[llvm][NFC] Refactor AutoUpgrade case 'w'

[urnathan]

Summary

Here's the refactoring of case 'w':. Primarily check a 'wasm' prefix before proceeding, and a bit of common handling for some of the intrinsics therein.

[nikic]

LG

llvm/lib/IR/AutoUpgrade.cpp

if (Name == "var.annotation" && F->arg_size() == 4) {
           F->getParent(), Intrinsic::var_annotation,
           {{F->arg_begin()->getType(), F->getArg(1)->getType()}});
       return true;
     }
     break;
   }
 
   case 'w':
-    if (Name.startswith("wasm.fma.")) {
-      rename(F);
-      NewFn = Intrinsic::getDeclaration(
-          F->getParent(), Intrinsic::wasm_relaxed_madd, F->getReturnType());
-      return true;
-    }
-    if (Name.startswith("wasm.fms.")) {
+    if (Name.consume_front("wasm.")) {
+      Intrinsic::ID ID =
+          StringSwitch<Intrinsic::ID>(Name)
+              .StartsWith("fma.", Intrinsic::wasm_relaxed_madd)
+              .StartsWith("fms.", Intrinsic::wasm_relaxed_nmadd)
+              .StartsWith("laneselect.", Intrinsic::wasm_relaxed_laneselect)
+              .Default(Intrinsic::not_intrinsic);
+      if (ID != Intrinsic::not_intrinsic) {
         rename(F);
-      NewFn = Intrinsic::getDeclaration(
-          F->getParent(), Intrinsic::wasm_relaxed_nmadd, F->getReturnType());
+        NewFn =
+            Intrinsic::getDeclaration(F->getParent(), ID, F->getReturnType());
         return true;
       }
-    if (Name.startswith("wasm.laneselect.")) {
+
+      if (Name.consume_front("dot.i8x16.i7x16.")) {
+        ID = StringSwitch<Intrinsic::ID>(Name)
+                 .Case("signed", Intrinsic::wasm_relaxed_dot_i8x16_i7x16_signed)
+                 .Case("add.signed",
+                       Intrinsic::wasm_relaxed_dot_i8x16_i7x16_add_signed)
+                 .Default(Intrinsic::not_intrinsic);
+        if (ID != Intrinsic::not_intrinsic) {
           rename(F);
-      NewFn = Intrinsic::getDeclaration(
-          F->getParent(), Intrinsic::wasm_relaxed_laneselect,
-          F->getReturnType());
+          NewFn = Intrinsic::getDeclaration(F->getParent(), ID);
           return true;
         }
-    if (Name == "wasm.dot.i8x16.i7x16.signed") {
-      rename(F);
-      NewFn = Intrinsic::getDeclaration(
-          F->getParent(), Intrinsic::wasm_relaxed_dot_i8x16_i7x16_signed);
-      return true;
+        break; // No other 'wasm.dot.i8x16.i7x16.*'
       }
-    if (Name == "wasm.dot.i8x16.i7x16.add.signed") {
-      rename(F);
-      NewFn = Intrinsic::getDeclaration(
-          F->getParent(), Intrinsic::wasm_relaxed_dot_i8x16_i7x16_add_signed);
-      return true;
+      break; // No other 'wasm.*'
     }
     break;
 
   case 'x':
     if (UpgradeX86IntrinsicFunction(F, Name, NewFn))
       return true;
   }