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116ff9ad18
Partial revert of bebc49030c. Even with the revert, ceil and floor are
still faster than libcpml's equivalent.
Fixes bug 5350.
Signed-off-by: Matt Turner <mattst88@gmail.com>
56 lines
1.8 KiB
C
56 lines
1.8 KiB
C
/* Copyright (C) 1998, 2000, 2007 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Richard Henderson.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library 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 GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <math.h>
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/* Use the -inf rounding mode conversion instructions to implement
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ceil, via something akin to -floor(-x). This is much faster than
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playing with the fpcr to achieve +inf rounding mode. */
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float
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__ceilf (float x)
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{
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if (isless (fabsf (x), 16777216.0f)) /* 1 << FLT_MANT_DIG */
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{
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/* Note that Alpha S_Floating is stored in registers in a
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restricted T_Floating format, so we don't even need to
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convert back to S_Floating in the end. The initial
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conversion to T_Floating is needed to handle denormals. */
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float tmp1, tmp2, new_x;
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new_x = -x;
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__asm ("cvtst/s %3,%2\n\t"
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#ifdef _IEEE_FP_INEXACT
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"cvttq/svim %2,%1\n\t"
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#else
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"cvttq/svm %2,%1\n\t"
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#endif
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"cvtqt/m %1,%0\n\t"
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: "=f"(new_x), "=&f"(tmp1), "=&f"(tmp2)
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: "f"(new_x));
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/* Fix up the negation we did above, as well as handling -0 properly. */
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x = copysignf(new_x, x);
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}
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return x;
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}
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weak_alias (__ceilf, ceilf)
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