From cb30e322150270ba30e1d22ab34f32eeb4176c17 Mon Sep 17 00:00:00 2001
From: Jonas Paulsson <paulson1@linux.ibm.com>
Date: Wed, 12 Mar 2025 12:28:01 -0600
Subject: [PATCH] [SystemZ] Use Function::hasAddressTaken() with
 verifyNarrowIntegerArgs() (NFC).

Use hasAddressTaken() in SystemZ instead of doing this computation
in isFullyInternal(), and make sure to only do this once per Function.
---
 .../Target/SystemZ/SystemZISelLowering.cpp    | 39 ++++++++-----------
 llvm/lib/Target/SystemZ/SystemZISelLowering.h | 10 +++--
 2 files changed, 23 insertions(+), 26 deletions(-)

diff --git a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
index 1e0c303a2e4da..8e61e6bcda57e 100644
--- a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
@@ -10200,22 +10200,6 @@ SDValue SystemZTargetLowering::lowerVECREDUCE_ADD(SDValue Op,
       DAG.getConstant(OpVT.getVectorNumElements() - 1, DL, MVT::i32));
 }
 
-// Only consider a function fully internal as long as it has local linkage
-// and is not used in any other way than acting as the called function at
-// call sites.
-bool SystemZTargetLowering::isFullyInternal(const Function *Fn) const {
-  if (!Fn->hasLocalLinkage())
-    return false;
-  for (const User *U : Fn->users()) {
-    if (auto *CB = dyn_cast<CallBase>(U)) {
-      if (CB->getCalledFunction() != Fn)
-        return false;
-    } else
-      return false;
-  }
-  return true;
-}
-
 static void printFunctionArgExts(const Function *F, raw_fd_ostream &OS) {
   FunctionType *FT = F->getFunctionType();
   const AttributeList &Attrs = F->getAttributes();
@@ -10234,6 +10218,16 @@ static void printFunctionArgExts(const Function *F, raw_fd_ostream &OS) {
   OS << ")\n";
 }
 
+bool SystemZTargetLowering::isInternal(const Function *Fn) const {
+  std::map<const Function *, bool>::iterator Itr = IsInternalCache.find(Fn);
+  if (Itr == IsInternalCache.end())
+    Itr = IsInternalCache
+              .insert(std::pair<const Function *, bool>(
+                  Fn, (Fn->hasLocalLinkage() && !Fn->hasAddressTaken())))
+              .first;
+  return Itr->second;
+}
+
 void SystemZTargetLowering::
 verifyNarrowIntegerArgs_Call(const SmallVectorImpl<ISD::OutputArg> &Outs,
                              const Function *F, SDValue Callee) const {
@@ -10246,8 +10240,8 @@ verifyNarrowIntegerArgs_Call(const SmallVectorImpl<ISD::OutputArg> &Outs,
   const Function *CalleeFn = nullptr;
   if (auto *G = dyn_cast<GlobalAddressSDNode>(Callee))
     if ((CalleeFn = dyn_cast<Function>(G->getGlobal())))
-      IsInternal = isFullyInternal(CalleeFn);
-  if (!verifyNarrowIntegerArgs(Outs, IsInternal)) {
+      IsInternal = isInternal(CalleeFn);
+  if (!IsInternal && !verifyNarrowIntegerArgs(Outs)) {
     errs() << "ERROR: Missing extension attribute of passed "
            << "value in call to function:\n" << "Callee:  ";
     if (CalleeFn != nullptr)
@@ -10268,7 +10262,7 @@ verifyNarrowIntegerArgs_Ret(const SmallVectorImpl<ISD::OutputArg> &Outs,
   if (!EnableIntArgExtCheck)
     return;
 
-  if (!verifyNarrowIntegerArgs(Outs, isFullyInternal(F))) {
+  if (!isInternal(F) && !verifyNarrowIntegerArgs(Outs)) {
     errs() << "ERROR: Missing extension attribute of returned "
            << "value from function:\n";
     printFunctionArgExts(F, errs());
@@ -10278,10 +10272,9 @@ verifyNarrowIntegerArgs_Ret(const SmallVectorImpl<ISD::OutputArg> &Outs,
 
 // Verify that narrow integer arguments are extended as required by the ABI.
 // Return false if an error is found.
-bool SystemZTargetLowering::
-verifyNarrowIntegerArgs(const SmallVectorImpl<ISD::OutputArg> &Outs,
-                        bool IsInternal) const {
-  if (IsInternal || !Subtarget.isTargetELF())
+bool SystemZTargetLowering::verifyNarrowIntegerArgs(
+    const SmallVectorImpl<ISD::OutputArg> &Outs) const {
+  if (!Subtarget.isTargetELF())
     return true;
 
   if (EnableIntArgExtCheck.getNumOccurrences()) {
diff --git a/llvm/lib/Target/SystemZ/SystemZISelLowering.h b/llvm/lib/Target/SystemZ/SystemZISelLowering.h
index 839a550012444..971a948c3c857 100644
--- a/llvm/lib/Target/SystemZ/SystemZISelLowering.h
+++ b/llvm/lib/Target/SystemZ/SystemZISelLowering.h
@@ -815,13 +815,17 @@ class SystemZTargetLowering : public TargetLowering {
   getTargetMMOFlags(const Instruction &I) const override;
   const TargetRegisterClass *getRepRegClassFor(MVT VT) const override;
 
-  bool isFullyInternal(const Function *Fn) const;
+private:
+  bool isInternal(const Function *Fn) const;
+  mutable std::map<const Function *, bool> IsInternalCache;
   void verifyNarrowIntegerArgs_Call(const SmallVectorImpl<ISD::OutputArg> &Outs,
                                     const Function *F, SDValue Callee) const;
   void verifyNarrowIntegerArgs_Ret(const SmallVectorImpl<ISD::OutputArg> &Outs,
                                    const Function *F) const;
-  bool verifyNarrowIntegerArgs(const SmallVectorImpl<ISD::OutputArg> &Outs,
-                               bool IsInternal) const;
+  bool
+  verifyNarrowIntegerArgs(const SmallVectorImpl<ISD::OutputArg> &Outs) const;
+
+public:
 };
 
 struct SystemZVectorConstantInfo {