On 11/24/19 8:43 PM, Segher Boessenkool wrote:
> But. Allowing autoinc into jump insns means those jump insns may then
> eventually need an output reload; it may just have been because of that?
That's almost certainly the reasoning, but as I pointed out in my
original mail - reload is careful around autoincs and emits the reload
sequence before the reloaded insn.
For example, see inc_for_reload:
/* Postincrement.
Because this might be a jump insn or a compare, and because RELOADREG
may not be available after the insn in an input reload, we must do
the incrementation before the insn being reloaded for.
On m68k with cc0 this is already necessary, because even a cmp insn
cannot have output reloads (they would overwrite the flags). This is why
I think it should be safe to allow them in jumps too.
Bernd
