Hi,
On Sun, 11 Jul 2004, Mark Mitchell wrote:
Mike Stump wrote:
On Wednesday, June 30, 2004, at 10:03 AM, Mark Mitchell wrote:
Yes. And without optimization enabled, I don't see any reason that the
compiler should be expected to reuse the stack space; that's an
optimization. The compiler might, for example, be able to generate code
more quickly by using a new stack slot for every variable. Or, using
different stack slots, might result in faster code on some machines, which
is nice even at -O0.
If people find no other way to make it work other than -Os, that's fine.
I think -Os is an optimization for code size, not for stack size. It's not
clear to me that reusing the stack slot will result in smaller code all the
time on all machines.
The probability for this is quite small. If such machine happens to exist
the testcase can be XFAILed for it. Equally unlikely are machines for
which not merging stack slots produces faster code, be it for smaller
stack frame, hence possibly shorter insn encoding, not to mention cache
effects. Why do you use such constructed examples?