Standard Libraries for EDK II.

This set of three packages: AppPkg, StdLib, StdLibPrivateInternalFiles; contains the implementation of libraries based upon non-UEFI standards such as ISO/IEC-9899, the library portion of the C Language Standard, POSIX, etc.

AppPkg contains applications that make use of the standard libraries defined in the StdLib Package.

StdLib contains header (include) files and the implementations of the standard libraries.

StdLibPrivateInternalFiles contains files for the exclusive use of the library implementations in StdLib.  These files should never be directly referenced from applications or other code.


git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@11600 6f19259b-4bc3-4df7-8a09-765794883524

StdLib/LibC/Math/e_fmod.c

@@ -0,0 +1,138 @@
+/* @(#)e_fmod.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.
+ * ====================================================
+ */
+#include  <LibConfig.h>
+#include  <sys/EfiCdefs.h>
+#if defined(LIBM_SCCS) && !defined(lint)
+__RCSID("$NetBSD: e_fmod.c,v 1.11 2002/05/26 22:01:49 wiz Exp $");
+#endif
+
+/*
+ * __ieee754_fmod(x,y)
+ * Return x mod y in exact arithmetic
+ * Method: shift and subtract
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+#if defined(_MSC_VER)           /* Handle Microsoft VC++ compiler specifics. */
+  // unary minus operator applied to unsigned type, result still unsigned
+  #pragma warning ( disable : 4146 )
+#endif
+
+static const double one = 1.0, Zero[] = {0.0, -0.0,};
+
+double
+__ieee754_fmod(double x, double y)
+{
+  int32_t n,hx,hy,hz,ix,iy,sx,i;
+  u_int32_t lx,ly,lz;
+
+  EXTRACT_WORDS(hx,lx,x);
+  EXTRACT_WORDS(hy,ly,y);
+  sx = hx&0x80000000;   /* sign of x */
+  hx ^=sx;    /* |x| */
+  hy &= 0x7fffffff; /* |y| */
+
+    /* purge off exception values */
+  if((hy|ly)==0||(hx>=0x7ff00000)|| /* y=0,or x not finite */
+    ((hy|((ly|-ly)>>31))>0x7ff00000)) /* or y is NaN */
+      return (x*y)/(x*y);
+  if(hx<=hy) {
+      if((hx<hy)||(lx<ly)) return x;  /* |x|<|y| return x */
+      if(lx==ly)
+    return Zero[(u_int32_t)sx>>31]; /* |x|=|y| return x*0*/
+  }
+
+    /* determine ix = ilogb(x) */
+  if(hx<0x00100000) { /* subnormal x */
+      if(hx==0) {
+    for (ix = -1043, i=lx; i>0; i<<=1) ix -=1;
+      } else {
+    for (ix = -1022,i=(hx<<11); i>0; i<<=1) ix -=1;
+      }
+  } else ix = (hx>>20)-1023;
+
+    /* determine iy = ilogb(y) */
+  if(hy<0x00100000) { /* subnormal y */
+      if(hy==0) {
+    for (iy = -1043, i=ly; i>0; i<<=1) iy -=1;
+      } else {
+    for (iy = -1022,i=(hy<<11); i>0; i<<=1) iy -=1;
+      }
+  } else iy = (hy>>20)-1023;
+
+    /* set up {hx,lx}, {hy,ly} and align y to x */
+  if(ix >= -1022)
+      hx = 0x00100000|(0x000fffff&hx);
+  else {    /* subnormal x, shift x to normal */
+      n = -1022-ix;
+      if(n<=31) {
+          hx = (hx<<n)|(lx>>(32-n));
+          lx <<= n;
+      } else {
+    hx = lx<<(n-32);
+    lx = 0;
+      }
+  }
+  if(iy >= -1022)
+      hy = 0x00100000|(0x000fffff&hy);
+  else {    /* subnormal y, shift y to normal */
+      n = -1022-iy;
+      if(n<=31) {
+          hy = (hy<<n)|(ly>>(32-n));
+          ly <<= n;
+      } else {
+    hy = ly<<(n-32);
+    ly = 0;
+      }
+  }
+
+    /* fix point fmod */
+  n = ix - iy;
+  while(n--) {
+      hz=hx-hy;lz=lx-ly; if(lx<ly) hz -= 1;
+      if(hz<0){hx = hx+hx+(lx>>31); lx = lx+lx;}
+      else {
+        if((hz|lz)==0)    /* return sign(x)*0 */
+        return Zero[(u_int32_t)sx>>31];
+        hx = hz+hz+(lz>>31); lx = lz+lz;
+      }
+  }
+  hz=hx-hy;lz=lx-ly; if(lx<ly) hz -= 1;
+  if(hz>=0) {hx=hz;lx=lz;}
+
+    /* convert back to floating value and restore the sign */
+  if((hx|lx)==0)      /* return sign(x)*0 */
+      return Zero[(u_int32_t)sx>>31];
+  while(hx<0x00100000) {    /* normalize x */
+      hx = hx+hx+(lx>>31); lx = lx+lx;
+      iy -= 1;
+  }
+  if(iy>= -1022) {  /* normalize output */
+      hx = ((hx-0x00100000)|((iy+1023)<<20));
+      INSERT_WORDS(x,hx|sx,lx);
+  } else {    /* subnormal output */
+      n = -1022 - iy;
+      if(n<=20) {
+    lx = (lx>>n)|((u_int32_t)hx<<(32-n));
+    hx >>= n;
+      } else if (n<=31) {
+    lx = (hx<<(32-n))|(lx>>n); hx = sx;
+      } else {
+    lx = hx>>(n-32); hx = sx;
+      }
+      INSERT_WORDS(x,hx|sx,lx);
+      x *= one;   /* create necessary signal */
+  }
+  return x;   /* exact output */
+}