Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
| From | jgk@panix.com (Joe keane) |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Performance of hand-optimised assembly |
| Date | 2012-01-05 21:26 +0000 |
| Organization | Public Access Networks Corp. |
| Message-ID | <je54io$t8r$1@reader1.panix.com> (permalink) |
| References | <0.d0ecd8f477637819bed2.20111223184332GMT.87pqffjfhn.fsf@bsb.me.uk> <0.e89b5b9d17f29006bc36.20120104224713GMT.87hb0b6q6m.fsf@bsb.me.uk> <je2oep$iqh$1@speranza.aioe.org> <0.7163c7a5dd6c98958adf.20120105002252GMT.87boqj6lr7.fsf@bsb.me.uk> |
In article <0.7163c7a5dd6c98958adf.20120105002252GMT.87boqj6lr7.fsf@bsb.me.uk>,
Ben Bacarisse <ben.usenet@bsb.me.uk> wrote:
> void ShiftVector(unsigned long long vector[static 8], int AmountToShift)
> {
> int rest = 64 - AmountToShift;
> vector[0] = (vector[0] << AmountToShift) | (vector[1] >> rest);
> vector[1] = (vector[1] << AmountToShift) | (vector[2] >> rest);
> vector[2] = (vector[2] << AmountToShift) | (vector[3] >> rest);
> vector[3] = (vector[3] << AmountToShift) | (vector[4] >> rest);
> vector[4] = (vector[4] << AmountToShift) | (vector[5] >> rest);
> vector[5] = (vector[5] << AmountToShift) | (vector[6] >> rest);
> vector[6] = (vector[6] << AmountToShift) | (vector[7] >> rest);
> vector[7] = (vector[7] << AmountToShift);
> }
I spent a bunch of time 'optimizing' this code [in C]; everything i did
made it worse!
Here's gcc:
.file "shi.c"
.text
.p2align 4,,15
.globl ShiftVector
.type ShiftVector, @function
ShiftVector:
.LFB0:
.cfi_startproc
movq 8(%rdi), %r9
movl $64, %eax
movq (%rdi), %r8
subl %esi, %eax
movl %eax, %ecx
movq %r9, %rdx
shrq %cl, %rdx
movl %esi, %ecx
salq %cl, %r8
movl %eax, %ecx
orq %r8, %rdx
movq 16(%rdi), %r8
movq %rdx, (%rdi)
movq %r8, %rdx
shrq %cl, %rdx
movl %esi, %ecx
salq %cl, %r9
movl %eax, %ecx
orq %r9, %rdx
movq 24(%rdi), %r9
movq %rdx, 8(%rdi)
movq %r9, %rdx
shrq %cl, %rdx
movl %esi, %ecx
salq %cl, %r8
movl %eax, %ecx
orq %r8, %rdx
movq 32(%rdi), %r8
movq %rdx, 16(%rdi)
movq %r8, %rdx
shrq %cl, %rdx
movl %esi, %ecx
salq %cl, %r9
movl %eax, %ecx
orq %r9, %rdx
movq 40(%rdi), %r9
movq %rdx, 24(%rdi)
movq %r9, %rdx
shrq %cl, %rdx
movl %esi, %ecx
salq %cl, %r8
movl %eax, %ecx
orq %r8, %rdx
movq 48(%rdi), %r8
movq %rdx, 32(%rdi)
movq %r8, %rdx
shrq %cl, %rdx
movl %esi, %ecx
salq %cl, %r9
movl %eax, %ecx
orq %r9, %rdx
movq %rdx, 40(%rdi)
movq 56(%rdi), %rdx
movq %rdx, %r9
shrq %cl, %r9
movl %esi, %ecx
movq %r9, %rax
salq %cl, %r8
salq %cl, %rdx
orq %r8, %rax
movq %rdx, 56(%rdi)
movq %rax, 48(%rdi)
ret
.cfi_endproc
.LFE0:
.size ShiftVector, .-ShiftVector
.ident "GCC: (Ubuntu/Linaro 4.6.1-9ubuntu3) 4.6.1"
.section .note.GNU-stack,"",@progbits
Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Performance of hand-optimised assembly Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-12-23 18:43 +0000
Re: Performance of hand-optimised assembly "BartC" <bc@freeuk.com> - 2011-12-23 19:40 +0000
Re: Performance of hand-optimised assembly Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-12-23 21:26 +0000
Re: Performance of hand-optimised assembly "BartC" <bc@freeuk.com> - 2011-12-23 22:02 +0000
Re: Performance of hand-optimised assembly Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-12-24 02:52 +0000
Re: Performance of hand-optimised assembly 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-23 20:32 -0800
Re: Performance of hand-optimised assembly "BartC" <bc@freeuk.com> - 2011-12-24 13:09 +0000
Re: Performance of hand-optimised assembly James Harris <james.harris.1@googlemail.com> - 2011-12-24 05:49 -0800
Re: Performance of hand-optimised assembly "BartC" <bc@freeuk.com> - 2011-12-24 15:30 +0000
Re: Performance of hand-optimised assembly James Harris <james.harris.1@googlemail.com> - 2011-12-24 08:15 -0800
Re: Performance of hand-optimised assembly "BartC" <bc@freeuk.com> - 2011-12-24 17:10 +0000
Re: Performance of hand-optimised assembly Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-12-24 23:25 +0000
Re: Performance of hand-optimised assembly jgk@panix.com (Joe keane) - 2012-01-04 03:24 +0000
Re: Performance of hand-optimised assembly jacob navia <jacob@spamsink.net> - 2012-01-04 09:59 +0100
Re: Performance of hand-optimised assembly jgk@panix.com (Joe keane) - 2012-01-04 20:57 +0000
Re: Performance of hand-optimised assembly "BartC" <bc@freeuk.com> - 2012-01-04 23:04 +0000
Re: Performance of hand-optimised assembly Noob <root@127.0.0.1> - 2012-01-05 13:32 +0100
Re: Performance of hand-optimised assembly Philip Lantz <prl@canterey.us> - 2011-12-24 15:29 -0800
Re: Performance of hand-optimised assembly "BartC" <bc@freeuk.com> - 2011-12-24 12:42 +0000
Re: Performance of hand-optimised assembly Jens Gustedt <jens.gustedt@loria.fr> - 2011-12-24 16:58 +0100
Re: Performance of hand-optimised assembly "BartC" <bc@freeuk.com> - 2011-12-24 13:55 +0000
Re: Performance of hand-optimised assembly Seebs <usenet-nospam@seebs.net> - 2011-12-24 19:24 +0000
Re: Performance of hand-optimised assembly Geoff <geoff@invalid.invalid> - 2011-12-24 13:44 -0800
Re: Performance of hand-optimised assembly Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-12-29 02:53 +0200
Re: Performance of hand-optimised assembly Rui Maciel <rui.maciel@gmail.com> - 2011-12-29 02:11 +0000
Re: Performance of hand-optimised assembly jgk@panix.com (Joe keane) - 2011-12-24 01:36 +0000
Re: Performance of hand-optimised assembly "io_x" <a@b.c.invalid> - 2011-12-24 06:44 +0100
Re: Performance of hand-optimised assembly "io_x" <a@b.c.invalid> - 2011-12-24 09:52 +0100
Re: Performance of hand-optimised assembly "io_x" <a@b.c.invalid> - 2011-12-26 08:05 +0100
Re: Performance of hand-optimised assembly 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-26 11:52 -0800
Re: Performance of hand-optimised assembly "io_x" <a@b.c.invalid> - 2011-12-27 07:28 +0100
Re: Performance of hand-optimised assembly Willem <willem@toad.stack.nl> - 2011-12-24 12:48 +0000
Re: Performance of hand-optimised assembly 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-24 04:56 -0800
Re: Performance of hand-optimised assembly Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-12-24 23:39 +0000
Re: Performance of hand-optimised assembly James Harris <james.harris.1@googlemail.com> - 2011-12-24 06:01 -0800
Re: Performance of hand-optimised assembly "BartC" <bc@freeuk.com> - 2011-12-24 14:55 +0000
Re: Performance of hand-optimised assembly James Harris <james.harris.1@googlemail.com> - 2011-12-28 03:46 -0800
Re: Performance of hand-optimised assembly 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-28 04:52 -0800
Re: Performance of hand-optimised assembly Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-12-25 00:07 +0000
Re: Performance of hand-optimised assembly James Harris <james.harris.1@googlemail.com> - 2011-12-28 03:21 -0800
Re: Performance of hand-optimised assembly "BartC" <bc@freeuk.com> - 2011-12-28 13:19 +0000
Re: Performance of hand-optimised assembly Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-12-28 16:01 +0000
Re: Performance of hand-optimised assembly "BartC" <bc@freeuk.com> - 2011-12-28 17:45 +0000
Re: Performance of hand-optimised assembly 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-28 18:56 -0800
Re: Performance of hand-optimised assembly Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-12-29 03:32 +0200
Re: Performance of hand-optimised assembly Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-25 17:03 -0800
Re: Performance of hand-optimised assembly Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-01-26 22:08 +0000
Re: Performance of hand-optimised assembly Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-31 22:20 -0800
Re: Performance of hand-optimised assembly James Kuyper <jameskuyper@verizon.net> - 2011-12-28 08:24 -0500
Re: Performance of hand-optimised assembly Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-12-28 14:27 +0000
Re: Performance of hand-optimised assembly Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-25 16:50 -0800
Re: Performance of hand-optimised assembly Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-01-26 21:59 +0000
Re: Performance of hand-optimised assembly James Harris <james.harris.1@googlemail.com> - 2011-12-28 11:12 -0800
Re: Performance of hand-optimised assembly Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-12-29 03:12 +0200
Re: Performance of hand-optimised assembly jacob navia <jacob@spamsink.net> - 2011-12-29 10:02 +0100
Re: Performance of hand-optimised assembly Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-12-29 12:06 +0000
Re: Performance of hand-optimised assembly Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-25 17:07 -0800
Re: Performance of hand-optimised assembly Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-02-13 01:18 +0200
Re: Performance of hand-optimised assembly Tim Rentsch <txr@alumni.caltech.edu> - 2012-03-08 10:54 -0800
Re: Performance of hand-optimised assembly jacob navia <jacob@spamsink.net> - 2011-12-29 10:02 +0100
Re: Performance of hand-optimised assembly "BartC" <bc@freeuk.com> - 2011-12-29 12:06 +0000
Re: Performance of hand-optimised assembly Keith Thompson <kst-u@mib.org> - 2011-12-29 11:44 -0800
Re: Performance of hand-optimised assembly Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-25 17:23 -0800
Re: Performance of hand-optimised assembly James Harris <james.harris.1@googlemail.com> - 2011-12-29 08:37 -0800
Re: Performance of hand-optimised assembly Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-01-05 22:19 +0200
Re: Performance of hand-optimised assembly James Dow Allen <gmail@jamesdowallen.nospam> - 2011-12-24 16:21 +0000
Re: Performance of hand-optimised assembly Weland <weland@otaku.freeshell.org> - 2011-12-25 10:54 +0000
Re: Performance of hand-optimised assembly "christian.bau" <christian.bau@cbau.wanadoo.co.uk> - 2011-12-24 14:52 -0800
Re: Performance of hand-optimised assembly jacob navia <jacob@spamsink.net> - 2011-12-25 20:12 +0100
Re: Performance of hand-optimised assembly 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-25 11:36 -0800
Re: Performance of hand-optimised assembly jacob navia <jacob@spamsink.net> - 2011-12-25 21:35 +0100
Re: Performance of hand-optimised assembly Stephen Sprunk <stephen@sprunk.org> - 2011-12-26 14:24 -0600
Re: Performance of hand-optimised assembly jacob navia <jacob@spamsink.net> - 2011-12-26 21:36 +0100
Re: Performance of hand-optimised assembly Stephen Sprunk <stephen@sprunk.org> - 2012-01-04 11:59 -0600
Re: Performance of hand-optimised assembly jacob navia <jacob@spamsink.net> - 2012-01-04 20:22 +0100
Re: Performance of hand-optimised assembly Dann Corbit <dcorbit@connx.com> - 2012-01-04 12:59 -0800
Re: Performance of hand-optimised assembly James Harris <james.harris.1@googlemail.com> - 2012-01-04 15:32 -0800
Re: Performance of hand-optimised assembly Stephen Sprunk <stephen@sprunk.org> - 2012-01-05 23:47 -0600
Re: Performance of hand-optimised assembly Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-01-04 22:47 +0000
Re: Performance of hand-optimised assembly jacob navia <jacob@spamsink.net> - 2012-01-05 00:47 +0100
Re: Performance of hand-optimised assembly Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-01-05 00:22 +0000
Re: Performance of hand-optimised assembly 88888 Dihedral <dihedral88888@googlemail.com> - 2012-01-04 23:44 -0800
Re: Performance of hand-optimised assembly "BartC" <bc@freeuk.com> - 2012-01-05 12:16 +0000
Re: Performance of hand-optimised assembly "BartC" <bc@freeuk.com> - 2012-01-05 12:49 +0000
Re: Performance of hand-optimised assembly jgk@panix.com (Joe keane) - 2012-01-05 21:26 +0000
Re: Performance of hand-optimised assembly "io_x" <a@b.c.invalid> - 2012-01-07 10:32 +0100
Re: Performance of hand-optimised assembly jacob navia <jacob@spamsink.net> - 2012-01-05 00:58 +0100
Re: Performance of hand-optimised assembly 88888 Dihedral <dihedral88888@googlemail.com> - 2012-01-05 13:39 -0800
Re: Performance of hand-optimised assembly 88888 Dihedral <dihedral88888@googlemail.com> - 2012-01-07 02:15 -0800
Re: Performance of hand-optimised assembly 88888 Dihedral <dihedral88888@googlemail.com> - 2012-01-10 01:07 -0800
Re: Performance of hand-optimised assembly jgk@panix.com (Joe keane) - 2012-01-07 00:49 +0000
Re: Performance of hand-optimised assembly jacob navia <jacob@spamsink.net> - 2012-01-07 08:54 +0100
Re: Performance of hand-optimised assembly jacob navia <jacob@spamsink.net> - 2012-01-07 10:11 +0100
Re: Performance of hand-optimised assembly "io_x" <a@b.c.invalid> - 2012-01-07 10:51 +0100
Re: Performance of hand-optimised assembly jgk@panix.com (Joe keane) - 2012-01-07 20:09 +0000
Re: Performance of hand-optimised assembly Stephen Sprunk <stephen@sprunk.org> - 2012-01-06 23:39 -0600
Re: Performance of hand-optimised assembly jacob navia <jacob@spamsink.net> - 2012-01-07 10:33 +0100
Re: Performance of hand-optimised assembly Stephen Sprunk <stephen@sprunk.org> - 2012-01-07 07:36 -0600
Re: Performance of hand-optimised assembly Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-01-07 21:03 +0000
Re: Performance of hand-optimised assembly Stephen Sprunk <stephen@sprunk.org> - 2012-01-07 16:42 -0600
Re: Performance of hand-optimised assembly "BartC" <bc@freeuk.com> - 2011-12-25 20:23 +0000
Re: Performance of hand-optimised assembly jacob navia <jacob@spamsink.net> - 2011-12-25 21:50 +0100
Re: Performance of hand-optimised assembly "BartC" <bc@freeuk.com> - 2011-12-25 22:10 +0000
Re: Performance of hand-optimised assembly 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-25 13:11 -0800
Re: Performance of hand-optimised assembly "BartC" <bc@freeuk.com> - 2011-12-25 22:07 +0000
Re: Performance of hand-optimised assembly 88888 Dihedral <dihedral88888@googlemail.com> - 2011-12-25 16:39 -0800
Re: Performance of hand-optimised assembly "io_x" <a@b.c.invalid> - 2011-12-26 05:55 +0100
Re: Performance of hand-optimised assembly "io_x" <a@b.c.invalid> - 2012-02-17 17:58 +0100
Re: Performance of hand-optimised assembly "Wolfgang.Draxinger" <Wolfgang.Draxinger@physik.uni-muenchen.de> - 2012-01-10 18:00 +0100
csiph-web