Changeset 2266

Timestamp:

08/08/11 16:41:40 (13 years ago)

Author:

KohjiNakamura

Message:

optimize NRODataset::getSpectrum()

Location:

branches/parallel/external-alma/atnf/PKSIO

Files:

• NRODataset.cc (modified) (8 diffs)
• NRODataset.h (modified) (1 diff)

branches/parallel/external-alma/atnf/PKSIO/NRODataset.cc

@@ -71 +71 @@
   dataid_ = -1 ;
 
-  // OS endian 
-  int i = 1 ;
-  endian_ = -1 ;
-  if ( *reinterpret_cast<char *>(&i) == 1 ) {
-    endian_ = LITTLE_ENDIAN ;
-    os << LogIO::NORMAL << "LITTLE_ENDIAN " << LogIO::POST ;
-  }
-  else {
-    endian_ = BIG_ENDIAN ;
-    os << LogIO::NORMAL << "BIG_ENDIAN " << LogIO::POST ;
-  }
+  // endian matches
   same_ = -1 ;
 
@@ -353 +343 @@
 vector< vector<double> > NRODataset::getSpectrum()
 {
-  vector< vector<double> > spec;
+  vector< vector<double> > spec(rowNum_);
 
   for ( int i = 0 ; i < rowNum_ ; i++ ) {
-    spec.push_back( getSpectrum( i ) ) ;
+    spec[i] = getSpectrum( i ) ;
   }
 
@@ -370 +360 @@
   //
   // size of spectrum is not chmax_ but dataset_->getNCH() after binding
-  int nchan = NUMCH ;
-  vector<double> spec( chmax_, 0.0 ) ;  // spectrum "before" binding
+  const int nchan = NUMCH ;
   vector<double> bspec( nchan, 0.0 ) ;  // spectrum "after" binding
   // DEBUG
@@ -379 +368 @@
   NRODataRecord *record = getRecord( i ) ;
 
-  int bit = IBIT ;   // fixed to 12 bit
+  const int bit = IBIT ;   // fixed to 12 bit
   double scale = record->SFCTR ;
   // DEBUG
@@ -392 +381 @@
     return bspec ;
   }
-  char *cdata = record->LDATA ;
+  unsigned char *cdata = (unsigned char *)record->LDATA ;
   vector<double> mscale = MLTSCF ;
   double dscale = mscale[getIndex( i )] ;
@@ -400 +389 @@
   // char -> int
   vector<int> ispec( chmax_, 0 ) ;
-  union SharedMemory {
-    int ivalue ;
-    unsigned char cbuf[4] ;
-  } ;
-  SharedMemory u ;
+
+  static const int shift_right[] = {
+    4, 0
+  };
+  static const int start_pos[] = {
+    0, 1
+  };
+  static const int incr[] = {
+    0, 3
+  };
   int j = 0 ;
-  char ctmp = 0x00 ;
-  int sw = 0 ;
   for ( int i = 0 ; i < chmax_ ; i++ ) {
+    int ivalue = 0 ;
     if ( bit == 12 ) {  // 12 bit qunatization
-      u.ivalue = 0 ;
-
-      if ( endian_ == BIG_ENDIAN ) {
-        // big endian
-        if ( sw == 0 ) {
-          char c0 = (cdata[j] >> 4) & 0x0f ;
-          char c1 = ((cdata[j] << 4) & 0xf0) | ((cdata[j+1] >> 4) & 0x0f) ;
-          ctmp = cdata[j+1] & 0x0f ;
-          u.cbuf[2] = c0 ;
-          u.cbuf[3] = c1 ;
-          j += 2 ;
-          sw = 1 ;
-        }
-        else if ( sw == 1 ) {
-          u.cbuf[2] = ctmp ;
-          u.cbuf[3] = cdata[j] ;
-          j++ ;
-          sw = 0 ;
-        }
-      }
-      else if ( endian_ == LITTLE_ENDIAN ) {
-        // little endian
-        if ( sw == 0 ) {
-          char c0 = (cdata[j] >> 4) & 0x0f ;
-          char c1 = ((cdata[j] << 4) & 0xf0) | ((cdata[j+1] >> 4) & 0x0f) ;
-          ctmp = cdata[j+1] & 0x0f ;
-          u.cbuf[1] = c0 ;
-          u.cbuf[0] = c1 ;
-          j += 2 ;
-          sw = 1 ;
-        }
-        else if ( sw == 1 ) {
-          u.cbuf[1] = ctmp ;
-          u.cbuf[0] = cdata[j] ;
-          j++ ;
-          sw = 0 ;
-        }
-      }
-    }
-    
-    ispec[i] = u.ivalue ;
+      const int idx = j + start_pos[i & 1];
+      const unsigned tmp = unsigned(cdata[idx]) << 8 | cdata[idx + 1];
+      ivalue = int((tmp >> shift_right[i & 1]) & 0xFFF);
+      j += incr[i & 1];
+    }
+
+    ispec[i] = ivalue ;
     if ( ( ispec[i] < 0 ) || ( ispec[i] > 4096 ) ) {
       //cerr << "NRODataset::getSpectrum()  ispec[" << i << "] is out of range" << endl ;
@@ -461 +420 @@
   }
 
+  double *const spec = new double[ chmax_ ] ;  // spectrum "before" binding
   // int -> double 
   for ( int i = 0 ; i < chmax_ ; i++ ) {
@@ -490 +450 @@
       bspec[i] = spec[i] ;
   }
+  delete[] spec;
 
   // DEBUG

branches/parallel/external-alma/atnf/PKSIO/NRODataset.h

@@ -506 +506 @@
 
   // OS endian
-  int endian_ ;
   int same_ ;