summaryrefslogtreecommitdiff
path: root/gcc/config/spu/mfc_multi_tag_reserve.c
diff options
context:
space:
mode:
authorupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
committerupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
commit554fd8c5195424bdbcabf5de30fdc183aba391bd (patch)
tree976dc5ab7fddf506dadce60ae936f43f58787092 /gcc/config/spu/mfc_multi_tag_reserve.c
downloadcbb-gcc-4.6.4-554fd8c5195424bdbcabf5de30fdc183aba391bd.tar.bz2
cbb-gcc-4.6.4-554fd8c5195424bdbcabf5de30fdc183aba391bd.tar.xz
obtained gcc-4.6.4.tar.bz2 from upstream website;upstream
verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository.
Diffstat (limited to 'gcc/config/spu/mfc_multi_tag_reserve.c')
-rw-r--r--gcc/config/spu/mfc_multi_tag_reserve.c84
1 files changed, 84 insertions, 0 deletions
diff --git a/gcc/config/spu/mfc_multi_tag_reserve.c b/gcc/config/spu/mfc_multi_tag_reserve.c
new file mode 100644
index 000000000..06d702592
--- /dev/null
+++ b/gcc/config/spu/mfc_multi_tag_reserve.c
@@ -0,0 +1,84 @@
+/* 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;
+
+/* 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);
+}
+