Re: [Patch AArch64] Switch constant pools to separate rodata sections.

[James Greenhalgh <james dot greenhalgh at arm dot com>]

On Mon, Nov 09, 2015 at 04:46:01PM +0000, Ramana Radhakrishnan wrote:
> 
> 
> On 08/11/15 11:42, Andreas Schwab wrote:
> > This is causing a bootstrap comparison failure in gcc/go/gogo.o.
> > 
> > Andreas.
> > 
> 
> I've had a look at this for sometime this afternoon and the trigger is the
> aarch64_use_constant_blocks_p change which appears to be causing a bootstrap
> comparison failure because of differences to offsets in add instructions when
> built with debug and without debug. For now, in the interest of go bootstraps
> continuing on trunk - I'm proposing a patch that partially rolls back the
> change in aarch64_use_constant_blocks_p and will still look into the
> underlying issue.
> 
> Bootstrapped on aarch64-none-linux-gnu including (c,c++ and go) - testing
> finished ok.
> 
> Ok ?

I agreem, this seems like the timely way to get the auto-testers back
building.

OK.

Thanks,
James

> 
> 
> Ramana
> 
> 
> PR bootstrap/68256
> 
> * config/aarch64/aarch64.c (aarch64_use_constant_blocks_p): Return false.

> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
> index 1b7be83..1fff878 100644
> --- a/gcc/config/aarch64/aarch64.c
> +++ b/gcc/config/aarch64/aarch64.c
> @@ -5251,9 +5251,11 @@ aarch64_can_use_per_function_literal_pools_p (void)
>  static bool
>  aarch64_use_blocks_for_constant_p (machine_mode, const_rtx)
>  {
> -  /* We can't use blocks for constants when we're using a per-function
> -     constant pool.  */
> -  return !aarch64_can_use_per_function_literal_pools_p ();
> +  /* Fixme:: In an ideal world this would work similar
> +     to the logic in aarch64_select_rtx_section but this
> +     breaks bootstrap in gcc go.  For now we workaround
> +     this by returning false here.  */
> +  return false;
>  }
>  
>  /* Select appropriate section for constants depending