diff options
Diffstat (limited to 'gcc-4.9/libgcc/config/spu/mfc_multi_tag_reserve.c')
| -rw-r--r-- | gcc-4.9/libgcc/config/spu/mfc_multi_tag_reserve.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/gcc-4.9/libgcc/config/spu/mfc_multi_tag_reserve.c b/gcc-4.9/libgcc/config/spu/mfc_multi_tag_reserve.c new file mode 100644 index 000000000..1ced0afbb --- /dev/null +++ b/gcc-4.9/libgcc/config/spu/mfc_multi_tag_reserve.c @@ -0,0 +1,84 @@ +/* Copyright (C) 2007-2014 Free Software Foundation, Inc. + +This file is part of GCC. + +GCC 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, or (at your option) any later +version. + +GCC 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 <spu_mfcio.h> +extern vector unsigned int __mfc_tag_table; + +/* Reserve a sequential group of tags for exclusive use. The number of + tags to be reserved is specified by the <number_of_tags> parameter. + This routine returns the first tag ID for a sequential list of + available tags and marks them as reserved. The reserved group + of tags is in the range starting from the returned tag through + the returned tag + <number_of_tags>-1. + + If the number of tags requested exceeds the number of available + sequential tags, then MFC_DMA_TAG_INVALID is returned indicating + that the request could not be serviced. */ + +unsigned int +__mfc_multi_tag_reserve (unsigned int number_of_tags) +{ + vector unsigned int table_copy; + vector unsigned int one = (vector unsigned int) + { 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF }; + vector unsigned int count_busy, is_valid; + vector unsigned int count_total; + vector unsigned int count_avail = (vector unsigned int) { 0, 0, 0, 0 }; + vector unsigned int index = (vector unsigned int) { 0, 0, 0, 0 }; + + table_copy = __mfc_tag_table; + + + /* count_busy: number of consecutive busy tags + count_avail: number of consecutive free tags + table_copy: temporary copy of the tag table + count_total: sum of count_busy and count_avail + index: index of the current working tag */ + do + { + table_copy = spu_sl (table_copy, count_avail); + + count_busy = spu_cntlz (table_copy); + table_copy = spu_sl (table_copy, count_busy); + count_avail = spu_cntlz (spu_xor(table_copy, -1)); + count_total = spu_add (count_busy, count_avail); + index = spu_add (index, count_total); + } + while (spu_extract (count_avail, 0) < number_of_tags + && spu_extract (table_copy, 0) != 0); + + index = spu_sub (index, count_avail); + + /* is_valid is set to 0xFFFFFFFF if table_copy == 0, 0 otherwise. */ + is_valid = spu_cmpeq (table_copy, 0); + index = spu_sel (index, is_valid, is_valid); + + /* Now I need to actually mark the tags as used. */ + table_copy = spu_sl (one, number_of_tags); + table_copy = spu_rl (table_copy, -number_of_tags - spu_extract (index, 0)); + table_copy = spu_sel (table_copy, __mfc_tag_table, table_copy); + __mfc_tag_table = spu_sel (table_copy, __mfc_tag_table, is_valid); + + return spu_extract (index, 0); +} + |