OverflowInstAnalysis.h 1.9 KB

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