Remove legacy bindings #5917

rdspring1 · 2026-02-03T21:59:51Z

This PR removes the nvfuser python module, corresponding pybind11 CPP bindings, and any references from csrc. Version is bumped to 0.2.36.

rdspring1 · 2026-02-03T21:59:57Z

!test

github-actions · 2026-02-03T22:01:44Z

Review updated until commit aa333da

Description

Remove legacy nvfuser Python module and bindings from build system
Update build scripts to only use nvfuser_direct module
Add TODO comments in documentation for migration to nvfuser_direct
Bump version from 0.2.35 to 0.2.36

Changes walkthrough

Relevant files

Enhancement

6 files

CMakeLists.txt `Remove legacy nvfuser Python library build section`	+3/-141
utils.py `Remove nvfuser._C references, keep only nvfuser_direct._C_DIRECT`	+2/-7
check_symbol_visibility.sh `Remove nvfuser extension checks, keep only nvfuser_direct`	+1/-16
version.txt `Bump version from 0.2.35 to 0.2.36`	+1/-1
type.h `Add NVF_API visibility to operator<< functions`	+2/-2
utils.h `Add NVF_API visibility to getShardedLogicalAxis function`	+2/-1

Documentation

5 files

autotune_inner_reduction.py `Add TODO comment to migrate to nvfuser_direct module`	+2/-0
autotune_pointwise.py `Add TODO comment to migrate to nvfuser_direct module`	+2/-0
autotune_matmul.py `Add TODO comment to migrate to nvfuser_direct module`	+2/-0
profile_matmul.py `Add TODO comment to migrate to nvfuser_direct module`	+1/-0
Serde.md `Update documentation about serialization being disabled`	+3/-1

Miscellaneous

1 files

fusion_segmenter.cpp `Update GitHub link reference in comment`	+1/-1

Additional files

36 files

options.cpp	+0/-2
options.h	+0/-2
fusion_kernel_runtime.cpp	+0/-12
fusion_record.cpp	+0/-952
fusion_record.h	+0/-124
README.md	+0/-210
__init__.py	+0/-649
__init__.pyi	+0/-4
benchmark_utils.py	+0/-160
__init__.py	+0/-9
__init__.py	+0/-13
normalization.py	+0/-725
nvfuser_version.py	+0/-69
pytorch_utils.py	+0/-190
fusion_cache.cpp	+0/-953
fusion_cache.h	+0/-320
fusion_definition.cpp	+0/-769
fusion_definition.h	+0/-389
fusion_record.h	+0/-3675
fusion_state.cpp	+0/-297
fusion_state.h	+0/-143
multidevice_bindings.cpp	+0/-103
python_bindings.cpp	+0/-4196
python_bindings.h	+0/-27
python_bindings_extension.cpp	+0/-18
schedule_bindings.cpp	+0/-517
segmentation.cpp	+0/-369
segmentation.h	+0/-246
translation.cpp	+0/-1484
translation.h	+0/-20
translation_utils.cpp	+0/-80
translation_utils.h	+0/-300
test_import.py	+0/-17
__init__.py	+0/-6
utils.py	+0/-358
env_options.yaml	+0/-12

PR Reviewer Guide

Here are some key observations to aid the review process:

🧪 PR contains tests
⚡ Recommended focus areas for review
Build System Logic Issue The build_extension method has incorrect indentation causing a syntax error. The conditional logic for nvfuser_direct._C_DIRECT is improperly nested inside the copy_library method instead of being a separate conditional branch. def build_extension(self, ext): if ext.name == "nvfuser_direct._C_DIRECT": self.copy_library(ext, "libnvfuser_direct") self.copy_shared_library("libnvfuser_codegen.so") else: super().build_extension(ext) Documentation References Multiple documentation files have TODO comments about updating to use nvfuser_direct module, but no actual updates are made. This leaves documentation in an inconsistent state that could confuse users. Script Logic Error The script logic has been modified to only check nvfuser_direct but the final results section still references NVFUSER_OK variable which is no longer set, potentially causing shell script errors. if [ $NVFUSER_DIRECT_OK -eq 0 ]; then

Test failures

(Medium, 3) Shape mismatch in thunderfx higher-order inplace alias update (thunder/tests/test_update_aliases)

Test Name A100 GB200 H100 Source

thunder.tests.test_update_aliases.test_higher_order_inplace_alias_update_nvfuser_cuda_thunder.dtypes.float32 ❌ ❌ ❌
(Medium, 1) Thunder nvFuser nanoGPT autograd scalar mismatch in test_networks

Test Name H100 Source

thunder.tests.test_networks.test_nanogpt_complete_autograd_nvfuser_cuda_thunder.dtypes.float32 ❌

greptile-apps · 2026-02-03T22:03:38Z

Greptile Overview

Greptile Summary

This PR removes the legacy nvfuser Python module and associated pybind11 bindings. The removal includes 17,590 lines deleted across 48 files, covering the entire python/nvfuser package, python/python_frontend C++ bindings, and serialization code in csrc/serde/fusion_record.cpp.

Major Changes:

Deleted entire python/nvfuser module (649 lines in __init__.py plus supporting files)
Removed python/python_frontend pybind11 bindings (4,196 lines in python_bindings.cpp plus other files)
Removed csrc/serde/fusion_record.cpp serialization code (952 lines)
Updated CMakeLists.txt to remove nvfuser build targets and move common sources to nvfuser_direct
Removed Python frontend debug options from csrc/options.h/cpp
Updated tools/check_symbol_visibility.sh to only check nvfuser_direct
Bumped version to 0.2.36

Critical Issues Found:

Four documentation scripts in doc/dev/python_scheduling/ have TODO comments added but still import from the removed nvfuser module. These scripts will fail at runtime with ModuleNotFoundError.

Confidence Score: 2/5

This PR has critical runtime failures in documentation scripts that prevent it from being safely merged
The core removal is clean, but four documentation scripts will fail at runtime due to imports from the removed nvfuser module. While TODOs were added, the imports were not updated, making these scripts completely non-functional
doc/dev/python_scheduling/autotune_inner_reduction.py, doc/dev/python_scheduling/autotune_matmul.py, doc/dev/python_scheduling/autotune_pointwise.py, doc/dev/python_scheduling/profile_matmul.py - all have broken imports

Important Files Changed

Filename	Overview
CMakeLists.txt	Removes nvfuser Python bindings build configuration, moves common sources to nvfuser_direct, removes symbolic link creation
doc/dev/python_scheduling/autotune_inner_reduction.py	TODO added but still imports from removed nvfuser module - script will fail at runtime
doc/dev/python_scheduling/autotune_matmul.py	TODO added but still imports from removed nvfuser module - script will fail at runtime
doc/dev/python_scheduling/autotune_pointwise.py	TODO added but still imports from removed nvfuser module - script will fail at runtime
doc/dev/python_scheduling/profile_matmul.py	TODO added but still imports from removed nvfuser module - script will fail at runtime
python/utils.py	Removes nvfuser._C extension from build configuration, updates comments
tools/check_symbol_visibility.sh	Removes nvfuser extension checks, only validates nvfuser_direct symbols

Sequence Diagram

sequenceDiagram
    participant Dev as Developer
    participant PR as PR (Remove Legacy Bindings)
    participant Build as Build System
    participant Python as Python Environment
    participant Scripts as Doc Scripts

    Dev->>PR: Remove nvfuser module files
    Dev->>PR: Remove python_frontend bindings
    Dev->>PR: Remove csrc/serde/fusion_record
    
    PR->>Build: Update CMakeLists.txt
    Build-->>Build: Remove nvfuser._C extension
    Build-->>Build: Move common sources to nvfuser_direct
    Build-->>Build: Remove nvfuser symlink
    
    PR->>Python: Update python/utils.py
    Python-->>Python: Remove nvfuser._C from setup
    
    PR->>Scripts: Add TODO comments
    Note over Scripts: Scripts still import nvfuser module!
    Scripts--xPython: import nvfuser (FAILS)
    
    PR->>Build: Update tools/check_symbol_visibility.sh
    Build-->>Build: Remove nvfuser extension checks

greptile-apps

_{7 files reviewed, 2 comments}

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greptile-apps · 2026-02-03T22:03:49Z

Additional Comments (2)

python/utils.py
stale reference to removed python_frontend directory

tools/env-config/env_options.yaml
stale entries for removed debug options python_definition_segments and python_frontend_debug should be removed

greptile-apps

_{8 files reviewed, 1 comment}

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greptile-apps · 2026-02-03T23:49:33Z

Additional Comments (1)

python/utils.py
outdated comment references nvfuser._C which was removed in this PR

    # "nvfuser_codegen" into "./nvfuser_direct/lib", and the former will be "nvfuser_direct._C_DIRECT".

greptile-apps

_{8 files reviewed, 1 comment}

_{Edit Code Review Agent Settings | Greptile}

python/utils.py

greptile-apps

_{5 files reviewed, 7 comments}

_{Edit Code Review Agent Settings | Greptile}

greptile-apps · 2026-02-04T06:20:54Z

Additional Comments (7)

tests/python/utils/utils.py
The nvfuser module has been removed in this PR. Update to import from nvfuser_direct instead:

from nvfuser_direct import FusionCache, FusionDefinition, DataType, clone, Tensor

doc/dev/python_scheduling/autotune_utils.py
The nvfuser module has been removed. Update to import from nvfuser_direct:

from nvfuser_direct import FusionCache, FusionDefinition

doc/dev/python_scheduling/autotune_pointwise.py
Update to use nvfuser_direct instead of removed nvfuser module:

from nvfuser_direct import FusionDefinition, SchedulerType, DataType

doc/dev/python_scheduling/autotune_inner_reduction.py
Update to use nvfuser_direct:

from nvfuser_direct import FusionDefinition, SchedulerType, DataType, ParallelType

_{Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!}

doc/dev/python_scheduling/autotune_persistent.py
Update imports to use nvfuser_direct:

from nvfuser_direct import FusionCache, FusionDefinition, SchedulerType, DataType
from nvfuser_direct.pytorch_utils import torch_dtype_to_nvfuser_dtype

_{Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!}

doc/dev/python_scheduling/autotune_matmul.py
Update to use nvfuser_direct:

from nvfuser_direct import FusionDefinition, SchedulerType

_{Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!}

doc/dev/python_scheduling/profile_matmul.py
Update imports to use nvfuser_direct instead of removed nvfuser module

greptile-apps

_{8 files reviewed, no comments}

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rdspring1 · 2026-02-04T19:24:50Z

!test --dev

greptile-apps

_{7 files reviewed, 6 comments}

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greptile-apps · 2026-02-04T19:28:45Z

doc/dev/python_scheduling/autotune_inner_reduction.py

+
+# TODO Update script to use nvfuser_direct module


TODO added but imports still reference removed nvfuser module - script will fail

Suggested change

# TODO Update script to use nvfuser_direct module

# TODO Update script to use nvfuser_direct module

from nvfuser_direct import FusionDefinition, SchedulerType, DataType, ParallelType

greptile-apps · 2026-02-04T19:28:46Z

doc/dev/python_scheduling/autotune_matmul.py

+
+# TODO Update script to use nvfuser_direct module


TODO added but imports still reference removed nvfuser module - script will fail

Suggested change

# TODO Update script to use nvfuser_direct module

# TODO Update script to use nvfuser_direct module

from nvfuser_direct import FusionDefinition, SchedulerType

greptile-apps · 2026-02-04T19:28:47Z

doc/dev/python_scheduling/autotune_pointwise.py

 import math
+


TODO added but imports still reference removed nvfuser module - script will fail

Suggested change

import math

# TODO Update script to use nvfuser_direct module

from nvfuser_direct import FusionDefinition, SchedulerType, DataType

greptile-apps · 2026-02-04T19:28:53Z

Additional Comments (3)

doc/dev/python_scheduling/autotune_utils.py
imports from removed nvfuser module will fail at runtime

from nvfuser_direct import FusionCache, FusionDefinition

doc/dev/python_scheduling/autotune_persistent.py
imports from removed nvfuser module will fail at runtime

from nvfuser_direct import FusionCache, FusionDefinition, SchedulerType, DataType
from nvfuser_direct.pytorch_utils import torch_dtype_to_nvfuser_dtype

doc/dev/python_scheduling/profile_matmul.py
TODO added but imports still reference removed nvfuser module - script will fail. All imports need updating to nvfuser_direct

greptile-apps

_{7 files reviewed, 4 comments}

_{Edit Code Review Agent Settings | Greptile}

greptile-apps · 2026-02-04T23:38:37Z

doc/dev/python_scheduling/autotune_inner_reduction.py

 import itertools
+
+# TODO Update script to use nvfuser_direct module
 from nvfuser import FusionDefinition, SchedulerType, DataType, ParallelType


Script imports from removed nvfuser module and will fail at runtime

Suggested change

from nvfuser import FusionDefinition, SchedulerType, DataType, ParallelType

from nvfuser_direct import FusionDefinition, SchedulerType, DataType, ParallelType

greptile-apps · 2026-02-04T23:38:41Z

doc/dev/python_scheduling/autotune_pointwise.py

@@ -6,6 +6,8 @@
 import torch
 import itertools
 import math


Script imports from removed nvfuser module and will fail at runtime

greptile-apps · 2026-02-04T23:38:46Z

Additional Comments (2)

doc/dev/python_scheduling/autotune_matmul.py
Script imports from removed nvfuser module and will fail at runtime

from nvfuser_direct import (
    FusionDefinition,
    SchedulerType,
    ClusterDims,
    MatMulTileOptions,
    GemmTile,
    MmaMacroEncode,
    MmaMacroArch,
    MatmulTileRasterizationOrder,

doc/dev/python_scheduling/profile_matmul.py
Script imports from removed nvfuser module and will fail at runtime

from nvfuser_direct import (
    FusionDefinition,
    SchedulerType,
    ClusterDims,
    MatMulTileOptions,
    GemmTile,
    MmaMacroEncode,
    MmaMacroArch,
    MatmulTileRasterizationOrder,
    MatmulCircularBufferingStrategy,
)

rdspring1 · 2026-02-05T23:26:49Z

!test --dev

rdspring1 added the Direct Bindings Python extension with direct mapping to NvFuser CPP objects. label Feb 3, 2026

greptile-apps bot reviewed Feb 3, 2026

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rdspring1 force-pushed the remove_legacy_bindings branch from 7d0a9ba to 904ab90 Compare February 4, 2026 05:13

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python/utils.py Show resolved Hide resolved

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rdspring1 added 2 commits February 4, 2026 11:24

Remove legacy bindings

05cd61c

bump version

5107f26

rdspring1 force-pushed the remove_legacy_bindings branch from 21cb6bd to 5107f26 Compare February 4, 2026 19:24

greptile-apps bot reviewed Feb 4, 2026

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Update tools/check_symbol_visibility.sh

aa333da

greptile-apps bot reviewed Feb 4, 2026

View reviewed changes

	import math
	# TODO Update script to use nvfuser_direct module
	from nvfuser_direct import FusionDefinition, SchedulerType, DataType

	from nvfuser import FusionDefinition, SchedulerType, DataType, ParallelType
	from nvfuser_direct import FusionDefinition, SchedulerType, DataType, ParallelType

Remove legacy bindings #5917

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Remove legacy bindings #5917

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Greptile Summary

Confidence Score: 2/5

Important Files Changed

Sequence Diagram

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