[llvm-branch-commits] [NFC] [hwasan] factor get[PC|FP] out of HWASan class (PR #84404)

[Florian Mayer via llvm-branch-commits]

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@@ -236,5 +238,37 @@ void alignAndPadAlloca(memtag::AllocaInfo &Info, llvm::Align Alignment) {
   Info.AI = NewAI;
 }
 
+Value *readRegister(IRBuilder<> &IRB, StringRef Name) {
+  Module *M = IRB.GetInsertBlock()->getParent()->getParent();
+  Function *ReadRegister = Intrinsic::getDeclaration(
+      M, Intrinsic::read_register, IRB.getIntPtrTy(M->getDataLayout()));
+  MDNode *MD =
+      MDNode::get(M->getContext(), {MDString::get(M->getContext(), Name)});
+  Value *Args[] = {MetadataAsValue::get(M->getContext(), MD)};
+  return IRB.CreateCall(ReadRegister, Args);
+}
+
+Value *getPC(const Triple &TargetTriple, IRBuilder<> &IRB) {
+  Module *M = IRB.GetInsertBlock()->getParent()->getParent();
+  if (TargetTriple.getArch() == Triple::aarch64)
+    return memtag::readRegister(IRB, "pc");
+  return IRB.CreatePtrToInt(IRB.GetInsertBlock()->getParent(),
+                            IRB.getIntPtrTy(M->getDataLayout()));
+}
+
+Value *getSP(IRBuilder<> &IRB) {
+  // FIXME: use addressofreturnaddress (but implement it in aarch64 backend
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fmayer wrote:

I think this is talking about the `llvm.addressofreturnaddress` intrinsic, which we don't use

https://github.com/llvm/llvm-project/pull/84404