[rock-devel] bc built with gcc4 dumps core
clifford at clifford.at
Fri Nov 18 16:03:10 CET 2005
On Fri, Nov 18, 2005 at 12:23:39PM +0100, Benjamin Schieder wrote:
> BTW: The same happens with glib/gdk-pixbuf/gtk+/gimp (one of these, couldn't
> nail it down) and Pentium-M optimisation. We should introduce a NOOPT flag
> which will force the package to be built non-optimised.
No! Not again! Every once in a while someone brings up this stupid idea..
As a matter of a fact we will never be able to even find a small portion of
what is going wrong when using a broken compiler optimization. So the
packages we do mark with such NOOPT flags would always be just the tip of
the iceberg and in the end we ship distributions full of broken bytecode.
Instead we should start creating a detailed documentation of broken
compiler optimizations and create testcases from what we find and confront
the GCC team with our results.
ocaml graphics.cma <( echo 'open Graphics;;open_graph " 640x480"let
,d)=(a+.c,b+.d);;let rec mandel c n=if n>0 then let z=mandel c(n-1)
in complex_add(complex_mul z z)c else (0.0,0.0);; for x=0 to 640 do
for y=0 to 480 do let c=((float_of_int(x-450))/.200.0,(float_of_int
(y-240))/.200.0) in let cabs2(a,b)=(a*.a)+.(b*.b)in if cabs2(mandel
c 50)<4.0 then plot x y done done;;read_line()' )
"Beware of bugs in the above code; I have only proved it correct,
not tried it." - Donald E. Knuth
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