* [PATCH][RFC] Consolidate -O3 torture options
@ 2015-07-14 11:58 Richard Biener
2015-07-14 15:25 ` Jeff Law
0 siblings, 1 reply; 4+ messages in thread
From: Richard Biener @ 2015-07-14 11:58 UTC (permalink / raw)
To: gcc-patches
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 <rguenther@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.
Index: gcc/testsuite/lib/c-torture.exp
===================================================================
--- gcc/testsuite/lib/c-torture.exp (revision 225768)
+++ gcc/testsuite/lib/c-torture.exp (working copy)
@@ -53,9 +53,7 @@ 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 } \
{ -Og -g } ]
Index: gcc/testsuite/lib/gcc-dg.exp
===================================================================
--- gcc/testsuite/lib/gcc-dg.exp (revision 225768)
+++ gcc/testsuite/lib/gcc-dg.exp (working copy)
@@ -74,9 +74,7 @@ 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 } ]
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH][RFC] Consolidate -O3 torture options
2015-07-14 11:58 [PATCH][RFC] Consolidate -O3 torture options Richard Biener
@ 2015-07-14 15:25 ` Jeff Law
2015-07-15 8:12 ` Richard Biener
0 siblings, 1 reply; 4+ messages in thread
From: Jeff Law @ 2015-07-14 15:25 UTC (permalink / raw)
To: Richard Biener, gcc-patches
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 <rguenther@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.
jeff
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH][RFC] Consolidate -O3 torture options
2015-07-14 15:25 ` Jeff Law
@ 2015-07-15 8:12 ` Richard Biener
2015-07-15 11:52 ` Richard Biener
0 siblings, 1 reply; 4+ messages in thread
From: Richard Biener @ 2015-07-15 8:12 UTC (permalink / raw)
To: Jeff Law; +Cc: gcc-patches
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 <rguenther@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).
Richard.
Index: gcc/testsuite/gcc.c-torture/execute/builtins/builtins.exp
===================================================================
--- gcc/testsuite/gcc.c-torture/execute/builtins/builtins.exp (revision
225768)
+++ gcc/testsuite/gcc.c-torture/execute/builtins/builtins.exp (working
copy)
@@ -37,7 +37,7 @@ load_lib c-torture.exp
torture-init
set-torture-options $C_TORTURE_OPTIONS {{}} $LTO_TORTURE_OPTIONS
-set additional_flags "-fno-tree-loop-distribute-patterns"
+set additional_flags "-fno-tree-loop-distribute-patterns -fno-tracer"
if [istarget "powerpc-*-darwin*"] {
lappend additional_flags "-Wl,-multiply_defined,suppress"
}
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH][RFC] Consolidate -O3 torture options
2015-07-15 8:12 ` Richard Biener
@ 2015-07-15 11:52 ` Richard Biener
0 siblings, 0 replies; 4+ messages in thread
From: Richard Biener @ 2015-07-15 11:52 UTC (permalink / raw)
To: Jeff Law; +Cc: gcc-patches
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 <rguenther@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 <rguenther@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 " ]
}
^ permalink raw reply [flat|nested] 4+ messages in thread
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2015-07-14 11:58 [PATCH][RFC] Consolidate -O3 torture options Richard Biener
2015-07-14 15:25 ` Jeff Law
2015-07-15 8:12 ` Richard Biener
2015-07-15 11:52 ` Richard Biener
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