodeGen] Add new pass for late cleanup of redundant definitions."

This reverts commit 122efef8ee9be57055d204d52c38700fe933c033.

- Patch fixed to not reuse definitions from predecessors in EH landing pads.
- Late review suggestions (by MaskRay) have been addressed.
- M68k/pipeline.ll test updated.
- Init captures added in processBlock() to avoid capturing structured bindings.
- RISCV has this disabled for now.

Original commit message:

A new pass MachineLateInstrsCleanup is added to be run after PEI.

This is a simple pass that removes redundant and identical instructions
whenever found by scanning the MF once while keeping track of register
definitions in a map. These instructions are typically immediate loads
resulting from rematerialization, and address loads emitted by target in
eliminateFrameInde().

This is enabled by default, but a target could easily disable it by means of
'disablePass(&MachineLateInstrsCleanupID);'.

This late cleanup is naturally not "optimal" in removing instructions as it
is done by looking at phys-regs, but still quite effective. It would be
desirable to improve other parts of CodeGen and avoid these redundant
instructions in the first place, but there are no ideas for this yet.

Differential Revision: https://reviews.llvm.org/D123394

Reviewed By: RKSimon, foad, craig.topper, arsenm, asb

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Revert "Reapply "[CodeGen] Add new pass for late cleanup of redundant definitions.""

This reverts commit 17db0de330f943833296ae72e26fa988bba39cb3.

Some more bots got broken - need to investigate.

Reapply "[CodeGen] Add new pass for late cleanup of redundant definitions."

Init captures added in processBlock() to avoid capturing structured bindings,
which caused the build problems (with clang)

Reapply "[CodeGen] Add new pass for late cleanup of redundant definitions."

Init captures added in processBlock() to avoid capturing structured bindings,
which caused the build problems (with clang).

RISCV has this disabled for now until problems relating to post RA pseudo
expansions are resolved.

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Revert "[CodeGen] Add new pass for late cleanup of redundant definitions."

Temporarily revert and fix buildbot failure.

This reverts commit 6d12599fd4134c1da63198c74a25490d28c733f6.

[CodeGen] Add new pass for late cleanup of redundant definitions.

A new pass MachineLateInstrsCleanup is added to be run after PEI.

This is a simple pass that removes redundant and identical instru

[CodeGen] Add new pass for late cleanup of redundant definitions.

A new pass MachineLateInstrsCleanup is added to be run after PEI.

This is a simple pass that removes redundant and identical instructions
whenever found by scanning the MF once while keeping track of register
definitions in a map. These instructions are typically immediate loads
resulting from rematerialization, and address loads emitted by target in
eliminateFrameInde().

This is enabled by default, but a target could easily disable it by means of
'disablePass(&MachineLateInstrsCleanupID);'.

This late cleanup is naturally not "optimal" in removing instructions as it
is done by looking at phys-regs, but still quite effective. It would be
desirable to improve other parts of CodeGen and avoid these redundant
instructions in the first place, but there are no ideas for this yet.

Differential Revision: https://reviews.llvm.org/D123394

Reviewed By: RKSimon, foad, craig.topper, arsenm, asb

show more ...

[AMDGPU] Unify uniform return and divergent unreachable blocks

This patch fixes a "failed to annotate CFG" error in
SIAnnotateControlFlow. The problem occurs when there are
divergent and uniform unr

[AMDGPU] Unify uniform return and divergent unreachable blocks

This patch fixes a "failed to annotate CFG" error in
SIAnnotateControlFlow. The problem occurs when there are
divergent and uniform unreachable/return blocks in the same
region. In this case, AMDGPUUnifyDivergentExitNodes does not
create a unified block so the region contains multiple exits.

StructurizeCFG does not work properly when there are multiple
exits, so the neccessary CFG transformations do not occur along
divergent control flow. Subsequently, SIAnnotateControlFlow
processes the path to the divergent exit block, but may only
partially process blocks along a unform control flow path to
another exit block.

This patch fixes the bug by creating a single exit block when
there is a divergent exit block in the function.

Differential revision: https://reviews.llvm.org/D136892

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