the idea was: if shift operations slower, than HW multiplier, use HW bits. At the moment, threshold value is 10 which somehow means that if: number of shifts + number of aux adds and subs more than 10 instructions - use HW mul. that's what you have.
cheers, ~d On Tuesday 02 September 2003 18:18, Steven Whitehouse wrote: > Hi, > > I'm using the latest CVS version of msp430-gcc with gcc-3.2.3 and bintuils > 2.14. I discovered that if I write: > > ticker = ms * 1024; > > as expected it gets optimised away to bit shifts (gcc -O2 of course), but > if I write: > > ticker = ms * 1024L; > > it creates code which tries to use the hw multiplier. Is this a bug or is > there a good reason for this? > > I'm also having link problems in that some part of the library is > apparently not found (I'm not sure whether its trying to find the > routine to do the multiplications in hardware or whether its looking > for the emulation routines). The only msp430 specific option that I've > used is: -mmcu=msp430x149 and I'm using gcc to do the linking as I > though that shoud know the right libs to load up rather than trying to > do it myself with ld. I'm getting errors like this though: > > gui_survey.o(.text+0xc4):/home/steve/src/embedded/gui_survey.c:29: > undefined reference to `__umulsi3hw' > > so perhaps someone can point me in the right direction. Thanks, > > Steve. > > > > ------------------------------------------------------- > This sf.net email is sponsored by:ThinkGeek > Welcome to geek heaven. > http://thinkgeek.com/sf > _______________________________________________ > Mspgcc-users mailing list > Mspgcc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/mspgcc-users -- /***************************************************************** ("`-''-/").___..--''"`-._ (\ Dimmy the Wild UA1ACZ `6_ 6 ) `-. ( ).`-.__.`) State Polytechnical Univ. (_Y_.)' ._ ) `._ `. ``-..-' Radio-Physics Departament _..`--'_..-_/ /--'_.' ,' Saint Petersburg, Russia (il),-'' (li),' ((!.-' +7 (812) 5403923, 5585314 *****************************************************************/
