[Bug go/79037] New: gccgo: Binaries crash with parforsetup: pos is not aligned on m68k

["glaubitz at physik dot fu-berlin.de" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79037

            Bug ID: 79037
           Summary: gccgo: Binaries crash with parforsetup: pos is not
                    aligned on m68k
           Product: gcc
           Version: 6.3.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: go
          Assignee: ian at airs dot com
          Reporter: glaubitz at physik dot fu-berlin.de
                CC: cmang at google dot com,
                    gcc-bugzilla at mkarcher dot dialup.fu-berlin.de,
                    schwab at gcc dot gnu.org
  Target Milestone: ---
            Target: m68k-*-*

Hi!

I have just built gccgo on linux-m68k for the first time (Debian unstable) and
tried to build and run a simple "Hello World" program.

Unfortunately, the compiled binary crashes with what looks like to be an
alignment issue:

(sid-m68k-sbuild)root@jessie64:~# cat hello-world.go 
package main

import "fmt"

func main() {
    fmt.Println("Hello World!")
}
(sid-m68k-sbuild)root@jessie64:~# gccgo-6 hello-world.go -o hello-world    
(sid-m68k-sbuild)root@jessie64:~# ./hello-world 
fatal error: parforsetup: pos is not aligned

runtime stack:
runtime_dopanic
        ../../../src/libgo/runtime/panic.c:135
runtime_throw
        ../../../src/libgo/runtime/panic.c:193
runtime_parforsetup
        ../../../src/libgo/runtime/parfor.c:63
gc
        ../../../src/libgo/runtime/mgc0.c:2259
mgc
        ../../../src/libgo/runtime/mgc0.c:2215
runtime_mstart
        ../../../src/libgo/runtime/proc.c:1076

goroutine 16 [garbage collection]:
runtime_mcall
        ../../../src/libgo/runtime/proc.c:295
runtime_gc
        ../../../src/libgo/runtime/mgc0.c:2191
runtime_mallocgc
        ../../../src/libgo/runtime/malloc.goc:259
__go_new
        ../../../src/libgo/runtime/go-new.c:16
main.main
        /root/hello-world.go:6
runtime_main
        ../../../src/libgo/runtime/proc.c:626

goroutine 17 [runnable]:
kickoff
        ../../../src/libgo/runtime/proc.c:232
created by runtime_main
        ../../../src/libgo/runtime/proc.c:598

goroutine 18 [runnable]:
kickoff
        ../../../src/libgo/runtime/proc.c:232
created by runtime_createfing
        ../../../src/libgo/runtime/mgc0.c:2577
(sid-m68k-sbuild)root@jessie64:~#

Could this be possibly caused by the fact that the default alignment on m68k is
16 bits despite being a 32-bits architcture?

In any case, let me know if you need more debug information.

Thanks,
Adrian