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SIMD.js has been taken out of active development in TC39 and removed from Stage 3. It is not being pursued by web browsers for implementation anymore. SIMD operations exposed to the web are under active development within WebAssembly, with operations based on the SIMD.js operations.

The static SIMD.%type%.notEqual() method returns a selection mask with values depending on an inequality comparison (a != b) in each lane.


SIMD.Float32x4.notEqual(a, b)
SIMD.Float64x2.notEqual(a, b)

SIMD.Int8x16.notEqual(a, b)
SIMD.Int16x8.notEqual(a, b)
SIMD.Int32x4.notEqual(a, b)

SIMD.Uint8x16.notEqual(a, b)
SIMD.Uint16x8.notEqual(a, b)
SIMD.Uint32x4.notEqual(a, b) 


An instance of a SIMD type.
Another instance of a SIMD type.

Return value

A selection mask (of type Bool64x2, Bool32x4, Bool16x8 or Bool8x16 depending on the size). The lane values of the mask are either true or false depending on the result of a != b.


The SIMD.%type%.notEqual method is one of the SIMD comparison operations and does not give you back the values of the inequality comparison of two instances directly. Instead, a selection mask with Boolean values is returned.


Selecting unequal lanes from two vectors

In this example, two SIMD Float32x4 data types are compared against inequality of their lane values and a selection mask gets created based on the result. This selection mask is then used to select the unequal values into a new Float32x4. At the lane positions where the vectors a and b have equal values, the result vector uses the zero vector and fills the lanes with 0.

var a = SIMD.Float32x4(1, 2, 3, 9);
var b = SIMD.Float32x4(1, 4, 7, 9);

var mask = SIMD.Float32x4.notEqual(a, b);
// Bool32x4[false, true, true, false]

var zero = SIMD.Float32x4(0, 0, 0, 0);

var result =, a, zero);
// Float32x4[0, 2, 3, 0]


Specification Status Comment
The definition of 'SIMDConstructor.notEqual' in that specification.
Draft Initial definition.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support No support Nightly build No support No support No support
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support No support No support Nightly build No support No support No support

See also

Document Tags and Contributors

 Contributors to this page: fscholz, nmve
 Last updated by: fscholz,