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[PATCH][libstdc++-v3 parallel mode]
- From: Johannes Singler <singler at ira dot uka dot de>
- To: libstdc++ <libstdc++ at gcc dot gnu dot org>, gcc-patches at gcc dot gnu dot org
- Date: Tue, 13 Nov 2007 09:41:54 +0100
- Subject: [PATCH][libstdc++-v3 parallel mode]
Fixes two small bugs concerning (partial) sort in parallel mode.
Tested, no regressions on x86_64-unknown-linux-gnu.
Please approve.
2007-11-13 Johannes Singler <singler@ira.uka.de>
* include/parallel/multiway_merge.h: More robust finding of an
arbitrary existing element inside the input sequences.
* include/bits/stl_algo.h: Fix typo to actually call appropriate
sequential version.
Johannes
Index: include/parallel/multiway_merge.h
===================================================================
--- include/parallel/multiway_merge.h (revision 129922)
+++ include/parallel/multiway_merge.h (working copy)
@@ -900,25 +900,34 @@
difference_type total_length = 0;
// Default value for potentially non-default-constructible types.
- value_type* defaultcons = NULL;
+ value_type* arbitrary_element = NULL;
+
for (int t = 0; t < k; t++)
{
- if (stable)
- {
- if (seqs_begin[t].first == seqs_begin[t].second)
- lt.insert_start_stable(*defaultcons, t, true);
- else
- lt.insert_start_stable(*seqs_begin[t].first, t, false);
- }
- else
- {
- if (seqs_begin[t].first == seqs_begin[t].second)
- lt.insert_start(*defaultcons, t, true);
- else
- lt.insert_start(*seqs_begin[t].first, t, false);
- }
+ if(arbitrary_element == NULL && LENGTH(seqs_begin[t]) > 0)
+ arbitrary_element = &(*seqs_begin[t].first);
+ total_length += LENGTH(seqs_begin[t]);
+ }
- total_length += LENGTH(seqs_begin[t]);
+ if(total_length == 0)
+ return target;
+
+ for (int t = 0; t < k; t++)
+ {
+ if (stable)
+ {
+ if (seqs_begin[t].first == seqs_begin[t].second)
+ lt.insert_start_stable(*arbitrary_element, t, true);
+ else
+ lt.insert_start_stable(*seqs_begin[t].first, t, false);
+ }
+ else
+ {
+ if (seqs_begin[t].first == seqs_begin[t].second)
+ lt.insert_start(*arbitrary_element, t, true);
+ else
+ lt.insert_start(*seqs_begin[t].first, t, false);
+ }
}
if (stable)
@@ -941,7 +950,7 @@
// Feed.
if (seqs_begin[source].first == seqs_begin[source].second)
- lt.delete_min_insert_stable(*defaultcons, true);
+ lt.delete_min_insert_stable(*arbitrary_element, true);
else
// Replace from same source.
lt.delete_min_insert_stable(*seqs_begin[source].first, false);
@@ -959,7 +968,7 @@
// Feed.
if (seqs_begin[source].first == seqs_begin[source].second)
- lt.delete_min_insert(*defaultcons, true);
+ lt.delete_min_insert(*arbitrary_element, true);
else
// Replace from same source.
lt.delete_min_insert(*seqs_begin[source].first, false);
Index: include/bits/stl_algo.h
===================================================================
--- include/bits/stl_algo.h (revision 129922)
+++ include/bits/stl_algo.h (working copy)
@@ -2028,7 +2028,7 @@
{
if (__depth_limit == 0)
{
- _GLIBCXX_STD_P:partial_sort(__first, __last, __last);
+ _GLIBCXX_STD_P::partial_sort(__first, __last, __last);
return;
}
--__depth_limit;