On Tue, Mar 6, 2012 at 12:51 AM, Richard Kenner <ken...@vlsi1.ultra.nyu.edu> wrote: >> I found a weird piece of code that was added by kenner in a really early >> revision. It checks for VAR_DECLs with frame or stack pointers as >> DECL_RTL, and the comment in front of it mentions strength reduction. >> Presumably this was for the old loop optimizer? I can't think of >> anything that would require this in a modern version of gcc. > > I think such a VAR_DECL would occur in cases of alloca. I don't understand > the comment about strength reduction (despite obviously having written it!) > because the old loop optimizer ran on RTL and this is talking about trees. > > My guess is that this isn't dead.
I don't see how a VAR_DECL can ever get a DECL_RTL equal to one of the mentioned regs. The patch is ok if a gcc_unreachable () inside the if () passes bootstrap. Thanks, Richard.
