[Bug binutils/20838] New: Strange disassembly for 4d in x86-64 mode

[jamesmikedupont at googlemail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=20838

            Bug ID: 20838
           Summary: Strange disassembly for 4d in x86-64 mode
           Product: binutils
           Version: 2.27
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: binutils
          Assignee: unassigned at sourceware dot org
          Reporter: jamesmikedupont at googlemail dot com
  Target Milestone: ---

GNU objdump (GNU Binutils for Debian) 2.27.51.20161108

The disam seems to skip the first byte if presented with another op afterwards.
please let me know if this is a bug or intended behavior.

Input to as :

.test16:
.byte 77
.byte 0
.byte 1
.byte 1
.byte 1
.byte 1
.test17:
.byte 77
.byte 1
.byte 0
.byte 0
.byte 0
.byte 0 

Output of objdump :

000000000000005a <.test16>:
5a: 4d 00 01 rex.WRB add %r8b,(%r9)
5d: 01 01 add %eax,(%rcx)
5f: 01 .byte 0x1

0000000000000060 <.test17>:
60: 4d 01 00 add %r8,(%r8)
63: 00 00 add %al,(%rax)




Next test :

.test17:
.byte 77
.byte 1

.test17b:
.byte 77
.byte 1
.byte 0

.test17c:
.byte 77
.byte 1
.byte 1

output :

Disassembly of section .text:

0000000000000000 <.test17>:
   0:   4d                      rex.WRB
   1:   01                      .byte 0x1

0000000000000002 <.test17b>:
   2:   4d 01 00                add    %r8,(%r8)

0000000000000005 <.test17c>:
   5:   4d 01 01                add    %r8,(%r9)

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