by robert.swiecki:

What steps will reproduce the problem?
1. Link a .6 file - 6l SIGSEGV.PC.0x4016ec.CODE.1.ADDR.\(nil\).INSTR.mov_rsi\,_\[rax\].6

What is the expected output?
6.out

What do you see instead?
Crash (SIGSEGV)

Which compiler are you using (5g, 6g, 8g, gccgo)?
6l

Which operating system are you using?
Linux/amd64

Which revision are you using?  (hg identify)
c5c62aeb6267 tip

Please provide any additional information below.
$ gdb /usr/local/google/src/go/bin/6l
(gdb) r SIGSEGV.PC.0x4016ec.CODE.1.ADDR.\(nil\).INSTR.mov_rsi\,_\[rax\].6
Program received signal SIGSEGV, Segmentation fault.
0x00000000004016ec in genasmsym (put=0x41b6a0 <putsymb>) at
/usr/local/google/src/go/src/cmd/6l/asm.c:1152
1152                    put(nil, a->asym->name, 'a', -a->aoffset, 0, 0, a->gotype);
(gdb) bt
#0  0x00000000004016ec in genasmsym (put=0x41b6a0 <putsymb>) at
/usr/local/google/src/go/src/cmd/6l/asm.c:1152
#1  0x000000000041586a in p9main (argc=1, argv=0x7fffffffe0c0) at
/usr/local/google/src/go/src/cmd/6l/obj.c:267
#2  0x000000000041d339 in main (argc=0, argv=0x7d16) at
/usr/local/google/src/go/src/lib9/main.c:35

(gdb) p *a
$3 = {asym = 0x0, link = 0x0, aoffset = 0, type = 115, gotype = 0x0}

Attachments:

1. SIGSEGV.PC.0x4016ec.CODE.1.ADDR.(nil).INSTR.mov_rsi,_[rax].6 (1516 bytes)