Re: changing "configure" to default to "gcc -g -O2 -fwrapv ..."

[Thorsten Glaser]

Paul Eggert dixit:

>Thorsten Glaser <address@hidden> writes:

>> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30477

>Do you have a test case illustrating the gcc3 bug?  If so,
>perhaps Autoconf could include that in its test of -fwrapv.

The test case is included in the PR above, but it's not
necessary to include this check because
* the autoconf checks succeed with gcc3, it doesn't optimise
  them away as aggressively as recent gcc4 versions
* the only way to disable it is using -O0

The idea of the PR is: there's a possibly unsafe optimsation,
but we can't turn it off with -fwrapv as we're supposed to,
only with using -O0, which sucks, so please fix -fwrapv. (It
does too few, not too much.)

bye,
//mirabile
-- 
  "Using Lynx is like wearing a really good pair of shades: cuts out
   the glare and harmful UV (ultra-vanity), and you feel so-o-o COOL."
                                         -- Henry Nelson, March 1999