diff options
Diffstat (limited to 'gas/config/tc-i386.c')
| -rw-r--r-- | gas/config/tc-i386.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c index 6aa9949d86..8a6779772b 100644 --- a/gas/config/tc-i386.c +++ b/gas/config/tc-i386.c @@ -2932,10 +2932,13 @@ md_assemble (char *line) if (!add_prefix (FWAIT_OPCODE)) return; - /* Check for lock without a lockable instruction. */ + /* Check for lock without a lockable instruction. Destination operand + must be memory unless it is xchg (0x86). */ if (i.prefix[LOCK_PREFIX] && (!i.tm.opcode_modifier.islockable - || i.mem_operands == 0)) + || i.mem_operands == 0 + || (i.tm.base_opcode != 0x86 + && !operand_type_check (i.types[i.operands - 1], anymem)))) { as_bad (_("expecting lockable instruction after `lock'")); return; |
