diff options
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 082dc020b0..b60d1fa972 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -536,6 +536,12 @@ static inline bool isEliminableCastOfCast(const CastInst &CI, if (SrcSize >= MidSize && MidSize >= DstSize) return true; + // Cases where the source and destination type are the same, but the middle + // type is bigger are noops. + // + if (SrcSize == DstSize && MidSize > SrcSize) + return true; + // If we are monotonically growing, things are more complex. // if (SrcSize <= MidSize && MidSize <= DstSize) { |