IntegerDivision.h

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//===- llvm/Transforms/Utils/IntegerDivision.h ------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains an implementation of 32bit integer division for targets
// that don't have native support. It's largely derived from compiler-rt's
// implementation of __udivsi3, but hand-tuned for targets that prefer less
// control flow.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_TRANSFORMS_UTILS_INTEGERDIVISION_H
#define LLVM_TRANSFORMS_UTILS_INTEGERDIVISION_H

namespace llvm {
  class BinaryOperator;
}

namespace llvm {

  /// Generate code to calculate the remainder of two integers, replacing Rem
  /// with the generated code. This currently generates code using the udiv
  /// expansion, but future work includes generating more specialized code,
  /// e.g. when more information about the operands are known. Currently only
  /// implements 32bit scalar division (due to udiv's limitation), but future
  /// work is removing this limitation.
  ///
  /// @brief Replace Rem with generated code.
  bool expandRemainder(BinaryOperator *Rem);

  /// Generate code to divide two integers, replacing Div with the generated
  /// code. This currently generates code similarly to compiler-rt's
  /// implementations, but future work includes generating more specialized code
  /// when more information about the operands are known. Currently only
  /// implements 32bit scalar division, but future work is removing this
  /// limitation.
  ///
  /// @brief Replace Div with generated code.
  bool expandDivision(BinaryOperator* Div);

  /// Generate code to calculate the remainder of two integers, replacing Rem
  /// with the generated code. Uses the above 32bit routine, therefore adequate
  /// for targets with little or no support for less than 32 bit arithmetic.
  ///
  /// @brief Replace Rem with generated code.
  bool expandRemainderUpTo32Bits(BinaryOperator *Rem);

  /// Generate code to divide two integers, replacing Div with the generated 
  /// code. Uses the above 32bit routine, therefore adequate for targets with 
  /// little or no support for less than 32 bit arithmetic.
  /// 
  /// @brief Replace Rem with generated code.
  bool expandDivisionUpTo32Bits(BinaryOperator *Div);

} // End llvm namespace

#endif