[llvm-branch-commits] [llvm] Add llvm.protected.field.ptr intrinsic and pre-ISel lowering. (PR #151647)

[Nikita Popov via llvm-branch-commits]

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@@ -461,6 +463,139 @@ bool PreISelIntrinsicLowering::expandMemIntrinsicUses(
   return Changed;
 }
 
+static bool expandProtectedFieldPtr(Function &Intr) {
+  Module &M = *Intr.getParent();
+
+  SmallPtrSet<GlobalValue *, 2> DSsToDeactivate;
+
+  Type *Int8Ty = Type::getInt8Ty(M.getContext());
+  Type *Int64Ty = Type::getInt64Ty(M.getContext());
+  PointerType *PtrTy = PointerType::get(M.getContext(), 0);
+
+  Function *SignIntr =
+      Intrinsic::getOrInsertDeclaration(&M, Intrinsic::ptrauth_sign, {});
+  Function *AuthIntr =
+      Intrinsic::getOrInsertDeclaration(&M, Intrinsic::ptrauth_auth, {});
+
+  auto *EmuFnTy = FunctionType::get(Int64Ty, {Int64Ty, Int64Ty}, false);
+  FunctionCallee EmuSignIntr = M.getOrInsertFunction("__emupac_pacda", EmuFnTy);
+  FunctionCallee EmuAuthIntr = M.getOrInsertFunction("__emupac_autda", EmuFnTy);
+
+  auto CreateSign = [&](IRBuilder<> &B, Value *Val, Value *Disc,
+                        OperandBundleDef DSBundle) {
+    Function *F = B.GetInsertBlock()->getParent();
+    Attribute FSAttr = F->getFnAttribute("target-features");
+    if (FSAttr.isValid() && FSAttr.getValueAsString().contains("+pauth"))
+      return B.CreateCall(SignIntr, {Val, B.getInt32(2), Disc}, DSBundle);
+    return B.CreateCall(EmuSignIntr, {Val, Disc}, DSBundle);
+  };
+
+  auto CreateAuth = [&](IRBuilder<> &B, Value *Val, Value *Disc,
+                        OperandBundleDef DSBundle) {
+    Function *F = B.GetInsertBlock()->getParent();
+    Attribute FSAttr = F->getFnAttribute("target-features");
+    if (FSAttr.isValid() && FSAttr.getValueAsString().contains("+pauth"))
+      return B.CreateCall(AuthIntr, {Val, B.getInt32(2), Disc}, DSBundle);
+    return B.CreateCall(EmuAuthIntr, {Val, Disc}, DSBundle);
+  };
+
+  auto GetDeactivationSymbol = [&](CallInst *Call) -> GlobalValue * {
+    if (auto Bundle =
+            Call->getOperandBundle(LLVMContext::OB_deactivation_symbol))
+      return cast<GlobalValue>(Bundle->Inputs[0]);
+    return nullptr;
+  };
+
+  for (User *U : llvm::make_early_inc_range(Intr.users())) {
+    auto *Call = cast<CallInst>(U);
+
+    auto *Pointer = Call->getArgOperand(0);
+    auto *Disc = Call->getArgOperand(1);
+    bool UseHWEncoding =
+        cast<ConstantInt>(Call->getArgOperand(2))->getZExtValue();
+    assert(UseHWEncoding && "software encoding currently unsupported");
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nikic wrote:

Make this a reportFatalUsageError() instead. asserts should not be reachable.

https://github.com/llvm/llvm-project/pull/151647