Re: etex and pdftex have diverging memory constraints?
jfbu via tex-live <[email protected]>
| Newsgroups | gmane.comp.tex.live |
|---|---|
| Message-ID | <[email protected]> |
Hello, Thanks for the comment. I had not thought about size occupied by the format itself. The small difference must come then perhaps from ... well I don't know. By the way, my experiment is on a 64bit machine with default TL2025 settings. Kind regards Jean-François > Le 27 août 2025 à 15:30, Jonathan Fine <[email protected]> a écrit : > > Hi > > You've found a nice puzzle. Any preloaded format files uses space in the main memory. I suspect that etex and pdftex do not occupy the same amount of main memory. And in fact that pdftex tex occupies more. > > From my phone. > > Jonathan > > On Wed, 27 Aug 2025, 14:15 jfbu via tex-live, <[email protected] <mailto:[email protected]>> wrote: >> Hi, >> >> Sorry if this is very basic, but I always thought the sole difference between etex and pdftex is that the former works to produce a dvi and the latter a pdf. >> >> So, I was surprised to discover (or perhaps I observed that years ago and forgot) that pdftex has slightly more constrained memory constraints on macro expansion. >> >> Here is a test file testxintLength.tex >> >> ---- >> \input xintkernel.sty >> \edef\x{\romannumeral\xintreplicate{% >> 2492679% >> }{F}} >> \expandafter\xintLength\expandafter{\x} >> \bye >> ---- >> >> (the code creates a macro \x expanding to 2492679 F's then attempts to measure how many F's there are). >> >> Compilation with etex succeeds (even with 2492694 in place of 2492679). >> >> $ etex testxintLength.tex >> This is pdfTeX, Version 3.141592653-2.6-1.40.28 (TeX Live 2025) (preloaded format=etex) >> restricted \write18 enabled. >> entering extended mode >> (./testxintLength.tex (./xintkernel.sty) [1] ) >> Output written on testxintLength.dvi (1 page, 216 bytes). >> Transcript written on testxintLength.log. >> >> But compilation with pdftex fails. >> >> $ pdftex testxintLength >> This is pdfTeX, Version 3.141592653-2.6-1.40.28 (TeX Live 2025) (preloaded format=pdftex) >> restricted \write18 enabled. >> entering extended mode >> (./testxintLength.tex (./xintkernel.sty) >> ! TeX capacity exceeded, sorry [main memory size=5000000]. >> <inserted text> 2492679 >> \xintlength ...xint_c_i \xint_c_ \xint_bye \relax l.5 \expandafter\xintLength\expandafter{\x} >> ! ==> Fatal error occurred, no output PDF file produced! >> Transcript written on testxintLength.log. >> >> I am a bit surprised because I can not connect the constraints on TeX macro expansion with the output format DVI or PDF. Needless to say I am completely ignorant of the innards. >> >> If replying please CC as I am not on the list. >> >> Kind regards >> >> Jean-François >> >>