1 /* s_floorl.c -- long double version of s_floor.c.
2 * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
3 */
4
5 /*
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8 *
9 * Developed at SunPro, a Sun Microsystems, Inc. business.
10 * Permission to use, copy, modify, and distribute this
11 * software is freely granted, provided that this notice
12 * is preserved.
13 * ====================================================
14 */
15
16 #if defined(LIBM_SCCS) && !defined(lint)
17 static char rcsid[] = "$NetBSD: $";
18 #endif
19
20 /*
21 * floorq(x)
22 * Return x rounded toward -inf to integral value
23 * Method:
24 * Bit twiddling.
25 */
26
27 #define NO_MATH_REDIRECT
28
29 #include "quadmath-imp.h"
30
floorq(__float128 x)31 __float128 floorq(__float128 x)
32 {
33 int64_t i0,i1,j0;
34 uint64_t i,j;
35 GET_FLT128_WORDS64(i0,i1,x);
36 j0 = ((i0>>48)&0x7fff)-0x3fff;
37 if(j0<48) {
38 if(j0<0) {
39 /* return 0*sign(x) if |x|<1 */
40 if(i0>=0) {i0=i1=0;}
41 else if(((i0&0x7fffffffffffffffLL)|i1)!=0)
42 { i0=0xbfff000000000000ULL;i1=0;}
43 } else {
44 i = (0x0000ffffffffffffULL)>>j0;
45 if(((i0&i)|i1)==0) return x; /* x is integral */
46 if(i0<0) i0 += (0x0001000000000000LL)>>j0;
47 i0 &= (~i); i1=0;
48 }
49 } else if (j0>111) {
50 if(j0==0x4000) return x+x; /* inf or NaN */
51 else return x; /* x is integral */
52 } else {
53 i = -1ULL>>(j0-48);
54 if((i1&i)==0) return x; /* x is integral */
55 if(i0<0) {
56 if(j0==48) i0+=1;
57 else {
58 j = i1+(1LL<<(112-j0));
59 if(j<i1) i0 +=1 ; /* got a carry */
60 i1=j;
61 }
62 }
63 i1 &= (~i);
64 }
65 SET_FLT128_WORDS64(x,i0,i1);
66 return x;
67 }
68