[R-SIG-Mac] 64-bit R compiling problem on Leopard

Simon Urbanek simon.urbanek at r-project.org
Thu Dec 13 14:59:19 CET 2007

Hi Herve,

On Dec 12, 2007, at 7:06 PM, Herve Pages wrote:

> Simon Urbanek wrote:
> [...]
>> FWIW: dual 32-bit and 64-bit binaries of current R 2.6.1 patched  
>> and R-
>> devel for Leopard are available from
>> http://r.research.att.com/
>> They support all four architectures. To start 64-bit Intel R use R --
>> arch=x86_64, for 64-bit ppc it is R --arch=ppc64.
> We are trying to help some Bioconductor users to use these nightly
> builds in 64-bit mode.
> I noticed that when I start them with R --arch=x86_64,  
> 'sessionInfo()' and 'version' still report i386 (this is with the  
> latest R-2.6-branch r R-devel builds for Leopard available at http://r.research.att.com/) 
> .

Yes - the platform is always i386 or powerpc since Mac OS X identifies  
as such (there is no 64-bit only Mac OS X).

The only reliable way of identifying 32-bit vs 64-bit (on any  
platform) is .Machine$sizeof.pointer

> However, when I try to install and load a Bioconductor binary  
> package, I do get the same error as reported by Tae-Hoon:
>> library(Biostrings)
>  Error: package 'Biostrings' is not installed for 'arch=x86_64'
> so it seems that I'm really running R in x86_64 mode (and then the  
> error I get with library(Biostrings) is perfectly normal since the  
> BioC universal binaries don't support the x86_64 arch yet).

Yes, you are - see .Platform$r_arch

> Also note that when I start R with --arch=ppc, 'sessionInfo()' and  
> 'version' report the powerpc arch. So why isn't it the case with the  
> x86_64 arch?

Because Mac OS X on PowerPC identifies itself as powerpc (and there is  
ppc-only Mac OS X). The same is true for --arch=ppc64.

I know that this is confusing, but this is the default. I could force  
the identifiers to be x86_64 and powerpc64 at build time (mainly  
because such platforms officially don't exist), but for now I have  
refrained from doing so. The Leopard 64-bit builds are experimental,  
so nothing is set in stone yet ...


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