[llvm] [MISched] Add templates for creating custom schedulers (PR #141935)

[Min-Yih Hsu via llvm-commits]

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@@ -1375,6 +1367,41 @@ std::unique_ptr<ScheduleDAGMutation>
 createCopyConstrainDAGMutation(const TargetInstrInfo *TII,
                                const TargetRegisterInfo *TRI);
 
+/// Create the standard converging machine scheduler. This will be used as the
+/// default scheduler if the target does not set a default.
+/// Adds default DAG mutations.
+template <typename Strategy = GenericScheduler>
+ScheduleDAGMILive *createGenericSchedLive(MachineSchedContext *C) {
+  ScheduleDAGMILive *DAG =
+      new ScheduleDAGMILive(C, std::make_unique<Strategy>(C));
+  // Register DAG post-processors.
+  //
+  // FIXME: extend the mutation API to allow earlier mutations to instantiate
+  // data and pass it to later mutations. Have a single mutation that gathers
+  // the interesting nodes in one pass.
+  DAG->addMutation(createCopyConstrainDAGMutation(DAG->TII, DAG->TRI));
+
+  const TargetSubtargetInfo &STI = C->MF->getSubtarget();
+  // Add MacroFusion mutation if fusions are not empty.
+  const auto &MacroFusions = STI.getMacroFusions();
+  if (!MacroFusions.empty())
+    DAG->addMutation(createMacroFusionDAGMutation(MacroFusions));
+  return DAG;
+}
+
+/// Create a generic scheduler with no vreg liveness or DAG mutation passes.
+template <typename Strategy = PostGenericScheduler>
+ScheduleDAGMI *createGenericSchedPostRA(MachineSchedContext *C) {
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mshockwave wrote:

ditto

https://github.com/llvm/llvm-project/pull/141935