[OE-core] [PATCH] gcc-configure-common.inc: drop --enable-target-optspace from configure

[Andre McCurdy]

On Mon, Feb 1, 2016 at 4:19 PM, Khem Raj <raj.khem at gmail.com> wrote:
> What is the size increase in gcc runtime when u do this

No significant changes.

Binaries which link statically with libgcc all grow a little
(somewhere between 10 and 50 bytes).

libgcc_s.so.1 itself grows by approx 1%:

   text       data        bss        dec        hex    filename
 114896        516         56     115468      1c30c    libgcc_s.so.1 (-Os)
 116148        516         56     116720      1c7f0    libgcc_s.so.1 (-O2)

libssp, libstdc++, libgomp and libatomic all ignore the
--enable-target-optspace configure option, so are not affected.

(Results from an armv7ve build).

> On Feb 1, 2016 2:01 PM, "Andre McCurdy" <armccurdy at gmail.com> wrote:
>>
>> Configuring gcc with --enable-target-optspace (which causes gcc to
>> append "-g -Os" to the default CFLAGS_FOR_TARGET and so force libgcc
>> etc target libraries to always be optimised for size) dates back to
>> the very first commit in oe-core git in 2005 (for gcc 3.4.3).
>>
>> Configuring gcc with --enable-target-optspace is not done widely
>> elsewhere (it's not used for Ubuntu or Fedora host gcc, the Linaro
>> binary toolchain or in Buildroot since early 2015). Sometime around
>> gcc 4.5.x it caused problems for powerpc and so was disabled for that
>> architecture:
>>
>>   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43810
>>
>> This patch removes --enable-target-optspace completely (ie powerpc is
>> no longer a special case) and allows optimisation of libgcc etc to be
>> controlled directly by the flags present in TARGET_CFLAGS.
>>
>> Signed-off-by: Andre McCurdy <armccurdy at gmail.com>
>> ---
>>  meta/recipes-devtools/gcc/gcc-configure-common.inc | 8 --------
>>  meta/recipes-devtools/gcc/gcc-cross-initial.inc    | 1 -
>>  2 files changed, 9 deletions(-)
>>
>> diff --git a/meta/recipes-devtools/gcc/gcc-configure-common.inc
>> b/meta/recipes-devtools/gcc/gcc-configure-common.inc
>> index 85e69db..f4f76bd 100644
>> --- a/meta/recipes-devtools/gcc/gcc-configure-common.inc
>> +++ b/meta/recipes-devtools/gcc/gcc-configure-common.inc
>> @@ -14,13 +14,6 @@ JAVA_sh3 ?= ""
>>  # gcc 3.x expects 'f77', 4.0 expects 'f95', 4.1 and 4.2 expect 'fortran'
>>  FORTRAN ?= ",f77"
>>  LANGUAGES ?= "c,c++${FORTRAN}${JAVA}"
>> -# disable --enable-target-optspace for powerpc SPE
>> -# at -Os libgcc.so.1 creates references into
>> -# hidden symbols in libgcc.a which linker complains
>> -# when linking shared libraries further in the build like (gnutls)
>> -
>> -SPECIAL_ARCH_LIST = "powerpc"
>> -OPTSPACE = '${@bb.utils.contains("SPECIAL_ARCH_LIST", "${TARGET_ARCH}",
>> "", "--enable-target-optspace",d)}'
>>
>>  EXTRA_OECONF_BASE ?= ""
>>  EXTRA_OECONF_PATHS ?= ""
>> @@ -42,7 +35,6 @@ EXTRA_OECONF = "\
>>      --enable-libstdcxx-pch \
>>      --program-prefix=${TARGET_PREFIX} \
>>      --without-local-prefix \
>> -    ${OPTSPACE} \
>>      ${EXTRA_OECONF_BASE} \
>>      ${EXTRA_OECONF_GCC_FLOAT} \
>>      ${EXTRA_OECONF_PATHS} \
>> diff --git a/meta/recipes-devtools/gcc/gcc-cross-initial.inc
>> b/meta/recipes-devtools/gcc/gcc-cross-initial.inc
>> index 910f2ef..048b530 100644
>> --- a/meta/recipes-devtools/gcc/gcc-cross-initial.inc
>> +++ b/meta/recipes-devtools/gcc/gcc-cross-initial.inc
>> @@ -22,7 +22,6 @@ EXTRA_OECONF = "\
>>      --disable-multilib \
>>      --disable-__cxa_atexit \
>>      --enable-languages=c \
>> -    ${OPTSPACE} \
>>      --program-prefix=${TARGET_PREFIX} \
>>      --with-sysroot=/not/exist \
>>      --with-build-sysroot=${GCCCROSS_BUILDSYSROOT} \
>> --
>> 1.9.1
>>
>> --
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