/// atIssueLimit - Return true if no more instructions may be issued in this
/// cycle.
+ ///
+ /// FIXME: remove this once MachineScheduler is the only client.
virtual bool atIssueLimit() const { return false; }
/// getHazardType - Return the hazard type of emitting this node. There are
/// other instruction is available, issue it first.
/// * NoopHazard: issuing this instruction would break the program. If
/// some other instruction can be issued, do so, otherwise issue a noop.
- virtual HazardType getHazardType(SUnit *m, int Stalls) {
+ virtual HazardType getHazardType(SUnit *m, int Stalls = 0) {
return NoHazard;
}
/// emitted, to advance the hazard state.
virtual void EmitInstruction(SUnit *) {}
+ /// PreEmitNoops - This callback is invoked prior to emitting an instruction.
+ /// It should return the number of noops to emit prior to the provided
+ /// instruction.
+ /// Note: This is only used during PostRA scheduling. EmitNoop is not called
+ /// for these noops.
+ virtual unsigned PreEmitNoops(SUnit *) {
+ return 0;
+ }
+
+ /// ShouldPreferAnother - This callback may be invoked if getHazardType
+ /// returns NoHazard. If, even though there is no hazard, it would be better to
+ /// schedule another available instruction, this callback should return true.
+ virtual bool ShouldPreferAnother(SUnit *) {
+ return false;
+ }
+
/// AdvanceCycle - This callback is invoked whenever the next top-down
/// instruction to be scheduled cannot issue in the current cycle, either
/// because of latency or resource conflicts. This should increment the