# simd_double8 A vector of eight 64-bit floating-point elements. ``` typealias simd_double8 = SIMD8 ``` ## Topics ### Functions to Create Eight-Element Vectors From Other Vectors [`simd_make_double8(_:)`](/documentation/simd/simd_make_double8(_:)-3wn9q) Returns a new vector from the specified two-element vector, and other elements set to zero. [`simd_make_double8(_:)`](/documentation/simd/simd_make_double8(_:)-40259) Returns a new vector from the specified three-element vector, and other elements set to zero. [`simd_make_double8(_:)`](/documentation/simd/simd_make_double8(_:)-3br50) Returns a new vector from the specified four-element vector, and other elements set to zero. [`simd_make_double8(_:)`](/documentation/simd/simd_make_double8(_:)-4i0aw) Returns a new vector from the specified vector. [`simd_make_double8(_:_:)`](/documentation/simd/simd_make_double8(_:_:)) Returns a new vector from the specified vectors. [`simd_make_double8_undef(_:)`](/documentation/simd/simd_make_double8_undef(_:)-7g0z0) Returns a new vector from the specified two-element vector, and other elements undefined. [`simd_make_double8_undef(_:)`](/documentation/simd/simd_make_double8_undef(_:)-7d127) Returns a new vector from the specified three-element vector, and other elements undefined. [`simd_make_double8_undef(_:)`](/documentation/simd/simd_make_double8_undef(_:)-7md0u) Returns a new vector from the specified four-element vector, and other elements undefined. ### Functions to Create Eight-Element Vectors From Scalar Values [`simd_make_double8(_:)`](/documentation/simd/simd_make_double8(_:)-56g8y) Returns a new vector with the first element set to a scalar value, and other elements set to zero. [`simd_make_double8_undef(_:)`](/documentation/simd/simd_make_double8_undef(_:)-5rmk5) 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_double`](/documentation/simd/simd_double-62zne) Returns a new vector from the specified vector of 8-bit, signed-integer elements. [`simd_double`](/documentation/simd/simd_double-639kq) Returns a new vector from the specified vector of 8-bit, unsigned-integer elements. [`simd_double`](/documentation/simd/simd_double-634oq) Returns a new vector from the specified vector of 16-bit, signed-integer elements. [`simd_double`](/documentation/simd/simd_double-63eii) Returns a new vector from the specified vector of 16-bit, unsigned-integer elements. [`simd_double`](/documentation/simd/simd_double-631ha) Returns a new vector from the specified vector of 32-bit, signed-integer elements. [`simd_double`](/documentation/simd/simd_double-63bi6) Returns a new vector from the specified vector of 32-bit, unsigned-integer elements. [`simd_double`](/documentation/simd/simd_double-63332) Returns a new vector from the specified vector of 64-bit, signed-integer elements. [`simd_double`](/documentation/simd/simd_double-63d26) Returns a new vector from the specified vector of 64-bit, unsigned-integer elements. [`simd_double`](/documentation/simd/simd_double-63b6q) Returns a new vector from the specified vector of 32-bit, floating-point elements. [`simd_double`](/documentation/simd/simd_double-63agu) Returns a new vector from the specified vector of 64-bit, floating-point elements. ### Common Functions [`simd_abs(_:)`](/documentation/simd/simd_abs(_:)-7p0dw) Returns the absolute value of each element in a vector. [`simd_clamp(_:_:_:)`](/documentation/simd/simd_clamp(_:_:_:)-q88m) Returns each element in a vector clamped to a specified range. [`simd_equal(_:_:)`](/documentation/simd/simd_equal(_:_:)-8pk1m) 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(_:)-3jcfd) Returns the fractional part of each element in a vector. [`simd_sign(_:)`](/documentation/simd/simd_sign(_:)-7hb8r) Returns the sign of each element in a vector. [`simd_step(_:_:)`](/documentation/simd/simd_step(_:_:)-1vckv) Returns zero for each element in a vector less than a specified edge, and otherwise returns one. ### Reduce Functions [`simd_reduce_min(_:)`](/documentation/simd/simd_reduce_min(_:)-3ode2) Returns the miniumum value in a vector. [`simd_reduce_max(_:)`](/documentation/simd/simd_reduce_max(_:)-55eqq) Returns the maximum value in a vector. [`simd_reduce_add(_:)`](/documentation/simd/simd_reduce_add(_:)-3aymg) Returns the sum of all elements in a vector. ### Interpolation Functions [`simd_smoothstep(_:_:_:)`](/documentation/simd/simd_smoothstep(_:_:_:)-99l4q) Returns an element-wise smoothly interpolated value between two vectors. [`simd_mix(_:_:_:)`](/documentation/simd/simd_mix(_:_:_:)-5afwd) Returns an element-wise linearly interpolated value between two vectors. ### Extrema Functions [`simd_min(_:_:)`](/documentation/simd/simd_min(_:_:)-6beor) Returns the minimum value of each element in a vector. [`simd_max(_:_:)`](/documentation/simd/simd_max(_:_:)-65po6) Returns the maximum value of each element in a vector. ### Reciprocal and Reciprocal Square Root Functions [`simd_recip(_:)`](/documentation/simd/simd_recip(_:)-98afu) Returns the reciprocal of each element in a vector. [`simd_fast_recip(_:)`](/documentation/simd/simd_fast_recip(_:)-16f97) Returns the fast reciprocal of each element in a vector. [`simd_precise_recip(_:)`](/documentation/simd/simd_precise_recip(_:)-74cqq) Returns the precise reciprocal of each element in a vector. [`simd_rsqrt(_:)`](/documentation/simd/simd_rsqrt(_:)-1ojpy) Returns the reciprocal square root of each element in a vector. [`simd_fast_rsqrt(_:)`](/documentation/simd/simd_fast_rsqrt(_:)-922us) Returns the fast reciprocal square root of each element in a vector. [`simd_precise_rsqrt(_:)`](/documentation/simd/simd_precise_rsqrt(_:)-1hq00) Returns the precise reciprocal square root of each element in a vector. ### Exponential and Logarithmic Functions [`exp(_:)`](/documentation/simd/exp(_:)-69tin) Returns *e* raised to the power of each element in a vector. [`exp2(_:)`](/documentation/simd/exp2(_:)-4m3mb) Returns 2 raised to the power of each element in a vector. [`exp10(_:)`](/documentation/simd/exp10(_:)-39f7r) Returns 10 raised to the power of each element in a vector. [`expm1(_:)`](/documentation/simd/expm1(_:)-8nn5x) Returns *eˣ-1* for each element in a vector. [`log(_:)`](/documentation/simd/log(_:)-7649l) Returns the natural logarithm of each element in a vector. [`log2(_:)`](/documentation/simd/log2(_:)-8k8nf) Returns the base 2 logarithm of each element in a vector. [`log10(_:)`](/documentation/simd/log10(_:)-24ung) Returns the base 10 logarithm of each element in a vector. [`log1p(_:)`](/documentation/simd/log1p(_:)-3fdfb) Returns *log(1+x)* of each element in a vector. ### Geometry Functions [`simd_dot`](/documentation/simd/simd_dot-5vlda) Returns the dot product of two vectors. [`simd_normalize`](/documentation/simd/simd_normalize-yjr) 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-8x3pc) Returns the fast normalized vector. [`simd_precise_normalize`](/documentation/simd/simd_precise_normalize-6237w) Returns the precise normalized vector. [`simd_project`](/documentation/simd/simd_project-8o56y) Returns the first vector projected onto the second vector. [`simd_fast_project`](/documentation/simd/simd_fast_project-61mm1) Returns the fast projected vector. [`simd_precise_project`](/documentation/simd/simd_precise_project-2x3bb) Returns the precise projected vector. ### Vector Norm Functions [`simd_norm_one`](/documentation/simd/simd_norm_one-fgqf) Returns the sum of the absolute values of a vector. [`simd_norm_inf`](/documentation/simd/simd_norm_inf-9maca) Returns the maximum absolute value of a vector. ### Length and Distance Functions [`simd_length`](/documentation/simd/simd_length-32x7b) Returns the length of a vector. [`simd_fast_length`](/documentation/simd/simd_fast_length-5utvc) Returns the fast length of a vector. [`simd_precise_length`](/documentation/simd/simd_precise_length-67k0i) Returns the precise length of a vector. [`simd_length_squared`](/documentation/simd/simd_length_squared-3x9ip) Returns the square of the length of a vector. [`simd_distance`](/documentation/simd/simd_distance-8f8o) Returns the distance between two vectors. [`simd_fast_distance`](/documentation/simd/simd_fast_distance-9mi5e) Returns the fast distance between two vectors. [`simd_precise_distance`](/documentation/simd/simd_precise_distance-82p17) Returns the precise distance between two vectors. [`simd_distance_squared`](/documentation/simd/simd_distance_squared-4kl6l) Returns the square of the distance between two vectors. ### Hyperbolic Functions [`acosh(_:)`](/documentation/simd/acosh(_:)-2zf9d) Returns the inverse hyperbolic cosine of each element in a vector. [`asinh(_:)`](/documentation/simd/asinh(_:)-5vu4r) Returns the inverse hyperbolic sine of each element in a vector. [`atanh(_:)`](/documentation/simd/atanh(_:)-d3b3) Returns the inverse hyperbolic tangent of each element in a vector. [`cosh(_:)`](/documentation/simd/cosh(_:)-1g57o) Returns the hyperbolic cosine of each element in a vector. [`sinh(_:)`](/documentation/simd/sinh(_:)-ip9w) Returns the hyperbolic sine of each element in a vector. [`tanh(_:)`](/documentation/simd/tanh(_:)-1ag6z) Returns the hyperbolic tangent of each element in a vector. ### Logic Functions [`simd_select(_:_:_:)`](/documentation/simd/simd_select(_:_:_:)-8wti7) 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(_:_:_:)-1yj5q) Returns a vector that contains elements from either the first or second parameter, based on the corresponding element in the third parameter. ### Math Functions [`cbrt(_:)`](/documentation/simd/cbrt(_:)-9dsjc) Returns the cube root of each element in a vector. [`erf(_:)`](/documentation/simd/erf(_:)-293ey) Returns the error function for each element in a vector. [`erfc(_:)`](/documentation/simd/erfc(_:)-vzkw) Returns the complementary error function for each element in a vector. [`fma(_:_:_:)`](/documentation/simd/fma(_:_:_:)-95vfo) Returns the multiply-add result for corresponding elements in three vectors. [`fmod(_:_:)`](/documentation/simd/fmod(_:_:)-7g7m) Returns the modulus after dividing each element in a vector by the corresponding element in a second vector. [`hypot(_:_:)`](/documentation/simd/hypot(_:_:)-8vke8) Returns the hypotenuse of a right-angled triangle with the sides that are adjacent to the right angle that two vectors define. [`lgamma(_:)`](/documentation/simd/lgamma(_:)-7t6g8) Returns the natural logarithm of the absolute value of the gamma function of each element in a vector. [`nextafter(_:_:)`](/documentation/simd/nextafter(_:_:)-2xerr) Returns the next representable value of each element in a vector in the direction of the corresponding element in a second vector. [`pow(_:_:)`](/documentation/simd/pow(_:_:)-9xmzf) Returns each element in a vector raised to the power of the corresponding element in a second vector. [`remainder(_:_:)`](/documentation/simd/remainder(_:_:)-326ci) Returns the remainder after dividing each element in an array by the corresponding element in a second array of double-precision values. [`round(_:)`](/documentation/simd/round(_:)-7t6q) Returns each element in a vector rounded to the nearest integer. [`simd_muladd(_:_:_:)`](/documentation/simd/simd_muladd(_:_:_:)-2vs0c) Returns the multiply-add result for corresponding elements in three vectors. [`tgamma(_:)`](/documentation/simd/tgamma(_:)-8qiri) Returns the gamma function for each element in a vector. ### Trigonometric Functions [`acos(_:)`](/documentation/simd/acos(_:)-2141m) Returns the arccosine of each element in a vector. [`asin(_:)`](/documentation/simd/asin(_:)-78d03) Returns the arcsine of each element in a vector. [`atan(_:)`](/documentation/simd/atan(_:)-7b52p) Returns the arctangent of each element in a vector. [`atan2(_:_:)`](/documentation/simd/atan2(_:_:)-8pfg9) Returns the arctangent of each pair of corresponding elements in two vectors. [`cos(_:)`](/documentation/simd/cos(_:)-7bqey) Returns the cosine of each element in a vector. [`cospi(_:)`](/documentation/simd/cospi(_:)-8d55q) Returns the cosine of each element in a vector multiplied by pi. [`sin(_:)`](/documentation/simd/sin(_:)-1joh9) Returns the sine of each element in a vector. [`sinpi(_:)`](/documentation/simd/sinpi(_:)-9tdix) Returns the sine of each element in a vector multiplied by pi. [`sincos(_:)`](/documentation/simd/sincos(_:)-3iwed) Returns the sine and cosine of each element in a vector. [`sincospi(_:)`](/documentation/simd/sincospi(_:)-5yfry) Returns the sine and cosine of each element in a vector multiplied by pi. [`tan(_:)`](/documentation/simd/tan(_:)-7a2xj) Returns the tangent of each element in a vector. [`tanpi(_:)`](/documentation/simd/tanpi(_:)-3lobh) Returns the tangent of each element in a vector multiplied by pi. ### Classification Functions [`isfinite(_:)`](/documentation/simd/isfinite(_:)-9iwij) Returns true for each element that is finite in a vector. [`isinf(_:)`](/documentation/simd/isinf(_:)-5i1uj) Returns true for each element that is infinite in a vector. [`isnan(_:)`](/documentation/simd/isnan(_:)-90lcg) Returns true for each element that is not a number (NaN) in a vector. [`isnormal(_:)`](/documentation/simd/isnormal(_:)-7lk2x) Returns true for each element that is normal in a vector. ### Alternative Type Alias [`vector_double8`](/documentation/simd/vector_double8) --- 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)