On Wed, 15 Jul 2015, Richard Biener wrote:
> On Tue, 14 Jul 2015, Jeff Law wrote:
>
> > On 07/14/2015 05:58 AM, Richard Biener wrote:
> > >
> > > The following patch tries to consolidate the -O3 torture testing
> > > options in the attempt to reduce testing time while not losing
> > > coverage.
> > >
> > > It drops testing of -funroll-all-loops (which nobody should use)
> > > and retains only one non-default -O3 set of options - namely
> > > -O3 plus those flags that would be enabled by -fprofile-use.
> > >
> > > One should hope for ~20% less time in the C and dg tortures this way.
> > >
> > > Didn't look into other tortures to apply the same yet (objc-torture?)
> > >
> > > Currently testing on x86_64-unknown-linux-gnu.
> > >
> > > For weird flag combinations we do have contributors that test
> > > them and regularly report bugzillas.
> > >
> > > Ok?
> > >
> > > Comments?
> > >
> > > Thanks,
> > > Richard.
> > >
> > > 2015-07-14 Richard Biener <rguent...@suse.de>
> > >
> > > * lib/c-torture.exp (C_TORTURE_OPTIONS): Remove
> > > { -O3 -fomit-frame-pointer },
> > > { -O3 -fomit-frame-pointer -funroll-loops } and
> > > { -O3 -fomit-frame-pointer -funroll-all-loops -finline-functions }
> > > in favor of
> > > { -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer
> > > -finline-functions }
> > > * lib/gcc-dg.exp (DG_TORTURE_OPTIONS): Likewise.
> > I think this is OK -- I've occasionally wondered about the additional
> > coverage
> > we get vs the amount of time spent for the various options.
> >
> > I can't recall specific cases where one of those 3 options would trigger a
> > failure, but the two didn't. I'm sure it's happened, but it's just common
> > enough to warrant the amount of time we spend testing it.
> >
> > This patch has the additional benefit that I think we can eliminate scanning
> > the source for loops and eliminating the -funroll[-all]-loops options.
> > Hmm,
> > that code may have already been dead... Hmmm.
>
> Testing reveals one fallout:
>
> FAIL: gcc.c-torture/execute/builtins/snprintf-chk.c execution, -O3
> -fomit-frame
> -pointer -funroll-loops -fpeel-loops -ftracer -finline-functions
> FAIL: gcc.c-torture/execute/builtins/vsnprintf-chk.c execution, -O3
> -fomit-fram
> e-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions
>
> this is because -ftracer manages to thread things in a way that we
> optimize away a _chk variant at compile-time and hit
>
> if (chk_calls != 5)
> abort ();
>
> with chk_calls == 4. I'm going to install the following alongside
> (we've had similar issues with -ftree-loop-distribute-patterns enabled
> by -O3).
The following adjusts objc-torture.exp (the only other I found with
the many -O3 variants).
Tested on x86_64-unknown-linux-gnu, applied.
Richard.
2015-07-15 Richard Biener <rguent...@suse.de>
* lib/objc-torture.exp (OBJC_TORTURE_OPTIONS): Remove
{ -O3 -fomit-frame-pointer },
{ -O3 -fomit-frame-pointer -funroll-loops } and
{ -O3 -fomit-frame-pointer -funroll-all-loops -finline-functions }
in favor of
{ -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer
-finline-functions }
Index: gcc/testsuite/lib/objc-torture.exp
===================================================================
--- gcc/testsuite/lib/objc-torture.exp (revision 225807)
+++ gcc/testsuite/lib/objc-torture.exp (working copy)
@@ -126,9 +126,7 @@ if [info exists TORTURE_OPTIONS] {
" -O0 " \
" -O1 " \
" -O2 " \
- " -O3 -fomit-frame-pointer " \
- " -O3 -fomit-frame-pointer -funroll-loops " \
- " -O3 -fomit-frame-pointer -funroll-all-loops -finline-functions " \
+ " -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer
-finline-functions " \
" -O3 -g " \
" -Os " ]
}
