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Re: PATCH: PR target/46519: Missing vzeroupper
- From: Mark Mitchell <mark at codesourcery dot com>
- To: "H.J. Lu" <hjl dot tools at gmail dot com>
- Cc: Uros Bizjak <ubizjak at gmail dot com>, gcc-patches at gcc dot gnu dot org, Richard Guenther <rguenther at suse dot de>, Jakub Jelinek <jakub at redhat dot com>
- Date: Fri, 31 Dec 2010 17:39:37 -0800
- Subject: Re: PATCH: PR target/46519: Missing vzeroupper
- References: <20101217190347.GA2856@intel.com> <AANLkTinempMG4qbZsZ_tHMnyHqpXd+2JDZEYzqdASEWo@mail.gmail.com> <AANLkTi=ky0A+oH9e23zX=yWrwjvFKzkNG1qVrvQ1bcJO@mail.gmail.com> <AANLkTi=K3bPqru+joTk1fsjthVnSe0EMkoEF=tGr7SxF@mail.gmail.com> <AANLkTi=0tNb1FX7XweRCUQBh6OUjNW7f6+vyO0YuYk=z@mail.gmail.com> <AANLkTi=e2ZemY8AaWx6sGOBS_RMiS3=LG9z9pZ8SMbsq@mail.gmail.com> <4D1E7DCE.6070604@codesourcery.com> <AANLkTikAV_hrz+4UA7-Q6KL6+XKB62W7vbjNaOjOhF6q@mail.gmail.com>
On 12/31/2010 5:38 PM, H.J. Lu wrote:
> I believe algorithm is correct, but probably not optimal. What we want to know
> is the precise state of the upper 128bits at exit of basic block. It rescans a
> basic block only if the exit state is unknown and the upper 128bits may be
> modified in the basic block.
What is the limit, then, on the number of iterations required for a
function with N basic blocks?
--
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713