diff options
Diffstat (limited to 'include/llvm/Instruction.h')
| -rw-r--r-- | include/llvm/Instruction.h | 33 |
1 files changed, 32 insertions, 1 deletions
diff --git a/include/llvm/Instruction.h b/include/llvm/Instruction.h index 9c5ac44..5512dcc 100644 --- a/include/llvm/Instruction.h +++ b/include/llvm/Instruction.h @@ -215,6 +215,27 @@ public: bool isCommutative() const { return isCommutative(getOpcode()); } static bool isCommutative(unsigned op); + /// isIdempotent - Return true if the instruction is idempotent: + /// + /// Idempotent operators satisfy: x op x === x + /// + /// In LLVM, the And and Or operators are idempotent. + /// + bool isIdempotent() const { return isIdempotent(getOpcode()); } + static bool isIdempotent(unsigned op); + + /// isNilpotent - Return true if the instruction is nilpotent: + /// + /// Nilpotent operators satisfy: x op x === Id, + /// + /// where Id is the identity for the operator, i.e. a constant such that + /// x op Id === x and Id op x === x for all x. + /// + /// In LLVM, the Xor operator is nilpotent. + /// + bool isNilpotent() const { return isNilpotent(getOpcode()); } + static bool isNilpotent(unsigned op); + /// mayWriteToMemory - Return true if this instruction may modify memory. /// bool mayWriteToMemory() const; @@ -260,6 +281,16 @@ public: /// ignores the SubclassOptionalData flags, which specify conditions /// under which the instruction's result is undefined. bool isIdenticalToWhenDefined(const Instruction *I) const; + + /// When checking for operation equivalence (using isSameOperationAs) it is + /// sometimes useful to ignore certain attributes. + enum OperationEquivalenceFlags { + /// Check for equivalence ignoring load/store alignment. + CompareIgnoringAlignment = 1<<0, + /// Check for equivalence treating a type and a vector of that type + /// as equivalent. + CompareUsingScalarTypes = 1<<1 + }; /// This function determines if the specified instruction executes the same /// operation as the current one. This means that the opcodes, type, operand @@ -269,7 +300,7 @@ public: /// @returns true if the specified instruction is the same operation as /// the current one. /// @brief Determine if one instruction is the same operation as another. - bool isSameOperationAs(const Instruction *I) const; + bool isSameOperationAs(const Instruction *I, unsigned flags = 0) const; /// isUsedOutsideOfBlock - Return true if there are any uses of this /// instruction in blocks other than the specified block. Note that PHI nodes |
