[RISCV] Add Zfh to typeIsScalarFPArith and simplify code. NFC

Now that we have Zfh supported and tested for every opcode that uses
typeIsScalarFPArith, we can fold Zfh into it.

Author: topperc

llvm/lib/Target/RISCV/GISel/RISCVLegalizerInfo.cpp

@@ -404,38 +404,28 @@ RISCVLegalizerInfo::RISCVLegalizerInfo(const RISCVSubtarget &ST)
                 typeIs(1, s16)(Query));
       });
 
-  auto &FCmpActions = getActionDefinitionsBuilder(G_FCMP).legalIf(
-      all(typeIs(0, sXLen), typeIsScalarFPArith(1, ST)));
-  // TODO: Fold this into typeIsScalarFPArith.
-  if (ST.hasStdExtZfh())
-    FCmpActions.legalFor({sXLen, s16});
-  FCmpActions.clampScalar(0, sXLen, sXLen);
+  getActionDefinitionsBuilder(G_FCMP)
+      .legalIf(all(typeIs(0, sXLen), typeIsScalarFPArith(1, ST)))
+      .clampScalar(0, sXLen, sXLen);
 
   // TODO: Support vector version of G_IS_FPCLASS.
-  auto &FClassActions =
-      getActionDefinitionsBuilder(G_IS_FPCLASS)
-          .customIf(all(typeIs(0, s1), typeIsScalarFPArith(1, ST)));
-  // TODO: Fold this into typeIsScalarFPArith.
-  if (ST.hasStdExtZfh())
-    FClassActions.customFor({s1, s16});
+  getActionDefinitionsBuilder(G_IS_FPCLASS)
+      .customIf(all(typeIs(0, s1), typeIsScalarFPArith(1, ST)));
 
   getActionDefinitionsBuilder(G_FCONSTANT)
       .legalIf(typeIsScalarFPArith(0, ST))
       .lowerFor({s32, s64});
 
-  auto &FPToIActions =
-      getActionDefinitionsBuilder({G_FPTOSI, G_FPTOUI})
-          .legalIf(all(typeInSet(0, {s32, sXLen}), typeIsScalarFPArith(1, ST)));
-  if (ST.hasStdExtZfh())
-    FPToIActions.legalFor({{s32, s16}, {sXLen, s16}});
-  FPToIActions.widenScalarToNextPow2(0).clampScalar(0, s32, sXLen).libcall();
-
-  auto &IToFPActions =
-      getActionDefinitionsBuilder({G_SITOFP, G_UITOFP})
-          .legalIf(all(typeIsScalarFPArith(0, ST), typeInSet(1, {s32, sXLen})));
-  if (ST.hasStdExtZfh())
-    IToFPActions.legalFor({{s16, s32}, {s16, sXLen}});
-  IToFPActions.widenScalarToNextPow2(1).clampScalar(1, s32, sXLen);
+  getActionDefinitionsBuilder({G_FPTOSI, G_FPTOUI})
+      .legalIf(all(typeInSet(0, {s32, sXLen}), typeIsScalarFPArith(1, ST)))
+      .widenScalarToNextPow2(0)
+      .clampScalar(0, s32, sXLen)
+      .libcall();
+
+  getActionDefinitionsBuilder({G_SITOFP, G_UITOFP})
+      .legalIf(all(typeIsScalarFPArith(0, ST), typeInSet(1, {s32, sXLen})))
+      .widenScalarToNextPow2(1)
+      .clampScalar(1, s32, sXLen);
 
   // FIXME: We can do custom inline expansion like SelectionDAG.
   // FIXME: Legal with Zfa.