Hi Simon -- and sorry for the dupe. On Wed, 17 Apr 2013 11:28:07 -0700, Simon Glass <s...@chromium.org> wrote:
> I tried using: > > #ifdef USE_HOSTCC > crc = htobe32(crc); > #else > crc = cpu_to_be32(crc); > #endif > memcpy(output, &crc, sizeof(crc)); > > > This is one instruction (4 bytes, 16%) smaller, but I suspect quite a > lot slower due to the overhead of a very small memcpy(). > > 43e2c1d8: e28d1008 add r1, sp, #8 > 43e2c1dc: e3a02004 mov r2, #4 > 43e2c1e0: e6bf0f30 rev r0, r0 > 43e2c1e4: e5210004 str r0, [r1, #-4]! > 43e2c1e8: e1a00004 mov r0, r4 > 43e2c1ec: eb001af7 bl 43e32dd0 <memcpy> How about replacing the memcpy with an explicit put_unaligned(), similar to what was done in http://www.mail-archive.com/u-boot@lists.denx.de/msg109555.html with get_unaligned()? The code will be longer than above, but shorter than the above plus the memcpy(), and faster too -- actually, I'm surprised that the compiler does not unroll the memcpy() on its own, considering the size argument is a constant. > Regards, > Simon Amicalement, -- Albert. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
