Rename fst240 to fst4 in Fortran routines.

lib/fst4/encode240_74.f90

@@ -0,0 +1,46 @@
+subroutine encode240_74(message,codeword)
+   use, intrinsic :: iso_c_binding
+   use iso_c_binding, only: c_loc,c_size_t
+   use crc
+
+   integer, parameter:: N=240, K=74, M=N-K
+   character*24 c24
+   integer*1 codeword(N)
+   integer*1 gen(M,K)
+   integer*1 message(K)
+   integer*1 pchecks(M)
+   integer*4 ncrc24
+   include "ldpc_240_74_generator.f90"
+   logical first
+   data first/.true./
+   save first,gen
+
+   if( first ) then ! fill the generator matrix
+      gen=0
+      do i=1,M
+         do j=1,19
+            read(g(i)(j:j),"(Z1)") istr
+            ibmax=4
+            if(j.eq.19) ibmax=2
+            do jj=1, ibmax
+               icol=(j-1)*4+jj
+               if( btest(istr,4-jj) ) gen(i,icol)=1
+            enddo
+         enddo
+      enddo
+      first=.false.
+   endif
+
+   do i=1,M
+      nsum=0
+      do j=1,K
+         nsum=nsum+message(j)*gen(i,j)
+      enddo
+      pchecks(i)=mod(nsum,2)
+   enddo
+
+   codeword(1:K)=message
+   codeword(K+1:N)=pchecks
+
+   return
+end subroutine encode240_74