-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 24-12-11 16:23, Matthew Flatt wrote: > At Wed, 14 Dec 2011 16:49:23 +0100, Marijn wrote: >> #lang racket (* .1 pi) >> >> produces 0.0 reliably in a freshly started drracket even when >> rerunning it, but: >> >> $ racket -e '(* .1 pi)' 0.3141592653589793 >> >> and the program: >> >> #lang racket pi (* .1 pi) >> >> on the first run (drracket again) produces: >> >> 3.141592653589793 0.0 >> >> while on subsequent runs it produces: >> >> 3.141592653589793 0.3141592653589793 > > Thanks --- this is very helpful! > > I'm still stumped, unfortunately. It looks the same as PR 12070, > which we never figured out: > > http://bugs.racket-lang.org/query/?debug=&database=default&cmd=view+audit-trail&cmd=view&pr=12070
Interesting!, > though it is a bit hard to read the Audit Trail because everything is jumbled together. I reproduce that bug and step 7) and 8) can be replaced with a single re-evaluate for me. It seems to indicate very clearly that the problem is in the floating point start-up somehow and has nothing to do with `pi' or variable references. Another possibility would be that multiplication (*) was at fault, but my new smallest test-case rules that out: #lang racket .1 => 0.0 And actually it works also directly in the REPL without running any program: Welcome to DrRacket, version 5.2.0.7--2011-12-15(-/f) [3m]. Language: racket; memory limit: 128 MB. > .1 0.0 > 1 1 > .1 0.0 > .2 0.0 > .3 0.0 > .4 0.0 > .5 0.0 > .6 0.0 > .7 0.0 > .8 0.0 > .9 0.0 > 1.0 1.0 > .1 0.1 So should we look at the byte-code produced for this (how does one do that and what is the expected code)? Is there some way to invoke racket from the command line in such a way that it behaves like the drracket initial repl? How does one run the byte-code? What external suspects are there? I suppose gcc, but are there any other? My CFLAGS are set to a very conservative AFAIK CFLAGS="-march=native -ggdb -O2 -pipe", currently on version 4.5.3. Marijn -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk75x5IACgkQp/VmCx0OL2xZRACcC8dubYCSNXScyOG8wdJQxxN1 xAgAnRVKv8YpTWODEKn2qEMMhcXHZLSk =n+xT -----END PGP SIGNATURE----- _________________________ Racket Developers list: http://lists.racket-lang.org/dev
