From mboxrd@z Thu Jan 1 00:00:00 1970 In-Reply-To: Date: Fri, 29 Oct 1999 13:58:48 +0200 To: Tony Mantler , linuxppc-dev@lists.linuxppc.org From: Benjamin Herrenschmidt Subject: Re: question about altivec registers Message-Id: <19991029135848.007534@mailhost.mipsys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Thu, Oct 28, 1999, Tony Mantler wrote: >I think saving registers in a subroutine is a pain no matter how it's >implemented. If the VRSAVE is used as a count, the subroutine still has to >save the old value, save the overwritten registers, calculate what the >proper new value is (think new < old = oops!) then restore the overwritten >registers and old VRSAVE value when it exits. In their latest Mac compiler, Metroweks added a pragma for manually optimising this when you know you'll use a bunch of those registers: << #pragma altivec_vrsave allon is now supported. It sets VRsave assuming that all altivec registers are in use, best used with "#pragma altivec_vrsave off" so only the parent routine updates the vrsave register. >> ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/