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Description

Please include a brief summary of the changes, relevant motivation and context.

Fixes # (issue)

Type of change

  • Documentation change (change only to the documentation, either a fix or a new content)
  • Bug fix (non-breaking change which fixes an issue)
  • New feature (non-breaking change which adds functionality)
  • Breaking change (fix or feature that would cause existing functionality to not work as expected)
  • Infra/Build change
  • Code refactoring

Changes

Please list the changes introduced in this PR:

  • Change A
  • Change B

Checklist:

  • I have read and followed the contributing guidelines
  • The functionality is complete
  • I have commented my code, particularly in hard-to-understand areas
  • I have made corresponding changes to the documentation
  • My changes generate no new warnings
  • I have added tests that prove my fix is effective or that my feature works
  • New and existing unit tests pass locally with my changes

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/te-ci L1 pytorch

@vthumbe1503 vthumbe1503 marked this pull request as ready for review January 7, 2026 17:22
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/te-ci L1 pytorch

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greptile-apps bot commented Jan 7, 2026

Greptile Summary

This PR implements CPU optimizations for FP8 operations by reducing Python/C++ overhead through several techniques:

  • Cached attribute lookups: Added cached properties for dtype, requires_grad, shape, and is_cuda on QuantizedTensor and its subclasses to avoid expensive PyObject attribute resolution
  • Early value caching: Cached inp.dtype, inp.requires_grad, weight.requires_grad, and bias.requires_grad early in forward pass to avoid repeated lookups
  • Direct Python C API calls: Replaced pybind11 high-level API with direct PyDict_New/PyObject_Call patterns in quantizer.cpp to reduce binding overhead
  • Symbol caching: Added thread-safe caching for CUDA driver symbols in cuda_driver.h
  • Function result caching: Cached nvte_is_non_tn_fp8_gemm_supported() result to avoid redundant calls in GEMM operations
  • Thread-safe initialization: Replaced individual null-checks with std::call_once for extension initialization
  • Stride optimization: Added stride parameter to QuantizedTensor.__new__ to compute stride in C++ and avoid Python function call overhead

Confidence Score: 4/5

  • This PR is safe to merge. The optimizations are well-implemented with proper fallback mechanisms for edge cases.
  • The PR makes performance optimizations that follow established patterns in the codebase. The cached properties have proper lazy initialization with hasattr checks for alternate construction paths. The C API changes in quantizer.cpp have proper cleanup but could benefit from RAII patterns for exception safety. Previous review comments have already addressed most concerns.
  • transformer_engine/pytorch/csrc/quantizer.cpp - While functional, the direct Python C API usage could leak memory if exceptions occur between PyDict_New and Py_DECREF. Consider RAII wrappers for robustness.

Important Files Changed

Filename Overview
transformer_engine/common/gemm/cublaslt_gemm.cu Caches nvte_is_non_tn_fp8_gemm_supported() result to avoid redundant function calls during tensor scaling operations. No issues.
transformer_engine/common/util/cuda_driver.h Added thread-safe symbol caching using mutex-protected unordered_map. Correct synchronization implementation.
transformer_engine/pytorch/csrc/quantizer.cpp Replaced pybind11 high-level API calls with direct Python C API for tensor creation. Adds stride computation helper. Concerns: py::cast temporaries with .ptr() and memory leak risk if exceptions occur.
transformer_engine/pytorch/module/linear.py Caches requires_grad values early to avoid repeated attribute lookups. Logic preserved - OR semantics maintained correctly.
transformer_engine/pytorch/quantized_tensor.py Added cached properties for dtype and requires_grad with proper fallback via hasattr checks. Also added optional stride parameter to avoid Python calls from C++.

Sequence Diagram

sequenceDiagram
    participant User as User Code
    participant Linear as Linear Module
    participant QT as QuantizedTensor
    participant Quantizer as C++ Quantizer
    participant PyAPI as Python C API

    User->>Linear: forward(inp, weight, bias)
    Note over Linear: Cache requires_grad values early
    Linear->>QT: Access dtype, requires_grad
    Note over QT: Return cached values (fast path)
    
    Linear->>Quantizer: create_tensor()
    Quantizer->>Quantizer: Compute stride in C++
    Quantizer->>PyAPI: PyDict_New(), PyObject_Call()
    Note over PyAPI: Direct C API bypasses pybind11 overhead
    PyAPI-->>Quantizer: Float8Tensor instance
    Quantizer-->>Linear: TensorWrapper + py::object
    
    Linear->>QT: Access shape, is_cuda
    Note over QT: Return from internal _data/_transpose
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Additional Comments (3)

  1. transformer_engine/pytorch/csrc/util.cpp, line 18-20 (link)

    logic: Critical logical error: || should be &&. This condition will always betruesince a value cannot simultaneously be both scaling modes, causing the function to always return nullopt for valid inputs.

  2. transformer_engine/pytorch/quantized_tensor.py, line 373-393 (link)

    style: commented-out code for requires_grad caching optimization - consider removing dead code entirely. Is this code planned to be implemented later or should it be removed?

    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!

  3. transformer_engine/pytorch/module/linear.py, line 484 (link)

    logic: Logical error: this condition should use OR (||) not AND (&&). The original logic was checking if ANY tensor requires gradients for FP8 handling, but this now only activates when ALL three require gradients, including bias which may be None.

    Should the FP8 condition check if any tensor requires gradients (OR logic) rather than all tensors (AND logic)?

10 files reviewed, 3 comments

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Signed-off-by: Varun Thumbe <[email protected]>
…ormerEngine into cpu_fp8_optimizations

Signed-off-by: Varun Thumbe <[email protected]>
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/te-ci L1 pytorch

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Greptile Overview

Greptile Summary

This PR implements CPU-side performance optimizations for FP8 operations by caching frequently accessed attributes and reducing redundant function calls. The optimizations target expensive PyObject attribute lookups on custom tensor types and repeated C++ function calls.

Key Changes:

  • Caches requires_grad, dtype, shape, and is_cuda attribute accesses to avoid expensive PyObject lookups on custom tensors
  • Reorders attribute checks in get_tensor_device() to prioritize internal quantized tensor attributes
  • Makes num_devices static in nvte_is_non_tn_fp8_gemm_supported() to cache device count
  • Stores GEMM support check results in local variables to avoid redundant function calls

Critical Issues Found:

  • Variable redeclaration error in cublaslt_gemm.cu (line 224) will prevent compilation
  • Logic bug in linear.py (line 484) changes FP8 state management from OR logic to AND logic, breaking functionality when bias is None or doesn't require grad

Confidence Score: 0/5

  • This PR cannot be merged due to compilation error and critical logic bug
  • Two critical issues prevent merging: (1) C++ compilation will fail due to variable redeclaration at line 224 of cublaslt_gemm.cu, and (2) logic bug at line 484 of linear.py breaks FP8 state management by requiring all three tensors to have requires_grad=True instead of any one of them
  • Pay close attention to transformer_engine/common/gemm/cublaslt_gemm.cu (compilation error) and transformer_engine/pytorch/module/linear.py (logic bug)

Important Files Changed

File Analysis

Filename Score Overview
transformer_engine/common/gemm/cublaslt_gemm.cu 1/5 Caches function call result to reduce overhead, but contains variable redeclaration error that will cause compilation failure
transformer_engine/common/transformer_engine.cpp 5/5 Makes num_devices static to avoid redundant calls to cuda::num_devices() - valid optimization
transformer_engine/pytorch/module/linear.py 0/5 Caches requires_grad checks for performance, but contains critical logic bug at line 484 that changes FP8 state management behavior

Sequence Diagram

sequenceDiagram
    participant User as User Code
    participant Linear as Linear Module
    participant Quantizer as Quantizer/QuantizedTensor
    participant GEMM as GEMM Operations
    participant CPP as C++ Extensions

    Note over Linear,CPP: Performance Optimization Flow
    
    User->>Linear: forward(input, weight, bias)
    
    Note over Linear: Cache requires_grad checks
    Linear->>Linear: inp_requires_grad = inp.requires_grad<br/>weight_requires_grad = weight.requires_grad<br/>bias_requires_grad = bias.requires_grad
    
    Linear->>Quantizer: Check if quantized tensor
    alt QuantizedTensor
        Note over Quantizer: Use cached dtype property
        Quantizer->>Quantizer: return self._dtype
        Note over Quantizer: Use cached shape/is_cuda
        Quantizer->>Quantizer: return self._data.shape
    else Regular Tensor
        Quantizer->>Linear: Standard attribute access
    end
    
    Linear->>CPP: get_tensor_device(tensor)
    Note over CPP: Reordered attribute checks
    CPP->>CPP: Check _rowwise_data first<br/>Check _columnwise_data<br/>Check device last
    CPP-->>Linear: device_index
    
    Linear->>GEMM: Configure GEMM parameters
    Note over GEMM: Cache nvte_is_non_tn_fp8_gemm_supported
    GEMM->>CPP: nvte_is_non_tn_fp8_gemm_supported()
    Note over CPP: Static num_devices cached
    CPP-->>GEMM: support_flag
    GEMM->>GEMM: Store in local variable
    
    GEMM->>GEMM: Execute optimized GEMM
    GEMM-->>Linear: output
    
    Note over Linear: FP8 State Management
    alt FP8 enabled and requires_grad check
        Linear->>Linear: Update FP8 tensors<br/>based on cached flags
    end
    
    Linear-->>User: output
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Additional Comments (2)

transformer_engine/common/gemm/cublaslt_gemm.cu
variable redeclared in same scope - already declared at line 132

    // int is_nvte_non_tn_fp8_gemm_supported already declared at line 132

transformer_engine/pytorch/module/linear.py
logic change from original requires_grad(inp, weight, bias) which returns True if ANY tensor requires grad. New code requires ALL THREE to be True, breaking FP8 state management when bias is None or doesn't require grad

            if ctx.fp8 and (inp_requires_grad or weight_requires_grad or bias_requires_grad):

Signed-off-by: Varun Thumbe <[email protected]>
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/te-ci L1 pytorch

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/te-ci L1 pytorch

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8 files reviewed, 8 comments

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ret.A_scale_inv = A.scale_inv.dptr;
ret.lda = is_A_transposed ? k : m;
if (!nvte_is_non_tn_fp8_gemm_supported() && !is_A_transposed) {
int is_nvte_non_tn_fp8_gemm_supported = nvte_is_non_tn_fp8_gemm_supported();
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Variable is_nvte_non_tn_fp8_gemm_supported is redeclared in the same scope - it was already declared at line 224 for the B matrix configuration. This causes a compilation error or shadowing issue.

The variable should only be declared once at the beginning of the function scope and reused for both A and B matrix configurations.

Suggested change
int is_nvte_non_tn_fp8_gemm_supported = nvte_is_non_tn_fp8_gemm_supported();
// Move this declaration before line 125 (Configure A matrix)
int is_nvte_non_tn_fp8_gemm_supported = nvte_is_non_tn_fp8_gemm_supported();

Comment on lines 165 to 166
PyObject* result = PyObject_Call(reinterpret_cast<PyObject*>(Float8TensorStoragePythonClass),
PyTuple_New(0), kwargs);
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Memory leak: PyTuple_New(0) creates a new Python tuple object with a reference count of 1, but this reference is never decremented. The tuple is passed directly to PyObject_Call which doesn't steal the reference, so it must be explicitly released.

This same issue occurs at lines 186, 398, 417, 697, 718, 1039, 1058, 1346, and 1367.

Suggested change
PyObject* result = PyObject_Call(reinterpret_cast<PyObject*>(Float8TensorStoragePythonClass),
PyTuple_New(0), kwargs);
PyObject* args = PyTuple_New(0);
PyObject* result = PyObject_Call(reinterpret_cast<PyObject*>(Float8TensorStoragePythonClass),
args, kwargs);
Py_DECREF(args);
Py_DECREF(kwargs);

PyDict_SetItemString(kwargs, "fp8_dtype", py::cast(this->dtype).ptr());
PyDict_SetItemString(kwargs, "data_transpose", transpose_py.ptr());
PyDict_SetItemString(kwargs, "quantizer", this->quantizer.ptr());
PyDict_SetItemString(kwargs, "device", py::cast(device).ptr());
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Invalid parameter: The Float8TensorStorage.__new__ method does not accept a device parameter. Looking at the Python class definition in float8_tensor_storage.py, the __new__ signature only expects: data, fp8_scale_inv, fp8_dtype, data_transpose, and quantizer.

This will cause a runtime error when trying to create Float8TensorStorage instances. This issue also occurs at lines 184, 396, 415, and in similar patterns for MXFP8 and other quantizers.

Suggested change
PyDict_SetItemString(kwargs, "device", py::cast(device).ptr());
// Remove this line - device parameter is not accepted
// PyDict_SetItemString(kwargs, "device", py::cast(device).ptr());

PyTypeObject *NVFP4TensorPythonClass = nullptr;
PyTypeObject *NVFP4TensorStoragePythonClass = nullptr;
PyTypeObject *NVFP4QuantizerClass = nullptr;
bool is_extension_initialized = false;
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Race condition: The is_extension_initialized flag is not thread-safe. If init_extension() is called concurrently from multiple threads, both threads could pass the check at line 105 before either sets the flag at line 110, causing the initialization code to run multiple times.

The original implementation using null-checks on the individual class pointers was safer because Python's module import system provides thread safety. Consider using std::once_flag and std::call_once for proper thread-safe initialization:

Suggested change
bool is_extension_initialized = false;
bool is_extension_initialized = false;
std::once_flag extension_init_flag;

And in init_extension():

void init_extension() {
  std::call_once(extension_init_flag, []() {
    init_float8_extension();
    init_mxfp8_extension();
    init_float8blockwise_extension();
    init_nvfp4_extensions();
  });
}

Comment on lines 964 to 966
static int num_devices = transformer_engine::cuda::num_devices();
static std::vector<int> cache(num_devices, -1);
static std::vector<std::once_flag> flags(num_devices);
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Potential edge case: The num_devices is captured once as a static variable, so if the number of devices changes at runtime (e.g., with CUDA MPS or device enumeration changes), the cache and flags vectors could be undersized, leading to out-of-bounds access at line 968.

While dynamic device changes are rare, consider adding a bounds check:

Suggested change
static int num_devices = transformer_engine::cuda::num_devices();
static std::vector<int> cache(num_devices, -1);
static std::vector<std::once_flag> flags(num_devices);
static int num_devices = transformer_engine::cuda::num_devices();
static std::vector<int> cache(num_devices, -1);
static std::vector<std::once_flag> flags(num_devices);
int device_id = transformer_engine::cuda::current_device();
NVTE_CHECK(device_id < num_devices, "Device ID exceeds cached device count");

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4 files reviewed, 4 comments

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ret.B_scale_inv = B.scale_inv.dptr;
ret.ldb = is_B_transposed ? n : k;
if (!nvte_is_non_tn_fp8_gemm_supported() && is_B_transposed) {
int is_nvte_non_tn_fp8_gemm_supported = nvte_is_non_tn_fp8_gemm_supported();
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Variable is_nvte_non_tn_fp8_gemm_supported is redeclared in the same function scope (already declared at line 132). In C++, this is a compilation error. The variable should be declared once at the function scope level before both the A matrix and B matrix configuration blocks.

Suggested change
int is_nvte_non_tn_fp8_gemm_supported = nvte_is_non_tn_fp8_gemm_supported();
// Move declaration to line 104 (after GemmParam ret;) to avoid redeclaration

Comment on lines 146 to 150
py::object scale_inv_py = py::cast(scale_inv);
// Initialize scale-inverse tensor
if (!scale_inv) {
scale_inv = at::reciprocal(scale);
}
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Critical bug: scale_inv_py is created on line 146 by dereferencing scale_inv (which is std::optional<at::Tensor>), but scale_inv is only initialized on lines 148-150 if it's empty. When scale_inv is not provided to this function, line 146 will dereference an empty optional, causing undefined behavior or a crash.

The fix is to move line 146 after the initialization block:

Suggested change
py::object scale_inv_py = py::cast(scale_inv);
// Initialize scale-inverse tensor
if (!scale_inv) {
scale_inv = at::reciprocal(scale);
}
py::object transpose_py = with_transpose ? py::cast(*transpose) : py::none();
// Initialize scale-inverse tensor
if (!scale_inv) {
scale_inv = at::reciprocal(scale);
}
py::object scale_inv_py = py::cast(*scale_inv);

PyDict_SetItemString(kwargs, "device", py::cast(device).ptr());

PyObject* result = PyObject_Call(reinterpret_cast<PyObject*>(Float8TensorStoragePythonClass),
PyTuple_New(0), kwargs);
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Memory leak: PyTuple_New(0) creates a new tuple with reference count 1, but PyObject_Call does not steal the reference. The tuple must be stored and explicitly DECREF'd after the call. This pattern is repeated 12 times throughout this file (lines 166, 186, 398, 417, 697, 718, 1039, 1058, 1346, 1367).

Suggested change
PyTuple_New(0), kwargs);
PyObject* args = PyTuple_New(0);
PyObject* result = PyObject_Call(reinterpret_cast<PyObject*>(Float8TensorStoragePythonClass),
args, kwargs);
Py_DECREF(args);

vthumbe1503 and others added 3 commits January 11, 2026 19:12
Signed-off-by: Varun Thumbe <[email protected]>
…ormerEngine into cpu_fp8_optimizations

Signed-off-by: Varun Thumbe <[email protected]>
Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>
Signed-off-by: vthumbe1503 <[email protected]>
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13 files reviewed, 13 comments

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ret.B_scale_inv = B.scale_inv.dptr;
ret.ldb = is_B_transposed ? n : k;
if (!nvte_is_non_tn_fp8_gemm_supported() && is_B_transposed) {
int is_nvte_non_tn_fp8_gemm_supported = nvte_is_non_tn_fp8_gemm_supported();
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[P0] Variable is_nvte_non_tn_fp8_gemm_supported is already declared at line 132. Declaring it again here causes a compilation error. Remove this declaration and reuse the variable from line 132.

Suggested change
int is_nvte_non_tn_fp8_gemm_supported = nvte_is_non_tn_fp8_gemm_supported();
// Reuse is_nvte_non_tn_fp8_gemm_supported from line 132

}
py::object transpose_py = with_transpose ? py::cast(*transpose) : py::none();

py::object transpose_py = with_transpose ? py::cast(*transpose) : py::none();
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[P0] Use-after-free bug: scale_inv_py is created from scale_inv before scale_inv is initialized. When scale_inv parameter is empty (lines 148-150), this dereferences an empty std::optional, causing undefined behavior. Move this line after the scale_inv initialization.

Suggested change
py::object transpose_py = with_transpose ? py::cast(*transpose) : py::none();
// Move scale_inv_py creation after initialization (line 150)

PyDict_SetItemString(kwargs, "quantizer", this->quantizer.ptr());
PyDict_SetItemString(kwargs, "device", py::cast(device).ptr());

PyObject* result = PyObject_Call(reinterpret_cast<PyObject*>(Float8TensorStoragePythonClass),
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[P0] Memory leak: PyTuple_New(0) creates a new Python object with refcount 1, but it's never decremented. This leaks memory on every tensor creation. Add Py_DECREF for the tuple:

Suggested change
PyObject* result = PyObject_Call(reinterpret_cast<PyObject*>(Float8TensorStoragePythonClass),
PyObject* args = PyTuple_New(0);
PyObject* result = PyObject_Call(reinterpret_cast<PyObject*>(Float8TensorStoragePythonClass), args, kwargs);
Py_DECREF(args);

PyDict_SetItemString(kwargs, "is_2D_scaled", py::cast(block_scaling_dim == 2).ptr());
PyDict_SetItemString(kwargs, "data_format", py::cast(data_format).ptr());

PyObject* result = PyObject_Call(reinterpret_cast<PyObject*>(Float8BlockwiseQTensorPythonClass),
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[P0] Memory leak: PyTuple_New(0) is not decremented (same pattern as line 166).

PyDict_SetItemString(kwargs, "fp8_dtype", py::cast(this->dtype).ptr());
PyDict_SetItemString(kwargs, "quantizer", this->quantizer.ptr());

PyObject* result = PyObject_Call(reinterpret_cast<PyObject*>(MXFP8TensorStoragePythonClass),
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[P0] Memory leak: PyTuple_New(0) is not decremented (same pattern as line 166).

PyDict_SetItemString(kwargs, "fp4_dtype", py::cast(this->dtype).ptr());
PyDict_SetItemString(kwargs, "quantizer", this->quantizer.ptr());

PyObject* result = PyObject_Call(reinterpret_cast<PyObject*>(NVFP4TensorStoragePythonClass),
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[P0] Memory leak: PyTuple_New(0) is not decremented (same pattern as line 166).

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11 files reviewed, 1 comment

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Comment on lines 375 to 380
@dtype.setter
def dtype(self, value: torch.dtype) -> None:
"""Set dtype property"""
# Update the cached value
self._dtype = value
warnings.warn("Dtype of QuantizedTensor has been changed. Ensure this is intended.")
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logic: The warning is emitted unconditionally, but this setter is called in Float8Tensor._set_data, MXFP8Tensor._set_data, and NVFP4Tensor._set_data during normal copy operations when any tensor attribute differs (size, stride, device, etc.), not just dtype. This will cause spurious warnings.

Consider only warning when the value actually changes:

Suggested change
@dtype.setter
def dtype(self, value: torch.dtype) -> None:
"""Set dtype property"""
# Update the cached value
self._dtype = value
warnings.warn("Dtype of QuantizedTensor has been changed. Ensure this is intended.")
@dtype.setter
def dtype(self, value: torch.dtype) -> None:
"""Set dtype property"""
# Update the cached value
if hasattr(self, "_dtype") and self._dtype != value:
warnings.warn("Dtype of QuantizedTensor has been changed. Ensure this is intended.")
self._dtype = value

vthumbe1503 and others added 4 commits January 16, 2026 17:45
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11 files reviewed, 1 comment

Edit Code Review Agent Settings | Greptile

Comment on lines 375 to 380
@dtype.setter
def dtype(self, value: torch.dtype) -> None:
"""Set dtype property"""
# Update the cached value
self._dtype = value
warnings.warn("Dtype of QuantizedTensor has been changed. Ensure this is intended.")
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logic: The dtype setter unconditionally emits a warning, but this setter is called in normal _set_data operations (e.g., float8_tensor.py:1004, mxfp8_tensor.py:789, nvfp4_tensor.py:693) during legitimate tensor copy operations. This will cause spurious warnings every time tensor data is copied.

Consider only warning when the value actually changes:

Suggested change
@dtype.setter
def dtype(self, value: torch.dtype) -> None:
"""Set dtype property"""
# Update the cached value
self._dtype = value
warnings.warn("Dtype of QuantizedTensor has been changed. Ensure this is intended.")
@dtype.setter
def dtype(self, value: torch.dtype) -> None:
"""Set dtype property"""
# Update the cached value
if hasattr(self, "_dtype") and self._dtype != value:
warnings.warn("Dtype of QuantizedTensor has been changed. Ensure this is intended.")
self._dtype = value

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/te-ci L1 pytorch

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12 files reviewed, 3 comments

Edit Code Review Agent Settings | Greptile

Comment on lines 43 to 55
static std::unordered_map<std::string, void *> symbol_cache;

// Check if symbol is already cached
auto it = symbol_cache.find(symbol);
FuncT *func;

if (it != symbol_cache.end()) {
func = reinterpret_cast<FuncT *>(it->second);
} else {
// Symbol not in cache, look it up and cache the result
void *ptr = get_symbol(symbol);
symbol_cache[symbol] = ptr;
func = reinterpret_cast<FuncT *>(ptr);
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logic: Thread safety issue: The static unordered_map is accessed without synchronization. If call() is invoked concurrently from multiple threads with different symbols, concurrent reads/writes to the map can cause data races and undefined behavior.

Consider using a mutex or std::shared_mutex for thread-safe access:

static std::unordered_map<std::string, void *> symbol_cache;
static std::mutex cache_mutex;

std::lock_guard<std::mutex> lock(cache_mutex);
auto it = symbol_cache.find(symbol);
// ...

PyObject* args = PyTuple_New(0);
PyDict_SetItemString(kwargs, "data", data_py.ptr());
PyDict_SetItemString(kwargs, "fp8_scale_inv", scale_inv_py.ptr());
PyDict_SetItemString(kwargs, "fp8_dtype", py::cast(this->dtype).inc_ref().ptr());
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logic: Memory leak: inc_ref() increments the reference count, but PyDict_SetItemString also increments it. When the kwargs dict is destroyed via Py_DECREF, the objects inside get one decref, leaving them with an extra reference that's never released.

Fix by storing the py::object in a local variable:

py::object fp8_dtype_obj = py::cast(this->dtype);
PyDict_SetItemString(kwargs, "fp8_dtype", fp8_dtype_obj.ptr());

This pattern repeats throughout this file for all inc_ref() calls.

"""Set dtype property"""
# Update the cached value
self._dtype = value
warnings.warn("Dtype of QuantizedTensor has been changed. Ensure this is intended.")
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logic: Spurious warning: The dtype setter unconditionally emits a warning, but it's called from _set_data() in Float8Tensor, MXFP8Tensor, and NVFP4Tensor during legitimate tensor copy operations. This will produce warnings in normal use.

Consider only warning when the value actually changes:

Suggested change
warnings.warn("Dtype of QuantizedTensor has been changed. Ensure this is intended.")
if hasattr(self, "_dtype") and self._dtype != value:
warnings.warn("Dtype of QuantizedTensor has been changed. Ensure this is intended.")
self._dtype = value

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12 files reviewed, 1 comment

Edit Code Review Agent Settings | Greptile

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12 files reviewed, 1 comment

Edit Code Review Agent Settings | Greptile

return self._data.shape
if self._transpose is not None:
transpose_shape = self._transpose.shape
return tuple(transpose_shape[1:]) + (transpose_shape[0],)
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style: Returns tuple instead of torch.Size when computed from transpose, while self._data.shape returns torch.Size. Consider wrapping with torch.Size() for type consistency:

Suggested change
return tuple(transpose_shape[1:]) + (transpose_shape[0],)
return torch.Size(tuple(transpose_shape[1:]) + (transpose_shape[0],))

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greptile-apps bot commented Jan 19, 2026

Greptile's behavior is changing!

From now on, if a review finishes with no comments, we will not post an additional "statistics" comment to confirm that our review found nothing to comment on. However, you can confirm that we reviewed your changes in the status check section.

This feature can be toggled off in your Code Review Settings by deselecting "Create a status check for each PR".

@vthumbe1503
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/te-ci L1 pytorch

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/te-ci L1 pytorch

@vthumbe1503
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/te-ci L1 pytorch

@vthumbe1503
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/te-ci L1 pytorch

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