Re: [Qemu-devel] [PATCH v2 1.3] build: compile translate.o with -fno-gcse option

[Alexander Graf <agraf@suse.de>]

On 11/27/2012 05:21 PM, Paolo Bonzini wrote:
> Some versions of GCC require insane (>2GB) amounts of memory to compile
> translate.o.  As a countermeasure, disable the culprit optimization pass.
> This should fix the buildbot failure for default_x86_64_fedora16.
> Anyway is a good thing to do because people will try to compile 1.3 with
> less than 2GB of memory and complain.
>
> Signed-off-by: Paolo Bonzini<pbonzini@redhat.com>
> ---
>   Makefile.target | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/Makefile.target b/Makefile.target
> index 8b658c0..d38bb58 100644
> --- a/Makefile.target
> +++ b/Makefile.target
> @@ -143,6 +143,12 @@ GENERATED_HEADERS += hmp-commands.h qmp-commands-old.h
>
>   endif # CONFIG_SOFTMMU
>
> +# Workaround for http://gcc.gnu.org/PR55489.  Happens with -fPIE/-fPIC
> +# and large functions that use global variables.  The bug is in all
> +# releases of GCC, but it became particularly acute in 4.7.x.  We
> +# should be able to delete this at the end of 2013.

Can we add a version check for gcc here?


Alex

> +%/translate.o: QEMU_CFLAGS += -fno-gcse
> +
>   nested-vars += obj-y
>
>   # This resolves all nested paths, so it must come last