Re: An i386 fp register name patch

[hjl@lucon.org (H.J. Lu)]

> 
> 
> On Fri, 27 Aug 1999, H.J. Lu wrote:
> 
> > Here is a patch to handle spaces ina i386 FP register names. I am
> > enclosing a testcase here.
> 
> Hello HJ,
>   As you probably know, we already allow spaces in lots of places.  eg.
> 	mov % al , 5 ( % ebp , % ebx , 1 )
> Notice that no spaces are allowed *in* a register name, or for that
> matter in an instruction mnemonic.  eg.
> 	mov $1, % a l
> is illegal.
> 
> So there is a philosophical question as to whether "st(1)" is really an
> indivisible register name token or not.  You seem to say that the register
> name is "st" with an index, so therefore we should allow spaces, eg.
> "st ( 1 )".  I'm inclined to say that "st(1)" is really just a name like
> any other register name, so spaces shouldn't be allowed (or if we do
> allow spaces here then why not in "% a l" - something I don't like).
> 
> Where did you run into a need for spaces in fp reg names?  C asm macros?
> 
> 

I got a report from Mesa people. FWIW, assembler on Solaris &/x86 takes

        fxch   %st( 1) 
        fxch   %st( 1 )
        fxch   %st ( 1 )
        fxch   %st (1) 
        fxch   %st(1)  

But not

        fxch   % st(1) 
        fxch   %           st(1)   

I got

# cat foo.s
        fxch   %st( 1)
        fxch   %st( 1 )
        fxch   %st ( 1 )
        fxch   %st (1)
        fxch   %st(1)
        fxch   % st(1)
        fxch   %           st(1)
# /usr/ccs/bin/as -o foo.o foo.s 
Assembler: 
        aline 6 : Illegal register
        aline 6 : syntax error
        aline 7 : Illegal register
        aline 7 : syntax error

It looks like gas has some extensions, but doesn't have features
supported by other x86 assemblers. In any case, I will support it
in the Linux version of binutils.

-- 
H.J. Lu (hjl@gnu.org)