[RISCV] Remove vfmerge.vf patterns with bf16 types.

These patterns are no longer used because we don't generate bf16
to vector splats except for constants that can be handled with
vmerge.vi.

Author: topperc

llvm/lib/Target/RISCV/RISCVInstrInfoVPseudos.td

@@ -382,17 +382,6 @@ class GetIntVTypeInfo<VTypeInfo vti> {
                                                  !cast<string>(vti))));
 }
 
-// This functor is used to obtain the fp vector type that has the same SEW and
-// multiplier as the input parameter type.
-class GetFpVTypeInfo<VTypeInfo vti> {
-  // Equivalent integer vector type. Eg.
-  //   VF16M1 → VF16M1 (identity)
-  //   VBF16M1 → VF16M1
-  VTypeInfo Vti = !cast<VTypeInfo>(!subst("VBF", "VF",
-                                          !subst("VI", "VF",
-                                                 !cast<string>(vti))));
-}
-
 class MTypeInfo<ValueType Mas, LMULInfo M, string Bx> {
   ValueType Mask = Mas;
   // {SEW, VLMul} values set a valid VType to deal with this mask type.
@@ -769,11 +758,6 @@ class GetVTypePredicates<VTypeInfo vti> {
                                      true : [HasVInstructions]);
 }
 
-class GetVTypeScalarPredicates<VTypeInfo vti> {
-  list<Predicate> Predicates = !cond(!eq(vti.Scalar, bf16) : [HasStdExtZfbfmin],
-                                     true : []);
-}
-
 class VPseudoUSLoadNoMask<VReg RetClass,
                           int EEW> :
       Pseudo<(outs RetClass:$rd),

llvm/lib/Target/RISCV/RISCVInstrInfoVSDPatterns.td

@@ -1412,9 +1412,10 @@ foreach fvti = !listconcat(AllFloatVectors, AllBFloatVectors) in {
                    fvti.RegClass:$rs2, 0, (fvti.Mask V0), fvti.AVL, fvti.Log2SEW)>;
 
   }
+}
 
-  let Predicates = !listconcat(GetVTypePredicates<GetFpVTypeInfo<fvti>.Vti>.Predicates,
-                               GetVTypeScalarPredicates<fvti>.Predicates) in 
+foreach fvti = AllFloatVectors in {
+  let Predicates = GetVTypePredicates<fvti>.Predicates in
     def : Pat<(fvti.Vector (vselect (fvti.Mask V0),
                                     (SplatFPOp fvti.ScalarRegClass:$rs1),
                                     fvti.RegClass:$rs2)),

llvm/lib/Target/RISCV/RISCVInstrInfoVVLPatterns.td

@@ -2638,9 +2638,10 @@ foreach fvti = !listconcat(AllFloatVectors, AllBFloatVectors) in {
                  fvti.RegClass:$merge, fvti.RegClass:$rs2, 0, (fvti.Mask V0),
                  GPR:$vl, fvti.Log2SEW)>;
   }
+}
 
-  let Predicates = !listconcat(GetVTypePredicates<GetFpVTypeInfo<fvti>.Vti>.Predicates,
-                               GetVTypeScalarPredicates<fvti>.Predicates) in {
+foreach fvti = AllFloatVectors in {
+  let Predicates = GetVTypePredicates<fvti>.Predicates in {
     def : Pat<(fvti.Vector (riscv_vmerge_vl (fvti.Mask V0),
                                             (SplatFPOp fvti.ScalarRegClass:$rs1),
                                             fvti.RegClass:$rs2,