Re: How to fix: asm output is not an lvalue

[Sam Ravnborg <sam@ravnborg.org>]

On Sat, Apr 26, 2014 at 04:44:13PM -0700, Linus Torvalds wrote:
> On Sat, Apr 26, 2014 at 2:57 PM, Sam Ravnborg <sam@ravnborg.org> wrote:
> >
> > Following code snippet generate these warnings:
> > t.c:9:9: warning: asm output is not an lvalue
> 
> Yeah. That code snippet is pure and utter garbage.
> 
> Gcc has this totally insane extension that makes casts be lvalues.
> It's stupid and horrid, and pointless to boot. So apparently gcc
> accepts that crap.
> 
> But it is very much total crap.
> 
> Those casts to (USItype) are all pointless to begin with (since the
> values are of that type already!) and they mean that the expression
> isn't something you can assign to (lvalue). The fact that gcc accepts
> code like that is an embarrassment.

Thanks.
When I dropped the casts to the output values the warnings were gone.

Now the code is down to ~30 warnings - looks like this.
math_32.c:371:17: warning: shift too big (4294967267) for type unsigned long
math_32.c:428:21: warning: shift too big (63) for type unsigned long

But this code is so full of macros that it is not funny :-(

	Sam