[LLVMdev] Intel vs. AT&T Assembly.

Ralph Corderoy ralph at inputplus.co.uk
Sat Apr 29 08:57:43 PDT 2006


Hi Jeff,

> > I notice `lli -print-machineinstrs -x86-asm-syntax=(att|intel)' both
> > prefix registers with `%'.  Is this right?  I thought AT&T did this
> > and Intel didn't.  The GNU gas manual concurs.
> >
> >     http://www.gnu.org/software/binutils/manual/gas-2.9.1/html_chapter/as_16.html
>
> The Intel version is just a clone of the AT&T version at this time.
> No one has yet taken the time to make it produce actual Intel syntax.

It's a long way towards it:

    # AT&T.                      # Intel.
            .text                        .text
            .align  16                   .align  16
            .globl  main                 .globl  main
                                         .type   main, @function
    main:                        main:
            subl $12, %esp               sub esp, 12
            fnstcw 10(%esp)              fnstcw word ptr [esp + 10]
            movb $2, 11(%esp)            mov byte ptr [esp + 11], 2
            fldcw 10(%esp)               fldcw word ptr [esp + 10]
            movl 20(%esp), %eax          mov eax, dword ptr [esp + 20]
            movl 4(%eax), %eax           mov eax, dword ptr [eax + 4]

Just some little bits to go.

Cheers,


Ralph.





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