master_june24: fbridge.inc interface was not modified

[valassi]

Another issue introduced in #830 and being reviewed in #882.

The fbridge.inc interface was not modified when adding channelids, it should have been modified

This is from 8e312bc (which is my first commit in WIP PR #882, where I regenerated all processes using 830 CODEGEN)

madgraph4gpu/epochX/cudacpp/gg_tt.mad/SubProcesses/fbridge.inc

Line 52 in 8e312bc

INTEGER*4 CHANID

C
C Execute the matrix-element calculation "sequence" via a Bridge on GPU/CUDA or CUDA/C++.
C - PBRIDGE: the memory address of the C++ Bridge
C - MOMENTA: the input 4-momenta Fortran array
C - GS:      the input Gs (running QCD coupling constant alphas) Fortran array
C - RNDHEL:  the input random number Fortran array for helicity selection
C - RNDCOL:  the input random number Fortran array for color selection
C - CHANID:  the input Feynman diagram to enhance in multi-channel mode if 1 to n
C - MES:     the output matrix element Fortran array
C - SELHEL:  the output selected helicity Fortran array
C - SELCOL:  the output selected color Fortran array
C
      INTERFACE
         SUBROUTINE FBRIDGESEQUENCE(PBRIDGE, MOMENTA, GS,
     &     RNDHEL, RNDCOL, CHANID, MES, SELHEL, SELCOL)
         INTEGER*8 PBRIDGE
         DOUBLE PRECISION MOMENTA(*)
         DOUBLE PRECISION GS(*)
         DOUBLE PRECISION RNDHEL(*)
         DOUBLE PRECISION RNDCOL(*)
         INTEGER*4 CHANID
         DOUBLE PRECISION MES(*)
         INTEGER*4 SELHEL(*)
         INTEGER*4 SELCOL(*)
         END SUBROUTINE FBRIDGESEQUENCE
      END INTERFACE

C

This is still using a scalar channelid. The main point of #830 should have been to allow passing an array of channelids from fortran to c++, so this file should have been modified. I will fix that.

I think that this explains what I mentioned in #914, that the way the channel array is passed from fortran to c++ is strange, for instance

           CALL FBRIDGESEQUENCE(FBRIDGE_PBRIDGE, P_MULTI, ALL_G,
-     &      HEL_RAND, COL_RAND, CHANNEL, OUT2,
+     &      HEL_RAND, COL_RAND, CHANNELS(1), OUT2,
      &      SELECTED_HEL2, SELECTED_COL2 ) ! 1-N: multi channel enabled

[valassi]

I have fixed #916 here 2b3025d

After fixing also #914, now the channelid printouts from madeven starts to make sense, and I get a cross section

This will be in #882. Closing

[valassi]

(Cross documentation, this is linked also to #892)