Intel® C++ Compiler Classic Developer Guide and Reference

ID 767249
Date 7/13/2023
Public
Document Table of Contents

_mm_atan2_pd, _mm256_atan2_pd

Calculates the inverse tangent of float64 variables x and y. Vector variant of atan2(x, y) function for a 128-bit/256-bit vector argument of float64 values.

Syntax

extern __m128d _mm_atan2_pd(__m128d v1, __m128 v2);

extern __m256d _mm256_atan2_pd(__m256d v1, __m256 v2);

Arguments

v1

vector with float64 values

v2

vector with float64 values

Description

Calculates the arc tangent of corresponding float64 elements of vectors v1 and v2. The following is an illustration of the atan2 operation:

Res[0]  = atan2(v1[0], v2[0])
Res[1]  = atan2(v1[1], v2[1])
Res[2]  = atan2(v1[2], v2[2])
Res[15] = atan2(v1[15], v2[15])
...

NOTE:

This calculation is similar to calculating the arc tangent of y / x, except that the signs of both arguments are used to determine the quadrant of the result.

Returns

Result of the bitwise operation.

NOTE:

Many routines in the Short Vector Math Library (SVML) are more optimized for Intel® microprocessors than for non-Intel microprocessors.