[clang] [Clang][CodeGen][Xtensa] Implement Xtensa ABI. (PR #225216)

[Andrei Safronov via cfe-commits]

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@@ -0,0 +1,249 @@
+//===- Xtensa.cpp ---------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "ABIInfoImpl.h"
+#include "TargetInfo.h"
+
+using namespace clang;
+using namespace clang::CodeGen;
+//===----------------------------------------------------------------------===//
+// Xtensa ABI Implementation
+//===----------------------------------------------------------------------===//
+
+namespace {
+class XtensaABIInfo : public DefaultABIInfo {
+private:
+  static const int MaxNumArgGPRs = 6;
+  static const int MaxNumRetGPRs = 4;
+
+public:
+  XtensaABIInfo(CodeGen::CodeGenTypes &CGT) : DefaultABIInfo(CGT) {}
+
+  // DefaultABIInfo's classifyReturnType and classifyArgumentType are
+  // non-virtual, but computeInfo is virtual, so we overload it.
+  void computeInfo(CGFunctionInfo &FI) const override;
+
+  ABIArgInfo classifyArgumentType(QualType Ty, int &ArgGPRsLeft) const;
+
+  ABIArgInfo classifyReturnType(QualType RetTy) const;
+
+  RValue EmitVAArg(CodeGenFunction &CGF, Address VAListAddr, QualType Ty,
+                   AggValueSlot Slot) const override;
+
+  ABIArgInfo extendType(QualType Ty) const;
+};
+} // end anonymous namespace
+
+void XtensaABIInfo::computeInfo(CGFunctionInfo &FI) const {
+  QualType RetTy = FI.getReturnType();
+  if (!getCXXABI().classifyReturnType(FI))
+    FI.getReturnInfo() = classifyReturnType(RetTy);
+
+  int ArgGPRsLeft = MaxNumArgGPRs;
+  for (auto &ArgInfo : FI.arguments()) {
+    ArgInfo.info = classifyArgumentType(ArgInfo.type, ArgGPRsLeft);
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andreisfr wrote:

@kazutakahirata,  thank you for suggestion, fixed.

https://github.com/llvm/llvm-project/pull/225216