Bug of gas (binutils-2.9.1.0.23): Wrong code for SETHI on SPARC

[H.J. Lu]

> 
>    From: hjl@lucon.org (H.J. Lu)
>    Date: Fri, 2 Apr 1999 16:10:48 -0800 (PST)
> 
>    > gas out of binutils-2.9.1.0.23 (and older versions) has a severe bug
>    > for the SPARC platform (sparc-sun-solaris2.6), i.e. it generates
>    > wrong code for
>    > 
>    >         sethi   0x4000,%i0
>    > 
>    > (and probably in all other cases where sethi is used without the
>    > %hi(...)-construct).
>    > 
>    > The sethi instruction has following suggested assembly syntax
>    > (see SPARC Architecture Manual):
>    > 
>    >         sethi   const22,reg
>    > 
>    > const22 is a 22-bit constant that is placed by sethi in the most
>    > significant 22 bits of reg (while it zeroes the 10 least significant
>    > bits of reg). Therefore we would expect the value 0x100000 in %i0
>    > after the execution of ``sethi 16384''. Instead of this, gas
>    > modifies the given constant such that 0x4000 will be found in %i0
>    > afterwards. This would have been equivalent to
>    > 
>    >         sethi %hi(0x4000),%i0
> 
>    Here is a new patch. Please discard my last patch to tc-sparc.c.
>    Let me know what you get.
> 
>    Thanks.
> 
> 
>    H.J.
>    ---
>    Fri Apr  2 16:05:25 1999  H.J. Lu  (hjl@gnu.org)
> 
> 	   * sparc-opc.c: Change "sethi" from "h,d" to "n,d".
> 
> I don't think that can be right.  I think it will do the wrong thing
> for
>     sethi foo,%i0
> 

You are right. That shows I know nothing about Sparc. Do you have
a fix for the bug?

Thanks.


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