[Llvm-bgq-discuss] Errors when compiling LLVM with Clang for BG/P

[Prentice Bisbal]

Hal,

Thanks for the reply. My responses are inline.

On 03/14/2013 04:22 PM, Hal Finkel wrote:
> ----- Original Message -----
>> From: "Prentice Bisbal" <prentice.bisbal at rutgers.edu>
>> To: llvm-bgq-discuss at lists.alcf.anl.gov
>> Sent: Thursday, March 14, 2013 3:08:59 PM
>> Subject: [Llvm-bgq-discuss] Errors when compiling LLVM with Clang for BG/P
>>
>> dear LLVM_BGQ list,
>>
>> I'm trying to build LLVM with Clang for BG/P. I downloaded the
>> patches
>> for the r157929-20120603 revision from
>> http://trac.alcf.anl.gov/projects/llvm-bgq, downloaded the
>> corresponding
>> revisions of LLVM and Clang and applied the patches. I downloaded the
>> latest version of compiler-rt, since non of the patches modified
>> compiler-rt, I figured that I could use the latest version. I
>> recognize
>> this may be a wrong assumption. My make eventually fails. Can someone
>> offer any assistance? My download/patch/make steps are shown below,
>> along with the warning/errors I get during the build.
>>
>> Questions/comments:
>>
>> 1. Do I need to download a specific version of compiler-rt to match
>> the
>> versions of LLVM and Clang?
> You don't need compiler-rt, and even if you did want to try to use it you'd probably need to compile it manually b/c it would need to be cross-compiled.

Good to know. Makes my job easier. I'm new to LLVM, so I don't know much 
about it yet.
>> 2. Are there any flags I should set in my environment, or as part of
>> the
>> configure command? I've seen a couple web pages that say to set
>> CXXFLAGS=-UPPC or CPPFLAGS=-UPPC. Since one page said CPPFLAGS, and
>> the
>> other said CXXFLAGS, I'm dubious.
> One problem that you'll have is that the base system compiler is too old to compile LLVM. When I last built on the BG/P, I used the following command line:
>
> make CXX=/soft/apps/fen/gcc-4.4.3/bin/g++ ENABLE_OPTIMIZED=1 \
> EXTRA_OPTIONS='-m64 -UPPC -fno-strict-aliasing -mminimal-toc' \
> EXTRA_LD_OPTIONS=-Wl,-rpath=/soft/apps/fen/gcc-4.4.3/lib64
>
> What version of gcc were you trying to use?

The gcc that came with SUSE 10.4, version 4.1.2. I'll install the latest 
version before I try again.
>> 3. I know Hal Finkel provided new patches on the mailing list on
>> December 13th
>> http://lists.alcf.anl.gov/pipermail/llvm-bgq-discuss/2012-December/000010.html)
>> (but I can't get these patches to work. One of the patche files ends
>> prematurely, so the patch process fails.
>>
>> 4 Since I'm compiling for a BG/P and the development is focused on
>> the
>> BG/Q, I figure these newer patches in (3) probably don't really
>> affect
>> me. Right or wrong?
> For the most part that is correct. There have not been many PPC32 improvements upstream since then. You will want future updates for frontend improvements, and I'll have rebased patches out soon.
>
>   -Hal
>
>
--
Prentice