Math functions required by win32k

svn path=/trunk/; revision=1199

reactos/subsys/win32k/misc/math.c

@@ -0,0 +1,209 @@
+/* Math functions for i387.
+   Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by John C. Bowman <bowman@ipp-garching.mpg.de>, 1995.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+
+double atan (double __x);
+double atan2 (double __y, double __x);
+double ceil (double __x);
+double cos (double __x);
+double fabs (double __x);
+double floor (double __x);
+long _ftol (double fl);
+double log (double __x);
+double __log2 (double __x);
+double pow (double __x, double __y);
+double sin (double __x);
+double sqrt (double __x);
+double tan (double __x);
+
+
+double atan (double __x)
+{
+  register double __value;
+  __asm __volatile__
+    ("fld1\n\t"
+     "fpatan"
+     : "=t" (__value) : "0" (__x));
+
+  return __value;
+}
+
+double atan2 (double __y, double __x)
+{
+  register double __value;
+  __asm __volatile__
+    ("fpatan\n\t"
+     "fld %%st(0)"
+     : "=t" (__value) : "0" (__x), "u" (__y));
+
+  return __value;
+}
+
+double ceil (double __x)
+{
+  register double __value;
+  __volatile unsigned short int __cw, __cwtmp;
+
+  __asm __volatile ("fnstcw %0" : "=m" (__cw));
+  __cwtmp = (__cw & 0xf3ff) | 0x0800; /* rounding up */
+  __asm __volatile ("fldcw %0" : : "m" (__cwtmp));
+  __asm __volatile ("frndint" : "=t" (__value) : "0" (__x));
+  __asm __volatile ("fldcw %0" : : "m" (__cw));
+
+  return __value;
+}
+
+double cos (double __x)
+{
+  register double __value;
+  __asm __volatile__
+    ("fcos"
+     : "=t" (__value): "0" (__x));
+
+  return __value;
+}
+
+double fabs (double __x)
+{
+  register double __value;
+  __asm __volatile__
+    ("fabs"
+     : "=t" (__value) : "0" (__x));
+
+  return __value;
+}
+
+double floor (double __x)
+{
+  register double __value;
+  __volatile unsigned short int __cw, __cwtmp;
+
+  __asm __volatile ("fnstcw %0" : "=m" (__cw));
+  __cwtmp = (__cw & 0xf3ff) | 0x0400; /* rounding down */
+  __asm __volatile ("fldcw %0" : : "m" (__cwtmp));
+  __asm __volatile ("frndint" : "=t" (__value) : "0" (__x));
+  __asm __volatile ("fldcw %0" : : "m" (__cw));
+
+  return __value;
+}
+
+long _ftol (double fl)
+{
+  return (long)fl;
+}
+
+double log (double __x)
+{
+  register double __value;
+  __asm __volatile__
+    ("fldln2\n\t"
+     "fxch\n\t"
+     "fyl2x"
+     : "=t" (__value) : "0" (__x));
+
+  return __value;
+}
+
+double __log2 (double __x)
+{
+  register double __value;
+  __asm __volatile__
+    ("fld1\n\t"
+     "fxch\n\t"
+     "fyl2x"
+     : "=t" (__value) : "0" (__x));
+
+  return __value;
+}
+
+double pow (double __x, double __y)
+{
+  register double __value, __exponent;
+  long __p = (long) __y;
+
+  if (__x == 0.0 && __y > 0.0)
+    return 0.0;
+  if (__y == (double) __p)
+    {
+      double __r = 1.0;
+      if (__p == 0)
+        return 1.0;
+      if (__p < 0)
+        {
+          __p = -__p;
+          __x = 1.0 / __x;
+        }
+      while (1)
+        {
+          if (__p & 1)
+            __r *= __x;
+          __p >>= 1;
+          if (__p == 0)
+            return __r;
+          __x *= __x;
+        }
+      /* NOTREACHED */
+    }
+  __asm __volatile__
+    ("fmul      %%st(1)         # y * log2(x)\n\t"
+     "fst       %%st(1)\n\t"
+     "frndint                   # int(y * log2(x))\n\t"
+     "fxch\n\t"
+     "fsub      %%st(1)         # fract(y * log2(x))\n\t"
+     "f2xm1                     # 2^(fract(y * log2(x))) - 1\n\t"
+     : "=t" (__value), "=u" (__exponent) :  "0" (__log2 (__x)), "1" (__y));
+  __value += 1.0;
+  __asm __volatile__
+    ("fscale"
+     : "=t" (__value) : "0" (__value), "u" (__exponent));
+
+  return __value;
+}
+
+double sin (double __x)
+{
+  register double __value;
+  __asm __volatile__
+    ("fsin"
+     : "=t" (__value) : "0" (__x));
+
+  return __value;
+}
+
+double sqrt (double __x)
+{
+  register double __value;
+  __asm __volatile__
+    ("fsqrt"
+     : "=t" (__value) : "0" (__x));
+
+  return __value;
+}
+
+double tan (double __x)
+{
+  register double __value;
+  register double __value2 __attribute__ ((unused));
+  __asm __volatile__
+    ("fptan"
+     : "=t" (__value2), "=u" (__value) : "0" (__x));
+
+  return __value;
+}