Re: enabling libgcc for 64-bit divisions, was Re: PROBLEM: XFS on ARM corruption 'Structure needs cl
From: Linus Torvalds
Date: Thu Aug 13 2015 - 12:28:41 EST
On Wed, Aug 12, 2015 at 11:11 PM, George Spelvin <linux@xxxxxxxxxxx> wrote:
> Agreed. But some x86 code I'm working on now, I have a *lot* of
> asm("divl") calls because even do_div isn't great for 64/32->32 division.
I'm not convinced that "64/32->32" is all that generic, though. If
the dividend in 64-bit, there's no fundamental type-based guarantee
that things will fit.
So your case is rather special, and depends (intimately) on knowing
the actual ranges and how they interact.
That's not a generic situation like "do_div()".
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/