On Tue, Jul 3, 2012 at 12:37 PM, Richard Guenther <richard.guent...@gmail.com> wrote:
>>>> Based on the observation above, the patch is OK for mainline, but >>>> please also handle "rep nop" case. >>> >>> Here's the new version of the patch that does that. Note that someone >>> needs to commit this for me, since I am not empowered to do it myself. >>> >>> gcc/ >>> 2012-07-02 Roland McGrath <mcgra...@google.com> >>> >>> * configure.ac (HAVE_AS_IX86_REP_LOCK_PREFIX): Also require that the >>> assembler accept 'rep bsf ...', 'rep bsr ...', 'rep ret', and 'rep >>> nop'. >>> * configure: Regenerated. >>> * config/i386/i386.md (simple_return_internal_long): Use %; >>> (ctz<mode>2): Likewise. >>> (*pause): Likewise. >> >> The patch is OK. >> >> I have committed it to the mainline SVN. > > Given that the latest binutils release (2.22) does not support 'rep > ret', does that > not pessimize people with just "partial" 'rep *' support? No, gcc just emits "rep; ret". Using older binutils, this is just cosmetic change in the asm dumps. IIUC, Roland worries that *future* binutils could insert something after the "rep" in "rep;INSN" combo. Uros.
