Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1398963

Re: [PATCH -v2] x86/hweight: Get rid of the special calling convention

From Peter Zijlstra <peterz@infradead.org>
Newsgroups linux.kernel
Subject Re: [PATCH -v2] x86/hweight: Get rid of the special calling convention
Date 2016-05-11 13:30 +0200
Message-ID <rxAv0-7hb-5@gated-at.bofh.it> (permalink)
References (5 earlier) <rxlcD-uF-29@gated-at.bofh.it> <rxlmh-zy-13@gated-at.bofh.it> <rxotQ-3v7-13@gated-at.bofh.it> <rxtMR-Fp-1@gated-at.bofh.it> <rxAlk-7bN-27@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw

On Wed, May 11, 2016 at 07:15:19AM -0400, Brian Gerst wrote:

> I think he meant the out of line version would be asm, so you could
> control what registers were clobbered.

Yeah, it might save a few cycles on the call, but given that most
machines should have popcnt these days is it worth the hassle/cost of
duplicating the lib/hweight.c magic in asm (and remember, twice, once
for 32bit and once for 64bit) ?

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[RFC PATCH] x86/hweight: Get rid of the special calling convention Borislav Petkov <bp@suse.de> - 2016-05-04 20:50 +0200
  Re: [RFC PATCH] x86/hweight: Get rid of the special calling convention Brian Gerst <brgerst@gmail.com> - 2016-05-04 21:40 +0200
    Re: [RFC PATCH] x86/hweight: Get rid of the special calling  convention "H. Peter Anvin" <hpa@zytor.com> - 2016-05-04 21:40 +0200
      Re: [RFC PATCH] x86/hweight: Get rid of the special calling  convention Borislav Petkov <bp@suse.de> - 2016-05-04 21:50 +0200
        Re: [RFC PATCH] x86/hweight: Get rid of the special calling  convention "H. Peter Anvin" <hpa@zytor.com> - 2016-05-04 22:00 +0200
          Re: [RFC PATCH] x86/hweight: Get rid of the special calling  convention Borislav Petkov <bp@suse.de> - 2016-05-04 22:30 +0200
            Re: [RFC PATCH] x86/hweight: Get rid of the special calling  convention "H. Peter Anvin" <hpa@zytor.com> - 2016-05-04 23:00 +0200
            Re: [RFC PATCH] x86/hweight: Get rid of the special calling  convention Andi Kleen <andi@firstfloor.org> - 2016-05-04 23:20 +0200
            Re: [RFC PATCH] x86/hweight: Get rid of the special calling convention Denys Vlasenko <dvlasenk@redhat.com> - 2016-05-05 15:10 +0200
              Re: [RFC PATCH] x86/hweight: Get rid of the special calling  convention Borislav Petkov <bp@suse.de> - 2016-05-05 16:10 +0200
                [PATCH -v2] x86/hweight: Get rid of the special calling convention Borislav Petkov <bp@suse.de> - 2016-05-10 19:00 +0200
                Re: [PATCH -v2] x86/hweight: Get rid of the special calling  convention Peter Zijlstra <peterz@infradead.org> - 2016-05-10 19:30 +0200
                Re: [PATCH -v2] x86/hweight: Get rid of the special calling convention "H. Peter Anvin" <hpa@zytor.com> - 2016-05-10 21:10 +0200
                Re: [PATCH -v2] x86/hweight: Get rid of the special calling  convention Borislav Petkov <bp@suse.de> - 2016-05-10 21:20 +0200
                Re: [PATCH -v2] x86/hweight: Get rid of the special calling  convention "H. Peter Anvin" <hpa@zytor.com> - 2016-05-11 00:40 +0200
                Re: [PATCH -v2] x86/hweight: Get rid of the special calling  convention Borislav Petkov <bp@suse.de> - 2016-05-11 06:20 +0200
                Re: [PATCH -v2] x86/hweight: Get rid of the special calling convention Brian Gerst <brgerst@gmail.com> - 2016-05-11 13:20 +0200
                Re: [PATCH -v2] x86/hweight: Get rid of the special calling  convention Peter Zijlstra <peterz@infradead.org> - 2016-05-11 13:30 +0200
                Re: [PATCH -v2] x86/hweight: Get rid of the special calling  convention Borislav Petkov <bp@suse.de> - 2016-05-11 14:50 +0200
                Re: [PATCH -v2] x86/hweight: Get rid of the special calling convention "H. Peter Anvin" <hpa@zytor.com> - 2016-05-12 07:00 +0200
                Re: [PATCH -v2] x86/hweight: Get rid of the special calling  convention Borislav Petkov <bp@suse.de> - 2016-05-12 14:00 +0200
                Re: [PATCH -v2] x86/hweight: Get rid of the special calling  convention Peter Zijlstra <peterz@infradead.org> - 2016-05-12 14:20 +0200
                Re: [PATCH -v2] x86/hweight: Get rid of the special calling  convention Borislav Petkov <bp@suse.de> - 2016-05-10 21:10 +0200

csiph-web