Imported gcc-4.4.3

[msp430-gcc.git] / gcc / config / spu / mfc_tag_reserve.c

diff --git a/gcc/config/spu/mfc_tag_reserve.c b/gcc/config/spu/mfc_tag_reserve.c
new file mode 100644 (file)
index 0000000..23b4817
--- /dev/null
+++ b/gcc/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);
+}
+