[llvm] [MCA] New option -scheduling-info (PR #130574)

[Min-Yih Hsu via llvm-commits]

================
@@ -174,3 +174,39 @@ MCSchedModel::getForwardingDelayCycles(ArrayRef<MCReadAdvanceEntry> Entries,
 
   return std::abs(DelayCycles);
 }
+
+unsigned MCSchedModel::getBypassDelayCycles(const MCSubtargetInfo &STI,
+                                            const MCSchedClassDesc &SCDesc) {
+
+  ArrayRef<MCReadAdvanceEntry> Entries = STI.getReadAdvanceEntries(SCDesc);
+  if (Entries.empty())
+    return 0;
+
+  unsigned Latency = 0;
+  unsigned MaxLatency = 0;
+  unsigned WriteResourceID = 0;
+  unsigned DefEnd = SCDesc.NumWriteLatencyEntries;
+
+  for (unsigned DefIdx = 0; DefIdx != DefEnd; ++DefIdx) {
+    // Lookup the definition's write latency in SubtargetInfo.
+    const MCWriteLatencyEntry *WLEntry =
+        STI.getWriteLatencyEntry(&SCDesc, DefIdx);
+    unsigned Cycles = (unsigned)WLEntry->Cycles;
+    // Invalid latency. Consider 0 cycle latency
+    if (WLEntry->Cycles < 0)
+      Cycles = 0;
----------------
mshockwave wrote:

nit:
```suggestion
    unsigned Cycles = 0;
    if (WLEntry->Cycles > 0)
      Cycles = (unsigned)WLEntry->Cycles;
```

https://github.com/llvm/llvm-project/pull/130574