04.09.09, 21:58, "Danny Backx" <danny.ba...@scarlet.be>:
> See exchange of messages on the gcc mailing list (archives at > http://gcc.gnu.org/ml/gcc/ . > Paul says "You lose". However, that is based on limited information. > Here are the answers I got, combined : > By Dave Korn : > > You should mention that long double alignment macro that the guy on > > the > > cegcc list thought it was connected with. ARM_DOUBLEWORD_ALIGN. If I > > was > > following that discussion correctly, the ABI requires it, and you have > > it > > #defined to zero to fix the problem you were getting with float double > > function argument passing, but maybe what this means is that it > > there's some > > more fundamental problem in the ABI-related MD macros, that fixing it > > this way > > ended up just papering over. > By Paul Brook, answer #1 : > > Both. By my reading the ABI you're trying to implement does not > > provide the > > guarantees required to use iwmmxt instructions. There are ways around > > this, > > but none of them are simple or pretty. The simplest answer is "don't > > do that". > By Paul Brook, answer #2 : > > iwmmxt instructions require doubleword data alignment . Your target > > [apparently] can't provide that. You loose. > Does anyone feel like looking up what we can do to provide the right > environment ? > Is it possible to implement this in the current compiler, or would this > require a completely new target (e.g. an iwmmx-mingw32ce-gcc) ? > Thanks, > Danny Seems that wmmx target cpu cannot be used, but it is still possible to use wmmx code. Here's how I made it work for me: -mtune=iwmmxt -mcpu=xscale -Wa,-mcpu=iwmmxt It works, but I had to disable half of my wmmx code since I was getting unaligned data errors. I don't know how different mcpu=xscale and mcpu=iwmmxt is, but it's possible that for wmmx gcc would generate different(better) code. Strange, but ARM_DOUBLEWORD_ALIGN shouldn't make corrupted binaries. But if it's defined to 1 then binaries cannot run at all (errors in some regular non-wmmx instructions) ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Cegcc-devel mailing list Cegcc-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/cegcc-devel
