diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstructionCombining.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstructionCombining.cpp | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp index 851569c4a3d..b74b3273acd 100644 --- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp +++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp @@ -89,11 +89,13 @@ Value *InstCombiner::EmitGEPOffset(User *GEP) { /// Return true if it is desirable to convert an integer computation from a /// given bit width to a new bit width. /// We don't want to convert from a legal to an illegal type or from a smaller -/// to a larger illegal type. +/// to a larger illegal type. A width of '1' is always treated as a legal type +/// because i1 is a fundamental type in IR, and there are many specialized +/// optimizations for i1 types. bool InstCombiner::shouldChangeType(unsigned FromWidth, unsigned ToWidth) const { - bool FromLegal = DL.isLegalInteger(FromWidth); - bool ToLegal = DL.isLegalInteger(ToWidth); + bool FromLegal = FromWidth == 1 || DL.isLegalInteger(FromWidth); + bool ToLegal = ToWidth == 1 || DL.isLegalInteger(ToWidth); // If this is a legal integer from type, and the result would be an illegal // type, don't do the transformation. @@ -110,7 +112,9 @@ bool InstCombiner::shouldChangeType(unsigned FromWidth, /// Return true if it is desirable to convert a computation from 'From' to 'To'. /// We don't want to convert from a legal to an illegal type or from a smaller -/// to a larger illegal type. +/// to a larger illegal type. i1 is always treated as a legal type because it is +/// a fundamental type in IR, and there are many specialized optimizations for +/// i1 types. bool InstCombiner::shouldChangeType(Type *From, Type *To) const { assert(From->isIntegerTy() && To->isIntegerTy()); |
