Re: Four problems with Scheme 48 1.8

Martin Ward <[email protected]> writes:

> (1) Compiling with gcc version 4.4.0 gives an error on "make test":
>
> FAILURES:
> Test case *3 [misc-big-tests] FAILED:
>>From expression (* 47123 46039) EXPECTED value 2169495797 of 2169495797
> INSTEAD got -2125471499
>
> '(#{Check-failure #{Test-case *3} (actual (* 47123 46039) -2125471499) 
> (expected 2169495797 2169495797) #{Procedure 983 (equal? in 
> scheme-level-1)}})
>
> Compiling with gcc 4.0.1 seems to work OK.

This appears to be a bug in gcc 4.4, I'm afraid.  The negative result is
an intermediate result of an overflow: The VM contains tests for this
that handle the situation, but gcc 4.4 with -O2 elides the test.  So
your options are to either compile with gcc 4.0.1 or without -O2.

I haven't found a way to extract a smaller code snippet from the VM that
exhibits the problem - I'd be happy to hear suggestions on how to best
report this bug to the gcc people.

-- 
Cheers =8-} Mike
Friede, Völkerverständigung und überhaupt blabla