101 lines
3.2 KiB
C
101 lines
3.2 KiB
C
/* Implementation of ishftc intrinsic.
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Copyright (C) 2002-2018 Free Software Foundation, Inc.
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Contributed by Paul Brook <paul@nowt.org>
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This file is part of the GNU Fortran 95 runtime library (libgfortran).
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Libgfortran is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public
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License as published by the Free Software Foundation; either
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version 3 of the License, or (at your option) any later version.
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Libgfortran 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 General Public License for more details.
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Under Section 7 of GPL version 3, you are granted additional
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permissions described in the GCC Runtime Library Exception, version
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3.1, as published by the Free Software Foundation.
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You should have received a copy of the GNU General Public License and
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a copy of the GCC Runtime Library Exception along with this program;
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see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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<http://www.gnu.org/licenses/>. */
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#include "libgfortran.h"
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extern GFC_INTEGER_4 ishftc4 (GFC_INTEGER_4, GFC_INTEGER_4, GFC_INTEGER_4);
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export_proto(ishftc4);
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GFC_INTEGER_4
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ishftc4 (GFC_INTEGER_4 i, GFC_INTEGER_4 shift, GFC_INTEGER_4 size)
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{
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GFC_UINTEGER_4 mask, bits;
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if (shift < 0)
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shift = shift + size;
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if (shift == 0 || shift == size)
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return i;
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/* In C, the result of the shift operator is undefined if the right operand
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is greater than or equal to the number of bits in the left operand. So we
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have to special case it for fortran. */
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mask = ~((size == 32) ? (GFC_UINTEGER_4)0 : (~(GFC_UINTEGER_4)0 << size));
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bits = i & mask;
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return (i & ~mask) | ((bits << shift) & mask) | (bits >> (size - shift));
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}
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extern GFC_INTEGER_8 ishftc8 (GFC_INTEGER_8, GFC_INTEGER_4, GFC_INTEGER_4);
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export_proto(ishftc8);
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GFC_INTEGER_8
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ishftc8 (GFC_INTEGER_8 i, GFC_INTEGER_4 shift, GFC_INTEGER_4 size)
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{
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GFC_UINTEGER_8 mask, bits;
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if (shift < 0)
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shift = shift + size;
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if (shift == 0 || shift == size)
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return i;
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/* In C, the result of the shift operator is undefined if the right operand
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is greater than or equal to the number of bits in the left operand. So we
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have to special case it for fortran. */
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mask = ~((size == 64) ? (GFC_UINTEGER_8)0 : (~(GFC_UINTEGER_8)0 << size));
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bits = i & mask;
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return (i & ~mask) | ((bits << shift) & mask) | (bits >> (size - shift));
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}
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#ifdef HAVE_GFC_INTEGER_16
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extern GFC_INTEGER_16 ishftc16 (GFC_INTEGER_16, GFC_INTEGER_4, GFC_INTEGER_4);
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export_proto(ishftc16);
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GFC_INTEGER_16
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ishftc16 (GFC_INTEGER_16 i, GFC_INTEGER_4 shift, GFC_INTEGER_4 size)
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{
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GFC_UINTEGER_16 mask, bits;
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if (shift < 0)
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shift = shift + size;
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if (shift == 0 || shift == size)
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return i;
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/* In C, the result of the shift operator is undefined if the right operand
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is greater than or equal to the number of bits in the left operand. So we
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have to special case it for fortran. */
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mask = ~((size == 128) ? (GFC_UINTEGER_16)0 : (~(GFC_UINTEGER_16)0 << size));
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bits = i & mask;
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return (i & ~mask) | ((bits << shift) & mask) | (bits >> (size - shift));
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}
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#endif
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