Re: assembler vs extension words
Peter Bigot <[email protected]> Wed, 3 Feb 2016 06:52:53 -0600
| Newsgroups | gmane.comp.hardware.texas-instruments.msp430.gcc.user |
|---|---|
| Message-ID | <CAPOJ94MUGszQcPCFpAB-0cL+zDOBw=t+_o+MmCZFU=4eY6cjrQ@mail.gmail.com> |
--===============6608345925885410309== Content-Type: multipart/alternative; boundary=e89a8ff25462b2ba51052add1859 --e89a8ff25462b2ba51052add1859 Content-Type: text/plain; charset=UTF-8 Just to note: this list doesn't transport patches. Sorry. Peter (still lurking, no longer active) On Wed, Feb 3, 2016 at 6:29 AM, Nick Clifton <[email protected]> wrote: > Hi David, > > I am having some trouble using the rpt functionality of the CPUX. While >> attempting to assemble some code for the msp430fr5969 I was surprised >> with this error: >> >> repeat count cannot be used with rrux >> >> In response to: >> rpt r15 { rrux.w r6 >> > > > Oops - this is definitely a bug. You should report it ... :-) > > The problem is that RRUX is a synthetic instruction, and GAS is > incorrectly checking it as if it were RRUM, which does not accept a RPT > count. > > After some fiddling around I was able to >> generate code that worked but I had to bang it in using .word >> directives. objdump produced: >> >> rpt r15 { rrcx.w r6 >> >> Which is almost but not quite correct because it ignores the little >> detail of the extension word having the ZC bit set. >> > > True - this is really the same bug. GAS is not encoding RRUX correctly, > so it is not being decoded correctly either. > > > Which brings up another problem. Not only is the use of rpt not >> documented for the GNU assembler, >> > > This is because there is no real documentation from TI describing how the > RPT pseudo-instruction ought to work. I assumed that they must have an > "assembler programming for the MSP430 " guide somewhere that described this > feature, and that I have just not seen it. In my opinion the GNU assembler > documentation should not be documenting features that are supposed to be a > standard part of the architecture's assembler. > > there isn't any hint of how to set the >> ZC bit in the extension word. >> > > It has to be through the use of different opcode mnemonics, ie RRUX vs > RRCX. > > > slau367 is a bit thin in describing the repeat feature as well. It >> barely gets a mention in the description of the extension word and >> appears a few times in examples. Other than that there is nothing. >> > > Agreed - it is very frustrating. > > There is also very little documentation on synthetic instructions and how > they ought to be implemented. > > Anyway, please try out the attached patch and let me know if it works for > you. > > Cheers > Nick > > > > > > ------------------------------------------------------------------------------ > Site24x7 APM Insight: Get Deep Visibility into Application Performance > APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month > Monitor end-to-end web transactions and take corrective actions now > Troubleshoot faster and improve end-user experience. Signup Now! > http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 > _______________________________________________ > Mspgcc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/mspgcc-users > > --e89a8ff25462b2ba51052add1859-- --===============6608345925885410309== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 --===============6608345925885410309== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Mspgcc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mspgcc-users --===============6608345925885410309==--