Messages in this thread | | | From | Rasmus Villemoes <> | Subject | Re: [PATCH 2/2] include/linux: apply __malloc attribute | Date | Sat, 26 Mar 2016 20:06:13 +0100 |
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On Thu, Mar 24 2016, Andrew Morton <akpm@linux-foundation.org> wrote:
> On Thu, 24 Mar 2016 00:42:32 +0100 Rasmus Villemoes <linux@rasmusvillemoes.dk> wrote: > >> Attach the malloc attribute to a few allocation functions. This helps >> gcc generate better code by telling it that the return value doesn't >> alias any existing pointers (which is even more valuable given the >> pessimizations implied by -fno-strict-aliasing). >> > Shaves 6 bytes off my 1MB i386 defconfig vmlinux. Winner!
Well, the full bloat-o-meter summary is
add/remove: 0/0 grow/shrink: 72/155 up/down: 1165/-1674 (-509)
which sure still isn't much, but this isn't (just) about saving a few bytes, but more about allowing gcc to generate better code; sometimes by not having to reload, but also by enabling it to reorder instructions (e.g. hoisting a load above a store) - the simple example was chosen because it was very easy to see the relationship between the source and the generated code.
Anyway, thanks for picking them up.
Rasmus
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