Using the vector libraries
If you want to explicitly call any
of the MASS vector functions, you can do so by including massv.h in your source
files and linking your application with the appropriate vector library.
Information about linking is provided in Compiling and linking a program with MASS.
- libmassv.a
- The generic vector library that runs on any supported POWER® processor. Unless your application requires this portability, use the appropriate architecture-specific library below for maximum performance.
- libmassvp8.a
- Contains functions that have been tuned for the POWER8® architecture.
The single-precision and double-precision floating-point functions contained in the vector libraries are summarized in Table 1. The integer functions contained in the vector libraries are summarized in Table 2. Note that in C and C++ applications, only call by reference is supported, even for scalar arguments.
With the exception of a few functions (described in the following
paragraph), all of the floating-point functions in the vector libraries
accept three parameters:
- A double-precision (for double-precision functions) or single-precision (for single-precision functions) vector output parameter
- A double-precision (for double-precision functions) or single-precision (for single-precision functions) vector input parameter
- An integer vector-length parameter.
function_name (y,x,n)#include <massv.h>
double x[500], y[500];
int n;
n = 500;
...
vexp (y, x, &n);The functions vdiv, vsincos, vpow, and vatan2 (and their single-precision versions, vsdiv, vssincos, vspow, and vsatan2) take four arguments. The functions vdiv, vpow, and vatan2 take the arguments (z,x,y,n). The function vdiv outputs a vector z whose elements are x[i]/y[i], where i=0,..,*n–1. The function vpow outputs a vector z whose elements are x[i]y[i], where i=0,..,*n–1. The function vatan2 outputs a vector z whose elements are atan(x[i]/y[i]), where i=0,..,*n–1. The function vsincos takes the arguments (y,z,x,n), and outputs two vectors, y and z, whose elements are sin(x[i]) and cos(x[i]), respectively.
In vcosisin(y,x,n) and vscosisin(y,x,n), x is a vector of n elements and the function outputs a vector y of n __Complex elements of the form (cos(x[i]),sin(x[i])).
| Double-precision function | Single-precision function | Description | Double-precision function prototype | Single-precision function prototype |
|---|---|---|---|---|
| vacos | vsacos | Sets y[i] to the arc cosine of x[i], for i=0,..,*n-1 | void vacos (double y[], double x[], int *n); | void vsacos (float y[], float x[], int *n); |
| vacosh | vsacosh | Sets y[i] to the hyperbolic arc cosine of x[i], for i=0,..,*n-1 | void vacosh (double y[], double x[], int *n); | void vsacosh (float y[], float x[], int *n); |
| vasin | vsasin | Sets y[i] to the arc sine of x[i], for i=0,..,*n-1 | void vasin (double y[], double x[], int *n); | void vsasin (float y[], float x[], int *n); |
| vasinh | vsasinh | Sets y[i] to the hyperbolic arc sine of x[i], for i=0,..,*n-1 | void vasinh (double y[], double x[], int *n); | void vsasinh (float y[], float x[], int *n); |
| vatan2 | vsatan2 | Sets z[i] to the arc tangent of x[i]/y[i], for i=0,..,*n-1 | void vatan2 (double z[], double x[], double y[], int *n); | void vsatan2 (float z[], float x[], float y[], int *n); |
| vatanh | vsatanh | Sets y[i] to the hyperbolic arc tangent of x[i], for i=0,..,*n-1 | void vatanh (double y[], double x[], int *n); | void vsatanh (float y[], float x[], int *n); |
| vcbrt | vscbrt | Sets y[i] to the cube root of x[i], for i=0,..,*n-1 | void vcbrt (double y[], double x[], int *n); | void vscbrt (float y[], float x[], int *n); |
| vcos | vscos | Sets y[i] to the cosine of x[i], for i=0,..,*n-1 | void vcos (double y[], double x[], int *n); | void vscos (float y[], float x[], int *n); |
| vcosh | vscosh | Sets y[i] to the hyperbolic cosine of x[i], for i=0,..,*n-1 | void vcosh (double y[], double x[], int *n); | void vscosh (float y[], float x[], int *n); |
| vcosisin | vscosisin | Sets the real part of y[i] to the cosine of x[i] and the imaginary part of y[i] to the sine of x[i], for i=0,..,*n-1 | void vcosisin (double _Complex y[], double x[], int *n); | void vscosisin (float _Complex y[], float x[], int *n); |
| vdint | Sets y[i] to the integer truncation of x[i], for i=0,..,*n-1 | void vdint (double y[], double x[], int *n); | ||
| vdiv | vsdiv | Sets z[i] to x[i]/y[i], for i=0,..,*n–1 | void vdiv (double z[], double x[], double y[], int *n); | void vsdiv (float z[], float x[], float y[], int *n); |
| vdnint | Sets y[i] to the nearest integer to x[i], for i=0,..,*n-1 | void vdnint (double y[], double x[], int *n); | ||
| verf | vserf | Sets y[i] to the error function of x[i], for i=0,..,*n-1 | void verf (double y[], double x[], int *n) | void vserf (float y[], float x[], int *n) |
| verfc | vserfc | Sets y[i] to the complimentary error function of x[i], for i=0,..,*n-1 | void verfc (double y[], double x[], int *n) | void vserfc (float y[], float x[], int *n) |
| vexp | vsexp | Sets y[i] to the exponential function of x[i], for i=0,..,*n-1 | void vexp (double y[], double x[], int *n); | void vsexp (float y[], float x[], int *n); |
| vexp2 | vsexp2 | Sets y[i] to 2 raised to the power of x[i], for i=1,..,*n-1 | void vexp2 (double y[], double x[], int *n); | void vsexp2 (float y[], float x[], int *n); |
| vexpm1 | vsexpm1 | Sets y[i] to (the exponential function of x[i])-1, for i=0,..,*n-1 | void vexpm1 (double y[], double x[], int *n); | void vsexpm1 (float y[], float x[], int *n); |
| vexp2m1 | vsexp2m1 | Sets y[i] to (2 raised to the power of x[i]) - 1, for i=1,..,*n-1 | void vexp2m1 (double y[], double x[], int *n); | void vsexp2m1 (float y[], float x[], int *n); |
| vhypot | vshypot | Sets z[i] to the square root of the sum of the squares of x[i] and y[i], for i=0,..,*n-1 | void vhypot (double z[], double x[], double y[], int *n) | void vshypot (float z[], float x[], float y[], int *n) |
| vlog | vslog | Sets y[i] to the natural logarithm of x[i], for i=0,..,*n-1 | void vlog (double y[], double x[], int *n); | void vslog (float y[], float x[], int *n); |
| vlog2 | vslog2 | Sets y[i] to the base-2 logarithm of x[i], for i=1,..,*n-1 | void vlog2 (double y[], double x[], int *n); | void vslog2 (float y[], float x[], int *n); |
| vlog10 | vslog10 | Sets y[i] to the base-10 logarithm of x[i], for i=0,..,*n-1 | void vlog10 (double y[], double x[], int *n); | void vslog10 (float y[], float x[], int *n); |
| vlog1p | vslog1p | Sets y[i] to the natural logarithm of (x[i]+1), for i=0,..,*n-1 | void vlog1p (double y[], double x[], int *n); | void vslog1p (float y[], float x[], int *n); |
| vlog21p | vslog21p | Sets y[i] to the base-2 logarithm of (x[i]+1), for i=1,..,*n-1 | void vlog21p (double y[], double x[], int *n); | void vslog21p (float y[], float x[], int *n); |
| vpow | vspow | Sets z[i] to x[i] raised to the power y[i], for i=0,..,*n-1 | void vpow (double z[], double x[], double y[], int *n); | void vspow (float z[], float x[], float y[], int *n); |
| vqdrt | vsqdrt | Sets y[i] to the fourth root of x[i], for i=0,..,*n-1 | void vqdrt (double y[], double x[], int *n); | void vsqdrt (float y[], float x[], int *n); |
| vrcbrt | vsrcbrt | Sets y[i] to the reciprocal of the cube root of x[i], for i=0,..,*n-1 | void vrcbrt (double y[], double x[], int *n); | void vsrcbrt (float y[], float x[], int *n); |
| vrec | vsrec | Sets y[i] to the reciprocal of x[i], for i=0,..,*n-1 | void vrec (double y[], double x[], int *n); | void vsrec (float y[], float x[], int *n); |
| vrqdrt | vsrqdrt | Sets y[i] to the reciprocal of the fourth root of x[i], for i=0,..,*n-1 | void vrqdrt (double y[], double x[], int *n); | void vsrqdrt (float y[], float x[], int *n); |
| vrsqrt | vsrsqrt | Sets y[i] to the reciprocal of the square root of x[i], for i=0,..,*n-1 | void vrsqrt (double y[], double x[], int *n); | void vsrsqrt (float y[], float x[], int *n); |
| vsin | vssin | Sets y[i] to the sine of x[i], for i=0,..,*n-1 | void vsin (double y[], double x[], int *n); | void vssin (float y[], float x[], int *n); |
| vsincos | vssincos | Sets y[i] to the sine of x[i] and z[i] to the cosine of x[i], for i=0,..,*n-1 | void vsincos (double y[], double z[], double x[], int *n); | void vssincos (float y[], float z[], float x[], int *n); |
| vsinh | vssinh | Sets y[i] to the hyperbolic sine of x[i], for i=0,..,*n-1 | void vsinh (double y[], double x[], int *n); | void vssinh (float y[], float x[], int *n); |
| vsqrt | vssqrt | Sets y[i] to the square root of x[i], for i=0,..,*n-1 | void vsqrt (double y[], double x[], int *n); | void vssqrt (float y[], float x[], int *n); |
| vtan | vstan | Sets y[i] to the tangent of x[i], for i=0,..,*n-1 | void vtan (double y[], double x[], int *n); | void vstan (float y[], float x[], int *n); |
| vtanh | vstanh | Sets y[i] to the hyperbolic tangent of x[i], for i=0,..,*n-1 | void vtanh (double y[], double x[], int *n); | void vstanh (float y[], float x[], int *n); |
Integer functions are of the form function_name (x[], *n), where x[] is a vector of 4-byte (for vpopcnt4) or 8-byte (for vpopcnt8) numeric objects (integral or floating-point), and *n is the vector length.
| Function | Description | Prototype |
|---|---|---|
| vpopcnt4 | Returns the total number of 1 bits in the concatenation of the binary representation of x[i], for i=0,..,*n–1 , where x is a vector of 32-bit objects. | unsigned int vpopcnt4 (void *x, int *n) |
| vpopcnt8 | Returns the total number of 1 bits in the concatenation of the binary representation of x[i], for i=0,..,*n–1 , where x is a vector of 64-bit objects. | unsigned int vpopcnt8 (void *x, int *n) |
Overlap of input and output vectors
In most applications, the MASS vector
functions are called with disjoint input and output vectors; that
is, the two vectors do not overlap in memory. Another common usage
scenario is to call them with the same vector for both input and output
parameters (for example, vsin (y, y, &n)). Other kinds of overlap (where input and output vectors
are neither disjoint nor identical) should be avoided, since they
might produce unexpected results:
- For calls to vector functions that take one input and one output
vector (for example, vsin (y, x, &n)):
The vectors x[0:n-1] and y[0:n-1] must be either disjoint or identical, or unexpected results might be obtained.
- For calls to vector functions that take two input vectors (for
example, vatan2 (y, x1, x2, &n)):
The previous restriction applies to both pairs of vectors y,x1 and y,x2. That is, y[0:n-1] and x1[0:n-1] must be either disjoint or identical; and y[0:n-1] and x2[0:n-1] must be either disjoint or identical.
- For calls to vector functions that take two output vectors (for
example, vsincos (y1, y2, x, &n)):
The above restriction applies to both pairs of vectors y1,x and y2,x. That is, y1[0:n-1] and x[0:n-1] must be either disjoint or identical; and y2[0:n-1] and x[0:n-1] must be either disjoint or identical. Also, the vectors y1[0:n-1] and y2[0:n-1] must be disjoint.
Alignment of input and output vectors
To get the best performance from the POWER8 vector libraries, align the input and output vectors on 8-byte (or better, 16-byte) boundaries.
Consistency of MASS vector functions
All the functions in the MASS vector libraries are consistent, in the sense that a given input value will always produce the same result, regardless of its position in the vector, and regardless of the vector length.
Related external information
