virtual const char *getOpcodeName() const = 0;
- // swapOperands - Exchange the two operands to this instruction
- void swapOperands() {
- swap(Operands[0], Operands[1]);
- }
+ // swapOperands - Exchange the two operands to this instruction.
+ // This instruction is safe to use on any binary instruction and
+ // does not modify the semantics of the instruction. If the
+ // instruction is order dependant (SetLT f.e.) the opcode is
+ // changed. If the instruction cannot be reversed (ie, it's a Div),
+ // then return true.
+ //
+ bool swapOperands();
// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const BinaryOperator *) { return true; }
}
}
+// swapOperands - Exchange the two operands to this instruction. This
+// instruction is safe to use on any binary instruction and does not
+// modify the semantics of the instruction. If the instruction is
+// order dependant (SetLT f.e.) the opcode is changed.
+//
+bool BinaryOperator::swapOperands() {
+ switch (getOpcode()) {
+ // Instructions that don't need opcode modification
+ case Add: case Mul:
+ case And: case Xor:
+ case Or:
+ case SetEQ: case SetNE:
+ break;
+ // Instructions that need opcode modification
+ case SetGT: iType = SetLT; break;
+ case SetLT: iType = SetGT; break;
+ case SetGE: iType = SetLE; break;
+ case SetLE: iType = SetGE; break;
+ // Error on the side of caution
+ default:
+ return true;
+ }
+ swap(Operands[0], Operands[1]);
+ return false;
+}
+
//===----------------------------------------------------------------------===//
// GenericBinaryInst Class