Messages in this thread | | | Date | Fri, 09 Jan 2009 11:17:38 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [patch] measurements, numbers about CONFIG_OPTIMIZE_INLINING=y impact |
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Richard Guenther wrote: > On Fri, Jan 9, 2009 at 8:21 PM, Andi Kleen <andi@firstfloor.org> wrote: >>> GCC 4.3 should be good in compiling the >>> kernel with default -Os settings. >> It's unfortunately not. It doesn't inline a lot of simple asm() inlines >> for example. > > Reading Ingos posting with the actual numbers states the opposite. >
Well, Andi's patch forcing inlining of the bitops chops quite a bit of size off the kernel, so there is clearly room for improvement. From my post yesterday:
: voreg 64 ; size o.*/vmlinux text data bss dec hex filename 57590217 24940519 15560504 98091240 5d8c0e8 o.andi/vmlinux 59421552 24912223 15560504 99894279 5f44407 o.noopt/vmlinux 57700527 24950719 15560504 98211750 5da97a6 o.opty/vmlinux
110 KB of code size reduction by force-inlining the small bitops.
-hpa
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