Using the MASS vector library

The MASS vector library provides a set of functions that compute the same mathematical function for vectors of operands. If you want to explicitly call the MASS vector functions, take the following steps:
  1. Provide the prototypes for the functions by including massv.h in your source files. See the table below for the location of header files.
  2. Link the appropriate library with your application. Names of libraries are described in the following table.
Table 1. Header files and library names for the MASS vector library
System Environment Header file location Library name for zEC12/zBC12 Library name for z13
USS /usr/include/massv.h /usr/lpp/cbclib/lib/libmassv.arch10.a /usr/lpp/cbclib/lib/libmassv.arch11.a
MVS™ CEE.SCEEH.H CBC.SCCNN10 CBC.SCCNN11
Note: MASS vector functions can only run on IBM® zEC12/zBC12/z13 and newer hardware models. A set of libraries tuned for each machine model group are provided.
The single-precision and double-precision floating-point functions contained in the vector library 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 library 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
Except for the special cases listed below, the functions are of the form: 
function_name (y,x,n)
where y is the target vector, x is the source vector, and n is the pointer to the vector length. The parameters y and x are assumed to be double-precision for functions with the prefix v, and single-precision for functions with the prefix vs. For example, the following code: 
#include <massv.h>

double x[500], y[500];
int n;
n = 500;
...
vexp (y, x, &n);
outputs a vector y of length 500 whose elements are exp(x[i]), where i=0,...,499.

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.

Note that some of the MASS floating point vector functions are only available when compiled with ARCHITECTURE(11). These functions are denoted by having a superscript 't' after their name (for example, "functiont" in the following table.)

Table 2. MASS floating-point vector functions
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);
vatant vsatant Sets y[i] to the arc tangent of x[i], for i=0,..,*n-1 void vatan (double y[], double x[], int *n); void vsatan (float y[], float x[], 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);  
verft vserft 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)
verfct vserfct 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);
vexp2t vsexp2t 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);
vexp2m1t vsexp2m1t 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);
vhypott vshypott 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);
vlog2t vslog2t 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);
vlog21pt vslog21pt 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.
Table 3. MASS integer vector functions
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)
Parent topic: Using the Mathematical Acceleration Subsystem (MASS) libraries