[lld] [llvm] [LLVM] Refactor Autoupgrade function attributes from Module attributes. (PR #84494)

[Daniel Kiss via llvm-commits]

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@@ -5182,65 +5182,46 @@ void llvm::UpgradeFunctionAttributes(Function &F) {
 static bool isModuleAttributeSet(Module &M, const StringRef &ModAttr) {
   const auto *Attr =
       mdconst::extract_or_null<ConstantInt>(M.getModuleFlag(ModAttr));
-  return Attr && Attr->getZExtValue();
+  return Attr && Attr->isOne();
 }
 
-// Copy an attribute from module to the function if exists.
-// First value of the pair is used when the module attribute is not zero
-// the second otherwise.
-static void
-CopyModuleAttributeToFunction(Function &F, StringRef FnAttrName,
-                              StringRef ModAttrName,
-                              std::pair<StringRef, StringRef> Values) {
-  if (F.hasFnAttribute(FnAttrName))
-    return;
-  F.addFnAttr(FnAttrName, isModuleAttributeSet(*F.getParent(), ModAttrName)
-                              ? Values.first
-                              : Values.second);
-}
-
-// Copy a boolean attribute from module to the function if exists.
-// Module attribute treated false if zero otherwise true.
-static void CopyModuleAttributeToFunction(Function &F, StringRef AttrName) {
-  CopyModuleAttributeToFunction(
-      F, AttrName, AttrName,
-      std::make_pair<StringRef, StringRef>("true", "false"));
-}
-
-// Copy an attribute from module to the function if exists.
-// First value of the pair is used when the module attribute is not zero
-// the second otherwise.
-static void
-CopyModuleAttributeToFunction(Function &F, StringRef AttrName,
-                              std::pair<StringRef, StringRef> Values) {
-  CopyModuleAttributeToFunction(F, AttrName, AttrName, Values);
+// Check if the function attribute is not present and set it.
+static void SetFunctionAttrIfNotSet(Function &F, StringRef FnAttrName,
+                                    StringRef Value) {
+  if (!F.hasFnAttribute(FnAttrName))
+    F.addFnAttr(FnAttrName, Value);
 }
 
 void llvm::CopyModuleAttrToFunctions(Module &M) {
   Triple T(M.getTargetTriple());
   if (!T.isThumb() && !T.isARM() && !T.isAArch64())
     return;
 
+  StringRef SignTypeValue = "none";
----------------
DanielKristofKiss wrote:

@dhoekwater I have a few changes that changes this behaviour to set flag only when enabled so if all dependency merged then the module flag won't be used anymore for function attribute so here could set only the positive flags.
also run the code only when the LTO object is from an older frontend.
#84804 

https://github.com/llvm/llvm-project/pull/84494