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bfff8b1b | 1 | /* Copyright (C) 1998-2017 Free Software Foundation, Inc. |
d7bb0de1 RH |
2 | This file is part of the GNU C Library. |
3 | Contributed by Richard Henderson. | |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
3214b89b AJ |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
d7bb0de1 RH |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
3214b89b | 13 | Lesser General Public License for more details. |
d7bb0de1 | 14 | |
3214b89b | 15 | You should have received a copy of the GNU Lesser General Public |
ab84e3ff PE |
16 | License along with the GNU C Library. If not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
d7bb0de1 | 18 | |
d7bb0de1 | 19 | #include <math.h> |
92ed9d7a | 20 | #include <math_ldbl_opt.h> |
d7bb0de1 | 21 | |
92a38c35 | 22 | |
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23 | /* Use the -inf rounding mode conversion instructions to implement |
24 | floor. We note when the exponent is large enough that the value | |
25 | must be integral, as this avoids unpleasant integer overflows. */ | |
d7bb0de1 RH |
26 | |
27 | double | |
28 | __floor (double x) | |
29 | { | |
65cc568c AJ |
30 | if (isnan (x)) |
31 | return x + x; | |
32 | ||
116ff9ad AJ |
33 | if (isless (fabs (x), 9007199254740992.0)) /* 1 << DBL_MANT_DIG */ |
34 | { | |
35 | double tmp1, new_x; | |
36 | ||
37 | __asm ( | |
116ff9ad | 38 | "cvttq/svm %2,%1\n\t" |
116ff9ad AJ |
39 | "cvtqt/m %1,%0\n\t" |
40 | : "=f"(new_x), "=&f"(tmp1) | |
41 | : "f"(x)); | |
42 | ||
43 | /* floor(-0) == -0, and in general we'll always have the same | |
44 | sign as our input. */ | |
45 | x = copysign(new_x, x); | |
46 | } | |
47 | return x; | |
d7bb0de1 RH |
48 | } |
49 | ||
50 | weak_alias (__floor, floor) | |
51 | #ifdef NO_LONG_DOUBLE | |
52 | strong_alias (__floor, __floorl) | |
53 | weak_alias (__floor, floorl) | |
54 | #endif | |
92ed9d7a RM |
55 | #if LONG_DOUBLE_COMPAT(libm, GLIBC_2_0) |
56 | compat_symbol (libm, __floor, floorl, GLIBC_2_0); | |
57 | #endif |