Lexiconfree beam search

Modules.make

@@ -148,6 +148,7 @@ endif
 
 # ****** Libraries ******
 LIBS_SEARCH = src/Search/libSprintSearch.$(a)
+LIBS_SEARCH += src/Search/LexiconfreeTimesyncBeamSearch/libSprintLexiconfreeTimesyncBeamSearch.$(a)
 ifdef MODULE_SEARCH_WFST
 LIBS_SEARCH += src/Search/Wfst/libSprintSearchWfst.$(a)
 LIBS_SEARCH += src/OpenFst/libSprintOpenFst.$(a)

apptainer/2022-10-21_tensorflow-1.15_arm_v1/makefiles/Modules.make

@@ -143,6 +143,7 @@ endif
 
 # ****** Libraries ******
 LIBS_SEARCH = src/Search/libSprintSearch.$(a)
+LIBS_SEARCH += src/Search/LexiconfreeTimesyncBeamSearch/libSprintLexiconfreeTimesyncBeamSearch.$(a)
 ifdef MODULE_SEARCH_WFST
 LIBS_SEARCH += src/Search/Wfst/libSprintSearchWfst.$(a)
 LIBS_SEARCH += src/OpenFst/libSprintOpenFst.$(a)

apptainer/2022-10-21_tensorflow-1.15_v1/makefiles/Modules.make

@@ -143,6 +143,7 @@ endif
 
 # ****** Libraries ******
 LIBS_SEARCH = src/Search/libSprintSearch.$(a)
+LIBS_SEARCH += src/Search/LexiconfreeTimesyncBeamSearch/libSprintLexiconfreeTimesyncBeamSearch.$(a)
 ifdef MODULE_SEARCH_WFST
 LIBS_SEARCH += src/Search/Wfst/libSprintSearchWfst.$(a)
 LIBS_SEARCH += src/OpenFst/libSprintOpenFst.$(a)

apptainer/2023-05-08_tensorflow-2.8_v1/makefiles/Modules.make

@@ -143,6 +143,7 @@ endif
 
 # ****** Libraries ******
 LIBS_SEARCH = src/Search/libSprintSearch.$(a)
+LIBS_SEARCH += src/Search/LexiconfreeTimesyncBeamSearch/libSprintLexiconfreeTimesyncBeamSearch.$(a)
 ifdef MODULE_SEARCH_WFST
 LIBS_SEARCH += src/Search/Wfst/libSprintSearchWfst.$(a)
 LIBS_SEARCH += src/OpenFst/libSprintOpenFst.$(a)

apptainer/2023-08-09_tensorflow-2.8_onnx-1.15_v1/makefiles/Modules.make

@@ -147,6 +147,7 @@ endif
 
 # ****** Libraries ******
 LIBS_SEARCH = src/Search/libSprintSearch.$(a)
+LIBS_SEARCH += src/Search/LexiconfreeTimesyncBeamSearch/libSprintLexiconfreeTimesyncBeamSearch.$(a)
 ifdef MODULE_SEARCH_WFST
 LIBS_SEARCH += src/Search/Wfst/libSprintSearchWfst.$(a)
 LIBS_SEARCH += src/OpenFst/libSprintOpenFst.$(a)

apptainer/2023-11-08_tensorflow-2.14_v1/makefiles/Modules.make

@@ -148,6 +148,7 @@ endif
 
 # ****** Libraries ******
 LIBS_SEARCH = src/Search/libSprintSearch.$(a)
+LIBS_SEARCH += src/Search/LexiconfreeTimesyncBeamSearch/libSprintLexiconfreeTimesyncBeamSearch.$(a)
 ifdef MODULE_SEARCH_WFST
 LIBS_SEARCH += src/Search/Wfst/libSprintSearchWfst.$(a)
 LIBS_SEARCH += src/OpenFst/libSprintOpenFst.$(a)

src/Core/Makefile

@@ -43,6 +43,7 @@ LIBSPRINTCORE_O	= $(OBJDIR)/Application.o \
 		  $(OBJDIR)/ReferenceCounting.o \
 		  $(OBJDIR)/ResourceUsageInfo.o \
 		  $(OBJDIR)/Statistics.o \
+		  $(OBJDIR)/StopWatch.o \
 		  $(OBJDIR)/StringExpression.o \
 		  $(OBJDIR)/StringUtilities.o \
 		  $(OBJDIR)/TextStream.o \

src/Core/StopWatch.cc

@@ -0,0 +1,78 @@
+/** Copyright 2025 RWTH Aachen University. All rights reserved.
+ *
+ *  Licensed under the RWTH ASR License (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.hltpr.rwth-aachen.de/rwth-asr/rwth-asr-license.html
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#include "StopWatch.hh"
+#include "Utility.hh"
+
+namespace Core {
+
+StopWatch::StopWatch()
+        : running_(false), startTime_(), elapsedSeconds_(0.0) {}
+
+void StopWatch::start() {
+    if (running_) {
+        return;
+    }
+
+    TIMER_START(startTime_);
+    running_ = true;
+}
+
+void StopWatch::stop() {
+    if (not running_) {
+        return;
+    }
+
+    timeval endTime;
+    TIMER_STOP(startTime_, endTime, elapsedSeconds_);
+
+    running_ = false;
+}
+
+void StopWatch::reset() {
+    elapsedSeconds_ = 0;
+    running_        = false;
+}
+
+double StopWatch::elapsedSeconds() const {
+    if (running_) {
+        timeval endTime;
+        double  currentTime = 0;  // in seconds
+
+        // Note: This macro doesn't actually "stop" anything, it just writes into `endTime` and `currentTime`
+        TIMER_STOP(const_cast<timeval&>(startTime_), endTime, currentTime);
+
+        return elapsedSeconds_ + currentTime;
+    }
+    return elapsedSeconds_;
+}
+
+double StopWatch::elapsedCentiseconds() const {
+    return elapsedSeconds() * 1e2;
+}
+
+double StopWatch::elapsedMilliseconds() const {
+    return elapsedSeconds() * 1e3;
+}
+
+double StopWatch::elapsedMicroseconds() const {
+    return elapsedSeconds() * 1e6;
+}
+
+double StopWatch::elapsedNanoseconds() const {
+    return elapsedSeconds() * 1e9;
+}
+
+}  // namespace Core

src/Core/StopWatch.hh

@@ -0,0 +1,63 @@
+/** Copyright 2025 RWTH Aachen University. All rights reserved.
+ *
+ *  Licensed under the RWTH ASR License (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.hltpr.rwth-aachen.de/rwth-asr/rwth-asr-license.html
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+#ifndef STOPWATCH_HH
+#define STOPWATCH_HH
+
+#include <sys/time.h>
+
+namespace Core {
+
+/*
+ * Simple timer class with start/stop functions that accumulates all the timed intervals
+ * to a total.
+ */
+struct StopWatch {
+public:
+    StopWatch();
+
+    /*
+     * Stops timer if it is running and resets accumulated time to zero.
+     */
+    void reset();
+
+    /*
+     * Start timer. Does nothing if timer is already running.
+     */
+    void start();
+
+    /*
+     * End running timer and add duration to total. Does nothing if timer is not running.
+     */
+    void stop();
+
+    /*
+     * Getter functions to get the total elapsed time in different units. Includes the current interval
+     * if the timer is running.
+     */
+    double elapsedSeconds() const;
+    double elapsedCentiseconds() const;
+    double elapsedMilliseconds() const;
+    double elapsedMicroseconds() const;
+    double elapsedNanoseconds() const;
+
+private:
+    bool    running_;
+    timeval startTime_;
+    double  elapsedSeconds_;
+};
+
+}  // namespace Core
+
+#endif  // TIMER_HH

src/Nn/LabelScorer/LabelScorer.hh

@@ -83,6 +83,8 @@ public:
         LABEL_TO_BLANK,
         BLANK_TO_LABEL,
         BLANK_LOOP,
+        INITIAL_LABEL,
+        INITIAL_BLANK,
     };
 
     // Request for scoring or context extension

src/Search/AdvancedTreeSearch/Helpers.hh

@@ -16,10 +16,9 @@
 #define HELPERS_HH
 
 #include <Core/ReferenceCounting.hh>
+#include <Core/StopWatch.hh>
 #include <Core/Types.hh>
-#include <Core/Utility.hh>
 #include <string>
-#include <time.h>
 #include "SearchSpaceStatistics.hh"
 
 namespace Search {
@@ -36,64 +35,41 @@ class Configuration;
 
 bool isBackwardRecognition(const Core::Configuration& config);
 
-class PerformanceCounter {
+class PerformanceCounter : public Core::StopWatch {
 public:
     PerformanceCounter(Search::SearchSpaceStatistics& stats, const std::string& name, bool start = true)
-            : running_(false),
-              totalTime_(0),
-              timeStats(stats.customStatistics("Profiling: " + name + ": Centiseconds")) {
-        if (start)
-            this->start();
+            : stopWatch_(), timeStats_(stats.customStatistics("Profiling: " + name + ": Centiseconds")) {
+        if (start) {
+            stopWatch_.start();
+        }
     }
 
     ~PerformanceCounter() {
         stopAndYield();
     }
 
     void start() {
-        stop();
-
-        running_ = true;
-        TIMER_START(starttime_);
+        stopWatch_.stop();
+        stopWatch_.start();
     }
 
     void stop() {
-        if (running_) {
-            running_ = false;
-
-            double  diff = 0;  // in secs
-            timeval end;
-
-            TIMER_STOP(starttime_, end, diff);
-            totalTime_ += diff * 100;  // centi secs
-        }
+        stopWatch_.stop();
     }
 
     /// Prints the current instruction count to the statistics object
     void stopAndYield(bool print = false) {
         stop();
-        timeStats += totalTime_;
-        if (print)
-            std::cout << " time: " << totalTime_ << std::endl;
-        totalTime_ = 0;
-    }
-
-    static inline u64 instructions() {
-        unsigned int a, d;
-        asm __volatile__(""
-                         :
-                         :
-                         : "memory");
-        asm volatile("rdtsc"
-                     : "=a"(a), "=d"(d));
-        return ((u64)a) | (((u64)d) << 32);
+        timeStats_ += stopWatch_.elapsedCentiseconds();
+        if (print) {
+            std::cout << " time: " << stopWatch_.elapsedCentiseconds() << std::endl;
+        }
+        stopWatch_.reset();
     }
 
 private:
-    bool                   running_;
-    timeval                starttime_;
-    f32                    totalTime_;
-    Core::Statistics<f32>& timeStats;
+    Core::StopWatch        stopWatch_;
+    Core::Statistics<f32>& timeStats_;
 };
 
 inline f32 scaledLogAdd(f32 a, f32 b, f32 scale, f32 invertedScale) {