[PATCH], PR 68404 patch #2 (disable power8/power9 fusion on PowerPC)
This patch disables -mcpu=power8/-mtune=power8 from setting -mpower8-fusion and -mcpu=power9/-mtune=power9 from setting -mpower9-fusion. I will look at the earlyclobber that Bernd Schmidt mentioned, but for now it may be safest to just disable it for GCC 6.0. I built it on a little endian power8 system, and there were no regressions. Is it ok to install? [gcc] 2016-02-10 Michael Meissner PR target/68404 * config/rs6000/predicates.md (fusion_gpr_addis): Revert 2016-02-09 change. * config/rs6000/rs6000-cpus.def (ISA_2_7_MASKS_SERVER): Do not set power8/power9 fusion by default. (ISA_3_0_MASKS_SERVER): Likewise. * config/rs6000/rs6000.c (rs6000_option_override_internal): Remove code setting -mpower8-fusion if -mtune=power8 and -mpower9-fusion if -mtune=power9. * doc/invoke.texi (RS/6000 and PowerPC Options): Document that -mpower8-fusion and -mpower9-fusion are not set by default. [gcc/testsuites] 2016-02-10 Michael Meissner PR target/68404 * gcc.target/powerpc/fusion.c: Do not assume that -mtune=power8 sets -mpower8-fusion or -mtune=power9 sets -mpower9-fusion. * gcc.target/powerpc/fusion2.c: Likewise. * gcc.target/powerpc/fusion3.c: Likewise. -- Michael Meissner, IBM IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA email: meiss...@linux.vnet.ibm.com, phone: +1 (978) 899-4797
Re: [PATCH], PR 68404 patch #2 (disable power8/power9 fusion on PowerPC)
On Wed, Feb 10, 2016 at 05:42:17PM -0500, Michael Meissner wrote: > This patch disables -mcpu=power8/-mtune=power8 from setting -mpower8-fusion > and > -mcpu=power9/-mtune=power9 from setting -mpower9-fusion. I will look at the > earlyclobber that Bernd Schmidt mentioned, but for now it may be safest to > just > disable it for GCC 6.0. > > I built it on a little endian power8 system, and there were no regressions. > Is > it ok to install? Doesn't this mean the bug is still there, just not enabled unless -mpower[89]-fusion (ok, perhaps mitigated by the previous workaround patch)? Wouldn't it be better to just forcefully clear the options (and thus ignore -them) for the time being if they are known to be broken? > [gcc] > 2016-02-10 Michael Meissner > > PR target/68404 > * config/rs6000/predicates.md (fusion_gpr_addis): Revert > 2016-02-09 change. > > * config/rs6000/rs6000-cpus.def (ISA_2_7_MASKS_SERVER): Do not set > power8/power9 fusion by default. > (ISA_3_0_MASKS_SERVER): Likewise. > > * config/rs6000/rs6000.c (rs6000_option_override_internal): Remove > code setting -mpower8-fusion if -mtune=power8 and -mpower9-fusion > if -mtune=power9. > > * doc/invoke.texi (RS/6000 and PowerPC Options): Document that > -mpower8-fusion and -mpower9-fusion are not set by default. > > [gcc/testsuites] > 2016-02-10 Michael Meissner > > PR target/68404 > * gcc.target/powerpc/fusion.c: Do not assume that -mtune=power8 > sets -mpower8-fusion or -mtune=power9 sets -mpower9-fusion. > * gcc.target/powerpc/fusion2.c: Likewise. > * gcc.target/powerpc/fusion3.c: Likewise. > > -- > Michael Meissner, IBM > IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA > email: meiss...@linux.vnet.ibm.com, phone: +1 (978) 899-4797 Jakub
Re: [PATCH], PR 68404 patch #2 (disable power8/power9 fusion on PowerPC)
On Wed, Feb 10, 2016 at 2:46 PM, Jakub Jelinek wrote: > On Wed, Feb 10, 2016 at 05:42:17PM -0500, Michael Meissner wrote: >> This patch disables -mcpu=power8/-mtune=power8 from setting -mpower8-fusion >> and >> -mcpu=power9/-mtune=power9 from setting -mpower9-fusion. I will look at the >> earlyclobber that Bernd Schmidt mentioned, but for now it may be safest to >> just >> disable it for GCC 6.0. >> >> I built it on a little endian power8 system, and there were no regressions. >> Is >> it ok to install? > > Doesn't this mean the bug is still there, just not enabled unless > -mpower[89]-fusion (ok, perhaps mitigated by the previous workaround patch)? > Wouldn't it be better to just forcefully clear the options (and thus ignore > -them) for the time being if they are known to be broken? > >> [gcc] >> 2016-02-10 Michael Meissner >> >> PR target/68404 >> * config/rs6000/predicates.md (fusion_gpr_addis): Revert >> 2016-02-09 change. >> >> * config/rs6000/rs6000-cpus.def (ISA_2_7_MASKS_SERVER): Do not set >> power8/power9 fusion by default. >> (ISA_3_0_MASKS_SERVER): Likewise. >> >> * config/rs6000/rs6000.c (rs6000_option_override_internal): Remove >> code setting -mpower8-fusion if -mtune=power8 and -mpower9-fusion >> if -mtune=power9. >> >> * doc/invoke.texi (RS/6000 and PowerPC Options): Document that >> -mpower8-fusion and -mpower9-fusion are not set by default. >> >> [gcc/testsuites] >> 2016-02-10 Michael Meissner >> >> PR target/68404 >> * gcc.target/powerpc/fusion.c: Do not assume that -mtune=power8 >> sets -mpower8-fusion or -mtune=power9 sets -mpower9-fusion. >> * gcc.target/powerpc/fusion2.c: Likewise. >> * gcc.target/powerpc/fusion3.c: Likewise. Because of the more recent patches that should fix the cause of this failure, this set of patches now are moot. - David
