[llvm] [RISCV][CostModel] Add getRISCVInstructionCost() to TTI for Cost… (PR #73651)

[Shih-Po Hung via llvm-commits]

================
@@ -34,6 +34,63 @@ static cl::opt<unsigned> SLPMaxVF(
         "exclusively by SLP vectorizer."),
     cl::Hidden);
 
+InstructionCost
+RISCVTTIImpl::getRISCVInstructionCost(ArrayRef<unsigned> OpCodes, MVT VT,
+                                      TTI::TargetCostKind CostKind) {
+  size_t NumInstr = OpCodes.size();
+  if (CostKind == TTI::TCK_CodeSize)
+    return NumInstr;
+  InstructionCost LMULCost = TLI->getLMULCost(VT);
+  if ((CostKind != TTI::TCK_RecipThroughput) && (CostKind != TTI::TCK_Latency))
+    return LMULCost * NumInstr;
+  InstructionCost Cost = 0;
+  for (auto Op : OpCodes) {
+    switch (Op) {
+    case RISCV::VRGATHER_VI:
+      Cost += TLI->getVRGatherVICost(VT);
+      break;
+    case RISCV::VRGATHER_VV:
+      Cost += TLI->getVRGatherVVCost(VT);
+      break;
+    case RISCV::VSLIDEUP_VI:
+    case RISCV::VSLIDEDOWN_VI:
+    case RISCV::VSLIDEUP_VX:
----------------
arcbbb wrote:

Yes, I think it would be good to expand getVSlideCost to getVSlideVXCost and getVSlideVICost. Fixed.

https://github.com/llvm/llvm-project/pull/73651