Bug in objdump disassemble?

[H.J. Lu]

On Wed, Mar 27, 2013 at 10:40 AM, Stavros Filargyropoulos
<stafil@gmail.com> wrote:
> Hey,
>
> I am running objdump with "-m i8086" and the opcode "67 66 c7 04 24 01
> 00 00 00" is translated to " movl   $0x1,(%eax,%eax,1)". It should be
> "movl  $0x1,(%esp)" I believe.
>

Thanks for the bug report.  We didn't check address size prefix when
retrieving the SIB byte.  I checked in this patch to fix it.

-- 
H.J.
---
diff --git a/gas/testsuite/ChangeLog b/gas/testsuite/ChangeLog
index 58fb22f..8206282 100644
--- a/gas/testsuite/ChangeLog
+++ b/gas/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2013-03-27  H.J. Lu  <hongjiu.lu@intel.com>
+
+	* gas/i386/addr32.s: Add an SIB test.
+	* gas/i386/addr32.d: Updated.
+
 2013-03-27  Alexis Deruelle  <alexis.deruelle@gmail.com>

 	PR binutils/15068
diff --git a/gas/testsuite/gas/i386/addr32.d b/gas/testsuite/gas/i386/addr32.d
index 5866a30..8553fc3 100644
--- a/gas/testsuite/gas/i386/addr32.d
+++ b/gas/testsuite/gas/i386/addr32.d
@@ -12,4 +12,5 @@ Disassembly of section .text:
 [	 ]*13:[	 ]+67 a2 98 08 60 00[	 ]+addr32[	 ]+mov[ 	]+%al,0x600898
 [	 ]*19:[	 ]+67 a3 98 08 60 00[	 ]+addr32[	 ]+mov[ 	]+%ax,0x600898
 [	 ]*1f:[	 ]+67 66 a3 98 08 60 00[	 ]+addr32[	 ]+mov[ 	]+%eax,0x600898
+[	 ]*26:[	 ]+67 66 c7 04 24 01 00 00 00[	 ]+movl[	 ]+\$0x1,\(%esp\)
 #pass
diff --git a/gas/testsuite/gas/i386/addr32.s b/gas/testsuite/gas/i386/addr32.s
index 3dab339..b899ebd 100644
--- a/gas/testsuite/gas/i386/addr32.s
+++ b/gas/testsuite/gas/i386/addr32.s
@@ -6,3 +6,4 @@
 	addr32 mov	%al,0x600898
 	addr32 mov	%ax,0x600898
 	addr32 mov	%eax,0x600898
+	addr32 movl	$0x1,(%esp)
diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index 533c4a3..39c256e 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,9 @@
+2013-03-27  H.J. Lu  <hongjiu.lu@intel.com>
+
+	* i386-dis.c (get_sib): Add the sizeflag argument.  Properly
+	check address mode.
+	(print_insn): Pass sizeflag to get_sib.
+
 2013-03-27  Alexis Deruelle  <alexis.deruelle@gmail.com>

 	PR binutils/15068
diff --git a/opcodes/i386-dis.c b/opcodes/i386-dis.c
index 5a77255..eeaf22e 100644
--- a/opcodes/i386-dis.c
+++ b/opcodes/i386-dis.c
@@ -11285,11 +11285,11 @@ get_valid_dis386 (const struct dis386 *dp,
disassemble_info *info)
 }

 static void
-get_sib (disassemble_info *info)
+get_sib (disassemble_info *info, int sizeflag)
 {
   /* If modrm.mod == 3, operand must be register.  */
   if (need_modrm
-      && address_mode != mode_16bit
+      && ((sizeflag & AFLAG) || address_mode == mode_64bit)
       && modrm.mod != 3
       && modrm.rm == 4)
     {
@@ -11574,7 +11574,7 @@ print_insn (bfd_vma pc, disassemble_info *info)

   if (dp->name == NULL && dp->op[0].bytemode == FLOATCODE)
     {
-      get_sib (info);
+      get_sib (info, sizeflag);
       dofloat (sizeflag);
     }
   else
@@ -11582,7 +11582,7 @@ print_insn (bfd_vma pc, disassemble_info *info)
       dp = get_valid_dis386 (dp, info);
       if (dp != NULL && putop (dp->name, sizeflag) == 0)
 	{
-	  get_sib (info);
+	  get_sib (info, sizeflag);
 	  for (i = 0; i < MAX_OPERANDS; ++i)
 	    {
 	      obufp = op_out[i];