Re: [PATCH] fs: dcache: Use bool return value instead of int
From: Al Viro
Date: Tue Jan 12 2016 - 17:21:19 EST
On Wed, Jan 13, 2016 at 05:42:20AM +0800, Chen Gang wrote:
> For me, it really generates a little better code:
> - Both 1-word store and 1-byte store are 1 instruction, normally, they
> have the same execution speed (although it is not quite precise).
> - But 1-byte store instruction has short length under CISC archs, which
> can generate a little better code globally.
> - For most of archs, 1-word store can process bytes nonalignment cases,
> for check_mount() individually, the parameter data may be not word
> alignment, which may cause the 1-word store slower than 1-byte store.
What the hell do you mean, unaligned? It's given an address of local
variable of type int; it _will_ be aligned, or the compiler is FUBAR.
As for the inlines... frankly, if gcc generates a different code from having
replaced int with bool in those, it's time to do something very nasty to