PR 58958: wrong aliasing info

[Jakub Jelinek]

On Tue, Nov 05, 2013 at 11:40:02AM +0100, Marc Glisse wrote:
> >Well, you cannot use the size argument unchanged for the null
> >return case.  You could fallback to get_base_address and -1 size
> >in that case.
> 
> Like this? Bootstrap+testsuite on x86_64-unknown-linux-gnu.
> (I think I'll disable cilk for my future bootstraps: it takes
> forever and confuses contrib/compare_tests)

Ah, I was wondering why my make check times (admittedly
--enable-checking=yes,rtl but I've done that for years) went up drastically
between Friday and Monday (from around 40 minutes to 70 minutes or more).

That is clearly highly undesirable.  Looking at
gcc.dg/cilk-plus/cilk-plus.exp
it seems every test is run 24 resp. 25 times, that is clearly way too much,
sure, we have torture kind of tests, but that is typically 6 or 8 times at
most, and it also depends on how expensive the tests are.
As the /AN/ tests were already preexisting, I guess we are talking about
the 9 new /CK/ dg-do run tests, so first of all, they must be very expensive
themselves, times 25:

dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -fcilkplus $ALWAYS_CFLAGS " " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -O0 -fcilkplus $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -O1 -fcilkplus $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -O2 -ftree-vectorize -fcilkplus $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -O3 -fcilkplus $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -g -fcilkplus $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -g -O0 -fcilkplus $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -g -O1 -fcilkplus $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -g -O2 -ftree-vectorize -fcilkplus $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -g -O3 -fcilkplus $ALWAYS_CFLAGS"  " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -O3 -ftree-vectorize -fcilkplus -g $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -fcilkplus -std=c99 $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -fcilkplus -O0 -std=c99 $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -fcilkplus -O1 -std=c99 $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -fcilkplus -O2 -ftree-vectorize -std=c99 $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -fcilkplus -O3 -std=c99 $ALWAYS_CFLAGS"  " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -fcilkplus -g -std=c99 $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -fcilkplus -g -O0 -std=c99 $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -fcilkplus -g -O1 -std=c99 $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -fcilkplus -g -O2 -ftree-vectorize -std=c99 $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -fcilkplus -g -O3 -std=c99 $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -O3 -ftree-vectorize -std=c99 -g -fcilkplus $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -O0 -flto -g -fcilkplus $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -O2 -flto -g -fcilkplus $ALWAYS_CFLAGS" " "
dg-runtest [lsort [glob -nocomplain $srcdir/c-c++-common/cilk-plus/CK/*.c]] " -O3  -flto -g -fcilkplus $ALWAYS_CFLAGS" " "

It doesn't make sense to test -g at all levels, just test it for one or two, it doesn't
make sense to test say no -O* vs. -O0, that is the same thing, or -O3 vs. -O3 -ftree-vectorize,
that is the same thing, testing -std=c99 vs. default is reasonable for compile time tests
if they particularly care for some reason, otherwise, just attach -std=c99 to one (doesn't matter
which one) variant.  So, please change this to at most 7 or so variants, and even then, if some of
the test is really expensive, use it as dg-do compile for all variants and dg-do run just for
one (say -O2 -ftree-vectorize or -O3 -g).

	Jakub