[llvm] [RISCV] Slightly simplify RVVArgDispatcher::constructArgInfos. NFC (PR #87308)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-risc-v

Author: Craig Topper (topperc)

<details>
<summary>Changes</summary>

Use a single insert for the non-mask case instead of a push_back followed by an insert that may contain 0 registers.

---
Full diff: https://github.com/llvm/llvm-project/pull/87308.diff


1 Files Affected:

- (modified) llvm/lib/Target/RISCV/RISCVISelLowering.cpp (+2-4) 


``````````diff
diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index f693cbd3bea51e..6424c6c27ad6f1 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -21106,12 +21106,10 @@ void RVVArgDispatcher::constructArgInfos(ArrayRef<Type *> TypeList) {
             RegisterVT.getVectorElementType() == MVT::i1) {
           RVVArgInfos.push_back({1, RegisterVT, true});
           FirstVMaskAssigned = true;
-        } else {
-          RVVArgInfos.push_back({1, RegisterVT, false});
+          --NumRegs;
         }
 
-        RVVArgInfos.insert(RVVArgInfos.end(), --NumRegs,
-                           {1, RegisterVT, false});
+        RVVArgInfos.insert(RVVArgInfos.end(), NumRegs, {1, RegisterVT, false});
       }
     }
   }

``````````

</details>


https://github.com/llvm/llvm-project/pull/87308