RE: Differences in GCC and ICC compiled objects, GCC relocations broken?

["Iyer, Balaji V" <balaji dot v dot iyer at intel dot com>]

Hello J. K.,
	Have you tried with a newer version of GCC? GCC 4.1 is pretty old....

Thanks,

Balaji V. Iyer.

-----Original Message-----
From: J K [mailto:jkwipub@gmail.com] 
Sent: Thursday, February 23, 2012 10:31 AM
To: gcc@gcc.gnu.org
Subject: Differences in GCC and ICC compiled objects, GCC relocations broken?

?Posted in the Intel forums but this may be more of a GCC issue.
 Please advise if I should post elsewhere.

?Compiling a C module in with a large app (>2GB data) and getting relocatable errors with GCC and  not ICC.

./classification_dpr_BB.o: In function `BB_detection_dpr':
/homedata/johnk/dpr/src_
20120126/DD2_V2.20120126/src/./
classification_dpr_BB.c:118: relocation truncated to fit:
R_X86_64_PC32 against `.bss'

?Can anyone familiar with the output of readelf see why the GCC
?object is not relocatable and the ICC one is? Would another tool
?be more suitable?

icc -I../include -g -v -sox -fPIC -mcmodel=medium -DDEBUG ?-c ./classification_dpr_BB.c cc -I../include -g -v -fPIC -mcmodel=medium -DDEBUG ?-c ./classification_dpr_BB.c

? This module does not use more than 2GB data itself, I just need it to be linked with
? code that does, so -fPIC. ?I left off the medium memory model switch on both with no impact.
? Everything is static except for the -shared-intel -mcmodel=medium on the main link (ifort is used).

? Could it have something to do with the relocation types? Are there switches to GCC to force relocations
  like ICC?

GCC
Relocation section '.rela.text' at offset 0xd040 contains 449 entries:
?Offset ? ? ? ? ?Info ? ? ? ? ? Type ? ? ? ? ? Sym. Value ? ?Sym.
Name + Addend
00000000004e ?001700000002 R_X86_64_PC32 ? ? 0000000000000000 .rodata
+ fffffffffffffffc
00000000008e ?000400000002 R_X86_64_PC32 ? ? 0000000000000000 .bss + 1e5c 0000000000bc ?000400000002 R_X86_64_PC32 ? ? 0000000000000000 .bss + 105c


ICC
Relocation section '.rela.text' at offset 0xf222 contains 732 entries:
?Offset ? ? ? ? ?Info ? ? ? ? ? Type ? ? ? ? ? Sym. Value ? ?Sym.
Name + Addend
000000000030 ?00780000001a R_X86_64_GOTPC32 ?0000000000000000 _GLOBAL_OFFSET_TABLE_ + fffffffffffffffc
000000000036 ?000600000019 R_X86_64_GOTOFF64 0000000000000000
_2il0floatpacket.15 + 0
000000000057 ?000700000019 R_X86_64_GOTOFF64 0000000000000008
_2il0floatpacket.16 + 0
00000000009f ?00780000001a R_X86_64_GOTPC32 ?0000000000000000 _GLOBAL_OFFSET_TABLE_ + fffffffffffffffc

gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-51) icc (ICC) 11.1 20100806

?The full output of readelf -all are at these links.

ICC
http://www.box.com/s/2iqnqydmi0mdz52xs9ac

GCC
http://www.box.com/s/jjcgq1x2s5ybpg7s9b6g

Thanks for any help.