]> Zhao Yanbai Git Server - minix.git/commitdiff
Original imported versions of s_rint.c and math_private.h.
authorBen Gras <ben@minix3.org>
Tue, 11 Dec 2007 12:32:26 +0000 (12:32 +0000)
committerBen Gras <ben@minix3.org>
Tue, 11 Dec 2007 12:32:26 +0000 (12:32 +0000)
lib/math/math_private.h [new file with mode: 0644]
lib/math/s_rint.c [new file with mode: 0644]

diff --git a/lib/math/math_private.h b/lib/math/math_private.h
new file mode 100644 (file)
index 0000000..d865d1f
--- /dev/null
@@ -0,0 +1,272 @@
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+/*
+ * from: @(#)fdlibm.h 5.1 93/09/24
+ * $FreeBSD: src/lib/msun/src/math_private.h,v 1.17.2.2 2007/06/13 18:17:25 bde Exp $
+ */
+
+#ifndef _MATH_PRIVATE_H_
+#define        _MATH_PRIVATE_H_
+
+#include <sys/types.h>
+#include <machine/endian.h>
+
+/*
+ * The original fdlibm code used statements like:
+ *     n0 = ((*(int*)&one)>>29)^1;             * index of high word *
+ *     ix0 = *(n0+(int*)&x);                   * high word of x *
+ *     ix1 = *((1-n0)+(int*)&x);               * low word of x *
+ * to dig two 32 bit words out of the 64 bit IEEE floating point
+ * value.  That is non-ANSI, and, moreover, the gcc instruction
+ * scheduler gets it wrong.  We instead use the following macros.
+ * Unlike the original code, we determine the endianness at compile
+ * time, not at run time; I don't see much benefit to selecting
+ * endianness at run time.
+ */
+
+/*
+ * A union which permits us to convert between a double and two 32 bit
+ * ints.
+ */
+
+#if BYTE_ORDER == BIG_ENDIAN
+
+typedef union
+{
+  double value;
+  struct
+  {
+    u_int32_t msw;
+    u_int32_t lsw;
+  } parts;
+} ieee_double_shape_type;
+
+#endif
+
+#if BYTE_ORDER == LITTLE_ENDIAN
+
+typedef union
+{
+  double value;
+  struct
+  {
+    u_int32_t lsw;
+    u_int32_t msw;
+  } parts;
+} ieee_double_shape_type;
+
+#endif
+
+/* Get two 32 bit ints from a double.  */
+
+#define EXTRACT_WORDS(ix0,ix1,d)                               \
+do {                                                           \
+  ieee_double_shape_type ew_u;                                 \
+  ew_u.value = (d);                                            \
+  (ix0) = ew_u.parts.msw;                                      \
+  (ix1) = ew_u.parts.lsw;                                      \
+} while (0)
+
+/* Get the more significant 32 bit int from a double.  */
+
+#define GET_HIGH_WORD(i,d)                                     \
+do {                                                           \
+  ieee_double_shape_type gh_u;                                 \
+  gh_u.value = (d);                                            \
+  (i) = gh_u.parts.msw;                                                \
+} while (0)
+
+/* Get the less significant 32 bit int from a double.  */
+
+#define GET_LOW_WORD(i,d)                                      \
+do {                                                           \
+  ieee_double_shape_type gl_u;                                 \
+  gl_u.value = (d);                                            \
+  (i) = gl_u.parts.lsw;                                                \
+} while (0)
+
+/* Set a double from two 32 bit ints.  */
+
+#define INSERT_WORDS(d,ix0,ix1)                                        \
+do {                                                           \
+  ieee_double_shape_type iw_u;                                 \
+  iw_u.parts.msw = (ix0);                                      \
+  iw_u.parts.lsw = (ix1);                                      \
+  (d) = iw_u.value;                                            \
+} while (0)
+
+/* Set the more significant 32 bits of a double from an int.  */
+
+#define SET_HIGH_WORD(d,v)                                     \
+do {                                                           \
+  ieee_double_shape_type sh_u;                                 \
+  sh_u.value = (d);                                            \
+  sh_u.parts.msw = (v);                                                \
+  (d) = sh_u.value;                                            \
+} while (0)
+
+/* Set the less significant 32 bits of a double from an int.  */
+
+#define SET_LOW_WORD(d,v)                                      \
+do {                                                           \
+  ieee_double_shape_type sl_u;                                 \
+  sl_u.value = (d);                                            \
+  sl_u.parts.lsw = (v);                                                \
+  (d) = sl_u.value;                                            \
+} while (0)
+
+/*
+ * A union which permits us to convert between a float and a 32 bit
+ * int.
+ */
+
+typedef union
+{
+  float value;
+  /* FIXME: Assumes 32 bit int.  */
+  unsigned int word;
+} ieee_float_shape_type;
+
+/* Get a 32 bit int from a float.  */
+
+#define GET_FLOAT_WORD(i,d)                                    \
+do {                                                           \
+  ieee_float_shape_type gf_u;                                  \
+  gf_u.value = (d);                                            \
+  (i) = gf_u.word;                                             \
+} while (0)
+
+/* Set a float from a 32 bit int.  */
+
+#define SET_FLOAT_WORD(d,i)                                    \
+do {                                                           \
+  ieee_float_shape_type sf_u;                                  \
+  sf_u.word = (i);                                             \
+  (d) = sf_u.value;                                            \
+} while (0)
+
+#ifdef _COMPLEX_H
+/*
+ * Inline functions that can be used to construct complex values.
+ *
+ * The C99 standard intends x+I*y to be used for this, but x+I*y is
+ * currently unusable in general since gcc introduces many overflow,
+ * underflow, sign and efficiency bugs by rewriting I*y as
+ * (0.0+I)*(y+0.0*I) and laboriously computing the full complex product.
+ * In particular, I*Inf is corrupted to NaN+I*Inf, and I*-0 is corrupted
+ * to -0.0+I*0.0.
+ */
+static __inline float complex
+cpackf(float x, float y)
+{
+       float complex z;
+
+       __real__ z = x;
+       __imag__ z = y;
+       return (z);
+}
+
+static __inline double complex
+cpack(double x, double y)
+{
+       double complex z;
+
+       __real__ z = x;
+       __imag__ z = y;
+       return (z);
+}
+
+static __inline long double complex
+cpackl(long double x, long double y)
+{
+       long double complex z;
+
+       __real__ z = x;
+       __imag__ z = y;
+       return (z);
+}
+#endif /* _COMPLEX_H */
+/*
+ * ieee style elementary functions
+ *
+ * We rename functions here to improve other sources' diffability
+ * against fdlibm.
+ */
+#define        __ieee754_sqrt  sqrt
+#define        __ieee754_acos  acos
+#define        __ieee754_acosh acosh
+#define        __ieee754_log   log
+#define        __ieee754_atanh atanh
+#define        __ieee754_asin  asin
+#define        __ieee754_atan2 atan2
+#define        __ieee754_exp   exp
+#define        __ieee754_cosh  cosh
+#define        __ieee754_fmod  fmod
+#define        __ieee754_pow   pow
+#define        __ieee754_lgamma lgamma
+#define        __ieee754_gamma gamma
+#define        __ieee754_lgamma_r lgamma_r
+#define        __ieee754_gamma_r gamma_r
+#define        __ieee754_log10 log10
+#define        __ieee754_sinh  sinh
+#define        __ieee754_hypot hypot
+#define        __ieee754_j0    j0
+#define        __ieee754_j1    j1
+#define        __ieee754_y0    y0
+#define        __ieee754_y1    y1
+#define        __ieee754_jn    jn
+#define        __ieee754_yn    yn
+#define        __ieee754_remainder remainder
+#define        __ieee754_scalb scalb
+#define        __ieee754_sqrtf sqrtf
+#define        __ieee754_acosf acosf
+#define        __ieee754_acoshf acoshf
+#define        __ieee754_logf  logf
+#define        __ieee754_atanhf atanhf
+#define        __ieee754_asinf asinf
+#define        __ieee754_atan2f atan2f
+#define        __ieee754_expf  expf
+#define        __ieee754_coshf coshf
+#define        __ieee754_fmodf fmodf
+#define        __ieee754_powf  powf
+#define        __ieee754_lgammaf lgammaf
+#define        __ieee754_gammaf gammaf
+#define        __ieee754_lgammaf_r lgammaf_r
+#define        __ieee754_gammaf_r gammaf_r
+#define        __ieee754_log10f log10f
+#define        __ieee754_sinhf sinhf
+#define        __ieee754_hypotf hypotf
+#define        __ieee754_j0f   j0f
+#define        __ieee754_j1f   j1f
+#define        __ieee754_y0f   y0f
+#define        __ieee754_y1f   y1f
+#define        __ieee754_jnf   jnf
+#define        __ieee754_ynf   ynf
+#define        __ieee754_remainderf remainderf
+#define        __ieee754_scalbf scalbf
+
+/* fdlibm kernel function */
+int    __ieee754_rem_pio2(double,double*);
+double __kernel_sin(double,double,int);
+double __kernel_cos(double,double);
+double __kernel_tan(double,double,int);
+int    __kernel_rem_pio2(double*,double*,int,int,int,const int*);
+
+/* float versions of fdlibm kernel functions */
+int    __ieee754_rem_pio2f(float,float*);
+float  __kernel_sindf(double);
+float  __kernel_cosdf(double);
+float  __kernel_tandf(double,int);
+int    __kernel_rem_pio2f(float*,float*,int,int,int,const int*);
+
+#endif /* !_MATH_PRIVATE_H_ */
diff --git a/lib/math/s_rint.c b/lib/math/s_rint.c
new file mode 100644 (file)
index 0000000..3454f5f
--- /dev/null
@@ -0,0 +1,87 @@
+/* @(#)s_rint.c 5.1 93/09/24 */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+#ifndef lint
+static char rcsid[] = "$FreeBSD: src/lib/msun/src/s_rint.c,v 1.11.2.1 2007/06/14 05:16:44 bde Exp $";
+#endif
+
+/*
+ * rint(x)
+ * Return x rounded to integral value according to the prevailing
+ * rounding mode.
+ * Method:
+ *     Using floating addition.
+ * Exception:
+ *     Inexact flag raised if x not equal to rint(x).
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+static const double
+TWO52[2]={
+  4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
+ -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */
+};
+
+double
+rint(double x)
+{
+       int32_t i0,j0,sx;
+       u_int32_t i,i1;
+       double w,t;
+       EXTRACT_WORDS(i0,i1,x);
+       sx = (i0>>31)&1;
+       j0 = ((i0>>20)&0x7ff)-0x3ff;
+       if(j0<20) {
+           if(j0<0) {
+               if(((i0&0x7fffffff)|i1)==0) return x;
+               i1 |= (i0&0x0fffff);
+               i0 &= 0xfffe0000;
+               i0 |= ((i1|-i1)>>12)&0x80000;
+               SET_HIGH_WORD(x,i0);
+               w = TWO52[sx]+x;
+               t =  w-TWO52[sx];
+               GET_HIGH_WORD(i0,t);
+               SET_HIGH_WORD(t,(i0&0x7fffffff)|(sx<<31));
+               return t;
+           } else {
+               i = (0x000fffff)>>j0;
+               if(((i0&i)|i1)==0) return x; /* x is integral */
+               i>>=1;
+               if(((i0&i)|i1)!=0) {
+                   /*
+                    * Some bit is set after the 0.5 bit.  To avoid the
+                    * possibility of errors from double rounding in
+                    * w = TWO52[sx]+x, adjust the 0.25 bit to a lower
+                    * guard bit.  We do this for all j0<=51.  The
+                    * adjustment is trickiest for j0==18 and j0==19
+                    * since then it spans the word boundary.
+                    */
+                   if(j0==19) i1 = 0x40000000; else
+                   if(j0==18) i1 = 0x80000000; else
+                   i0 = (i0&(~i))|((0x20000)>>j0);
+               }
+           }
+       } else if (j0>51) {
+           if(j0==0x400) return x+x;   /* inf or NaN */
+           else return x;              /* x is integral */
+       } else {
+           i = ((u_int32_t)(0xffffffff))>>(j0-20);
+           if((i1&i)==0) return x;     /* x is integral */
+           i>>=1;
+           if((i1&i)!=0) i1 = (i1&(~i))|((0x40000000)>>(j0-20));
+       }
+       INSERT_WORDS(x,i0,i1);
+       *(volatile double *)&w = TWO52[sx]+x;   /* clip any extra precision */
+       return w-TWO52[sx];
+}