[llvm] [AMDGPU] Support function attribute to override postRA scheduling direction (PR #147708)

[Harrison Hao via llvm-commits]

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@@ -340,6 +340,45 @@ void GCNSubtarget::overrideSchedPolicy(MachineSchedPolicy &Policy,
     Policy.ShouldTrackLaneMasks = true;
 }
 
+void GCNSubtarget::overridePostRASchedPolicy(MachineSchedPolicy &Policy,
+                                             const SchedRegion &Region) const {
+  const Function &F = Region.RegionBegin->getMF()->getFunction();
+  Attribute PostRADirectionAttr = F.getFnAttribute("amdgpu-post-ra-direction");
+  if (!PostRADirectionAttr.isValid())
+    return;
+
+  StringRef PostRADirectionStr = PostRADirectionAttr.getValueAsString();
+  if (PostRADirectionStr == "topdown") {
+    Policy.OnlyTopDown = true;
+    Policy.OnlyBottomUp = false;
+  } else if (PostRADirectionStr == "bottomup") {
+    Policy.OnlyTopDown = false;
+    Policy.OnlyBottomUp = true;
+  } else if (PostRADirectionStr == "bidirectional") {
+    Policy.OnlyTopDown = false;
+    Policy.OnlyBottomUp = false;
+  } else {
+    DiagnosticInfoOptimizationFailure Diag(
+        F, F.getSubprogram(),
+        Twine("invalid value for postRa direction attribute: '") +
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harrisonGPU wrote:

Done.

https://github.com/llvm/llvm-project/pull/147708