Optimizations of JT9 and JT65 decoders; change clock in timer routine.

Both decoders now have slightly better performance and faster
execution.  The rare "duplicate decodes" in JT9 were eliminated.
On Windows, at least, calls to f90 routine system_clock() do not
provide correct wall time increments.  Changed to using secnds()
instead.


git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@4571 ab8295b8-cf94-4d9e-aec4-7959e3be5d79

lib/decoder.f90

@@ -21,7 +21,6 @@ subroutine decoder(ss,id2)
   common/tracer/limtrace,lu
   save
 
-  call system_clock(iclock0,iclock_rate,iclock_max)           !###
   nfreqs0=0
   nfreqs1=0
   ndecodes0=0
@@ -84,13 +83,13 @@ subroutine decoder(ss,id2)
   dblim=db(864.0/nsps8) - 26.2
 
   do nqd=1,0,-1
-     limit=1000
+     limit=5000
-     ccflim=4.0
+     ccflim=3.0
      red2lim=1.6
      schklim=2.2
      if(ndepth.eq.2) then
         limit=10000
-        ccflim=3.5
+        ccflim=2.7
      endif
      if(ndepth.ge.3 .or. nqd.eq.1) then
         limit=100000
@@ -135,17 +134,15 @@ subroutine decoder(ss,id2)
                 freq,drift,schk,i1SoftSymbols)
            call timer('softsym ',1)
 
-!           write(71,3001) nqd,i,f,fpk,ccfred(i),red2(i),schk
+           sync=(syncpk+1)/4.0
-!3001       format(2i6,2f8.1,3f6.1)
+           if(maxval(i1SoftSymbols).eq.0) cycle
-!           call flush(71)
+           if(nqd.eq.1 .and. ((sync.lt.0.5) .or. (schk.lt.2.0))) cycle
-
+           if(nqd.ne.1 .and. ((sync.lt.1.0) .or. (schk.lt.schklim))) cycle
-           if(schk.lt.schklim) cycle
 
            call timer('decode9 ',0)
            call decode9(i1SoftSymbols,limit,nlim,msg)
            call timer('decode9 ',1)
 
-           sync=(syncpk+1)/4.0
            if(sync.lt.0.0 .or. snrdb.lt.dblim-2.0) sync=0.0
            nsync=sync
            if(nsync.gt.10) nsync=10
@@ -183,7 +180,7 @@ subroutine decoder(ss,id2)
      call jt65a(dd,npts65,newdat,nutc,nf1,nf2,nfqso,ntol65,nagain,ndecoded)
   endif
 
-!### JT65 is not yet producing info for nsynced, ndecoded.
+! JT65 is not yet producing info for nsynced, ndecoded.
 800 write(*,1010) nsynced,ndecoded
 1010 format('<DecodeFinished>',2i4)
   call flush(6)

lib/demod64a.f90

@@ -1,4 +1,4 @@
-subroutine demod64a(s3,nadd,mrsym,mrprob,mr2sym,mr2prob,ntest,nlow)
+subroutine demod64a(s3,nadd,afac1,mrsym,mrprob,mr2sym,mr2prob,ntest,nlow)
 
 ! Demodulate the 64-bin spectra for each of 63 symbols in a frame.
 
@@ -10,23 +10,16 @@ subroutine demod64a(s3,nadd,mrsym,mrprob,mr2sym,mr2prob,ntest,nlow)
 !    mr2prob  probability that mr2sym was the transmitted value
 
   implicit real*8 (a-h,o-z)
-  real*4 s3(64,63)
+  real*4 s3(64,63),afac1
   real*8 fs(64)
   integer mrsym(63),mrprob(63),mr2sym(63),mr2prob(63)
-!  common/mrscom/ mrs(63),mrs2(63)
 
   if(nadd.eq.-999) return
-  afac=1.1 * float(nadd)**0.64
+  afac=afac1 * float(nadd)**0.64
   scale=255.999
 
 ! Compute average spectral value
-  sum=0.
+  ave=sum(s3)/(64.*63.)
-  do j=1,63
-     do i=1,64
-        sum=sum+s3(i,j)
-     enddo
-  enddo
-  ave=sum/(64.*63.)
   i1=1                                      !Silence warning
   i2=1
 
@@ -57,17 +50,13 @@ subroutine demod64a(s3,nadd,mrsym,mrprob,mr2sym,mr2prob,ntest,nlow)
      mr2sym(j)=i2-1
      mrprob(j)=scale*p1
      mr2prob(j)=scale*p2
-!     mrs(j)=i1
-!     mrs2(j)=i2
   enddo
 
-  sum=0.
   nlow=0
   do j=1,63
-     sum=sum+mrprob(j)
      if(mrprob(j).le.5) nlow=nlow+1
   enddo
-  ntest=sum/63
+  ntest=sum(mrprob)/63.0
 
   return
 end subroutine demod64a

lib/extract.F90

@@ -1,4 +1,7 @@
 subroutine extract(s3,nadd,ncount,nhist,decoded,ltext,nbmkv)
+!subroutine extract(s3,nadd,nbirdie,afac1,xlambda,ncount,nhist,decoded,   &
+!     ltext,nbmkv,ntest)
+
 
 ! Input:
 !   s3       64-point spectra for each of 63 data symbols
@@ -15,30 +18,35 @@ subroutine extract(s3,nadd,ncount,nhist,decoded,ltext,nbmkv)
 
   real s3(64,63)
   character decoded*22
-  integer era(51),dat4(12),indx(64)
+  integer dat4(12)
   integer mrsym(63),mr2sym(63),mrprob(63),mr2prob(63)
   logical nokv,ltext
   data nokv/.false./,nsec1/0/
   save
 
+  nbirdie=7
+  npct=40
+  afac1=10.1
+  xlambda=8.0
   nbmkv=0
   nfail=0
+  decoded='                      '
+  call pctile(s3,4032,npct,base)
+  s3=s3/base
 
 ! Get most reliable and second-most-reliable symbol values, and their 
 ! probabilities
-1 call demod64a(s3,nadd,mrsym,mrprob,mr2sym,mr2prob,ntest,nlow)
+1 call demod64a(s3,nadd,afac1,mrsym,mrprob,mr2sym,mr2prob,ntest,nlow)
-  if(ntest.lt.50 .or. nlow.gt.20) then
+  if(ntest.lt.100) then
      ncount=-999                      !Flag and reject bad data
      go to 900
   endif
-  call chkhist(mrsym,nhist,ipk)       !Test for birdies and QRM
 
-  if(nhist.ge.20) then
+  call chkhist(mrsym,nhist,ipk)       !Test for birdies and QRM
+  if(nhist.ge.nbirdie) then
      nfail=nfail+1
-     call pctile(s3,4032,50,base)
+     call pctile(s3,4032,npct,base)
-     do j=1,63
+     s3(ipk,1:63)=base
-        s3(ipk,j)=base
-     enddo
      if(nfail.gt.30) then
         decoded='                      '
         ncount=-1
@@ -47,42 +55,27 @@ subroutine extract(s3,nadd,ncount,nhist,decoded,ltext,nbmkv)
      go to 1
   endif
 
-  call graycode65(mrsym,63,-1)
+  call graycode65(mrsym,63,-1)        !Remove gray code and interleaving
-  call interleave63(mrsym,-1)
+  call interleave63(mrsym,-1)         !from most reliable symbols
   call interleave63(mrprob,-1)
 
 ! Decode using Berlekamp-Massey algorithm
-  nemax=30                                         !Max BM erasures
+  call timer('rs_decod',0)
-  call indexx(63,mrprob,indx)
+  call rs_decode(mrsym,0,0,dat4,ncount)
-  do i=1,nemax
+  call timer('rs_decod',1)
-     j=indx(i)
+  if(ncount.ge.0) then
-     if(mrprob(j).gt.120) then
+     call unpackmsg(dat4,decoded)
-        ne2=i-1
+     if(iand(dat4(10),8).ne.0) ltext=.true.
-        go to 2
+     nbmkv=1
-     endif
+     go to 900
-     era(i)=j-1
+  endif
-  enddo
-  ne2=nemax
-2 decoded='                      '
-  do nerase=0,ne2,2
-     call rs_decode(mrsym,era,nerase,dat4,ncount)
-     if(ncount.ge.0) then
-        call unpackmsg(dat4,decoded)
-        if(iand(dat4(10),8).ne.0) ltext=.true.
-        nbmkv=1
-        go to 900
-     endif
-  enddo
 
 ! Berlekamp-Massey algorithm failed, try Koetter-Vardy
-
   if(nokv) go to 900
 
   maxe=8                             !Max KV errors in 12 most reliable symbols
-!  xlambda=12.0
+  call graycode65(mr2sym,63,-1)      !Remove gray code and interleaving
-  xlambda=7.99
+  call interleave63(mr2sym,-1)       !from second-most-reliable symbols
-  call graycode65(mr2sym,63,-1)
-  call interleave63(mr2sym,-1)
   call interleave63(mr2prob,-1)
 
   nsec1=nsec1+1
@@ -92,8 +85,8 @@ subroutine extract(s3,nadd,ncount,nhist,decoded,ltext,nbmkv)
   call flush(22)
   call timer('kvasd   ',0)
 
-! TODO G4WJS: Take out '-q' argument once kvasd 1.12 is available for Mac and in the repo
+! TODO G4WJS: Take out '-q' argument once kvasd 1.12 is available for 
-!      	      where CMake fetches it from.
+! Mac and in the repo where CMake fetches it from.
 #ifdef WIN32
   iret=system('""'//trim(exe_dir)//'/kvasd" -q >dev_null"')
 !  iret=system('""'//trim(exe_dir)//'/kvasd" kvasd.dat >dev_null"')
@@ -101,6 +94,7 @@ subroutine extract(s3,nadd,ncount,nhist,decoded,ltext,nbmkv)
   iret=system('"'//trim(exe_dir)//'/kvasd" -q >/dev/null')
 !  iret=system('"'//trim(exe_dir)//'/kvasd" kvasd.dat >/dev/null')
 #endif
+
   call timer('kvasd   ',1)
   if(iret.ne.0) then
      if(.not.nokv) write(*,1000) iret
@@ -110,7 +104,7 @@ subroutine extract(s3,nadd,ncount,nhist,decoded,ltext,nbmkv)
   endif
 
   read(22,rec=2,err=900) nsec2,ncount,dat4
-  j=nsec2                !Silence compiler warning
+  j=nsec2                             !Silence compiler warning
   decoded='                      '
   ltext=.false.
   if(ncount.ge.0) then

lib/symspec2.f90

@@ -34,7 +34,10 @@ subroutine symspec2(c5,nz3,nsps8,nspsd,fsample,freq,drift,snrdb,schk,    &
   enddo
 
   call chkss2(ss2,freq,drift,schk)
-  if(schk.lt.2.0) go to 900
+  if(schk.lt.2.0) then
+     i1SoftSymbolsScrambled=0
+     go to 900
+  endif
 
   ss=0.
   sig=0.

lib/timer.f90

@@ -38,7 +38,9 @@ subroutine timer(dname,k)
      on(n)=.true.
 !     call system_clock(icount,irate)
 !     ut0(n)=float(icount)/irate
-     call cpu_time(ut0(n))
+!     call cpu_time(ut0(n))
+     ut0(n)=secnds(0.0)
+
      ncall(n)=ncall(n)+1
      if(ncall(n).gt.1.and.nlevel(n).ne.level) then
         nlevel(n)=-1
@@ -53,7 +55,9 @@ subroutine timer(dname,k)
         on(n)=.false.
 !        call system_clock(icount,irate)
 !        ut1=float(icount)/irate
-        call cpu_time(ut1)
+!        call cpu_time(ut1)
+        ut1=secnds(0.0)
+
         ut(n)=ut(n)+ut1-ut0(n)
      endif
      level=level-1