bfin: set an invalid insn for abort

[uclinux-h8/uClibc.git] / libm / s_rint.c

diff --git a/libm/s_rint.c b/libm/s_rint.c
index 358ce76..06432c6 100644 (file)
--- a/libm/s_rint.c
+++ b/libm/s_rint.c
@@ -30,41 +30,57 @@ TWO52[2]={
 
 double rint(double x)
 {
-       int32_t i0,j0,sx;
+       int32_t i0, j0, sx;
        u_int32_t i,i1;
-       double w,t;
+       double t;
+       /* We use w = x + 2^52; t = w - 2^52; trick to round x to integer.
+        * This trick requires that compiler does not optimize it
+        * by keeping intermediate result w in a register wider than double.
+        * Declaring w volatile assures that value gets truncated to double
+        * (unfortunately, it also forces store+load):
+        */
+       volatile double w;
+
        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;
+       /* Unbiased exponent */
+       j0 = ((((u_int32_t)i0) >> 20)&0x7ff)-0x3ff;
+
+       if (j0 > 51) {
+               //Why bother? Just returning x works too
+               //if (j0 == 0x400)  /* inf or NaN */
+               //      return x+x;
+               return x;  /* x is integral */
+       }
+
+       /* Sign */
+       sx = ((u_int32_t)i0) >> 31;
+
+       if (j0<20) {
+           if (j0<0) { /* |x| < 1 */
+               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];
+               w = TWO52[sx]+x;
+               t = w-TWO52[sx];
                GET_HIGH_WORD(i0,t);
                SET_HIGH_WORD(t,(i0&0x7fffffff)|(sx<<31));
-               return t;
+               return t;
            } else {
                i = (0x000fffff)>>j0;
-               if(((i0&i)|i1)==0) return x; /* x is integral */
+               if (((i0&i)|i1)==0) return x; /* x is integral */
                i>>=1;
-               if(((i0&i)|i1)!=0) {
-                   if(j0==19) i1 = 0x40000000; else
-                   i0 = (i0&(~i))|((0x20000)>>j0);
+               if (((i0&i)|i1)!=0) {
+                   if (j0==19) i1 = 0x40000000;
+                   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 */
+           if ((i1&i)==0) return x;    /* x is integral */
            i>>=1;
-           if((i1&i)!=0) i1 = (i1&(~i))|((0x40000000)>>(j0-20));
+           if ((i1&i)!=0) i1 = (i1&(~i))|((0x40000000)>>(j0-20));
        }
        INSERT_WORDS(x,i0,i1);
        w = TWO52[sx]+x;