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| author | Michael Stahl <mstahl@redhat.com> | 2016-11-28 17:22:16 +0100 |
|---|---|---|
| committer | Michael Stahl <mstahl@redhat.com> | 2016-12-01 16:50:11 +0000 |
| commit | 6982598524491ee087e69c149eaa958af91b1999 (patch) | |
| tree | df2390dbd0240b167d85b5998b11a7bf54b7fe32 /solenv | |
| parent | d6a1ba29a512aec9b4aa3d0ab4bd6b92aea7fef4 (diff) | |
gbuild: replace -O0 with -Og for GCC --enable-debug/dbgutil builds
With Fedora 25 GCC 6.2.1 and my usual config (except without
--with-package-format since that is slowest now) on commit
086631af59636cd9a6a45b747a1bc59b4b547794 i get with CCACHE_DISABLE=1:
With -O0:
"make check"
44490.70user 3127.01system 1:15:23elapsed 1052%CPU (0avgtext+0avgdata 2541312maxresident)k
"make check", incremental
7368.19user 153.98system 15:30.06elapsed 808%CPU (0avgtext+0avgdata 510200maxresident)k
"make CppunitTest_sc_functions_test"
272.13user 0.65system 4:33.47elapsed 99%CPU (0avgtext+0avgdata 258884maxresident)k
With -Og:
"make check"
46076.01user 3170.91system 1:16:19elapsed 1075%CPU (0avgtext+0avgdata 2613716maxresident)k
"make check", incremental
5478.33user 157.07system 11:50.42elapsed 793%CPU (0avgtext+0avgdata 454980maxresident)k
"make CppunitTest_sc_functions_test"
188.48user 0.62system 3:09.59elapsed 99%CPU (0avgtext+0avgdata 259096maxresident)k
So we now have so many tests that the time taken by GCC doing optimization
is brought back via the tests finishing faster, particularly if we
assume a non-negligible ccache hit rate for developers in practice.
Add this to gb_DEBUG_CFLAGS instead of gb_COMPILERNOOPTFLAGS because
presumably the bridges code that uses gb_COMPILERNOOPTFLAGS really wants
-O0; the gb_DEBUG_CFLAGS is added later so -Og overrides -O0.
It is an open question how well debugging in gdb actually works with
-Og, some experimentation is needed; "man gcc" claims:
If you are not using some other optimization option, consider using -Og
with -g. With no -O option at all, some compiler passes that collect
information useful for debugging do not run at all, so that -Og may
result in a better debugging experience.
Change-Id: I103499f398b69397cf5aa9993a242680966ce999
Reviewed-on: https://gerrit.libreoffice.org/31334
Reviewed-by: Norbert Thiebaud <nthiebaud@gmail.com>
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Stahl <mstahl@redhat.com>
Diffstat (limited to 'solenv')
| -rw-r--r-- | solenv/gbuild/platform/com_GCC_defs.mk | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/solenv/gbuild/platform/com_GCC_defs.mk b/solenv/gbuild/platform/com_GCC_defs.mk index 6b697fc9461c..25125334840c 100644 --- a/solenv/gbuild/platform/com_GCC_defs.mk +++ b/solenv/gbuild/platform/com_GCC_defs.mk @@ -186,7 +186,9 @@ ifeq ($(HAVE_GCC_FNO_DEFAULT_INLINE),TRUE) FNO_DEFAULT_INLINE=-fno-default-inline endif -gb_DEBUG_CFLAGS := $(FINLINE_LIMIT0) $(FNO_INLINE) +# note: this overrides -O0 from the gb_COMPILERNOOPTFLAGS with -Og if +# available, so that the former remains no-optimization for when that is needed +gb_DEBUG_CFLAGS := $(if $(HAVE_GCC_OG),-Og) $(FINLINE_LIMIT0) $(FNO_INLINE) gb_DEBUG_CXXFLAGS := $(FNO_DEFAULT_INLINE) |