From mboxrd@z Thu Jan 1 00:00:00 1970 From: "John David Anglin" To: dave@hiauly1.hia.nrc.ca (John David Anglin) Cc: gcc-patches@gcc.gnu.org, law@redhat.com Subject: Re: pa.md bugfix Date: Tue, 23 Jan 2001 08:32:00 -0000 Message-id: <200101231632.LAA22851@hiauly1.hia.nrc.ca> References: X-SW-Source: 2001-01/msg01714.html > There is one issue and one potential optimisation that I can see with respect > to this patch. > > > + ;; This can only be used in a leaf function, so we do > > + ;; not need to use the PIC register. > > (define_insn "return" > > This may not be correct. The ABI indicates that the PIC register must > be correctly set when the function returns. This enables a correct return > via a stub from a shared library. If +O3 is used, rename registers may > use the PIC register if we don't have a use in the return. Remember, > the PIC register is not a fixed register any more. Hit self on head. It is fixed and as a result register rename won't touch it. -- J. David Anglin dave.anglin@nrc.ca National Research Council of Canada (613) 990-0752 (FAX: 952-6605)