}
+static bool isZeroLengthInterval(LiveInterval *li) {
+ for (LiveInterval::Ranges::const_iterator
+ i = li->ranges.begin(), e = li->ranges.end(); i != e; ++i)
+ if (i->end - i->start > LiveIntervals::InstrSlots::NUM)
+ return false;
+ return true;
+}
+
+
/// runOnMachineFunction - Register allocate the whole function
///
bool LiveIntervals::runOnMachineFunction(MachineFunction &fn) {
}
}
+ for (iterator I = begin(), E = end(); I != E; ++I) {
+ LiveInterval &li = I->second;
+ if (MRegisterInfo::isVirtualRegister(li.reg))
+ // If the live interval legnth is essentially zero, i.e. in every live
+ // range the use follows def immediately, it doesn't make sense to spill
+ // it and hope it will be easier to allocate for this li.
+ if (isZeroLengthInterval(&li))
+ li.weight = float(HUGE_VAL);
+ }
+
DEBUG(dump());
return true;
}