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From: | Vladimir 'φ-coder/phcoder' Serbinenko |
Subject: | Re: Image scaling performance |
Date: | Wed, 25 Feb 2015 19:56:55 +0100 |
User-agent: | Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.4.0 |
On 25.02.2015 19:46, Michael Zimmermann wrote:
Please try my patch (reattached here after minor fixes). The patch by anonymous source, sent by third-party through pastebin isn't acceptable from legal perspectiveoh ok so linux's div/mod/... assembler is as slow/fast as grub's code? Linux uses armv5>= ifdefs. Maybe we could optimized things a little :) About scale_nn, amarullz(https://plus.google.com/u/0/+AhmadAmarullah/about) wrote a optimized version without divs: loops: http://pastebin.com/MaZqWSA9 memcpy: http://pastebin.com/iNq0V5Tw
this code works a little faster. I'm still questioning the efficiency math operations because on slow devices there are other bottlenecks of the same kind(like de/compression). On Wed, Feb 25, 2015 at 7:41 PM, Vladimir 'phcoder' Serbinenko <address@hidden> wrote:ARMv7 doesn't mandate div instructions. It's a separate flag in features. GRUB supports earlier CPUs as well and we use them for testing. My only test machine is armv6 Le 2015-02-25 19:38, "Michael Zimmermann" <address@hidden> a écrit :Why u think the native div code would crash on most devices? I support ARMv7+ only anyway. On Wed, Feb 25, 2015 at 5:23 PM, Leif Lindholm <address@hidden> wrote:On Wed, Feb 25, 2015 at 03:45:40PM +0000, Leif Lindholm wrote:Some technical info: ARMv7 Linaro GCC 4.9I don't see any calls to any of the __aeabi helpers generated for this file with current head. Which specific Linaro toolchain are you using? (mine is"Linaro GCC 4.9-2014.09").Scratch that, I do see them. Just failing to drive the tools properly. / Leif _______________________________________________ Grub-devel mailing list address@hidden https://lists.gnu.org/mailman/listinfo/grub-devel_______________________________________________ Grub-devel mailing list address@hidden https://lists.gnu.org/mailman/listinfo/grub-devel_______________________________________________ Grub-devel mailing list address@hidden https://lists.gnu.org/mailman/listinfo/grub-devel_______________________________________________ Grub-devel mailing list address@hidden https://lists.gnu.org/mailman/listinfo/grub-devel
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