diff options
Diffstat (limited to 'libgcc/config/spu/mfc_tag_reserve.c')
-rw-r--r-- | libgcc/config/spu/mfc_tag_reserve.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/libgcc/config/spu/mfc_tag_reserve.c b/libgcc/config/spu/mfc_tag_reserve.c new file mode 100644 index 00000000000..23b4817c74f --- /dev/null +++ b/libgcc/config/spu/mfc_tag_reserve.c @@ -0,0 +1,51 @@ +/* Copyright (C) 2007, 2009 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; + +/* Reserves a DMA tag for exclusive use. This routine returns an available + tag id in the range 0 to 31 and marks the tag as reserved. If no tags + are available, MFC_DMA_TAG_INVALID is returned indicating that all tags + are already reserved. */ + +unsigned int +__mfc_tag_reserve (void) +{ + vector unsigned int mask = (vector unsigned int) + { 0x80000000, 0x80000000, 0x80000000, 0x80000000 }; + vector unsigned int count_zeros, is_valid; + vector signed int count_neg; + + count_zeros = spu_cntlz (__mfc_tag_table); + count_neg = spu_sub (0, (vector signed int) count_zeros); + + mask = spu_rlmask (mask, (vector signed int) count_neg); + __mfc_tag_table = spu_andc (__mfc_tag_table, mask); + + is_valid = spu_cmpeq (count_zeros, 32); + count_zeros = spu_sel (count_zeros, is_valid, is_valid); + + return spu_extract (count_zeros, 0); +} + |