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b168057a | 1 | /* Copyright (C) 1998-2015 Free Software Foundation, Inc. |
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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 | |
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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. | |
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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 |
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16 | License along with the GNU C Library. If not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
d7bb0de1 | 18 | |
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19 | #include <math.h> |
20 | ||
8380d488 | 21 | |
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22 | /* Use the -inf rounding mode conversion instructions to implement |
23 | floor. We note when the exponent is large enough that the value | |
24 | must be integral, as this avoids unpleasant integer overflows. */ | |
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25 | |
26 | float | |
27 | __floorf (float x) | |
28 | { | |
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29 | if (isless (fabsf (x), 16777216.0f)) /* 1 << FLT_MANT_DIG */ |
30 | { | |
31 | /* Note that Alpha S_Floating is stored in registers in a | |
32 | restricted T_Floating format, so we don't even need to | |
33 | convert back to S_Floating in the end. The initial | |
34 | conversion to T_Floating is needed to handle denormals. */ | |
35 | ||
36 | float tmp1, tmp2, new_x; | |
37 | ||
38 | __asm ("cvtst/s %3,%2\n\t" | |
068bbaf6 | 39 | #ifdef _IEEE_FP_INEXACT |
116ff9ad | 40 | "cvttq/svim %2,%1\n\t" |
068bbaf6 | 41 | #else |
116ff9ad | 42 | "cvttq/svm %2,%1\n\t" |
068bbaf6 | 43 | #endif |
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44 | "cvtqt/m %1,%0\n\t" |
45 | : "=f"(new_x), "=&f"(tmp1), "=&f"(tmp2) | |
46 | : "f"(x)); | |
47 | ||
48 | /* floor(-0) == -0, and in general we'll always have the same | |
49 | sign as our input. */ | |
50 | x = copysignf(new_x, x); | |
51 | } | |
52 | return x; | |
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53 | } |
54 | ||
55 | weak_alias (__floorf, floorf) |