On Wed, 2009-05-06 at 17:44 +0200, Michael Matz wrote: > Hi, > > On Wed, 6 May 2009, Ramana Radhakrishnan wrote: > > > >>> The slush that I requested last week has been lifted. However, I > > >>> have asked for relative calm until the cond-optab branch has been > > >>> merged to mainline, which will hopefully occur on Friday, May 8th. > > >> > > >> As of this morning (UK), native bootstrap on ARM is still broken. > > > > > > Is this PR 39978? > > > > I see what's been reported at > > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40031#c2 on gcc55 which appears > > to be the same crash as what Julian's been seeing with > > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39929#c12. > > As written by Andrew Pinski already, you'll need a different method of > emitting the load of the PIC register. The ARM backend tries to emit that > load as soon as it sees the PIC register being used (which is a slightly > odd method as it magically emits instructions at a place unrelated to the > instruction that currently are supposed to be emitted). > > With expand from SSA this happens earlier than before, in fact so early > that you don't have any basic block in RTL yet. All are still in gimple > form. That's why the emission of RTL insns after the function entry is > not going to work. That's only possible if everything is transformed > already. > > The easiest solution would be to just make a note that you need the PIC > register and then, when expanding the prologue emit the necessary > instructions. IMO that makes sense as PIC register setup usually is > something the prologue does, like all the other register setups necessary. >
That won't work because the PIC register on ARM is a pseudo, so generating it during prologue generation is too late. It needs to exist before data flow analysis starts on the RTL. R. -- Richard Earnshaw Email: richard.earns...@arm.com Engineering Manager Phone: +44 1223 400569 (Direct + VoiceMail) OpenSource Tools Switchboard: +44 1223 400400 ARM Ltd Fax: +44 1223 400410 110 Fulbourn Rd Web: http://www.arm.com/ Cambridge, UK. CB1 9NJ
