[llvm] [NFC][WASM] refactor `WebAssembly::parseType` with `StringSwitch` (PR #90149)

[Congcong Cai via llvm-commits]

https://github.com/HerrCai0907 created https://github.com/llvm/llvm-project/pull/90149

None

>From 2812dbeed2691d596cabb70ca5e923a01f4fdf8b Mon Sep 17 00:00:00 2001
From: Congcong Cai <congcongcai0907 at 163.com>
Date: Fri, 26 Apr 2024 07:27:19 +0800
Subject: [PATCH] [NFC][WASM] refactor `WebAssembly::parseType` with
 `StringSwitch`

---
 .../WebAssemblyMCTypeUtilities.cpp            | 28 +++++++------------
 1 file changed, 10 insertions(+), 18 deletions(-)

diff --git a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTypeUtilities.cpp b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTypeUtilities.cpp
index b7b5b2a97c59e2..8ea02bd2ad1ff0 100644
--- a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTypeUtilities.cpp
+++ b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTypeUtilities.cpp
@@ -18,24 +18,16 @@
 using namespace llvm;
 
 std::optional<wasm::ValType> WebAssembly::parseType(StringRef Type) {
-  // FIXME: can't use StringSwitch because wasm::ValType doesn't have a
-  // "invalid" value.
-  if (Type == "i32")
-    return wasm::ValType::I32;
-  if (Type == "i64")
-    return wasm::ValType::I64;
-  if (Type == "f32")
-    return wasm::ValType::F32;
-  if (Type == "f64")
-    return wasm::ValType::F64;
-  if (Type == "v128" || Type == "i8x16" || Type == "i16x8" || Type == "i32x4" ||
-      Type == "i64x2" || Type == "f32x4" || Type == "f64x2")
-    return wasm::ValType::V128;
-  if (Type == "funcref")
-    return wasm::ValType::FUNCREF;
-  if (Type == "externref")
-    return wasm::ValType::EXTERNREF;
-  return std::nullopt;
+  return llvm::StringSwitch<std::optional<wasm::ValType>>{Type}
+      .Case("i32", wasm::ValType::I32)
+      .Case("i64", wasm::ValType::I64)
+      .Case("f32", wasm::ValType::F32)
+      .Case("f64", wasm::ValType::F64)
+      .Cases("v128", "i8x16", "i16x8", "i32x4", "i64x2", "f32x4", "f64x2",
+             wasm::ValType::V128)
+      .Case("funcref", wasm::ValType::FUNCREF)
+      .Case("externref", wasm::ValType::EXTERNREF)
+      .Default(std::nullopt);
 }
 
 WebAssembly::BlockType WebAssembly::parseBlockType(StringRef Type) {