[clang] [aarch64] Add more MSVC intrinsics (PR #194632)

[Adhemerval Zanella via cfe-commits]

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@@ -4823,9 +4824,45 @@ Value *CodeGenFunction::EmitAArch64BuiltinExpr(unsigned BuiltinID,
     llvm::MDNode *RegName = llvm::MDNode::get(Context, Ops);
     llvm::Value *Metadata = llvm::MetadataAsValue::get(Context, RegName);
 
-    llvm::Function *F =
-        CGM.getIntrinsic(Intrinsic::read_register, {Int64Ty});
-    return Builder.CreateCall(F, Metadata);
+    CallInst *CI;
+    if (BuiltinID == clang::AArch64::BI__getReg) {
+      llvm::Function *F = CGM.getIntrinsic(Intrinsic::read_register, {Int64Ty});
+      CI = Builder.CreateCall(F, Metadata);
+    } else {
+      llvm::Function *F =
+          CGM.getIntrinsic(Intrinsic::write_register, {Int64Ty});
+      CI = Builder.CreateCall(F, {Metadata, EmitScalarExpr(E->getArg(1))});
+    }
+    return CI;
+  }
+
+  if (BuiltinID == clang::AArch64::BI__getRegFp ||
+      BuiltinID == clang::AArch64::BI__setRegFp) {
+    Expr::EvalResult Result;
+    if (!E->getArg(0)->EvaluateAsInt(Result, CGM.getContext()))
+      llvm_unreachable("Sema will ensure that the parameter is constant");
+
+    llvm::APSInt Value = Result.Val.getInt();
+    LLVMContext &Context = CGM.getLLVMContext();
+    std::string Reg = "d" + toString(Value, 10);
+
+    llvm::Metadata *Ops[] = {llvm::MDString::get(Context, Reg)};
+    llvm::MDNode *RegName = llvm::MDNode::get(Context, Ops);
+    llvm::Value *Metadata = llvm::MetadataAsValue::get(Context, RegName);
+
+    llvm::Value *Ret;
+    if (BuiltinID == clang::AArch64::BI__getRegFp) {
+      llvm::Function *F = CGM.getIntrinsic(Intrinsic::read_register, {Int64Ty});
+      llvm::Value *Bits = Builder.CreateCall(F, Metadata);
+      Ret = Builder.CreateBitCast(Bits, llvm::Type::getDoubleTy(Context));
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zatrazz wrote:

Ack, I will check this out.

https://github.com/llvm/llvm-project/pull/194632