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authorZack Weinberg <zackw@panix.com>2017-06-08 15:39:03 -0400
committerZack Weinberg <zackw@panix.com>2017-06-08 15:39:03 -0400
commit5046dbb4a7eba5eccfd258f92f4735c9ffc8d069 (patch)
tree4470480d904b65cf14ca524f96f79eca818c3eaf /math/fromfp.h
parent199fc19d3aaaf57944ef036e15904febe877fc93 (diff)
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Prepare for radical source tree reorganization.zack/build-layout-experiment
All top-level files and directories are moved into a temporary storage directory, REORG.TODO, except for files that will certainly still exist in their current form at top level when we're done (COPYING, COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which are moved to the new directory OldChangeLogs, instead), and the generated file INSTALL (which is just deleted; in the new order, there will be no generated files checked into version control).
Diffstat (limited to 'math/fromfp.h')
-rw-r--r--math/fromfp.h174
1 files changed, 0 insertions, 174 deletions
diff --git a/math/fromfp.h b/math/fromfp.h
deleted file mode 100644
index db60a00491..0000000000
--- a/math/fromfp.h
+++ /dev/null
@@ -1,174 +0,0 @@
-/* Round to integer type. Common helper functions.
- Copyright (C) 2016-2017 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <http://www.gnu.org/licenses/>. */
-
-#include <errno.h>
-#include <fenv.h>
-#include <float.h>
-#include <math.h>
-#include <math_private.h>
-#include <stdbool.h>
-#include <stdint.h>
-
-/* The including file should have defined UNSIGNED to 0 (signed return
- type) or 1 (unsigned return type), INEXACT to 0 (no inexact
- exceptions) or 1 (raise inexact exceptions) and RET_TYPE to the
- return type (intmax_t or uintmax_t). */
-
-/* Return the maximum unbiased exponent for an argument (negative if
- NEGATIVE is set) that might be in range for a call to a fromfp
- function with width WIDTH (greater than 0, and not exceeding that
- of intmax_t). The truncated argument may still be out of range in
- the case of negative arguments, and if not out of range it may
- become out of range as a result of rounding. */
-
-static int
-fromfp_max_exponent (bool negative, int width)
-{
- if (UNSIGNED)
- return negative ? -1 : width - 1;
- else
- return negative ? width - 1 : width - 2;
-}
-
-/* Return the result of rounding an integer value X (passed as the
- absolute value; NEGATIVE is true if the value is negative), where
- HALF_BIT is true if the bit with value 0.5 is set and MORE_BITS is
- true if any lower bits are set, in the rounding direction
- ROUND. */
-
-static uintmax_t
-fromfp_round (bool negative, uintmax_t x, bool half_bit, bool more_bits,
- int round)
-{
- switch (round)
- {
- case FP_INT_UPWARD:
- return x + (!negative && (half_bit || more_bits));
-
- case FP_INT_DOWNWARD:
- return x + (negative && (half_bit || more_bits));
-
- case FP_INT_TOWARDZERO:
- default:
- /* Unknown rounding directions are defined to mean unspecified
- rounding; treat this as truncation. */
- return x;
-
- case FP_INT_TONEARESTFROMZERO:
- return x + half_bit;
-
- case FP_INT_TONEAREST:
- return x + (half_bit && ((x & 1) || more_bits));
- }
-}
-
-/* Integer rounding, of a value whose exponent EXPONENT did not exceed
- the maximum exponent MAX_EXPONENT and so did not necessarily
- overflow, has produced X (possibly wrapping to 0); the sign is
- negative if NEGATIVE is true. Return whether this overflowed the
- allowed width. */
-
-static bool
-fromfp_overflowed (bool negative, uintmax_t x, int exponent, int max_exponent)
-{
- if (UNSIGNED)
- {
- if (negative)
- return x != 0;
- else if (max_exponent == INTMAX_WIDTH - 1)
- return exponent == INTMAX_WIDTH - 1 && x == 0;
- else
- return x == (1ULL << (max_exponent + 1));
- }
- else
- {
- if (negative)
- return exponent == max_exponent && x != (1ULL << max_exponent);
- else
- return x == (1ULL << (max_exponent + 1));
- }
-}
-
-/* Handle a domain error for a call to a fromfp function with an
- argument which is negative if NEGATIVE is set, and specified width
- (not exceeding that of intmax_t) WIDTH. The return value is
- unspecified (with it being unclear if the result needs to fit
- within WIDTH bits in this case); we choose to saturate to the given
- number of bits (treating NaNs like any other value). */
-
-static RET_TYPE
-fromfp_domain_error (bool negative, unsigned int width)
-{
- feraiseexcept (FE_INVALID);
- __set_errno (EDOM);
- /* The return value is unspecified; we choose to saturate to the
- given number of bits (treating NaNs like any other value). */
- if (UNSIGNED)
- {
- if (negative)
- return 0;
- else if (width == INTMAX_WIDTH)
- return -1;
- else
- return (1ULL << width) - 1;
- }
- else
- {
- if (width == 0)
- return 0;
- else if (negative)
- return -(1ULL << (width - 1));
- else
- return (1ULL << (width - 1)) - 1;
- }
-}
-
-/* Given X, the absolute value of a floating-point number (negative if
- NEGATIVE is set) truncated towards zero, where HALF_BIT is true if
- the bit with value 0.5 is set and MORE_BITS is true if any lower
- bits are set, round it in the rounding direction ROUND, handle
- errors and exceptions and return the appropriate return value for a
- fromfp function. X originally had floating-point exponent
- EXPONENT, which does not exceed MAX_EXPONENT, the return value from
- fromfp_max_exponent with width WIDTH. */
-
-static RET_TYPE
-fromfp_round_and_return (bool negative, uintmax_t x, bool half_bit,
- bool more_bits, int round, int exponent,
- int max_exponent, unsigned int width)
-{
- uintmax_t uret = fromfp_round (negative, x, half_bit, more_bits, round);
- if (fromfp_overflowed (negative, uret, exponent, max_exponent))
- return fromfp_domain_error (negative, width);
-
- if (INEXACT && (half_bit || more_bits))
- {
- /* There is no need for this to use the specific floating-point
- type for which this header is included, and there is no need
- for this header to know that type at all, so just use float
- here. */
- float force_inexact = 1.0f + FLT_MIN;
- math_force_eval (force_inexact);
- }
- if (UNSIGNED)
- /* A negative argument not rounding to zero will already have
- produced a domain error. */
- return uret;
- else
- return negative ? -uret : uret;
-}