[gclist] Experience with Boehm-Demers-Weiser on Alpha in 32 bit mode?

Allyn Dimock dimock@deas.harvard.edu
Thu, 8 Oct 1998 21:28:29 -0400 (EDT)

I would like to use conservative garbage collection for the runtime
system of a compiler that produces code in 32 bit mode on the
DEC/COMPAC/INTEL Alpha:  our tests of the compiler have gotten to
large enough programs to require garbage collection.

I assumed that the latest (non-alpha-point) release of
Boehm-Demers-Weiser ( gc4.12.tar.gz 07-Aug-98 17:23 ) would work out
of the box, but this isn't the case: after making what seemed the
reasonable tweaks for word size 32 and 4 byte alignment to the
parameters for compiling gc4 on the Alpha, we ended up with a garbage
collector that crashed during initialization.  (64 bit mode tested out
fine but can't be used with our code generator).

Our pointers use the low 2 bits for tag info, but that shouldn't be an
issue.  Our calling conventions follow the standard Alpha convention
so stack traces shouldn't have any difficulty.

I took a look at the FAQ for this group and the group seems more
oriented towards GC work and development than towards product
maintenance, _but_ if you have experience porting the BDW collector to
32 bit mode on the Alpha, I would appreciate your assistance.

Alternatively if there is another free conservative GC out there that
I should consider for 32 bit mode on the Alpha, I would be interested
in hearing about it.

Thank you for your help.

-- Allyn Dimock
Allyn Dimock             dimock@deas.harvard.edu  Eng. Sci. Lab #227
348 Harvard St. #1       h (617) 661-9299         40 Oxford St.
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