On Thu, 2010-10-14 at 16:33 +0000, stephen.clarke at st dot com wrote: > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43129 > > Stephen Clarke <stephen.clarke at st dot com> changed: > > What |Removed |Added > ---------------------------------------------------------------------------- > CC| |stephen.clarke at st dot > | |com > > --- Comment #8 from Stephen Clarke <stephen.clarke at st dot com> 2010-10-14 > 16:32:56 UTC --- > For arm instruction set, could you fold pc into the indexing > to save an instruction? > > foo: > ldr r3, .L2 // C > .LPIC0: > ldr r3, [r3,pc] // C
You'll find that the ARM-ARM thinks that PC in any of the 3 locations in this instruction form is *unpredictable*. Thus this form of the instruction should not be used. cheers Ramana
