undefined reference to .LB2480 / .LB2486

Accelerated Computing HPC Compilers Legacy PGI Compilers
1

Would you normally expect linking errors when using the higher compiler optimisation levels?

I’m building IMB 3.1 / 3.2 with MVAPICH2 1.4 and PGI 10.0 on a 64-bit RHEL5.4 system. The default makefile uses an optimisation level of “-O2”, which generates the following error:

/scratch/issmcd/m/bin/mpicc -o IMB-IO IMB.o IMB_declare.o IMB_init.o IMB_mem_manager.o IMB_init_file.o IMB_benchlist.o IMB_parse_name_io.o IMB_strgs.o IMB_user_set_info.o IMB_cpu_exploit.o IMB_err_handler.o IMB_g_info.o IMB_warm_up.o IMB_output.o IMB_open_close.o IMB_write.o IMB_read.o IMB_init_transfer.o IMB_chk_diff.o
IMB_output.o:(.debug_info+0x1060): undefined reference to .LB2480' IMB_output.o:(.debug_info+0x1068): undefined reference to .LB2486’

This error disappears when using “-O1” or lower.

IMB_output.o is generated from:

/scratch/issmcd/m/bin/mpicc -I/scratch/issmcd/m/include -DMPIIO -O2 -c IMB_output.c

Which does a:

pgcc -g -I/scratch/issmcd/m/include -DMPIIO -O2 -c IMB_output.c -I/scratch/issmcd/m/include

Which does:

/apps/compilers/pgi/10.0/1/linux86-64/10.0/bin/pgc IMB_output.c -debug -x 120 0x200 -opt 2 -x 119 0xa10000 -x 122 0x40 -x 123 0x1000 -x 127 4 -x 127 17 -x 19 0x400000 -x 28 0x40000 -x 120 0x10000000 -x 70 0x8000 -x 122 1 -quad -x 59 4 -x 59 4 -tp nehalem-64 -astype 0 -stdinc /apps/compilers/pgi/10.0/1/linux86-64/10.0/include:/usr/local/include:/usr/lib/gcc/x86_64-redhat-linux/4.1.2/include:/usr/lib/gcc/x86_64-redhat-linux/4.1.2/include:/usr/include -def unix -def __unix -def unix -def linux -def __linux -def linux -def __NO_MATH_INLINES -def x86_64 -def LONG_MAX=9223372036854775807L -def ‘SIZE_TYPE=unsigned long int’ -def ‘PTRDIFF_TYPE=long int’ -def __THROW= -def extension= -def amd64 -def SSE -def MMX -def SSE2 -def SSE3 -def SSSE3 -predicate ‘#machine(x86_64) #lint(off) #system(posix) #cpu(x86_64)’ -idir /scratch/issmcd/m/include -idir /scratch/issmcd/m/include -def MPIIO -cmdline ‘+pgcc IMB_output.c -v -g -I/scratch/issmcd/m/include -DMPIIO -O2 -c -I/scratch/issmcd/m/include’ -x 123 0x80000000 -x 123 4 -x 119 0x20 -alwaysinline /apps/compilers/pgi/10.0/1/linux86-64/10.0/lib/libintrinsics.il 4 -x 120 0x200000 -asm /tmp/pgcc6iDbUda95i8A.s
PGC-I-0222-Redundant definition for symbol __THROW (/usr/include/sys/cdefs.h: 63)
PGC-I-0222-Redundant definition for symbol extension (/usr/include/sys/cdefs.h: 287)
PGC/x86-64 Linux 10.0-1: compilation completed with informational messages

/usr/bin/as /tmp/pgcc6iDbUda95i8A.s -I/scratch/issmcd/m/include -I/scratch/issmcd/m/include -o IMB_output.o
Unlinking /tmp/pgcc6iDbUda95i8A.s

Looking at the temporary assembler file, it looks like the symbols are being used but not being defined.

2

Hi Mark,

These are compiler debug labels that are most likely being optimized away. To work around, try removing “-g” from your MVAPICH compilation flags. If you do want to keep debugging enabled, changing “-g” to “-gopt” might work as well.

I’d like to try and recreate the issue here. Is IMB publicly available? If so, can you post a pointer? Unfortunately, a simple search of “IMB” yield too many extraneous results.

Thanks,
Mat

3

Thanks Mat, I’ll have a play with -g - and see why MVAPICH2 is specifying it in the first place.

IMB is available from:

MVAPICH2 is available from:

http://mvapich.cse.ohio-state.edu/

I’ve been building MVAPICH2 for our InfiniBand cluster (OFED 1.4.1) with configure arguments:

./configure --with-rdma=gen2 --enable-sharedlibs=gcc --enable-romio --with-file-system=lustre+ufs+nfs


All the best,

Mark

4

Hi Mat, I can provide an environment for you which reproduces this issue if you would like to see first hand. lmk.

5

Thanks Jason, but I was able to recreate the problem here and have sent it to our engineers as TPR#16589.

Note that the error can also be worked around by adding “-fast” to the OPTFLAGS and LDFLAGS or changing “-g” to “-gopt”.

  • Mat
6

Jason,

We believe TPR 16589 has been corrected in the current 10.3 release.

regards,
dave

7

Dave, thank you for the update. i’ll upgrade to 10.3 and fire off a ofed build.

Jason