[llvm] [AMDGPU] Add AMDGPU specific variadic operation MCExprs (PR #82022)

[Pierre van Houtryve via llvm-commits]

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@@ -0,0 +1,69 @@
+//===- AMDGPUMCExpr.h - AMDGPU specific MC expression classes ---*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_AMDGPU_MCTARGETDESC_AMDGPUMCEXPR_H
+#define LLVM_LIB_TARGET_AMDGPU_MCTARGETDESC_AMDGPUMCEXPR_H
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/MC/MCExpr.h"
+
+namespace llvm {
+
+/// AMDGPU target specific variadic MCExpr operations.
+///
+/// Takes in a minimum of 1 argument to be used with an operation. The supported
+/// operations are:
+///   - (logic) or
+///   - max
+///
+class AMDGPUVariadicMCExpr : public MCTargetExpr {
+public:
+  enum AMDGPUVariadicKind { AGVK_None, AGVK_Or, AGVK_Max };
+
+private:
+  AMDGPUVariadicKind Kind;
+  SmallVector<const MCExpr *, 2> Args;
+
+  AMDGPUVariadicMCExpr(AMDGPUVariadicKind Kind, ArrayRef<const MCExpr *> Args)
+      : Kind(Kind), Args(Args) {
+    assert(Args.size() >= 1 && "Needs a minimum of one expression.");
+  }
+
+public:
+  static const AMDGPUVariadicMCExpr *create(AMDGPUVariadicKind Kind,
+                                            ArrayRef<const MCExpr *> Args,
+                                            MCContext &Ctx);
+
+  static const AMDGPUVariadicMCExpr *createOr(ArrayRef<const MCExpr *> Args,
+                                              MCContext &Ctx) {
+    return create(AMDGPUVariadicKind::AGVK_Or, Args, Ctx);
+  }
+
+  static const AMDGPUVariadicMCExpr *createMax(ArrayRef<const MCExpr *> Args,
+                                               MCContext &Ctx) {
+    return create(AMDGPUVariadicKind::AGVK_Max, Args, Ctx);
+  }
+
+  AMDGPUVariadicKind getKind() const { return Kind; }
+  const MCExpr *getSubExpr(size_t index) const;
+
+  void printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const override;
+  bool evaluateAsRelocatableImpl(MCValue &Res, const MCAsmLayout *Layout,
+                                 const MCFixup *Fixup) const override;
+  void visitUsedExpr(MCStreamer &Streamer) const override;
+  MCFragment *findAssociatedFragment() const override;
+  static bool classof(const MCExpr *E) {
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Pierre-vh wrote:

move this at the bottom with a newline before it, it's just the RTTI helper so it should be isolated
I also think it's better for style to not mix one-liners (the decls) with multiple line functions (this def) without a newline in between

https://github.com/llvm/llvm-project/pull/82022