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

Ian Lance Taylor ian@airs.com
Fri Apr 2 16:42:00 GMT 1999

   From: hjl@lucon.org (H.J. Lu)
   Date: Fri, 2 Apr 1999 16:10:48 -0800 (PST)

   > gas out of binutils- (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.


   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
    sethi foo,%i0


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