Re: is there a 2GB limit on amd64 link?
Yes, that (-mcmodel=medium) is the solution. Thanks! John On 2020-02-05 22:03, Philip Guenther wrote: On Wed, Feb 5, 2020 at 7:38 PM wrote: I am encountering a linker error when compiling with ports-gcc Fortran: ld: error: lbug2.f90:(function MAIN__: .text+0x80): relocation R_X86_64_PC32 out o f range: 2456507324 is not in [-2147483648, 2147483647] The code has several large arrays, the total size of which exceeds 2GB. Is this a linker issue, a gcc fortran issue, or a pebkac? It's at least a gnu fortran issue: it needs to generate object code in a larger "model" than it currently is. I've never used gnu fortran, but it might accept the -mcmodel=medium option like gcc and generate code sequences for data symbols that don't limit them to the bottom 2GB (or to within 2GB of the involved code, depending on gcc's choices in implementing the model). If it doesn't accept that option, then you'll need to work with the the docs, mailling lists, etc of the upstream gnu fortran project about how to have it generate code for the medium or large data models per the amd64 ABI. Philip Guenther
Re: is there a 2GB limit on amd64 link?
On Wed, Feb 5, 2020 at 7:38 PM wrote: > I am encountering a linker error when compiling with ports-gcc Fortran: > > ld: error: lbug2.f90:(function MAIN__: .text+0x80): relocation > R_X86_64_PC32 out o > f range: 2456507324 is not in [-2147483648, 2147483647] > > The code has several large arrays, the total size of which exceeds 2GB. > > Is this a linker issue, a gcc fortran issue, or a pebkac? > It's at least a gnu fortran issue: it needs to generate object code in a larger "model" than it currently is. I've never used gnu fortran, but it might accept the -mcmodel=medium option like gcc and generate code sequences for data symbols that don't limit them to the bottom 2GB (or to within 2GB of the involved code, depending on gcc's choices in implementing the model). If it doesn't accept that option, then you'll need to work with the the docs, mailling lists, etc of the upstream gnu fortran project about how to have it generate code for the medium or large data models per the amd64 ABI. Philip Guenther
is there a 2GB limit on amd64 link?
I am encountering a linker error when compiling with ports-gcc Fortran: ld: error: lbug2.f90:(function MAIN__: .text+0x80): relocation R_X86_64_PC32 out o f range: 2456507324 is not in [-2147483648, 2147483647] The code has several large arrays, the total size of which exceeds 2GB. Is this a linker issue, a gcc fortran issue, or a pebkac? $ cat lbug1.f90 program lbug implicit none save realr3(ng,ng,ng) print *,'hello bug' ! essential: call someexternal(r3,3) print *,r3(3,3,3) endprogram $ cat lbuge.f90 subroutine someexternal(a,b) endsubroutine $ echo $(( 4* 850*850*850 )) 245650 $# the memory use of array r3 exceeds 2^31 bytes $ egfortran -cpp -Dng=850 lbug1.f90 -c $ egfortran -c lbuge.f90 $ egfortran lbug1.o lbuge.o o66$ ./a.out hello bug 0. The object files are linked into separate files so we can examine with $ objdump --syms lbug1.o | grep -B 1 -A 2 r3 l F .text 0116 MAIN__ l O .bss 926b3720 r3.3768 0030 l O .rodata001c options.2.3777 ld .eh_frame .eh_frame $ cat lbug2.f90 program lbug implicit none save realr3(ng,ng,ng) complex c3(ng/2,ng,ng) print *,'hello bug' ! essential: call someexternal(r3,c3) print *,r3(3,3,3), ubound(r3) endprogram $ egfortran -cpp -Dng=850 lbug2.f90 -c $ egfortran -cpp -Dng=850 lbuge.f90 -c $ egfortran lbug2.o lbuge.o ld: error: lbug2.f90:(function MAIN__: .text+0x80): relocation R_X86_64_PC32 out of range: 2456507324 is not in [-2147483648, 2147483647] $ objdump --syms lbug2.o | grep -B 1 -A 2 r3 926b3720 l O .bss 926b3720 c3.3768 l O .bss 926b3720 r3.3770 0028 l O .rodata000c A.2.3775 0040 l O .rodata001c options.4.3783 It seems the compiler generates 64-bit offsets but the linker limits itself to 32-bit offsets. Is this correct? Is there a fix? John Environment: $ sysctl kern.version kern.version=OpenBSD 6.6 (GENERIC.MP) #0: Sat Oct 26 08:08:07 MDT 2019 r...@syspatch-66-amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC.MP $ sysctl hw hw.machine=amd64 hw.model=Intel(R) Core(TM) i3-6100U CPU @ 2.30GHz hw.ncpu=2 $ pkg_info | grep g95 g95-8.3.0p4 GNU compiler collection: f95 compiler
