On Wed, Mar 12, 2008 at 4:23 PM, Joel Sherrill <[EMAIL PROTECTED]> wrote: > Hi, > > Did the default i386 CPU model that gcc generates > code for change between 4.2.x and 4.3.0? I didn't > see anything in the release notes that jumps out at > me about this. > > Using i386-rtems4.9 as the target, I was running > code compiled by gcc 4.3.0 on a vanilla i386 and > was getting illegal instruction exceptions. I looked > at the assembly and noticed instructions which were > not on the i386. Obviosuly, when I added -mtune=i386 > and the issue went away. > > This probably impacts no one on a GNU/Linux computer > since very few of those are base i386's anymore. Just > venerable embedded systems. :)
-mtune doesn't change the instruction set, -march/-mcpu does. So this is probably a bug in the instruction predicates. What is the illegal instruction gcc emits? Richard.
