Re: [committed, PATCH] Remove Disp16|Disp32 from 64-bit direct branches

[Michael Matz <matz@suse.de>]

Hi,

On Tue, 12 May 2015, H.J. Lu wrote:

> This is what I got now:
> 
> [hjl@gnu-6 tmp]$  cat x.s
> .text
> data16 jmp foo
> bar:
> mov %eax,%edx
> [hjl@gnu-6 tmp]$ gcc -c x.s
> [hjl@gnu-6 tmp]$ objdump -dwr x.o
> 
> x.o:     file format elf64-x86-64
> 
> 
> Disassembly of section .text:
> 
> 0000000000000000 <bar-0x4>:
>    0: 66 e9 00 00 89 c2     data16 jmpq ffffffffc2890006
> <bar+0xffffffffc2890002> 2: R_X86_64_PC16 foo-0x2
> 
> 0000000000000004 <bar>:
>    4: 89 c2                 mov    %eax,%edx
> [hjl@gnu-6 tmp]$
> 
> Is that the same as what you got with binutils 2.25?

This is with 2.23, so your patch would cause a regression:

x.o:     file format elf64-x86-64


Disassembly of section .text:

0000000000000000 <bar-0x4>:
   0:   66 e9 00 00             jmpw   4 <bar>
                        2: R_X86_64_PC16        foo-0x2

0000000000000004 <bar>:
   4:   89 c2                   mov    %eax,%edx


Ciao,
Michael.