various optimizations to make CYK+ parser several times faster and eat less memory.

speed-up of decoding depends on how much time is spent in parser:
10-50% speed-up for string-to-tree systems observed (more on long sentences and with high max-chart-span).

if you only use hiero or string-to-tree models (but none with source syntax), use compile-option --unlabelled-source for (small) efficiency gains.

1 files changed, 5 insertions, 1 deletions

diff --git a/moses/ChartParser.cpp b/moses/ChartParser.cpp
index 6a9ec2efb..b77a5c20c 100644
--- a/moses/ChartParser.cpp
+++ b/moses/ChartParser.cpp
@@ -181,8 +181,12 @@ void ChartParser::Create(const WordsRange &wordsRange, ChartParserCallback &to)
     assert(decodeGraph.GetSize() == 1);
     ChartRuleLookupManager &ruleLookupManager = **iterRuleLookupManagers;
     size_t maxSpan = decodeGraph.GetMaxChartSpan();
+    size_t last = m_source.GetSize()-1;
+    if (maxSpan != 0) {
+        last = min(last, wordsRange.GetStartPos()+maxSpan);
+    }
     if (maxSpan == 0 || wordsRange.GetNumWordsCovered() <= maxSpan) {
-      ruleLookupManager.GetChartRuleCollection(wordsRange, to);
+      ruleLookupManager.GetChartRuleCollection(wordsRange, last, to);
     }
   }