class

RoundBackward

RoundBackward

source edit

Python wrappers

pylucid.ops.roundfunction

Autograd node for element-wise round-to-nearest-even: $y = \operatorname{round}(x)$ .

Piecewise-constant; derivative is zero almost everywhere and undefined at half-integer boundaries. kHasGradient = false causes UnaryKernel::forward to skip autograd wiring entirely.

Math

$y_i = \operatorname{round}(x_i)$

Ties round to even ("banker's rounding"), matching IEEE-754.

See Also

FloorBackward, CeilBackward.

Attributes

kSavesInputbool

false — no tensor needs to be saved across the backward pass.

kHasGradientbool

false — predicate-style op; the backward node is never invoked in practice.

schema_v1OpSchema

Op name "round" with AmpPolicy::KeepInput (integer inputs pass through unchanged).

Notes

CPU dispatch routes through backend::IBackend::round; GPU uses MLX's round primitive. Integer dtypes are a no-op.

Static methods

static

dispatch

int dispatch(backend::IBackend & be, const int & a, const int & s, Dtype dt)

source edit

Forward — calls IBackend::round to compute $y = \operatorname{round}(x)$ with banker's rounding.

Methods

grad_formula

→Storage

int grad_formula(const int & g)

source edit

Zero-gradient sentinel — returns an empty CpuStorage because kHasGradient = false guarantees this is never called.

Parameters

gconst Storage&

Incoming upstream gradient (ignored).

Returns

Storage

Empty CpuStorage placeholder.

class

RoundBackward

RoundBackward

source edit

Python wrappers

pylucid.ops.roundfunction

Autograd node for element-wise round-to-nearest-even: $y = \operatorname{round}(x)$ .

Piecewise-constant; derivative is zero almost everywhere and undefined at half-integer boundaries. kHasGradient = false causes UnaryKernel::forward to skip autograd wiring entirely.

Math

$y_i = \operatorname{round}(x_i)$

Ties round to even ("banker's rounding"), matching IEEE-754.

See Also

FloorBackward, CeilBackward.

Attributes

kSavesInputbool

false — no tensor needs to be saved across the backward pass.

kHasGradientbool

false — predicate-style op; the backward node is never invoked in practice.

schema_v1OpSchema

Op name "round" with AmpPolicy::KeepInput (integer inputs pass through unchanged).

Notes

CPU dispatch routes through backend::IBackend::round; GPU uses MLX's round primitive. Integer dtypes are a no-op.

Static methods

static

dispatch

int dispatch(backend::IBackend & be, const int & a, const int & s, Dtype dt)

source edit

Forward — calls IBackend::round to compute $y = \operatorname{round}(x)$ with banker's rounding.

Methods

grad_formula

→Storage

int grad_formula(const int & g)

source edit

Zero-gradient sentinel — returns an empty CpuStorage because kHasGradient = false guarantees this is never called.

Parameters

gconst Storage&

Incoming upstream gradient (ignored).

Returns

Storage

Empty CpuStorage placeholder.