[llvm] [NFC][LLVM][AArch64] Simplify `checkPartialMappingIdx` (PR #173050)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-aarch64

Author: Rahul Joshi (jurahul)

<details>
<summary>Changes</summary>

Remove `First` check by skipping iterating over first element.

---
Full diff: https://github.com/llvm/llvm-project/pull/173050.diff


1 Files Affected:

- (modified) llvm/lib/Target/AArch64/AArch64GenRegisterBankInfo.def (+1-6) 


``````````diff
diff --git a/llvm/lib/Target/AArch64/AArch64GenRegisterBankInfo.def b/llvm/lib/Target/AArch64/AArch64GenRegisterBankInfo.def
index 8ff59f60968be..bc15805d08626 100644
--- a/llvm/lib/Target/AArch64/AArch64GenRegisterBankInfo.def
+++ b/llvm/lib/Target/AArch64/AArch64GenRegisterBankInfo.def
@@ -155,12 +155,7 @@ bool AArch64GenRegisterBankInfo::checkPartialMappingIdx(
     return false;
 
   PartialMappingIdx Previous = Order.front();
-  bool First = true;
-  for (const auto &Current : Order) {
-    if (First) {
-      First = false;
-      continue;
-    }
+  for (const auto &Current : Order.drop_front()) {
     if (Previous + 1 != Current)
       return false;
     Previous = Current;

``````````

</details>


https://github.com/llvm/llvm-project/pull/173050