How to install 64bit binaries for TeX Live on Windows


In the following, $INSTALLDIR is $SELFAUTOPARENT in the TeX Live,
that is, the parent directory of "texmf-dist". Actually the
directory $INSTALLDIR is shown by a command:

    kpsewhich --var-value=SELFAUTOPARENT


(1) Expand the file tl-win64.zip in $INSTALLDIR.
    In the case of update, remove all files in $INSTALLDIR/bin/win64
    before expanding tl-win64.zip, because it is possible that
    some files are deleted in a new tl-win64.zip.

(2) After expanding tl-win64.zip in $INSTALLDIR,
    change related command PATH from
    $INSTALLDIR\bin\win32
    to
    $INSTALLDIR\bin\win64;$INSTALLDIR\bin\win32

    Note that the following 32bit binaries in $INSTALLDIR\bin\win32
    are still used on WOW64:

    gunzip.exe      gzip.exe        jbig2.exe       latexindent.exe
    psviewer.exe    tex2xindy.exe   texindy.exe     tlaunch.exe
    tlshell.exe     unzip.exe       xindy.exe       xindy-lisp.exe
    xindy.mem       zip.exe
    
    Moreover, tlmgr.bat does not exist in $INSTALLDIR\bin\win64
    due to an obvious reason.

    Thus $INSTALLDIR\bin\win32 is necessary "after"
    $INSTALLDIR\bin\win64.

    If there are problems in 64bit binaries, it is easy to recover
    the original TeX Live win32, by changing back the PATH:
    $INSTALLDIR\bin\win64;$INSTALLDIR\bin\win32 --->
    $INSTALLDIR\bin\win32

(3) Ghostscript is assumed to be 64bit. The dvisvgm.exe searches
    for gsdll64.dll by reading registry, and gsftopk.exe searches
    for gsdll64.dll in the command PATH. Therefore users should
    install 64bit Ghostscript and set the command PATH for the
    Ghostscript. However, don't define TEXLIVE_WINDOWS_EXTERNAL_GS
    in texmf.cnf, because the preinstalled 32bit Ghostscript is
    also used in several cases.

    From TeX Live 2020, the version of 64bit binaries will be
    synchronized with that of 32bit binaries. It is expected that
    common format files can be usable for 32bit/64bit binaries.

-- 
Akira Kakuto