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6f2e90e78f
The mantissa of mp_no is intended to take only integral values. This is a relatively good choice for powerpc due to its 4 fpus, but not for other architectures, which suffer due to this choice. This change makes the default mantissa a long integer and allows powerpc to override it. Additionally, some operations have been optimized for integer manipulation, resulting in a significant improvement in performance.
48 lines
1.7 KiB
C
48 lines
1.7 KiB
C
/* Overridable constants and operations.
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Copyright (C) 2013 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program; if not, see <http://www.gnu.org/licenses/>. */
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#include <stdint.h>
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typedef long mantissa_t;
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typedef int64_t mantissa_store_t;
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#define TWOPOW(i) (1L << i)
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#define RADIX_EXP 24
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#define RADIX TWOPOW (RADIX_EXP) /* 2^24 */
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/* Divide D by RADIX and put the remainder in R. D must be a non-negative
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integral value. */
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#define DIV_RADIX(d, r) \
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({ \
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r = d & (RADIX - 1); \
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d >>= RADIX_EXP; \
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})
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/* Put the integer component of a double X in R and retain the fraction in
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X. This is used in extracting mantissa digits for MP_NO by using the
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integer portion of the current value of the number as the current mantissa
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digit and then scaling by RADIX to get the next mantissa digit in the same
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manner. */
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#define INTEGER_OF(x, i) \
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({ \
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i = (mantissa_t) x; \
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x -= i; \
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})
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/* Align IN down to F. The code assumes that F is a power of two. */
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#define ALIGN_DOWN_TO(in, f) ((in) & -(f))
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