| /* Helper function for cshift functions. |
| Copyright (C) 2008-2018 Free Software Foundation, Inc. |
| Contributed by Thomas Koenig <tkoenig@gcc.gnu.org> |
| |
| This file is part of the GNU Fortran runtime library (libgfortran). |
| |
| Libgfortran is free software; you can redistribute it and/or |
| modify it under the terms of the GNU General Public |
| License as published by the Free Software Foundation; either |
| version 3 of the License, or (at your option) any later version. |
| |
| Libgfortran 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 General Public License for more details. |
| |
| Under Section 7 of GPL version 3, you are granted additional |
| permissions described in the GCC Runtime Library Exception, version |
| 3.1, as published by the Free Software Foundation. |
| |
| You should have received a copy of the GNU General Public License and |
| a copy of the GCC Runtime Library Exception along with this program; |
| see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include "libgfortran.h" |
| #include <string.h> |
| |
| |
| #if defined (HAVE_GFC_REAL_8) |
| |
| void |
| cshift0_r8 (gfc_array_r8 *ret, const gfc_array_r8 *array, ptrdiff_t shift, |
| int which) |
| { |
| /* r.* indicates the return array. */ |
| index_type rstride[GFC_MAX_DIMENSIONS]; |
| index_type rstride0; |
| index_type roffset; |
| GFC_REAL_8 *rptr; |
| |
| /* s.* indicates the source array. */ |
| index_type sstride[GFC_MAX_DIMENSIONS]; |
| index_type sstride0; |
| index_type soffset; |
| const GFC_REAL_8 *sptr; |
| |
| index_type count[GFC_MAX_DIMENSIONS]; |
| index_type extent[GFC_MAX_DIMENSIONS]; |
| index_type dim; |
| index_type len; |
| index_type n; |
| |
| bool do_blocked; |
| index_type r_ex, a_ex; |
| |
| which = which - 1; |
| sstride[0] = 0; |
| rstride[0] = 0; |
| |
| extent[0] = 1; |
| count[0] = 0; |
| n = 0; |
| /* Initialized for avoiding compiler warnings. */ |
| roffset = 1; |
| soffset = 1; |
| len = 0; |
| |
| r_ex = 1; |
| a_ex = 1; |
| |
| if (which > 0) |
| { |
| /* Test if both ret and array are contiguous. */ |
| do_blocked = true; |
| dim = GFC_DESCRIPTOR_RANK (array); |
| for (n = 0; n < dim; n ++) |
| { |
| index_type rs, as; |
| rs = GFC_DESCRIPTOR_STRIDE (ret, n); |
| if (rs != r_ex) |
| { |
| do_blocked = false; |
| break; |
| } |
| as = GFC_DESCRIPTOR_STRIDE (array, n); |
| if (as != a_ex) |
| { |
| do_blocked = false; |
| break; |
| } |
| r_ex *= GFC_DESCRIPTOR_EXTENT (ret, n); |
| a_ex *= GFC_DESCRIPTOR_EXTENT (array, n); |
| } |
| } |
| else |
| do_blocked = false; |
| |
| n = 0; |
| |
| if (do_blocked) |
| { |
| /* For contiguous arrays, use the relationship that |
| |
| dimension(n1,n2,n3) :: a, b |
| b = cshift(a,sh,3) |
| |
| can be dealt with as if |
| |
| dimension(n1*n2*n3) :: an, bn |
| bn = cshift(a,sh*n1*n2,1) |
| |
| we can used a more blocked algorithm for dim>1. */ |
| sstride[0] = 1; |
| rstride[0] = 1; |
| roffset = 1; |
| soffset = 1; |
| len = GFC_DESCRIPTOR_STRIDE(array, which) |
| * GFC_DESCRIPTOR_EXTENT(array, which); |
| shift *= GFC_DESCRIPTOR_STRIDE(array, which); |
| for (dim = which + 1; dim < GFC_DESCRIPTOR_RANK (array); dim++) |
| { |
| count[n] = 0; |
| extent[n] = GFC_DESCRIPTOR_EXTENT(array,dim); |
| rstride[n] = GFC_DESCRIPTOR_STRIDE(ret,dim); |
| sstride[n] = GFC_DESCRIPTOR_STRIDE(array,dim); |
| n++; |
| } |
| dim = GFC_DESCRIPTOR_RANK (array) - which; |
| } |
| else |
| { |
| for (dim = 0; dim < GFC_DESCRIPTOR_RANK (array); dim++) |
| { |
| if (dim == which) |
| { |
| roffset = GFC_DESCRIPTOR_STRIDE(ret,dim); |
| if (roffset == 0) |
| roffset = 1; |
| soffset = GFC_DESCRIPTOR_STRIDE(array,dim); |
| if (soffset == 0) |
| soffset = 1; |
| len = GFC_DESCRIPTOR_EXTENT(array,dim); |
| } |
| else |
| { |
| count[n] = 0; |
| extent[n] = GFC_DESCRIPTOR_EXTENT(array,dim); |
| rstride[n] = GFC_DESCRIPTOR_STRIDE(ret,dim); |
| sstride[n] = GFC_DESCRIPTOR_STRIDE(array,dim); |
| n++; |
| } |
| } |
| if (sstride[0] == 0) |
| sstride[0] = 1; |
| if (rstride[0] == 0) |
| rstride[0] = 1; |
| |
| dim = GFC_DESCRIPTOR_RANK (array); |
| } |
| |
| rstride0 = rstride[0]; |
| sstride0 = sstride[0]; |
| rptr = ret->base_addr; |
| sptr = array->base_addr; |
| |
| /* Avoid the costly modulo for trivially in-bound shifts. */ |
| if (shift < 0 || shift >= len) |
| { |
| shift = len == 0 ? 0 : shift % (ptrdiff_t)len; |
| if (shift < 0) |
| shift += len; |
| } |
| |
| while (rptr) |
| { |
| /* Do the shift for this dimension. */ |
| |
| /* If elements are contiguous, perform the operation |
| in two block moves. */ |
| if (soffset == 1 && roffset == 1) |
| { |
| size_t len1 = shift * sizeof (GFC_REAL_8); |
| size_t len2 = (len - shift) * sizeof (GFC_REAL_8); |
| memcpy (rptr, sptr + shift, len2); |
| memcpy (rptr + (len - shift), sptr, len1); |
| } |
| else |
| { |
| /* Otherwise, we will have to perform the copy one element at |
| a time. */ |
| GFC_REAL_8 *dest = rptr; |
| const GFC_REAL_8 *src = &sptr[shift * soffset]; |
| |
| for (n = 0; n < len - shift; n++) |
| { |
| *dest = *src; |
| dest += roffset; |
| src += soffset; |
| } |
| for (src = sptr, n = 0; n < shift; n++) |
| { |
| *dest = *src; |
| dest += roffset; |
| src += soffset; |
| } |
| } |
| |
| /* Advance to the next section. */ |
| rptr += rstride0; |
| sptr += sstride0; |
| count[0]++; |
| n = 0; |
| while (count[n] == extent[n]) |
| { |
| /* When we get to the end of a dimension, reset it and increment |
| the next dimension. */ |
| count[n] = 0; |
| /* We could precalculate these products, but this is a less |
| frequently used path so probably not worth it. */ |
| rptr -= rstride[n] * extent[n]; |
| sptr -= sstride[n] * extent[n]; |
| n++; |
| if (n >= dim - 1) |
| { |
| /* Break out of the loop. */ |
| rptr = NULL; |
| break; |
| } |
| else |
| { |
| count[n]++; |
| rptr += rstride[n]; |
| sptr += sstride[n]; |
| } |
| } |
| } |
| |
| return; |
| } |
| |
| #endif |