PR66870 PowerPC64 Enable gold linker with split stack

On 07.10.2015 17:36, Lynn A. Boger wrote:
> Pretty sure this is the fix, but still doing some testing.

linux.h isn't included for multilib enabled builds defaulting to 
powerpc-linux-gnu, I am currently testing

On Wed, Oct 7, 2015 at 3:37 PM, Lynn A. Boger
<laboger@linux.vnet.ibm.com> wrote:
> Right I didn't think of the multilib on powerpc-linux-gnu (actually didn't
> think that was allowed).
>
> I don't think TARGET_64BIT will work here (I tried it), because on ppc64 &
> ppc64le it gets replaced with a code snippet to check
> a value in rs6000_isa_flags.  Based on how it is used here, it has to be a
> compile time define, not a bit checked
> at runtime.
>
> However, I think #if TARGET_POWERPC64 == 1 should work instead of
> TARGET_64BIT and I believe that will do the trick.
>
> Let me try that out on the ppc64 & ppc64le targets to make sure it still
> works as it should.

TARGET_POWERPC64 is not the correct test.

- David

I think my original fix with linux.h doing the #undef on 
TARGET_CAN_SPLIT_STACK_64BIT is the right fix at least
for powerpc-linux-gnu 32 bit only.

It works for powerpc-linux-gnu without multilib and doesn't break 
powerpc64-linux-gnu or powerpc64le-linux-gnu.

Can you tell me how you are configuring the multilib build that defaults 
to powerpc-linux-gnu and how it
fails?  Maybe there is another problem for that combination.

As David noted, the use of TARGET_64BIT or TARGET_POWERPC64 won't work 
for this #define.

On 10/07/2015 12:31 PM, Matthias Klose wrote:
> On 07.10.2015 17:36, Lynn A. Boger wrote:
>> Pretty sure this is the fix, but still doing some testing.
>
> linux.h isn't included for multilib enabled builds defaulting to 
> powerpc-linux-gnu, I am currently testing
>
> --- gcc/config/rs6000/sysv4.h    (revision 228571)
> +++ gcc/config/rs6000/sysv4.h    (working copy)
> @@ -943,8 +943,9 @@
>  /* On ppc64 and ppc64le, split stack is only support for
>     64 bit. */
>  #undef TARGET_CAN_SPLIT_STACK_64BIT
> -#if TARGET_GLIBC_MAJOR > 2 \
> -  || (TARGET_GLIBC_MAJOR == 2 && TARGET_GLIBC_MINOR >= 18)
> +#if TARGET_64BIT \
> +  && (TARGET_GLIBC_MAJOR > 2 \
> +      || (TARGET_GLIBC_MAJOR == 2 && TARGET_GLIBC_MINOR >= 18))
>  #define TARGET_CAN_SPLIT_STACK_64BIT
>  #endif
>
>
>
>

On 08.10.2015 20:56, Lynn A. Boger wrote:
> I think my original fix with linux.h doing the #undef on
> TARGET_CAN_SPLIT_STACK_64BIT is the right fix at least
> for powerpc-linux-gnu 32 bit only.
>
> It works for powerpc-linux-gnu without multilib and doesn't break
> powerpc64-linux-gnu or powerpc64le-linux-gnu.
>
> Can you tell me how you are configuring the multilib build that defaults to
> powerpc-linux-gnu and how it
> fails?  Maybe there is another problem for that combination.

Configured with: -v
	 --with-pkgversion='Ubuntu 20151005-0ubuntu1'
	 --with-bugurl='file:///usr/share/doc/gcc-snapshot/README.Bugs'
	 --enable-languages=c,ada,c++,java,go,fortran,objc,obj-c++
	 --prefix=/usr/lib/gcc-snapshot
	 --enable-shared
	 --enable-linker-build-id
	 --disable-nls
	 --with-sysroot=/
	 --enable-clocale=gnu
	 --enable-libstdcxx-debug
	 --enable-libstdcxx-time=yes
	 --with-default-libstdcxx-abi=new
	 --enable-gnu-unique-object
	 --disable-libitm
	 --disable-libquadmath
	 --enable-plugin
	 --with-system-zlib
	 --disable-browser-plugin
	 --enable-java-awt=gtk
	 --enable-gtk-cairo
	 --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-6-snap-powerpc/jre
	 --enable-java-home
	 --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-6-snap-powerpc
	 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-6-snap-powerpc
	 --with-arch-directory=ppc
	 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar
	 --enable-objc-gc
	 --enable-secureplt
	 --disable-softfloat
	 --with-cpu=default32
	 --disable-softfloat
	 --enable-targets=powerpc-linux,powerpc64-linux
	 --enable-multiarch
	 --disable-werror
	 --with-long-double-128
	 --enable-multilib
	 --enable-checking=yes
	 --build=powerpc-linux-gnu
	 --host=powerpc-linux-gnu
	 --target=powerpc-linux-gnu

fails in gotools with:
cc1: error: '-fsplit-stack' currently only supported on PowerPC64 GNU/Linux with 
glibc-2.18 or later
cc1: error: '-fsplit-stack' is not supported by this compiler configuration

this information is from the log below, but it's a parallel build, so a bit useless
https://launchpadlibrarian.net/220374353/buildlog_ubuntu-wily-powerpc.gcc-snapshot_20151005-0ubuntu1_BUILDING.txt.gz

> As David noted, the use of TARGET_64BIT or TARGET_POWERPC64 won't work for this
> #define.

I found that out too =)  Note that ada builds are currently broken on the trunk.

Matthias