# simd_half8 A vector of eight 16-bit floating-point elements. ``` typealias simd_half8 = SIMD8 ``` ## Topics ### Functions to create eight-element vectors from other vectors [`simd_make_half8(_:)`](/documentation/simd/simd_make_half8(_:)-97ut4) Returns a new vector from the specified two-element vector, and other elements set to zero. [`simd_make_half8(_:)`](/documentation/simd/simd_make_half8(_:)-9anaf) Returns a new vector from the specified three-element vector, and other elements set to zero. [`simd_make_half8(_:)`](/documentation/simd/simd_make_half8(_:)-9e4ki) Returns a new vector from the specified four-element vector, and other elements set to zero. [`simd_make_half8(_:)`](/documentation/simd/simd_make_half8(_:)-9slsm) Returns a new vector from the specified vector. [`simd_make_half8(_:)`](/documentation/simd/simd_make_half8(_:)-4xf3n) Returns a new vector by truncating the specified 16-element vector. [`simd_make_half8(_:)`](/documentation/simd/simd_make_half8(_:)-94pmz) Returns a new vector by truncating the specified 32-element vector. [`simd_make_half8_undef(_:)`](/documentation/simd/simd_make_half8_undef(_:)-3on10) Returns a new vector from the specified two-element vector, and other elements undefined. [`simd_make_half8_undef(_:)`](/documentation/simd/simd_make_half8_undef(_:)-3l5sn) Returns a new vector from the specified three-element vector, and other elements undefined. [`simd_make_half8_undef(_:)`](/documentation/simd/simd_make_half8_undef(_:)-337am) Returns a new vector from the specified four-element vector, and other elements undefined. [`simd_make_half8(_:_:)`](/documentation/simd/simd_make_half8(_:_:)) Returns a new vector from the specified vectors. ### Functions to create eight-element vectors from scalar values [`simd_make_half8(_:)`](/documentation/simd/simd_make_half8(_:)-ivna) Returns a new vector with the first element set to a scalar value, and other elements set to zero. [`simd_make_half8_undef(_:)`](/documentation/simd/simd_make_half8_undef(_:)-4lqrh) Returns a new vector with the first element set to a scalar value, and other elements undefined. ### Functions to create eight-element vectors from vectors of other types [`simd_half`](/documentation/simd/simd_half-3u66l) Returns a new vector from the specified vector of 8-bit, signed-integer elements. [`simd_half`](/documentation/simd/simd_half-3ufyl) Returns a new vector from the specified vector of 8-bit, unsigned-integer elements. [`simd_half`](/documentation/simd/simd_half-3uazx) Returns a new vector from the specified vector of 16-bit, signed-integer elements. [`simd_half`](/documentation/simd/simd_half-3ukx9) Returns a new vector from the specified vector of 16-bit, unsigned-integer elements. [`simd_half`](/documentation/simd/simd_half-3u7w5) Returns a new vector from the specified vector of 32-bit, signed-integer elements. [`simd_half`](/documentation/simd/simd_half-3ui0l) Returns a new vector from the specified vector of 32-bit, unsigned-integer elements. [`simd_half`](/documentation/simd/simd_half-3u9dz) Returns a new vector from the specified vector of 64-bit, signed-integer elements. [`simd_half`](/documentation/simd/simd_half-3ujk7) Returns a new vector from the specified vector of 64-bit, unsigned-integer elements. [`simd_half`](/documentation/simd/simd_half-3ui4n) Returns a new vector from the specified vector of 16-bit, floating-point elements. [`simd_half`](/documentation/simd/simd_half-3uhij) Returns a new vector from the specified vector of 32-bit, floating-point elements. [`simd_half`](/documentation/simd/simd_half-3uh2v) Returns a new vector from the specified vector of 64-bit, floating-point elements. ### Common functions [`simd_abs(_:)`](/documentation/simd/simd_abs(_:)-7p1mc) Returns the absolute value of each element in a vector. [`simd_clamp(_:_:_:)`](/documentation/simd/simd_clamp(_:_:_:)-7a090) Returns each element in a vector clamped to a specified range. [`simd_equal(_:_:)`](/documentation/simd/simd_equal(_:_:)-8nejo) Returns true if every element in a vector is exactly equal to the corresponding element in a second vector, and otherwise returns false. [`simd_fract(_:)`](/documentation/simd/simd_fract(_:)-3jdnl) Returns the fractional part of each element in a vector. [`simd_sign(_:)`](/documentation/simd/simd_sign(_:)-7hck3) Returns the sign of each element in a vector. [`simd_step(_:_:)`](/documentation/simd/simd_step(_:_:)-5v3vi) Returns zero for each element in a vector less than a specified edge, and otherwise returns one. ### Reduce functions [`simd_reduce_add(_:)`](/documentation/simd/simd_reduce_add(_:)-3auqo) Returns the sum of all elements in a vector. [`simd_reduce_max(_:)`](/documentation/simd/simd_reduce_max(_:)-55ayy) Returns the maximum value in a vector. [`simd_reduce_min(_:)`](/documentation/simd/simd_reduce_min(_:)-3o9ia) Returns the minimum value in a vector. ### Interpolation functions [`simd_mix(_:_:_:)`](/documentation/simd/simd_mix(_:_:_:)-6gojc) Returns an element-wise linearly interpolated value between two vectors. [`simd_smoothstep(_:_:_:)`](/documentation/simd/simd_smoothstep(_:_:_:)-96q78) Returns an element-wise smoothly interpolated value between two vectors. ### Extrema functions [`simd_max(_:_:)`](/documentation/simd/simd_max(_:_:)-ei84) Returns the maximum value of each element in a vector. [`simd_min(_:_:)`](/documentation/simd/simd_min(_:_:)-55b3r) Returns the minimum value of each element in a vector. ### Reciprocal and reciprocal square root functions [`simd_recip(_:)`](/documentation/simd/simd_recip(_:)-98e5u) Returns the reciprocal of each element in a vector. [`simd_rsqrt(_:)`](/documentation/simd/simd_rsqrt(_:)-1ofzq) Returns the reciprocal square root of each element in a vector. [`simd_precise_recip(_:)`](/documentation/simd/simd_precise_recip(_:)-74du2) Returns the precise reciprocal of each element in a vector. [`simd_precise_rsqrt(_:)`](/documentation/simd/simd_precise_rsqrt(_:)-1hm48) Returns the precise reciprocal square root of each element in a vector. [`simd_fast_recip(_:)`](/documentation/simd/simd_fast_recip(_:)-16ixv) Returns the fast reciprocal of each element in a vector. [`simd_fast_rsqrt(_:)`](/documentation/simd/simd_fast_rsqrt(_:)-923z8) Returns the fast reciprocal square root of each element in a vector. ### Geometry functions [`simd_dot`](/documentation/simd/simd_dot-16ezc) Returns the dot product of two vectors. [`simd_normalize`](/documentation/simd/simd_normalize-us7) Returns a vector pointing in the same direction of the supplied vector, with a length of 1. [`simd_fast_normalize`](/documentation/simd/simd_fast_normalize-8x56w) Returns the fast normalized vector. [`simd_precise_normalize`](/documentation/simd/simd_precise_normalize-621rw) Returns the precise normalized vector. [`simd_project`](/documentation/simd/simd_project-472vy) Returns the first vector projected onto the second vector. [`simd_precise_project`](/documentation/simd/simd_precise_project-8kipf) Returns the precise projected vector. [`simd_fast_project`](/documentation/simd/simd_fast_project-2k6sp) Returns the fast projected vector. ### Vector norm functions [`simd_norm_one`](/documentation/simd/simd_norm_one-fkef) Returns the sum of the absolute values of a vector. [`simd_norm_inf`](/documentation/simd/simd_norm_inf-9m6k2) Returns the maximum absolute value of a vector. ### Length and distance functions [`simd_length`](/documentation/simd/simd_length-32yfr) Returns the length of a vector. [`simd_fast_length`](/documentation/simd/simd_fast_length-5uxn4) Returns the fast length of a vector. [`simd_precise_length`](/documentation/simd/simd_precise_length-67lfe) Returns the precise length of a vector. [`simd_length_squared`](/documentation/simd/simd_length_squared-3xd95) Returns the square of the length of a vector. [`simd_distance`](/documentation/simd/simd_distance-2j394) Returns the distance between two vectors. [`simd_fast_distance`](/documentation/simd/simd_fast_distance-66qhh) Returns the fast distance between two vectors. [`simd_precise_distance`](/documentation/simd/simd_precise_distance-9fb2f) Returns the precise distance between two vectors. [`simd_distance_squared`](/documentation/simd/simd_distance_squared-3sgxy) Returns the square of the distance between two vectors. ### Logic functions [`simd_select(_:_:_:)`](/documentation/simd/simd_select(_:_:_:)-7qsat) Returns a vector that contains elements from either the first or second parameter, based on the corresponding element’s high-order bit in the mask. [`simd_bitselect(_:_:_:)`](/documentation/simd/simd_bitselect(_:_:_:)-1kwpu) Returns a vector that contains elements from either the first or second parameter, based on the corresponding element in the third parameter. ### Math functions [`simd_muladd(_:_:_:)`](/documentation/simd/simd_muladd(_:_:_:)-1vfnf) Returns the multiply-add result for corresponding elements in three vectors. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)