freebsd-skq/lib/msun/man/sincos.3
mmel d02641556c Implement sincos, sincosf, and sincosl.
The primary benefit of these functions is that argument
reduction is done once instead of twice in independent
calls to sin() and cos().

* lib/msun/Makefile:
  . Add s_sincos[fl].c to the build.
  . Add sincos.3 documentation.
  . Add appropriate MLINKS.

* lib/msun/Symbol.map:
  . Expose sincos[fl] symbols in dynamic libm.so.

* lib/msun/man/sincos.3:
  . Documentation for sincos[fl].

* lib/msun/src/k_sincos.h:
  . Kernel for sincos() function.  This merges the individual kernels
    for sin() and cos().  The merger offered an opportunity to re-arrange
    the individual kernels for better performance.

* lib/msun/src/k_sincosf.h:
   . Kernel for sincosf() function.  This merges the individual kernels
     for sinf() and cosf(). The merger offered an opportunity to re-arrange
     the individual kernels for better performance.

* lib/msun/src/k_sincosl.h:
   . Kernel for sincosl() function.  This merges the individual kernels
     for sinl() and cosl(). The merger offered an opportunity to re-arrange
     the individual kernels for better performance.

* lib/msun/src/math.h:
  . Add prototytpes for sincos[fl]().

* lib/msun/src/math_private.h:
  . Add RETURNV macros.  This is needed to reset fpsetprec on I386
    hardware for a function with type void.

* lib/msun/src/s_sincos.c:
  . Implementation of sincos() where sin() and cos() were merged into
    one routine and possibly re-arranged for better performance.

* lib/msun/src/s_sincosf.c:
  . Implementation of sincosf() where sinf() and cosf() were merged into
    one routine and possibly re-arranged for better performance.

* lib/msun/src/s_sincosl.c:
  . Implementation of sincosl() where sinl() and cosl() were merged into
    one routine and possibly re-arranged for better performance.

PR:		215977, 218300
Submitted by:	Steven G. Kargl <sgk@troutmask.apl.washington.edu>
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D10765
2017-05-28 06:13:38 +00:00

83 lines
2.4 KiB
Groff

.\" Copyright (c) 2011 Steven G. Kargl.
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.\" $FreeBSD$
.\"
.Dd March 12, 2011
.Dt SINCOS 3
.Os
.Sh NAME
.Nm sincos ,
.Nm sincosf ,
.Nm sincosl
.Nd sine and cosine functions
.Sh LIBRARY
.Lb libm
.Sh SYNOPSIS
.In math.h
.Ft void
.Fn sincos "double x" "double *s" "double *c"
.Ft void
.Fn sincosf "float x" "float *s" "float *c"
.Ft void
.Fn sincosl "long double x" "long double *s" "long double *c"
.Sh DESCRIPTION
The
.Fn sincos ,
.Fn sincosf ,
and
.Fn sincosl
functions compute the sine and cosine of
.Fa x .
Using these functions allows argument reduction to occur only
once instead of twice with individual invocations of
.Fn sin
and
.Fn cos .
Like
.Fn sin
and
.Fn cos ,
a large magnitude argument may yield a result with little
or no significance.
.Sh RETURN VALUES
Upon returning from
.Fn sincos ,
.Fn sincosf ,
and
.Fn sincosl ,
the memory pointed to by
.Ar "*s"
and
.Ar "*c"
are assigned the values of sine and cosine, respectively.
.Sh SEE ALSO
.Xr cos 3 ,
.Xr sin 3 ,
.Sh HISTORY
These functions were added to
.Fx 9.0
to aid in writing various complex function contained in
.St -isoC-99 .