[Beowulf] re: Quick question... on Fortran

[Bill Broadley]

> The limit is 2GB for Intel ia-32 compilers, fortran or not. You may
> need to compile -static to get it. Since this is half the 4GB limit of
> a 32 bit system (maybe the last bit is lost because of signed
> arithmetic?), I'm guessing the ia-64 compilers can have much larger
> arrays.

For g77 with a 32 bit binary I think you are right:
bigmem.f:119: error: size of variable 'a' is too large

pathf90 producing a 32 bit binary:
### Assertion failure at line 726 of ../../be/cg/x8664/exp_loadstore.cxx:
### Compiler Error in file bigmem.f during Code_Expansion phase:
### NYI: 64-bit offset under -m32

Gcc and a 32 bit binary seems fine with 3GB:

# file ./a.out
./a.out: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for 
GNU/Linux 2.2.5, dynamically linked (uses shared libs), not stripped

Verified with top:
   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
16246 root      25   0 3073m 3.0g  288 R  100 76.7   0:07.09 a.out

with x86-64 binaries I've tried 6GB arrays, and could try 12 GB if
there is interest.