On Tuesday 21 June 2005 09:58, [email protected] wrote:
> Examine each case individually...
>
> Any code that did a "sizeof(foo)" is [very] likely to give different
> results.
>
> Also, if there are several instances of "foo" being passed around as
> parameter, you may find the generated code gets somewhat worse if "foo" used
> to be a stack based autovar. On x86, the const[] implementation will always
> cause a 5 byte PUSH for a parameter, whereas the autovar pointer
> implementation often will be a shorter 3 byte EBP relative push. With many
> instances of 'foo' usage (or used in a loop), you may be better off paying
> the price of an autovar init during prolog to get the cheaper parm pushes
> later.
But that 3 byte push is fetching data from stack, while 5 byte const push
does not. I ike smaller code, but not _this_ much.
Also this smallish size advantage may be i386-specific only.
--
vda
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
