Tom Rini wrote:
>
> Hello. Currently when fs/fat/inode.c is compiled with gcc-3.0.x, there
> are to lines which will cause a __divdi3 call to be used. But on most
> archs, there isn't currently a __divdi3 implementation in the kernel, so
> FAT will no longer link (or load as a module). The easy fix (pointed
> out by Andrew Morton) is to replace the divide by 512 with a shift right
> by 9, which has the same effect but doesn't use a divide.
>
> This is vs 2.4.18-pre3, but applies to 2.5.2-pre9 as well (and probably
> pre10 too..)
>
> --
> Tom Rini (TR1265)
> http://gate.crashing.org/~trini/
>
> ===== fs/fat/inode.c 1.10 vs edited =====
> --- 1.10/fs/fat/inode.c Wed Nov 21 15:12:16 2001
> +++ edited/fs/fat/inode.c Thu Jan 10 15:40:11 2002
> @@ -406,7 +406,7 @@
> }
> inode->i_blksize = 1 << sbi->cluster_bits;
> inode->i_blocks = ((inode->i_size + inode->i_blksize - 1)
> - & ~(inode->i_blksize - 1)) / 512;
> + & ~(inode->i_blksize - 1)) >> 9;
> MSDOS_I(inode)->i_logstart = 0;
> MSDOS_I(inode)->mmu_private = inode->i_size;
>
wow, I always assumed the compiler was smart enough to replace a "/ 512"
with a shift.
Jeff
-- Jeff Garzik | Alternate titles for LOTR: Building 1024 | Fast Times at Uruk-Hai MandrakeSoft | The Took, the Elf, His Daughter and Her Lover | Samwise Gamgee: International Hobbit of Mystery - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Tue Jan 15 2002 - 21:00:33 EST