Revert "[RISCV][CostModel] VPIntrinsics have same cost as their non-vp counterparts (#67178)"

This reverts commit fc865c2.

Triggering assert on X86:

```
iree-compile: /work/third_party/llvm-project/llvm/include/llvm/Support/Casting.h:662: decltype(auto) llvm::dyn_cast(From *) [To = llvm::PointerType, From = llvm::Type]: Assertion `detail::isPresent(Val) && "dyn_cast on a non-existent value"' failed.
```

See PR for comments and full stack trace.

Author: stellaraccident

llvm/include/llvm/CodeGen/BasicTTIImpl.h

@@ -1691,62 +1691,6 @@ class BasicTTIImplBase : public TargetTransformInfoImplCRTPBase<T> {
     }
     }
 
-    // VP Intrinsics should have the same cost as their non-vp counterpart.
-    // TODO: Adjust the cost to make the vp intrinsic cheaper than its non-vp
-    // counterpart when the vector length argument is smaller than the maximum
-    // vector length.
-    if (VPIntrinsic::isVPIntrinsic(ICA.getID())) {
-      std::optional<unsigned> FOp =
-          VPIntrinsic::getFunctionalOpcodeForVP(ICA.getID());
-      if (FOp) {
-        // TODO: Support other kinds of Intrinsics (i.e. reductions)
-        if (ICA.getID() == Intrinsic::vp_load) {
-          Align Alignment;
-          if (auto *VPI = dyn_cast_or_null<VPIntrinsic>(ICA.getInst()))
-            Alignment = VPI->getPointerAlignment().valueOrOne();
-          unsigned AS = 0;
-          if (ICA.getArgs().size() > 1)
-            if (auto *PtrTy =
-                    dyn_cast<PointerType>(ICA.getArgs()[0]->getType()))
-              AS = PtrTy->getAddressSpace();
-          return thisT()->getMemoryOpCost(*FOp, ICA.getReturnType(), Alignment,
-                                          AS, CostKind);
-        }
-        if (ICA.getID() == Intrinsic::vp_store) {
-          Align Alignment;
-          if (auto *VPI = dyn_cast_or_null<VPIntrinsic>(ICA.getInst()))
-            Alignment = VPI->getPointerAlignment().valueOrOne();
-          unsigned AS = 0;
-          if (ICA.getArgs().size() >= 2)
-            if (auto *PtrTy =
-                    dyn_cast<PointerType>(ICA.getArgs()[1]->getType()))
-              AS = PtrTy->getAddressSpace();
-          return thisT()->getMemoryOpCost(*FOp, Args[0]->getType(), Alignment,
-                                          AS, CostKind);
-        }
-        if (VPBinOpIntrinsic::isVPBinOp(ICA.getID())) {
-          return thisT()->getArithmeticInstrCost(*FOp, ICA.getReturnType(),
-                                                 CostKind);
-        }
-      }
-
-      std::optional<Intrinsic::ID> FID =
-          VPIntrinsic::getFunctionalIntrinsicIDForVP(ICA.getID());
-      if (FID) {
-        // Non-vp version will have same Args/Tys except mask and vector length.
-        assert(ICA.getArgs().size() >= 2 && ICA.getArgTypes().size() >= 2 &&
-               "Expected VPIntrinsic to have Mask and Vector Length args and "
-               "types");
-        ArrayRef<const Value *> NewArgs = ArrayRef(ICA.getArgs()).drop_back(2);
-        ArrayRef<Type *> NewTys = ArrayRef(ICA.getArgTypes()).drop_back(2);
-
-        IntrinsicCostAttributes NewICA(*FID, ICA.getReturnType(), NewArgs,
-                                       NewTys, ICA.getFlags(), ICA.getInst(),
-                                       ICA.getScalarizationCost());
-        return thisT()->getIntrinsicInstrCost(NewICA, CostKind);
-      }
-    }
-
     // Assume that we need to scalarize this intrinsic.
     // Compute the scalarization overhead based on Args for a vector
     // intrinsic.

llvm/test/Analysis/CostModel/RISCV/gep.ll

@@ -270,7 +270,7 @@ define void @non_foldable_vector_uses(ptr %base, <2 x ptr> %base.vec) {
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %4 = getelementptr i8, ptr %base, i32 42
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 5 for instruction: %x4 = call <2 x i8> @llvm.masked.expandload.v2i8(ptr %4, <2 x i1> undef, <2 x i8> undef)
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %5 = getelementptr i8, ptr %base, i32 42
-; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %x5 = call <2 x i8> @llvm.vp.load.v2i8.p0(ptr %5, <2 x i1> undef, i32 undef)
+; RVI-NEXT:  Cost Model: Found an estimated cost of 5 for instruction: %x5 = call <2 x i8> @llvm.vp.load.v2i8.p0(ptr %5, <2 x i1> undef, i32 undef)
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %6 = getelementptr i8, ptr %base, i32 42
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 5 for instruction: %x6 = call <2 x i8> @llvm.experimental.vp.strided.load.v2i8.p0.i64(ptr %6, i64 undef, <2 x i1> undef, i32 undef)
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %7 = getelementptr i8, ptr %base, i32 42
@@ -282,7 +282,7 @@ define void @non_foldable_vector_uses(ptr %base, <2 x ptr> %base.vec) {
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %10 = getelementptr i8, ptr %base, i32 42
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 12 for instruction: call void @llvm.masked.compressstore.v2i8(<2 x i8> undef, ptr %10, <2 x i1> undef)
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %11 = getelementptr i8, ptr %base, i32 42
-; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: call void @llvm.vp.store.v2i8.p0(<2 x i8> undef, ptr %11, <2 x i1> undef, i32 undef)
+; RVI-NEXT:  Cost Model: Found an estimated cost of 12 for instruction: call void @llvm.vp.store.v2i8.p0(<2 x i8> undef, ptr %11, <2 x i1> undef, i32 undef)
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %12 = getelementptr i8, ptr %base, i32 42
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 12 for instruction: call void @llvm.experimental.vp.strided.store.v2i8.p0.i64(<2 x i8> undef, ptr %12, i64 undef, <2 x i1> undef, i32 undef)
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret void
@@ -340,7 +340,7 @@ define void @foldable_vector_uses(ptr %base, <2 x ptr> %base.vec) {
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %4 = getelementptr i8, ptr %base, i32 0
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 5 for instruction: %x4 = call <2 x i8> @llvm.masked.expandload.v2i8(ptr %4, <2 x i1> undef, <2 x i8> undef)
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %5 = getelementptr i8, ptr %base, i32 0
-; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: %x5 = call <2 x i8> @llvm.vp.load.v2i8.p0(ptr %5, <2 x i1> undef, i32 undef)
+; RVI-NEXT:  Cost Model: Found an estimated cost of 5 for instruction: %x5 = call <2 x i8> @llvm.vp.load.v2i8.p0(ptr %5, <2 x i1> undef, i32 undef)
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %6 = getelementptr i8, ptr %base, i32 0
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 5 for instruction: %x6 = call <2 x i8> @llvm.experimental.vp.strided.load.v2i8.p0.i64(ptr %6, i64 undef, <2 x i1> undef, i32 undef)
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %7 = getelementptr i8, ptr %base, i32 0
@@ -352,7 +352,7 @@ define void @foldable_vector_uses(ptr %base, <2 x ptr> %base.vec) {
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %10 = getelementptr i8, ptr %base, i32 0
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 12 for instruction: call void @llvm.masked.compressstore.v2i8(<2 x i8> undef, ptr %10, <2 x i1> undef)
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %11 = getelementptr i8, ptr %base, i32 0
-; RVI-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: call void @llvm.vp.store.v2i8.p0(<2 x i8> undef, ptr %11, <2 x i1> undef, i32 undef)
+; RVI-NEXT:  Cost Model: Found an estimated cost of 12 for instruction: call void @llvm.vp.store.v2i8.p0(<2 x i8> undef, ptr %11, <2 x i1> undef, i32 undef)
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: %12 = getelementptr i8, ptr %base, i32 0
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 12 for instruction: call void @llvm.experimental.vp.strided.store.v2i8.p0.i64(<2 x i8> undef, ptr %12, i64 undef, <2 x i1> undef, i32 undef)
 ; RVI-NEXT:  Cost Model: Found an estimated cost of 0 for instruction: ret void