[𝘀𝗽𝗿] initial version

Created using spr 1.3.4

llvm/docs/LangRef.rst

@@ -934,10 +934,11 @@ IFuncs
 -------
 
 IFuncs, like as aliases, don't create any new data or func. They are just a new
-symbol that dynamic linker resolves at runtime by calling a resolver function.
+symbol that is resolved at runtime by calling a resolver function.
 
-IFuncs have a name and a resolver that is a function called by dynamic linker
-that returns address of another function associated with the name.
+On ELF platforms, IFuncs are resolved by the dynamic linker at load time. On
+MachO platforms, they are lowered in terms of ``.symbol_resolver``s, which
+lazily resolve the callee the first time they are called.
 
 IFunc may have an optional :ref:`linkage type <linkage>` and an optional
 :ref:`visibility style <visibility>`.

llvm/include/llvm/CodeGen/AsmPrinter.h

@@ -882,7 +882,11 @@ class AsmPrinter : public MachineFunctionPass {
 
   GCMetadataPrinter *getOrCreateGCPrinter(GCStrategy &S);
   void emitGlobalAlias(Module &M, const GlobalAlias &GA);
-  void emitGlobalIFunc(Module &M, const GlobalIFunc &GI);
+
+protected:
+  virtual void emitGlobalIFunc(Module &M, const GlobalIFunc &GI);
+
+private:
 
   /// This method decides whether the specified basic block requires a label.
   bool shouldEmitLabelForBasicBlock(const MachineBasicBlock &MBB) const;

llvm/lib/CodeGen/GlobalISel/CallLowering.cpp

@@ -144,7 +144,12 @@ bool CallLowering::lowerCall(MachineIRBuilder &MIRBuilder, const CallBase &CB,
   // Try looking through a bitcast from one function type to another.
   // Commonly happens with calls to objc_msgSend().
   const Value *CalleeV = CB.getCalledOperand()->stripPointerCasts();
-  if (const Function *F = dyn_cast<Function>(CalleeV))
+  if (const GlobalIFunc *IF = dyn_cast<GlobalIFunc>(CalleeV);
+      IF && MF.getTarget().getTargetTriple().isOSBinFormatMachO()) {
+    // ld64 requires that .symbol_resolvers to be called via a stub, so these
+    // must always be a diret call.
+    Info.Callee = MachineOperand::CreateGA(IF, 0);
+  } else if (const Function *F = dyn_cast<Function>(CalleeV))
     Info.Callee = MachineOperand::CreateGA(F, 0);
   else
     Info.Callee = MachineOperand::CreateReg(GetCalleeReg(), false);

llvm/lib/IR/Verifier.cpp

@@ -959,6 +959,7 @@ void Verifier::visitGlobalIFunc(const GlobalIFunc &GI) {
       GlobalIFunc::getResolverFunctionType(GI.getValueType());
   Check(ResolverTy == ResolverFuncTy->getPointerTo(GI.getAddressSpace()),
         "IFunc resolver has incorrect type", &GI);
+
 }
 
 void Verifier::visitNamedMDNode(const NamedMDNode &NMD) {
@@ -2239,13 +2240,10 @@ void Verifier::verifyFunctionAttrs(FunctionType *FT, AttributeList Attrs,
   }
 
   // Check EVEX512 feature.
-  if (MaxParameterWidth >= 512 && Attrs.hasFnAttr("target-features")) {
-    Triple T(M.getTargetTriple());
-    if (T.isX86()) {
-      StringRef TF = Attrs.getFnAttr("target-features").getValueAsString();
-      Check(!TF.contains("+avx512f") || !TF.contains("-evex512"),
-            "512-bit vector arguments require 'evex512' for AVX512", V);
-    }
+  if (MaxParameterWidth >= 512 && Attrs.hasFnAttr("target-features") && TT.isX86()) {
+    StringRef TF = Attrs.getFnAttr("target-features").getValueAsString();
+    Check(!TF.contains("+avx512f") || !TF.contains("-evex512"),
+          "512-bit vector arguments require 'evex512' for AVX512", V);
   }
 
   checkUnsignedBaseTenFuncAttr(Attrs, "patchable-function-prefix", V);