Imported Upstream version 5.18.0.205

Former-commit-id: 7f59f7e792705db773f1caecdaa823092f4e2927

external/llvm/lib/Target/AArch64/AArch64PBQPRegAlloc.h

@@ -0,0 +1,41 @@
+//==- AArch64PBQPRegAlloc.h - AArch64 specific PBQP constraints --*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_AARCH64_AARCH64PBQPREGALOC_H
+#define LLVM_LIB_TARGET_AARCH64_AARCH64PBQPREGALOC_H
+
+#include "llvm/ADT/SetVector.h"
+#include "llvm/CodeGen/PBQPRAConstraint.h"
+
+namespace llvm {
+
+class TargetRegisterInfo;
+
+/// Add the accumulator chaining constraint to a PBQP graph
+class A57ChainingConstraint : public PBQPRAConstraint {
+public:
+  // Add A57 specific constraints to the PBQP graph.
+  void apply(PBQPRAGraph &G) override;
+
+private:
+  SmallSetVector<unsigned, 32> Chains;
+  const TargetRegisterInfo *TRI;
+
+  // Add the accumulator chaining constraint, inside the chain, i.e. so that
+  // parity(Rd) == parity(Ra).
+  // \return true if a constraint was added
+  bool addIntraChainConstraint(PBQPRAGraph &G, unsigned Rd, unsigned Ra);
+
+  // Add constraints between existing chains
+  void addInterChainConstraint(PBQPRAGraph &G, unsigned Rd, unsigned Ra);
+};
+
+} // end namespace llvm
+
+#endif // LLVM_LIB_TARGET_AARCH64_AARCH64PBQPREGALOC_H