Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

Rev

Blame | Last modification | View Log | Download | RSS feed

  1. //===-- OverflowInstAnalysis.h - Utils to fold overflow insts ----*- C++ -*-==//
  2. //
  3. // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  4. // See https://llvm.org/LICENSE.txt for license information.
  5. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  6. //
  7. //===----------------------------------------------------------------------===//
  8. //
  9. // This file holds routines to help analyse overflow instructions
  10. // and fold them into constants or other overflow instructions
  11. //
  12. //===----------------------------------------------------------------------===//
  13.  
  14. #ifndef LLVM_ANALYSIS_OVERFLOWINSTANALYSIS_H
  15. #define LLVM_ANALYSIS_OVERFLOWINSTANALYSIS_H
  16.  
  17. namespace llvm {
  18. class Use;
  19. class Value;
  20.  
  21. /// Match one of the patterns up to the select/logic op:
  22. ///   %Op0 = icmp ne i4 %X, 0
  23. ///   %Agg = call { i4, i1 } @llvm.[us]mul.with.overflow.i4(i4 %X, i4 %Y)
  24. ///   %Op1 = extractvalue { i4, i1 } %Agg, 1
  25. ///   %ret = select i1 %Op0, i1 %Op1, i1 false / %ret = and i1 %Op0, %Op1
  26. ///
  27. ///   %Op0 = icmp eq i4 %X, 0
  28. ///   %Agg = call { i4, i1 } @llvm.[us]mul.with.overflow.i4(i4 %X, i4 %Y)
  29. ///   %NotOp1 = extractvalue { i4, i1 } %Agg, 1
  30. ///   %Op1 = xor i1 %NotOp1, true
  31. ///   %ret = select i1 %Op0, i1 true, i1 %Op1 / %ret = or i1 %Op0, %Op1
  32. ///
  33. /// Callers are expected to align that with the operands of the select/logic.
  34. /// IsAnd is set to true if the Op0 and Op1 are used as the first pattern.
  35. /// If Op0 and Op1 match one of the patterns above, return true and fill Y's
  36. /// use.
  37.  
  38. bool isCheckForZeroAndMulWithOverflow(Value *Op0, Value *Op1, bool IsAnd,
  39.                                       Use *&Y);
  40. bool isCheckForZeroAndMulWithOverflow(Value *Op0, Value *Op1, bool IsAnd);
  41. } // end namespace llvm
  42.  
  43. #endif
  44.