[llvm] [AMDGPU] Simplicy the logic in checkWMMACoexecutionHazards, NFC (PR #200717)

[Shilei Tian via llvm-commits]

================
@@ -2048,45 +2048,49 @@ static bool isCoexecutableVALUInst(const MachineInstr &MI) {
          !SIInstrInfo::isSWMMAC(MI) && !SIInstrInfo::isLDSDMA(MI);
 }
 
-static bool IsWMMAHazardInstInCategory(const MachineInstr &MI,
-                                       const SIInstrInfo *TII, unsigned Latency,
-                                       unsigned Category) {
-  assert(TII->isXDLWMMA(MI) && (Latency == 8 || Latency == 16) &&
-         "Handle me if the xdl wmma instruction latency changes");
-
-  switch (Category) {
-  case 0: // Dense WMMA Instructions:
-          //   WMMA_*F16, WMMA_*BF16
-          //   WMMA_*FP8FP8
-          //   WMMA_*FP8BF8
-          //   WMMA_*BF8FP8
-          //   WMMA_*BF8BF8
-          //   WMMA_*F8F6F4 if SRCA & SRCB != F8
-    return Latency == 8 && SIInstrInfo::isWMMA(MI);
-
-  case 1: // Dense WMMA Instructions:
-          //   WMMA_IU8
-          //   WMMA_IU4
-          //   WMMA_*F8F6F4 if SRCA OR SRCB == F8
-    return Latency == 16 && SIInstrInfo::isWMMA(MI);
-
-  case 2: // Dense SWMMAC Instructions
-          //   SWMMAC_*F16, SWMMAC_*BF16,
-          //   SWMMAC_*FP8FP8
-          //   SWMMAC_*BF8FP8
-          //   SWMMAC_*FP8BF8
-          //   SWMMAC_*BF8BF8
-    return Latency == 8 && SIInstrInfo::isSWMMAC(MI);
-
-  case 3: // Sparse WMMA Instructions:
-          //   SWMMAC_IU8
-          //   SWMMAC_IU4
-    return Latency == 16 && SIInstrInfo::isSWMMAC(MI);
-  default:
+// Classify XDL WMMA instructions into co-execution hazard categories
+// (Refer to SPG 4.6.12.1), mainly based on instruction latency.
+//
+// Category 0: WMMA with Latency 8
+//   WMMA_*F16, WMMA_*BF16
+//   WMMA_*FP8FP8
+//   WMMA_*FP8BF8
+//   WMMA_*BF8FP8
+//   WMMA_*BF8BF8
+//   WMMA_*F8F6F4 if SRCA & SRCB != F8
+//
+// Category 1: WMMA Latency 16
+//   WMMA_IU8
+//   WMMA_*F8F6F4 if SRCA OR SRCB == F8
+//
+// Category 2: SWMMAC with Latency 8
+//   SWMMAC_*F16, SWMMAC_*BF16,
+//   SWMMAC_*FP8FP8
+//   SWMMAC_*BF8FP8
+//   SWMMAC_*FP8BF8
+//   SWMMAC_*BF8BF8
+//
+// Category 3: SWMMAC with Latency 16
+//   SWMMAC_IU8
+static unsigned getWMMAHazardInstInCategory(const MachineInstr &MI,
----------------
shiltian wrote:

from interface's perspective, I'd do `computeInstrLatency` inside this function, if `Latency` is not used anywhere else in its caller.

https://github.com/llvm/llvm-project/pull/200717