schwartz@shire.cs.psu.edu (Scott Schwartz) (02/10/89)
In article <21606@ames.arc.nasa.gov>, lamaster@ames (Hugh LaMaster) writes: >I notice that, recently, some results from the GNU compiler on some RISC's >has been a challenge to the object code size of VAX code. Obviously, GNU >is doing something interesting there. Does anyone know why the code from >the GNU C compiler appears to be significantly more compact than other >compilers on the RISC machines? Which RISCs did you notice this on? My experience with gcc-1.33 on a SPARC (sun4) is that Sun's compiler generates smaller and faster code. A brief look at the assembler output shows that gcc generates lots of nops where Sun's compiler generates annuled branches, although it doesn't do this in every case. -- Scott Schwartz <schwartz@shire.cs.psu.edu>
lamaster@ames.arc.nasa.gov (Hugh LaMaster) (02/11/89)
In article <4280@psuvax1.cs.psu.edu> schwartz@shire.cs.psu.edu (Scott Schwartz) writes: >Which RISCs did you notice this on? My experience with gcc-1.33 on a Well, in looking back at my references, the data are incomplete. But, I seem to recall now that in this newsgroup a few months ago the folks from Motorola were using gcc generated code for code speed and size comparisons but I don't remember the details. So, please let me retract my statement: it appears to be speculation at this point. I believe that Sun has made substantial improvements over their early release for Sparc also. -- Hugh LaMaster, m/s 233-9, UUCP ames!lamaster NASA Ames Research Center ARPA lamaster@ames.arc.nasa.gov Moffett Field, CA 94035 Phone: (415)694-6117