[llvm] [llvm][NFC] Refactor autoupdater's 'c' intrinsics (PR #73333)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-ir

Author: Nathan Sidwell (urnathan)

<details>
<summary>Changes</summary>

With these three intrinsics it's probable faster to check the number of arguments first and then check the names.  We can also handle ctlz and cttz in the same block.

---
Full diff: https://github.com/llvm/llvm-project/pull/73333.diff


1 Files Affected:

- (modified) llvm/lib/IR/AutoUpgrade.cpp (+13-12) 


``````````diff
diff --git a/llvm/lib/IR/AutoUpgrade.cpp b/llvm/lib/IR/AutoUpgrade.cpp
index 63c4b2c71299900..e6ff864a9140118 100644
--- a/llvm/lib/IR/AutoUpgrade.cpp
+++ b/llvm/lib/IR/AutoUpgrade.cpp
@@ -971,19 +971,20 @@ static bool UpgradeIntrinsicFunction1(Function *F, Function *&NewFn) {
     break;
   }
   case 'c': {
-    if (Name.starts_with("ctlz.") && F->arg_size() == 1) {
-      rename(F);
-      NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::ctlz,
-                                        F->arg_begin()->getType());
-      return true;
-    }
-    if (Name.starts_with("cttz.") && F->arg_size() == 1) {
-      rename(F);
-      NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::cttz,
-                                        F->arg_begin()->getType());
-      return true;
+    if (F->arg_size() == 1) {
+      Intrinsic::ID ID = StringSwitch<Intrinsic::ID>(Name)
+                             .StartsWith("ctlz.", Intrinsic::ctlz)
+                             .StartsWith("cttz.", Intrinsic::cttz)
+                             .Default(Intrinsic::not_intrinsic);
+      if (ID != Intrinsic::not_intrinsic) {
+        rename(F);
+        NewFn = Intrinsic::getDeclaration(F->getParent(), ID,
+                                          F->arg_begin()->getType());
+        return true;
+      }
     }
-    if (Name.equals("coro.end") && F->arg_size() == 2) {
+
+    if (F->arg_size() == 2 && Name.equals("coro.end")) {
       rename(F);
       NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::coro_end);
       return true;

``````````

</details>


https://github.com/llvm/llvm-project/pull/73333