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

[Shih-Po Hung via llvm-commits]

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@@ -398,24 +468,34 @@ InstructionCost RISCVTTIImpl::getShuffleCost(TTI::ShuffleKind Kind,
       //   vmv.v.x v8, a0
       //   vmsne.vi  v0, v8, 0
 
-      return LT.first * TLI->getLMULCost(LT.second) * 6;
+      return LT.first *
+             (TLI->getLMULCost(LT.second) + // FIXME: this should be 1 for andi
+              TLI->getLMULCost(
+                  LT.second) + // FIXME: vmv.x.s is the same as extractelement
+              getRISCVInstructionCost({RISCV::VMV_V_I, RISCV::VMERGE_VIM,
+                                       RISCV::VMV_V_X, RISCV::VMSNE_VI},
+                                      LT.second, CostKind));
     }
 
     if (HasScalar) {
       // Example sequence:
       //   vmv.v.x v8, a0
-      return LT.first * TLI->getLMULCost(LT.second);
+      return LT.first *
+             getRISCVInstructionCost(RISCV::VMV_V_X, LT.second, CostKind);
     }
 
     // Example sequence:
     //   vrgather.vi     v9, v8, 0
-    return LT.first * TLI->getVRGatherVICost(LT.second);
+    return LT.first *
+           getRISCVInstructionCost(RISCV::VRGATHER_VI, LT.second, CostKind);
   }
   case TTI::SK_Splice:
     // vslidedown+vslideup.
     // TODO: Multiplying by LT.first implies this legalizes into multiple copies
     // of similar code, but I think we expand through memory.
-    return 2 * LT.first * TLI->getVSlideCost(LT.second);
+    return LT.first *
+           getRISCVInstructionCost({RISCV::VSLIDEDOWN_VX, RISCV::VSLIDEUP_VX},
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arcbbb wrote:

Yes, the index should be known and I can check if it is a 5-bit imm for .vi.

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