Messages in this thread | | | Date | Mon, 08 Nov 2010 18:39:24 +0000 | From | Dave Korn <> | Subject | Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ? |
| |
On 08/11/2010 11:20, Andi Kleen wrote:
> An asm with live inputs and outputs should never be optimized > way. If 4.5.1 started doing that it's seriously broken.
I don't see that. Consider:
void foo (void) { int x, y, z; x = 23; y = x + 1; z = y + 1; }
So far, you'd agree the compiler may optimise the entire function away? So why not this:
void foo (void) { int x, y, z; x = 23; asm ("do something" : "=r" (y) : "r" (x) ); z = y + 1; }
?
cheers, DaveK
| |