[llvm] [SDAG] Remove invalid check (NFC) (PR #146899)

[Benjamin Maxwell via llvm-commits]

https://github.com/MacDue updated https://github.com/llvm/llvm-project/pull/146899

>From 7b25ff23e394e722a683d308cfe109320eadd32b Mon Sep 17 00:00:00 2001
From: Benjamin Maxwell <benjamin.maxwell at arm.com>
Date: Thu, 3 Jul 2025 14:10:07 +0000
Subject: [PATCH 1/2] [SDAG] Remove invalid check (NFC)

It does not make sense to do !LC. LC is an RTLIB::Libcall enum, and zero
is a valid value.
---
 llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 30ee6a99b9dfc..07c44350c026e 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -2518,7 +2518,7 @@ bool SelectionDAG::expandMultipleResultFPLibCall(
   unsigned NumResults = Node->getNumValues();
 
   const char *LCName = TLI->getLibcallName(LC);
-  if (!LC || !LCName)
+  if (!LCName)
     return false;
 
   auto getVecDesc = [&]() -> VecDesc const * {

>From adfd94d1c2a9e40cabb03804cbfd6bc939a66151 Mon Sep 17 00:00:00 2001
From: Benjamin Maxwell <benjamin.maxwell at arm.com>
Date: Mon, 7 Jul 2025 12:40:46 +0000
Subject: [PATCH 2/2] Fixups

---
 llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 07c44350c026e..8b5eedb210c9f 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -2517,6 +2517,9 @@ bool SelectionDAG::expandMultipleResultFPLibCall(
   EVT VT = Node->getValueType(0);
   unsigned NumResults = Node->getNumValues();
 
+  if (LC == RTLIB::UNKNOWN_LIBCALL)
+    return false;
+
   const char *LCName = TLI->getLibcallName(LC);
   if (!LCName)
     return false;