| Message ID | or7gxpe6qt.fsf@livre.localdomain |
|---|---|
| State | New |
| Headers | show |
On Apr 9, 2012, Alexandre Oliva <aoliva@redhat.com> wrote: >>> I think this will restore proper functioning to SMS in the presence of >>> debug insns. A while ago, we'd never generate deps of non-debug insns >>> on debug insns. I introduced them to enable sched to adjust (reset) >>> debug insns when non-debug insns were moved before them. I believe it >>> is safe to leave them out of the SCCs. Even though this will end up >>> causing some loss of debug info, that's probably unavoidable, and the >>> end result after this change is pobably the best we can hope for. Your >>> thoughts? > for gcc/ChangeLog > from Alexandre Oliva <aoliva@redhat.com> > * ddg.c (build_intra_loop_deps): Discard deps of nondebug on debug. > Ping? http://gcc.gnu.org/ml/gcc-patches/2012-04/msg00419.html
Apologies for the duplicate ping, this one is now properly addressed to the pass maintainer. On Apr 9, 2012, Alexandre Oliva <aoliva@redhat.com> wrote: > On May 4, 2011, Revital1 Eres <ERES@il.ibm.com> wrote: >> Hello Alexandre >>> I think this will restore proper functioning to SMS in the presence of >>> debug insns. A while ago, we'd never generate deps of non-debug insns >>> on debug insns. I introduced them to enable sched to adjust (reset) >>> debug insns when non-debug insns were moved before them. I believe it >>> is safe to leave them out of the SCCs. Even though this will end up >>> causing some loss of debug info, that's probably unavoidable, and the >>> end result after this change is pobably the best we can hope for. Your >>> thoughts? >> Thanks for the patch! >> I actually discussed this issue with Ayal yesterday. >> Ayal also suggested to reconsider the edges that are created in >> the DDG between real instructions and debug_insns. Currently, we create >> bidirectional anti deps edges between them. This leads to the problem you >> were trying to solve in the current patch (described below) where these >> extra edges influence the construction of the strongly connected component >> and the code generated with and w\o -g. Your patch seems to solve this >> problem. >> However I can not approve it as I'm not the maintainer (Ayal is). > Ping? > (Retested on x86_64-linux-gnu and i686-pc-linux-gnu) > for gcc/ChangeLog > from Alexandre Oliva <aoliva@redhat.com> > * ddg.c (build_intra_loop_deps): Discard deps of nondebug on debug. Ping? http://gcc.gnu.org/ml/gcc-patches/2012-04/msg00419.html
Thanks for the duplicate ping. This is fine. So this indeed solves the discrepancy between running SMS w/ and w/o debugging? Please include a comment next to the code stating why it's important not to create such deps. You may also want to store the result of "DEP_PRO (dep)" in src_<something> and use it twice, for clarity. Thanks, Ayal. On Thu, Jun 14, 2012 at 1:00 AM, Alexandre Oliva <aoliva@redhat.com> wrote: > > Apologies for the duplicate ping, this one is now properly addressed to > the pass maintainer. > > On Apr 9, 2012, Alexandre Oliva <aoliva@redhat.com> wrote: > > > On May 4, 2011, Revital1 Eres <ERES@il.ibm.com> wrote: > >> Hello Alexandre > >>> I think this will restore proper functioning to SMS in the presence of > >>> debug insns. A while ago, we'd never generate deps of non-debug insns > >>> on debug insns. I introduced them to enable sched to adjust (reset) > >>> debug insns when non-debug insns were moved before them. I believe it > >>> is safe to leave them out of the SCCs. Even though this will end up > >>> causing some loss of debug info, that's probably unavoidable, and the > >>> end result after this change is pobably the best we can hope for. > >>> Your > >>> thoughts? > > >> Thanks for the patch! > > >> I actually discussed this issue with Ayal yesterday. > >> Ayal also suggested to reconsider the edges that are created in > >> the DDG between real instructions and debug_insns. Currently, we create > >> bidirectional anti deps edges between them. This leads to the problem > >> you > >> were trying to solve in the current patch (described below) where these > >> extra edges influence the construction of the strongly connected > >> component > >> and the code generated with and w\o -g. Your patch seems to solve this > >> problem. > >> However I can not approve it as I'm not the maintainer (Ayal is). > > > Ping? > > > (Retested on x86_64-linux-gnu and i686-pc-linux-gnu) > > > > for gcc/ChangeLog > > from Alexandre Oliva <aoliva@redhat.com> > > > * ddg.c (build_intra_loop_deps): Discard deps of nondebug on > > debug. > > Ping? http://gcc.gnu.org/ml/gcc-patches/2012-04/msg00419.html > > -- > Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/ > You must be the change you wish to see in the world. -- Gandhi > Be Free! -- http://FSFLA.org/ FSF Latin America board member > Free Software Evangelist Red Hat Brazil Compiler Engineer
for gcc/ChangeLog from Alexandre Oliva <aoliva@redhat.com> * ddg.c (build_intra_loop_deps): Discard deps of nondebug on debug. Index: gcc/ddg.c =================================================================== --- gcc/ddg.c.orig 2012-01-04 21:06:38.000000000 -0200 +++ gcc/ddg.c 2012-04-08 02:10:44.711511989 -0300 @@ -532,7 +532,12 @@ build_intra_loop_deps (ddg_ptr g) FOR_EACH_DEP (dest_node->insn, SD_LIST_BACK, sd_it, dep) { - ddg_node_ptr src_node = get_node_of_insn (g, DEP_PRO (dep)); + ddg_node_ptr src_node; + + if (DEBUG_INSN_P (DEP_PRO (dep)) && !DEBUG_INSN_P (dest_node->insn)) + continue; + + src_node = get_node_of_insn (g, DEP_PRO (dep)); if (!src_node) continue;