This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH] -fopt-info: add indentation via DUMP_VECT_SCOPE


On Tue, 2018-07-03 at 09:37 +0200, Richard Biener wrote:
> On Mon, Jul 2, 2018 at 7:00 PM David Malcolm <dmalcolm@redhat.com>
> wrote:
> > 
> > On Mon, 2018-07-02 at 14:23 +0200, Christophe Lyon wrote:
> > > On Fri, 29 Jun 2018 at 10:09, Richard Biener <richard.guenther@gm
> > > ail.
> > > com> wrote:
> > > > 
> > > > On Tue, Jun 26, 2018 at 5:43 PM David Malcolm <dmalcolm@redhat.
> > > > com>
> > > > wrote:
> > > > > 
> > > > > This patch adds a concept of nested "scopes" to dumpfile.c's
> > > > > dump_*_loc
> > > > > calls, and wires it up to the DUMP_VECT_SCOPE macro in tree-
> > > > > vectorizer.h,
> > > > > so that the nested structure is shown in -fopt-info by
> > > > > indentation.
> > > > > 
> > > > > For example, this converts -fopt-info-all e.g. from:
> > > > > 
> > > > > test.c:8:3: note: === analyzing loop ===
> > > > > test.c:8:3: note: === analyze_loop_nest ===
> > > > > test.c:8:3: note: === vect_analyze_loop_form ===
> > > > > test.c:8:3: note: === get_loop_niters ===
> > > > > test.c:8:3: note: symbolic number of iterations is (unsigned
> > > > > int)
> > > > > n_9(D)
> > > > > test.c:8:3: note: not vectorized: loop contains function
> > > > > calls or
> > > > > data references that cannot be analyzed
> > > > > test.c:8:3: note: vectorized 0 loops in function
> > > > > 
> > > > > to:
> > > > > 
> > > > > test.c:8:3: note: === analyzing loop ===
> > > > > test.c:8:3: note:  === analyze_loop_nest ===
> > > > > test.c:8:3: note:   === vect_analyze_loop_form ===
> > > > > test.c:8:3: note:    === get_loop_niters ===
> > > > > test.c:8:3: note:   symbolic number of iterations is
> > > > > (unsigned
> > > > > int) n_9(D)
> > > > > test.c:8:3: note:   not vectorized: loop contains function
> > > > > calls
> > > > > or data references that cannot be analyzed
> > > > > test.c:8:3: note: vectorized 0 loops in function
> > > > > 
> > > > > showing that the "symbolic number of iterations" message is
> > > > > within
> > > > > the "=== analyze_loop_nest ===" (and not within the
> > > > > "=== vect_analyze_loop_form ===").
> > > > > 
> > > > > This is also enabling work for followups involving
> > > > > optimization
> > > > > records
> > > > > (allowing the records to directly capture the nested
> > > > > structure of
> > > > > the
> > > > > dump messages).
> > > > > 
> > > > > Successfully bootstrapped & regrtested on x86_64-pc-linux-
> > > > > gnu.
> > > > > 
> > > > > OK for trunk?
> > > 
> > > Hi,
> > > 
> > > I've noticed that this patch (r262246) caused regressions on
> > > aarch64:
> > >     gcc.dg/vect/slp-perm-1.c -flto -ffat-lto-objects  scan-tree-
> > > dump
> > > vect "note: Built SLP cancelled: can use load/store-lanes"
> > >     gcc.dg/vect/slp-perm-1.c scan-tree-dump vect "note: Built SLP
> > > cancelled: can use load/store-lanes"
> > >     gcc.dg/vect/slp-perm-2.c -flto -ffat-lto-objects  scan-tree-
> > > dump
> > > vect "note: Built SLP cancelled: can use load/store-lanes"
> > >     gcc.dg/vect/slp-perm-2.c scan-tree-dump vect "note: Built SLP
> > > cancelled: can use load/store-lanes"
> > >     gcc.dg/vect/slp-perm-3.c -flto -ffat-lto-objects  scan-tree-
> > > dump
> > > vect "note: Built SLP cancelled: can use load/store-lanes"
> > >     gcc.dg/vect/slp-perm-3.c scan-tree-dump vect "note: Built SLP
> > > cancelled: can use load/store-lanes"
> > >     gcc.dg/vect/slp-perm-5.c -flto -ffat-lto-objects  scan-tree-
> > > dump
> > > vect "note: Built SLP cancelled: can use load/store-lanes"
> > >     gcc.dg/vect/slp-perm-5.c scan-tree-dump vect "note: Built SLP
> > > cancelled: can use load/store-lanes"
> > >     gcc.dg/vect/slp-perm-6.c -flto -ffat-lto-objects  scan-tree-
> > > dump
> > > vect "note: Built SLP cancelled: can use load/store-lanes"
> > >     gcc.dg/vect/slp-perm-6.c scan-tree-dump vect "note: Built SLP
> > > cancelled: can use load/store-lanes"
> > >     gcc.dg/vect/slp-perm-7.c -flto -ffat-lto-objects  scan-tree-
> > > dump
> > > vect "note: Built SLP cancelled: can use load/store-lanes"
> > >     gcc.dg/vect/slp-perm-7.c scan-tree-dump vect "note: Built SLP
> > > cancelled: can use load/store-lanes"
> > >     gcc.dg/vect/slp-perm-8.c -flto -ffat-lto-objects  scan-tree-
> > > dump
> > > vect "note: Built SLP cancelled: can use load/store-lanes"
> > >     gcc.dg/vect/slp-perm-8.c scan-tree-dump vect "note: Built SLP
> > > cancelled: can use load/store-lanes"
> > > 
> > > The problem is that now there are more spaces between "note:" and
> > > "Built", the attached small patch does that for slp-perm-1.c.
> > 
> > Sorry about the breakage.
> > 
> > > Is it the right way of fixing it or do we want to accept any
> > > amount
> > > of
> > > spaces for instance?
> > 
> > I don't think we want to hardcode the amount of space in the
> > dumpfile.
> > The idea of my patch was to make the dump more human-readable (I
> > hope)
> > by visualizing the nesting structure of the dump messages, but I
> > think
> > we shouldn't "bake" that into the expected strings, as someone
> > might
> > want to add an intermediate nesting level.
> > 
> > Do we really need to look for the "note:" in the scan-tree-dump?
> > Should that directive be rewritten to:
> > 
> > -/* { dg-final { scan-tree-dump "note: Built SLP cancelled: can use
> > load/store-lanes" "vect" { target { vect_perm3_int &&
> > vect_load_lanes } } } } */
> > +/* { dg-final { scan-tree-dump "Built SLP cancelled: can use
> > load/store-lanes" "vect" { target { vect_perm3_int &&
> > vect_load_lanes } } } } */
> > 
> > which I believe would match any amount of spaces.
> > 
> > Alternatively a regex accepting any amount of space ought to work,
> > if
> > we care that the message begins with "note: ".
> > 
> > The "note: " comes from dumpfile.c's dump_loc, and is emitted
> > regardless of whether it's a MSG_NOTE vs a MSG_MISSED_OPTIMIZATION
> > or
> > whatever.  Given that, maybe we should just drop the "note: "
> > prefix
> > from these scan-tree-dump expected regexes?  (assuming that works)
> 
> I guess it was done for the -fopt-info output channel to match what
> we emit with inform () given those are neither warnings nor errors.
> 
> But yes, lets elide "note: " from dumpfiles.  Be prepared to fiddle
> with expected scan-dumps though.

Re-reading, I think I was unclear, but I was proposing removing it from
the scan-tree-dump regexes, *not* from dumpfile.c (though I'm open to
the latter).

> 
> > > I'm surprised there is such little impact on the testsuite
> > > though.
> > 
> > I see lots of scan-tree-dump* directives in the vect part of the
> > testsuite, but it seems that only these ones use the "note: "
> > prefix; I
> > think everything else was matching against the message whilst
> > ignoring
> > the prefix, so it didn't matter when the prefix changed
> > (I double-checked and these scan-tree-dump directives didn't
> > trigger on
> > my x86_64 testing of the patch, due to { target { vect_perm3_int &&
> > vect_load_lanes } }, where I see
> > check_effective_target_vect_load_lanes: returning 0 in the log)
> > 
> > > If OK, I'll update the patch to take the other slp-perm-
> > > [235678].c
> > > tests into account.
> > > 
> > > Thanks,
> > > 
> > > Christophe
> > 
> > Sorry again about the breakage.
> > Dave
> > 


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]