fix hwcap access in powerpc-sf setjmp/longjmp

[musl] / src / math / fmodf.c

diff --git a/src/math/fmodf.c b/src/math/fmodf.c
index 837e937..ff58f93 100644 (file)
--- a/src/math/fmodf.c
+++ b/src/math/fmodf.c
@@ -1,104 +1,65 @@
-/* origin: FreeBSD /usr/src/lib/msun/src/e_fmodf.c */
-/*
- * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
- */
-/*
- * ====================================================
- * 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.
- * ====================================================
- */
-/*
- * fmodf(x,y)
- * Return x mod y in exact arithmetic
- * Method: shift and subtract
- */
-
-#include "libm.h"
-
-static const float Zero[] = {0.0, -0.0,};
+#include <math.h>
+#include <stdint.h>
 
 float fmodf(float x, float y)
 {
-       int32_t n,hx,hy,hz,ix,iy,sx,i;
+       union {float f; uint32_t i;} ux = {x}, uy = {y};
+       int ex = ux.i>>23 & 0xff;
+       int ey = uy.i>>23 & 0xff;
+       uint32_t sx = ux.i & 0x80000000;
+       uint32_t i;
+       uint32_t uxi = ux.i;
 
-       GET_FLOAT_WORD(hx, x);
-       GET_FLOAT_WORD(hy, y);
-       sx = hx & 0x80000000;  /* sign of x */
-       hx ^= sx;              /* |x| */
-       hy &= 0x7fffffff;      /* |y| */
-
-       /* purge off exception values */
-       if (hy == 0 || hx >= 0x7f800000 ||  /* y=0,or x not finite */
-           hy > 0x7f800000)                /* or y is NaN */
+       if (uy.i<<1 == 0 || isnan(y) || ex == 0xff)
                return (x*y)/(x*y);
-       if (hx < hy)                        /* |x| < |y| */
+       if (uxi<<1 <= uy.i<<1) {
+               if (uxi<<1 == uy.i<<1)
+                       return 0*x;
                return x;
-       if (hx == hy)                       /* |x| = |y|, return x*0 */
-               return Zero[(uint32_t)sx>>31];
-
-       /* determine ix = ilogb(x) */
-       if (hx < 0x00800000) {     /* subnormal x */
-               for (ix = -126, i = hx<<8; i > 0; i <<= 1)
-                       ix -= 1;
-       } else
-               ix = (hx>>23) - 127;
-
-       /* determine iy = ilogb(y) */
-       if (hy < 0x00800000) {     /* subnormal y */
-               for (iy = -126, i = hy<<8; i >= 0; i <<= 1)
-                       iy -= 1;
-       } else
-               iy = (hy>>23) - 127;
+       }
 
-       /* set up {hx,lx}, {hy,ly} and align y to x */
-       if (ix >= -126)
-               hx = 0x00800000|(0x007fffff&hx);
-       else {          /* subnormal x, shift x to normal */
-               n = -126-ix;
-               hx = hx<<n;
+       /* normalize x and y */
+       if (!ex) {
+               for (i = uxi<<9; i>>31 == 0; ex--, i <<= 1);
+               uxi <<= -ex + 1;
+       } else {
+               uxi &= -1U >> 9;
+               uxi |= 1U << 23;
        }
-       if (iy >= -126)
-               hy = 0x00800000|(0x007fffff&hy);
-       else {          /* subnormal y, shift y to normal */
-               n = -126-iy;
-               hy = hy<<n;
+       if (!ey) {
+               for (i = uy.i<<9; i>>31 == 0; ey--, i <<= 1);
+               uy.i <<= -ey + 1;
+       } else {
+               uy.i &= -1U >> 9;
+               uy.i |= 1U << 23;
        }
 
-       /* fix point fmod */
-       n = ix - iy;
-       while (n--) {
-               hz = hx-hy;
-               if (hz<0)
-                       hx = hx+hx;
-               else {
-                       if(hz == 0)   /* return sign(x)*0 */
-                               return Zero[(uint32_t)sx>>31];
-                       hx = hz+hz;
+       /* x mod y */
+       for (; ex > ey; ex--) {
+               i = uxi - uy.i;
+               if (i >> 31 == 0) {
+                       if (i == 0)
+                               return 0*x;
+                       uxi = i;
                }
+               uxi <<= 1;
        }
-       hz = hx-hy;
-       if (hz >= 0)
-               hx = hz;
-
-       /* convert back to floating value and restore the sign */
-       if (hx == 0)               /* return sign(x)*0 */
-               return Zero[(uint32_t)sx>>31];
-       while (hx < 0x00800000) {  /* normalize x */
-               hx = hx+hx;
-               iy -= 1;
+       i = uxi - uy.i;
+       if (i >> 31 == 0) {
+               if (i == 0)
+                       return 0*x;
+               uxi = i;
        }
-       if (iy >= -126) {          /* normalize output */
-               hx = ((hx-0x00800000)|((iy+127)<<23));
-               SET_FLOAT_WORD(x, hx|sx);
-       } else {                   /* subnormal output */
-               n = -126 - iy;
-               hx >>= n;
-               SET_FLOAT_WORD(x, hx|sx);
+       for (; uxi>>23 == 0; uxi <<= 1, ex--);
+
+       /* scale result up */
+       if (ex > 0) {
+               uxi -= 1U << 23;
+               uxi |= (uint32_t)ex << 23;
+       } else {
+               uxi >>= -ex + 1;
        }
-       return x;  /* exact output */
+       uxi |= sx;
+       ux.i = uxi;
+       return ux.f;
 }