libgcc/config/spu/mfc_tag_release.c

/* 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;

/* Release the specified DMA tag from exclusive use.  Once released, the
   tag is available for future reservation.  Upon successful release,
   MFC_DMA_TAG_VALID is returned.  If the specified tag is not in the
   range 0 to 31, or had not been reserved, no action is taken and
   MFC_DMA_TAG_INVALID is returned.  */

unsigned int
__mfc_tag_release (unsigned int tag)
{
  vector unsigned int is_invalid;
  vector unsigned int mask = (vector unsigned int)
	{ 0x80000000, 0x80000000, 0x80000000, 0x80000000 };
  vector signed int zero = (vector signed int) { 0, 0, 0, 0 };

  vector signed int has_been_reserved;

  /* Check if the tag is out of range.  */
  is_invalid = spu_cmpgt (spu_promote (tag, 0), 31);

  /* Check whether the tag has been reserved, set to all 1 if has not
     been reserved, 0 otherwise.  */
  has_been_reserved = (vector signed int) spu_rl (__mfc_tag_table, tag);
  has_been_reserved = (vector signed int) spu_cmpgt (zero, has_been_reserved);

  /* Set invalid.  */
  is_invalid = spu_or ((vector unsigned int) has_been_reserved, is_invalid);

  mask = spu_rlmask (mask, (int)(-tag));
  __mfc_tag_table = spu_or (__mfc_tag_table, mask);

  return spu_extract(is_invalid, 0);
}