[llvm] [ABI][AMDGPU] Add AMDGPU target ABI classifier to the LLVM ABI library (PR #220177)

[via llvm-commits]

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@@ -0,0 +1,300 @@
+//===- AMDGPU.cpp - AMDGPU ABI Implementation ----------------------------===//
+//
+// 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 "llvm/ABI/FunctionInfo.h"
+#include "llvm/ABI/TargetInfo.h"
+#include "llvm/ABI/Types.h"
+#include "llvm/Support/AMDGPUAddrSpace.h"
+#include "llvm/Support/Alignment.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/TypeSize.h"
+#include <algorithm>
+#include <cassert>
+#include <cstdint>
+
+namespace llvm {
+namespace abi {
+
+class AMDGPUTargetInfo : public TargetInfo {
+private:
+  static const unsigned MaxNumRegsForArgsRet = 16;
+
+  /// HIP coerces a generic scalar-pointer kernel argument to the global
+  /// address space. Gated by the front end, which alone can see LangOpts.HIP.
+  bool CoerceGenericPtrArgToGlobal;
+
+  ArgInfo classifyReturnType(const Type *RetTy) const;
+  ArgInfo classifyKernelArgumentType(const Type *Ty) const;
+  ArgInfo classifyArgumentType(const Type *Ty, bool Variadic,
+                               unsigned &NumRegsLeft) const;
+
+  /// Target-independent fallback classification for arguments and returns.
+  ArgInfo classifyDefaultArgumentType(const Type *Ty) const;
+  ArgInfo classifyDefaultReturnType(const Type *Ty) const;
+
+  /// Estimate number of registers the type will use when passed in registers.
+  uint64_t numRegsForType(const Type *Ty) const;
+
+public:
+  AMDGPUTargetInfo(TypeBuilder &TypeBuilder, const ABICompatInfo &Compat,
+                   bool CoerceGenericPtrArgToGlobal)
+      : TargetInfo(TypeBuilder, Compat),
+        CoerceGenericPtrArgToGlobal(CoerceGenericPtrArgToGlobal) {}
+
+  void computeInfo(FunctionInfo &FI) const override;
+};
+
+uint64_t AMDGPUTargetInfo::numRegsForType(const Type *Ty) const {
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skc7 wrote:

Renamed `numRegsForType` to `getNumRegsForType` in latest patch.

https://github.com/llvm/llvm-project/pull/220177