[llvm][NFC] Refactor autoupdater's 'c' intrinsics

[urnathan]

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.

[llvmbot]

@llvm/pr-subscribers-llvm-ir

Author: Nathan Sidwell (urnathan)

Changes

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 --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;