[llvm] [RISCV][TableGen] Correct vTtoGetLlvmTyString for RISC-V tuples. (PR #162152)

[Craig Topper via llvm-commits]

https://github.com/topperc created https://github.com/llvm/llvm-project/pull/162152

RISC-V tuples use "NF" not "nElem" to store the number of fields in the segment.

This fixes a crash when lowering a function with tuple return. getReturnInfo in CallLowering.cpp does Type*->EVT->Type* and we were incorrectly converting EVT to Type*.

>From c7711e113d6d36feab0fa16e4a8130ae902a5e04 Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper at sifive.com>
Date: Mon, 6 Oct 2025 13:23:35 -0700
Subject: [PATCH] [RISCV][TableGen] Correct vTtoGetLlvmTyString for RISC-V
 tuples.

RISC-V tuples use "NF" not "nElem" to store the number of fields
in the segment.

This fixes a crash when lowering a function with tuple return.
getReturnInfo in CallLowering.cpp does Type*->EVT->Type* and we
were incorrectly converting EVT to Type*.
---
 llvm/utils/TableGen/Basic/VTEmitter.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/llvm/utils/TableGen/Basic/VTEmitter.cpp b/llvm/utils/TableGen/Basic/VTEmitter.cpp
index c6b4d0b56c02b..301b27d2ebc5c 100644
--- a/llvm/utils/TableGen/Basic/VTEmitter.cpp
+++ b/llvm/utils/TableGen/Basic/VTEmitter.cpp
@@ -33,11 +33,11 @@ static void vTtoGetLlvmTyString(raw_ostream &OS, const Record *VT) {
   bool IsRISCVVecTuple = VT->getValueAsBit("isRISCVVecTuple");
 
   if (IsRISCVVecTuple) {
-    unsigned NElem = VT->getValueAsInt("nElem");
+    unsigned NF = VT->getValueAsInt("NF");
     unsigned Sz = VT->getValueAsInt("Size");
     OS << "TargetExtType::get(Context, \"riscv.vector.tuple\", "
           "ScalableVectorType::get(Type::getInt8Ty(Context), "
-       << (Sz / (NElem * 8)) << "), " << NElem << ")";
+       << (Sz / (NF * 8)) << "), " << NF << ")";
     return;
   }