SMPInstr.cpp

							}
							else { // global name
								this->BasicBlock->GetFunc()->ResetProcessedBlocks(); // set Processed to false
								(void) this->BasicBlock->PropagateGlobalDefType(DefOp, NUMERIC,
									SSANum, IsMemOp);
							}
						}
					}
					++CurrDef;
				}
				this->SetCategoryInferenceComplete();
				break;

			case 4: // Unary INC, DEC, etc.: dest=source, so type remains the same
				assert(1 == this->RTL.GetCount());
				assert(this->RTL.GetRT(0)->HasRightSubTree());
				UseOp = this->RTL.GetRT(0)->GetLeftOperand(); // USE == DEF
				CurrUse = this->Uses.FindRef(UseOp);
				assert(CurrUse != this->GetLastUse());
				if (UNINIT != CurrUse->GetType()) {
					// Only one USE, and it has a type assigned, so assign that type
					// to the DEF.
					CurrDef = this->GetFirstDef();
					while (CurrDef != this->GetLastDef()) {
						// Two DEFs: EFLAGS is NUMERIC, dest==source
						DefOp = CurrDef->GetOp();
						SSANum = CurrDef->GetSSANum();
						if (DefOp.is_reg(X86_FLAGS_REG)) {
							; // SetImmedTypes already made it NUMERIC
						}
						else {
							CurrDef = this->SetDefType(DefOp, CurrUse->GetType());
							// Be conservative and only propagate register DEFs and SAFE stack locs. We
							//  can improve this in the future. **!!**
							bool IsMemOp = (o_reg != DefOp.type);
							MemPropagate = MDIsStackAccessOpnd(DefOp, UseFP);
#if SMP_PROPAGATE_MEM_TYPES
							;
#else
							// Be conservative and only propagate register DEFs and SAFE stack locs.
							//  We can improve this in the future. **!!**
							MemPropagate = MemPropagate && SafeFunc;
#endif
							if ((o_reg == DefOp.type) || MemPropagate) {
								if (this->BasicBlock->IsLocalName(DefOp)) {
									(void) this->BasicBlock->PropagateLocalDefType(DefOp, CurrUse->GetType(),
										this->GetAddr(), SSANum, IsMemOp);
								}
								else { // global name
									this->BasicBlock->GetFunc()->ResetProcessedBlocks(); // set Processed to false
									(void) this->BasicBlock->PropagateGlobalDefType(DefOp, CurrUse->GetType(),
										SSANum, IsMemOp);
								}
							}
						}
						++CurrDef;
					}
					this->SetCategoryInferenceComplete();
					changed = true;
					this->SetTypeInferenceComplete();
				}
				break;

			case 6: // Result is always POINTER
				DefOp = this->GetFirstDef()->GetOp();
				SSANum = this->GetFirstDef()->GetSSANum();
				CurrDef = this->SetDefType(DefOp, POINTER);
				this->SetCategoryInferenceComplete();
				changed = true;
				// Be conservative and only propagate register DEFs and SAFE stack locs. We
				//  can improve this in the future. **!!**
				IsMemOp = (o_reg != DefOp.type);
				MemPropagate = MDIsStackAccessOpnd(DefOp, UseFP);
#if SMP_PROPAGATE_MEM_TYPES
				;
#else
				// Be conservative and only propagate register DEFs and SAFE stack locs.
				//  We can improve this in the future. **!!**
				MemPropagate = MemPropagate && SafeFunc;
#endif
				if ((o_reg == DefOp.type) || MemPropagate)  {
					if (this->BasicBlock->IsLocalName(DefOp)) {
						(void) this->BasicBlock->PropagateLocalDefType(DefOp, POINTER,
							this->GetAddr(), SSANum, IsMemOp);
					}
					else { // global name
						this->BasicBlock->GetFunc()->ResetProcessedBlocks(); // set Processed to false
						(void) this->BasicBlock->PropagateGlobalDefType(DefOp, POINTER,
							SSANum, IsMemOp);
					}
				}
				break;

			default:
				SMP_msg("ERROR: Unknown type category for %s\n", DisAsmText.GetDisAsm(this->GetAddr()));
				this->SetCategoryInferenceComplete();
				break;
		} // end switch on TypeCategory
	} // end if (!CategoryInference)

	// Walk the RTL and infer types based on operators and operands.
	if (DebugFlag) {
		SMP_msg("RTcount: %zu\n", this->RTL.GetCount());
	}
	for (size_t index = 0; index < this->RTL.GetCount(); ++index) {
		SMPRegTransfer *CurrRT = this->RTL.GetRT(index);
		if (SMP_NULL_OPERATOR == CurrRT->GetOperator()) // nothing to infer
			continue;
		if (!(CurrRT->IsTypeInferenceComplete())) {
			changed |= this->InferOperatorType(CurrRT);
		}
		if (DebugFlag) {
			SMP_msg("returned from InferOperatorType\n");
		}
	} // end for all RTs in the RTL
	return changed;
} // end of SMPInstr::InferTypes()

// Infer the type of an operator within an RT based on the types of its operands and
//  based on the operator itself. Recurse down the tree if necessary.
// Return true if the operator type of the RT is updated.
bool SMPInstr::InferOperatorType(SMPRegTransfer *CurrRT) {
	bool updated = false;
	bool LeftNumeric, RightNumeric, OperNumeric;
	bool LeftPointer, RightPointer, OperPointer;
	bool UseFP = this->BasicBlock->GetFunc()->UsesFramePointer();
	bool SafeFunc = this->BasicBlock->GetFunc()->IsSafe();
	set<DefOrUse, LessDefUse>::iterator CurrDef;
	set<DefOrUse, LessDefUse>::iterator CurrUse;
	set<DefOrUse, LessDefUse>::iterator LeftUse;
	set<DefOrUse, LessDefUse>::iterator RightUse;
	SMPOperandType LeftType = UNINIT;
	SMPOperandType RightType = UNINIT;
	SMPOperandType OperType = UNINIT;
	op_t UseOp = InitOp, DefOp = InitOp, LeftOp = InitOp, RightOp = InitOp;
	SMPoperator CurrOp = CurrRT->GetOperator();
	bool TypeInferenceFinished = false;
#if SMP_VERBOSE_DEBUG_INFER_TYPES
	bool DebugFlag = false;
#if 1
	DebugFlag |= (0 == strcmp("InputMove", this->BasicBlock->GetFunc()->GetFuncName()));
#endif
	DebugFlag = DebugFlag || ((this->address == 0x806453b) || (this->address == 0x806453e));
#endif

#if SMP_VERBOSE_DEBUG_INFER_TYPES
	if (DebugFlag) {
		SMP_msg("Entered InferOperatorType for CurrOp: %d at %x\n", CurrOp, this->GetAddr());
	}
#endif

	if (CurrRT->IsTypeInferenceComplete()) {
		return updated;
	}

	switch (CurrOp) {
		case SMP_NULL_OPERATOR:
			TypeInferenceFinished = true;
			break;

		case SMP_CALL:  // CALL instruction
			if (UNINIT == CurrRT->GetOperatorType()) {
				CurrRT->SetOperatorType(CODEPTR, this);
				updated = true;
				UseOp = CurrRT->GetRightOperand();
				CurrUse = this->Uses.FindRef(UseOp);
				assert(CurrUse != this->GetLastUse());
				if (UNINIT == CurrUse->GetType()) {
					CurrUse = this->SetUseType(UseOp, CODEPTR);
				}
				else if (CODEPTR != CurrUse->GetType()) {
					SMP_msg("WARNING: call target is type %d, setting to CODEPTR at %x in %s\n",
						CurrUse->GetType(), this->GetAddr(), DisAsmText.GetDisAsm(this->GetAddr()));
					CurrUse = this->SetUseType(UseOp, CODEPTR);
				}
			}
			TypeInferenceFinished = true;
			break;

		case SMP_INPUT:  // input from port
			if (UNINIT == CurrRT->GetOperatorType()) {
				CurrRT->SetOperatorType(NUMERIC, this);
				updated = true;
			}
			break;

		case SMP_OUTPUT: // output to port
			if (UNINIT == CurrRT->GetOperatorType()) {
				CurrRT->SetOperatorType(NUMERIC, this);
				updated = true;
			}
			break;

		case SMP_SIGN_EXTEND:
		case SMP_ZERO_EXTEND:
			// Should we infer that all operands are NUMERIC?  !!!???!!!!
			break;

		case SMP_ADDRESS_OF: // take effective address
			if (UNINIT == CurrRT->GetOperatorType()) {
				CurrRT->SetOperatorType(POINTER, this);
				// Left operand is having its address taken, but we cannot infer what its
				//  type is.
				updated = true;
			}
			break;

		case SMP_U_LEFT_SHIFT: // unsigned left shift
		case SMP_S_LEFT_SHIFT: // signed left shift
		case SMP_U_RIGHT_SHIFT: // unsigned right shift
		case SMP_S_RIGHT_SHIFT: // signed right shift
		case SMP_ROTATE_LEFT:
		case SMP_ROTATE_LEFT_CARRY: // rotate left through carry
		case SMP_ROTATE_RIGHT:
		case SMP_ROTATE_RIGHT_CARRY: // rotate right through carry
		case SMP_U_MULTIPLY:
		case SMP_S_MULTIPLY:
		case SMP_U_DIVIDE:
		case SMP_S_DIVIDE:
		case SMP_U_REMAINDER:
		case SMP_BITWISE_NOT: // unary operator
		case SMP_BITWISE_XOR:
		case SMP_S_COMPARE: // signed compare (subtraction-based)
		case SMP_U_COMPARE: // unsigned compare (AND-based)
		case SMP_LESS_THAN: // boolean test operators
		case SMP_GREATER_THAN:
		case SMP_LESS_EQUAL:
		case SMP_GREATER_EQUAL:
		case SMP_EQUAL:
		case SMP_NOT_EQUAL:
		case SMP_LOGICAL_AND:
		case SMP_LOGICAL_OR:
		case SMP_UNARY_NUMERIC_OPERATION:  // miscellaneous; produces NUMERIC result
		case SMP_BINARY_NUMERIC_OPERATION:  // miscellaneous; produces NUMERIC result
		case SMP_SYSTEM_OPERATION:   // for instructions such as CPUID, RDTSC, etc.; NUMERIC
		case SMP_UNARY_FLOATING_ARITHMETIC:  // all the same to our type system; all NUMERIC
		case SMP_BINARY_FLOATING_ARITHMETIC:  // all the same to our type system; all NUMERIC
		case SMP_REVERSE_SHIFT_U:   // all the same to our type system; all NUMERIC
		case SMP_SHUFFLE:   // all the same to our type system; all NUMERIC
		case SMP_COMPARE_EQ_AND_SET:   // packed compare for equality and set bits; all NUMERIC
		case SMP_COMPARE_GT_AND_SET:   // packed compare for greater-than and set bits; all NUMERIC
		case SMP_PACK_S:  // Pack operands into extended-precision register, signed saturation for loss of precision
		case SMP_PACK_U:  // Pack operands into extended-precision register, unsigned saturation for loss of precision
		case SMP_AVERAGE_U: // Average of unsigned operands
		case SMP_MULTIPLY_AND_ADD: // multiply and add (or multiply and accumulate)
		case SMP_SUM_OF_DIFFS: // sum over two vectors of absolute values of differences of their elements
		case SMP_INTERLEAVE:  // interleave fields from two packed operands; NUMERIC
		case SMP_CONCATENATE:   // all the same to our type system; all NUMERIC
			if (UNINIT == CurrRT->GetOperatorType()) {
				CurrRT->SetOperatorType(NUMERIC, this);
				updated = true;
			}
			// Left operand should be NUMERIC if it exists.
			UseOp = CurrRT->GetLeftOperand();
			if (UseOp.type != o_void) {
				CurrUse = this->Uses.FindRef(UseOp);
				if (CurrUse == this->GetLastUse()) {
					SMP_msg("SERIOUS WARNING: Adding missing USE of ");
					PrintOperand(UseOp);
					SMP_msg(" at %x in %s\n", this->GetAddr(), DisAsmText.GetDisAsm(this->GetAddr()));
					this->Uses.SetRef(UseOp, NUMERIC, -1);
					updated = true;
				}
				else if (UNINIT == CurrUse->GetType()) {
					CurrUse = this->SetUseType(UseOp, NUMERIC);
					updated = true;
				}
			}
			// Right operand should be NUMERIC if it exists.
			if (CurrRT->HasRightSubTree()) {
				// Recurse into subtree
#if SMP_AGGRESSIVE_TYPE_INFERENCE
				if (UNINIT == CurrRT->GetRightTree()->GetOperatorType()) {
					CurrRT->GetRightTree()->SetOperatorType(NUMERIC, this);
				}
#endif
				updated |= this->InferOperatorType(CurrRT->GetRightTree());
			}
			else {
				UseOp = CurrRT->GetRightOperand();
				if (UseOp.type != o_void) {
					CurrUse = this->Uses.FindRef(UseOp);
					if (CurrUse == this->GetLastUse()) {
						SMP_msg("SERIOUS WARNING: Adding missing USE of ");
						PrintOperand(UseOp);
						SMP_msg(" at %x in %s\n", this->GetAddr(), DisAsmText.GetDisAsm(this->GetAddr()));
						this->Uses.SetRef(UseOp, NUMERIC, -1);
						updated = true;
					}
					else if (UNINIT == CurrUse->GetType()) {
						CurrUse = this->SetUseType(UseOp, NUMERIC);
						updated = true;
					}
				}
			}
			break;

		case SMP_NEGATE:    // unary negation
			UseOp = CurrRT->GetLeftOperand();
			assert(o_void != UseOp.type);
			CurrUse = this->Uses.FindRef(UseOp);
			if (CurrUse == this->GetLastUse()) {
				SMP_msg("SERIOUS WARNING: Adding missing USE of ");
				PrintOperand(UseOp);
				SMP_msg(" at %x in %s\n", this->GetAddr(), DisAsmText.GetDisAsm(this->GetAddr()));
				updated = true;
			}
			else {
				OperType = CurrRT->GetOperatorType();
				LeftType = CurrUse->GetType();
				// Only tricky cases are the negation of a POINTER or PTROFFSET.
				//  Negation of PTROFFSET could be inefficient code that computed
				//  PTR1 - PTR2 and later corrected it to PTR2 - PTR1 by negation.
				//  The type remains PTROFFSET. Negating a POINTER could be an unusual
				//  case similar to subtracting a POINTER from a NUMERIC. See comments
				//  in the SMP_ADD case below, and also the SMP_SUBTRACT case.
				if (LeftType == PTROFFSET) {
					// Override any prior operator type, in case PTROFFSET was inferred late
					//  in our analysis and the operator was set to NUMERIC.
					CurrRT->SetOperatorType(PTROFFSET, this);
					updated = true;
				}
				else if (IsDataPtr(LeftType)) {
					// Override any prior operator type, in case POINTER was inferred late
					//  in our analysis and the operator was set to NUMERIC.
					CurrRT->SetOperatorType(NEGATEDPTR, this);
					updated = true;
				}
				else if (OperType == UNINIT) {
					// Default to NUMERIC for most negations.
					CurrRT->SetOperatorType(NUMERIC, this);
					// But, leave left operand type alone, in case an UNINIT operand
					//  might be determined later to be PTROFFSET or NEGATEDPTR.
					//  Leaving it alone causes us not to set TypeInferenceFinished to true
					//  at the end of this function in the UNINIT case.
					updated = true;
				}
			}
			break;

		case SMP_INCREMENT:
		case SMP_DECREMENT:
			// The type of the left operand is propagated to the operator, or vice
			//  versa, whichever receives a type first.
			assert(!CurrRT->HasRightSubTree());
			UseOp = CurrRT->GetLeftOperand();
			assert(o_void != UseOp.type);
			CurrUse = this->Uses.FindRef(UseOp);
			if (CurrUse == this->GetLastUse()) {
				SMP_msg("SERIOUS WARNING: Adding missing USE of ");
				PrintOperand(UseOp);
				SMP_msg(" at %x in %s\n", this->GetAddr(), DisAsmText.GetDisAsm(this->GetAddr()));
				this->Uses.SetRef(UseOp);
				updated = true;
				break;
			}
			if (UNINIT == CurrRT->GetOperatorType()) {
				if (UNINIT != CurrUse->GetType()) {
					// Propagate operand type up to the operator.
					CurrRT->SetOperatorType(CurrUse->GetType(), this);
					updated = true;
				}
			}
			else if (UNINIT == CurrUse->GetType()) {
				// Propagate operator type to operand.
				CurrUse = this->SetUseType(UseOp, CurrRT->GetOperatorType());
				updated = true;
			}
			break;

		case SMP_ADD:
		case SMP_ADD_CARRY:   // add with carry
		case SMP_BITWISE_AND:
		case SMP_BITWISE_OR:
			// Extract the current types of right and left operands and the operator.
			OperType = CurrRT->GetOperatorType();
			LeftOp = CurrRT->GetLeftOperand();
			CurrUse = this->Uses.FindRef(LeftOp);
			assert(CurrUse != this->GetLastUse()); // found it
			LeftType = CurrUse->GetType();
			if (CurrRT->HasRightSubTree()) {
				updated |= this->InferOperatorType(CurrRT->GetRightTree());
				RightType = CurrRT->GetRightTree()->GetOperatorType();
			}
			else {
				RightOp = CurrRT->GetRightOperand();
				if (o_void == RightOp.type) {
					SMP_msg("ERROR: void operand at %x in %s\n", this->GetAddr(), DisAsmText.GetDisAsm(this->GetAddr()));
					return updated;
				}
				else {
					CurrUse = this->Uses.FindRef(RightOp);
					if (CurrUse == this->GetLastUse()) {
						SMP_msg("SERIOUS WARNING: Adding missing USE of ");
						PrintOperand(RightOp);
						SMP_msg(" at %x in %s\n", this->GetAddr(), DisAsmText.GetDisAsm(this->GetAddr()));
						this->Uses.SetRef(RightOp);
						updated = true;
						break;
					}
					else {
						RightType = CurrUse->GetType();
					}
				}
			}

			// We have to know both operand types to infer the operator, or know the
			//  operator type and one operand type to infer the other operand type.
			if ((UNINIT == OperType) 
				&& ((UNINIT == LeftType) || (UNINIT == RightType)))
				break;

			// If both operands are NUMERIC, operator and result are NUMERIC.
			// If one operand is NUMERIC and the other is a pointer type,
			//  then the ADD operator and the result will inherit this second type,
			//  while AND and OR operators will remain UNINIT (we don't know what
			//  type "ptr AND 0xfffffff8" has until we see how it is used).
			LeftNumeric = IsEqType(NUMERIC, LeftType);
			RightNumeric = IsEqType(NUMERIC, RightType);
			LeftPointer = IsDataPtr(LeftType);
			RightPointer = IsDataPtr(RightType);
			if (UNINIT == OperType) {
				// Infer operator type from left and right operands.
				if (LeftNumeric && RightNumeric) {
					CurrRT->SetOperatorType(NUMERIC, this);
					updated = true;
					break;
				}
				else if (LeftNumeric || RightNumeric) {
					// ADD of NUMERIC to non-NUMERIC preserves non-NUMERIC type.
					// AND and OR operations should leave the operator UNINIT for now.
					if (LeftNumeric && (UNINIT != RightType) 
						&& ((SMP_ADD == CurrOp) || (SMP_ADD_CARRY == CurrOp))) {
						CurrRT->SetOperatorType(RightType, this);
						updated = true;
						break;
					}
					else if (RightNumeric && (UNINIT != LeftType) 
						&& ((SMP_ADD == CurrOp) || (SMP_ADD_CARRY == CurrOp))) {
						CurrRT->SetOperatorType(LeftType, this);
						updated = true;
						break;
					}
				}
				else if (LeftPointer && RightPointer) {
					// Arithmetic on two pointers
					if ((SMP_ADD == CurrOp) || (SMP_ADD_CARRY == CurrOp)) {
						CurrRT->SetOperatorType(UNKNOWN, this);
						updated = true;
					}
					else { // bitwise AND or OR of two pointers
						SMP_msg("WARNING: hash of two pointers at %x in %s\n",
							this->GetAddr(), DisAsmText.GetDisAsm(this->GetAddr()));
						// hash operation? leave operator as UNINIT
					}
					break;
				}
				else if ((LeftPointer && IsEqType(RightType, PTROFFSET))
					|| (RightPointer && IsEqType(LeftType, PTROFFSET))) {
					// Arithmetic on PTR and PTROFFSET
					if ((SMP_ADD == CurrOp) || (SMP_ADD_CARRY == CurrOp)) {
						// We assume (A-B) is being added to B or vice versa **!!**
						CurrRT->SetOperatorType(POINTER, this);
						updated = true;
					}
					else { // bitwise AND or OR of pointer and pointer difference
						SMP_msg("WARNING: hash of PTROFFSET and POINTER at %x in %s\n",
							this->GetAddr(), DisAsmText.GetDisAsm(this->GetAddr()));
						// hash operation? leave operator as UNINIT
					}
					break;
				}
				else if ((LeftPointer && IsEqType(RightType, NEGATEDPTR))
					|| (RightPointer && IsEqType(LeftType, NEGATEDPTR))) {
					// Compiler optimizations can take a ptr expression such as:
					//  PTR1 - PTR2 + 1
					//  and hoist the loop-invariant subexpression " - PTR2 + 1"
					//  out of the loop as "1 - PTR2", which produces a NEGATEDPTR type.
					//  When PTR1 gets its value determined inside the loop, then the
					//  addition of PTR1 finally happens, producing a PTROFFSET type,
					//  which is what the whole expression is.
					if ((SMP_ADD == CurrOp) || (SMP_ADD_CARRY == CurrOp)) {
						CurrRT->SetOperatorType(PTROFFSET, this);
						updated = true;
					}
					else { // bitwise AND or OR of pointer and pointer difference
						SMP_msg("WARNING: hash of NEGATEDPTR and POINTER at %x in %s\n",
							this->GetAddr(), DisAsmText.GetDisAsm(this->GetAddr()));
						// hash operation? leave operator as UNINIT
					}
					break;
				}
			} // end if UNINIT operator type
			else { // operator has type other than UNINIT
				// We make add-with-carry and subtract-with-borrow exceptions
				//  to the type propagation. LeftOp could have POINTER type
				//  inferred later; these instructions can change the type of
				//  the register from POINTER to NUMERIC, unlike regular
				//  add and subtract opcodes.
				OperNumeric = IsEqType(NUMERIC, OperType);
				OperPointer = IsDataPtr(OperType);
				if (OperNumeric) {
					if ((UNINIT == LeftType)
						&& (SMP_ADD_CARRY != CurrOp)) {
						CurrUse = this->SetUseType(LeftOp, CurrRT->GetOperatorType());
						updated = true;
						assert(CurrUse != this->GetLastUse());
						break;
					}
					if (CurrRT->HasRightSubTree()) {
						// Must need to iterate through the right tree again, as the operator
						//  has been typed.
						if (UNINIT == RightType) {
							CurrRT->GetRightTree()->SetOperatorType(CurrRT->GetOperatorType(), this);
							updated = true;
							updated |= this->InferOperatorType(CurrRT->GetRightTree());
						}
						break;
					}
					else { // right operand; propagate operator type if needed
						if (UNINIT == RightType) {
							CurrUse = this->SetUseType(RightOp, CurrRT->GetOperatorType());
							updated = true;
							assert(CurrUse != this->GetLastUse());
							break;
						}
					}
				}
			}
			break;

		case SMP_SUBTRACT:
		case SMP_SUBTRACT_BORROW:  // subtract with borrow
			// Extract the current types of right and left operands and the operator.
			OperType = CurrRT->GetOperatorType();
			LeftOp = CurrRT->GetLeftOperand();
			LeftUse = this->Uses.FindRef(LeftOp);
			assert(LeftUse != this->GetLastUse()); // found it
			LeftType = LeftUse->GetType();
			if (CurrRT->HasRightSubTree()) {
				updated |= this->InferOperatorType(CurrRT->GetRightTree());
				RightType = CurrRT->GetRightTree()->GetOperatorType();
			}
			else {
				RightOp = CurrRT->GetRightOperand();
				if (o_void == RightOp.type) {
					SMP_msg("ERROR: void operand in %s\n", DisAsmText.GetDisAsm(this->GetAddr()));
					return false;
				}
				else {
					RightUse = this->Uses.FindRef(RightOp);
					if (RightUse == this->GetLastUse()) {
						SMP_msg("WARNING: Adding missing USE of ");
						PrintOperand(RightOp);
						SMP_msg(" in %s\n", DisAsmText.GetDisAsm(this->GetAddr()));
						this->Uses.SetRef(RightOp);
						updated = true;
						break;
					}
					else {
						RightType = RightUse->GetType();
					}
				}
			}
			// If left operand is NUMERIC, operator is NUMERIC.
			LeftNumeric = IsEqType(NUMERIC, LeftType);
			RightNumeric = IsEqType(NUMERIC, RightType);
			LeftPointer = IsDataPtr(LeftType);
			RightPointer = IsDataPtr(RightType);
			if (LeftNumeric) {
				// Subtracting anything from a NUMERIC leaves it NUMERIC or NEGATEDPTR,
				//  in the special case in which a POINTER is subtracted from a NUMERIC.
				//  See NEGATEDPTR comments in the ADD/AND operators case above.
				if (RightPointer) {
					CurrRT->SetOperatorType(NEGATEDPTR, this);
					updated = true;
				}
				else if (UNINIT == OperType) {
					CurrRT->SetOperatorType(NUMERIC, this);
					updated = true;
				}
				else if (IsNotEqType(NUMERIC, OperType) && IsNotEqType(NEGATEDPTR, OperType)) {
					SMP_msg("ERROR: SMP_SUBTRACT from NUMERIC should be NUMERIC or NEGATEDPTR operator.");
					SMP_msg(" Operator type is %d in: %s\n", OperType, DisAsmText.GetDisAsm(this->GetAddr()));
				}
#if 0
				if (!RightNumeric) {
					// Right operand is being used as a NUMERIC, so propagate NUMERIC to it.
					if (CurrRT->HasRightSubTree()) {
						CurrRT->GetRightTree()->SetOperatorType(NUMERIC, this);
					}
					else {
						RightUse = this->SetUseType(RightOp, NUMERIC);
					}
					updated = true;
				}
#endif
			} // end if LeftNumeric
			else if (LeftPointer) {
				if (UNINIT == OperType) {
					// If we subtract another pointer type, we produce PTROFFSET.
					if (RightPointer) {
						CurrRT->SetOperatorType(PTROFFSET, this);
						updated = true;
					}
					else if (RightType == PTROFFSET) {
						// We assume B - (B - A) == A    **!!**
						CurrRT->SetOperatorType(POINTER, this);
						SMP_msg("WARNING: PTR - PTROFFSET produces PTR at %x in %s\n", 
							this->GetAddr(), DisAsmText.GetDisAsm(this->GetAddr()));
						updated = true;
					}
					else if (RightNumeric) {
						// pointer minus NUMERIC keeps same pointer type
						CurrRT->SetOperatorType(LeftType, this);
						updated = true;
					}
				}
				else { // we have an operator type for the SMP_SUBTRACT
					OperNumeric = IsEqType(NUMERIC, OperType);
					OperPointer = IsDataPtr(OperType);
					if (CurrRT->HasRightSubTree()) {
						// Might need to iterate through the right tree again, if its operator
						//  can be typed.
						if (UNINIT == RightType) {
							if (OperPointer) {
								// PTR := PTR - ?? ==> ?? is NUMERIC  Why? ?? could be PTROFFSET
								CurrRT->GetRightTree()->SetOperatorType(NUMERIC, this);
								updated = true;
								updated |= this->InferOperatorType(CurrRT->GetRightTree());
							}
							else if (OperType == PTROFFSET) {
								// PTROFFSET := PTR - ?? ==> ?? is PTR
								CurrRT->GetRightTree()->SetOperatorType(LeftType, this);
								updated = true;
								updated |= this->InferOperatorType(CurrRT->GetRightTree());
							}
							else if (OperNumeric) {
								SMP_msg("WARNING: PTR - ?? produces NUMERIC at %x in %s\n", 
									this->GetAddr(), DisAsmText.GetDisAsm(this->GetAddr()));
							}
						}
						break;
					}
					else { // right operand; propagate operator type if needed
						if (UNINIT == RightType) {
							if (OperPointer) {
								// PTR := PTR - ?? ==> ?? is NUMERIC  Why? ?? could be PTROFFSET
								RightUse = this->SetUseType(RightOp, NUMERIC);
								updated = true;
								assert(RightUse != this->GetLastUse());
							}
							else if (OperType == PTROFFSET) {
								// PTROFFSET := PTR - ?? ==> ?? is PTR
								RightUse = this->SetUseType(RightOp, LeftType);
								updated = true;
							}
							else if (OperNumeric) {
								SMP_msg("WARNING: PTR - ?? produces NUMERIC at %x in %s\n", 
									this->GetAddr(), DisAsmText.GetDisAsm(this->GetAddr()));
							}
							break;
						}
					}
				} // end if OperType is UNINIT ... else ...
			} // end if LeftNumeric ... else if LeftPointer ...
			else if (UNINIT == LeftType) {
				// We make add-with-carry and subtract-with-borrow exceptions
				//  to the type propagation. LeftOp could have POINTER type
				//  inferred later; these instructions can change the type of
				//  the register from POINTER to NUMERIC, unlike regular
				//  add and subtract opcodes.
				if ((UNINIT != OperType)
					&& (SMP_SUBTRACT_BORROW != CurrOp)) {
					LeftUse = this->SetUseType(LeftOp, OperType);
					assert(LeftUse != this->GetLastUse());
					updated = true;
				}
			}
			break;

		case SMP_ASSIGN:
			// Extract the current types of right and left operands and SMP_ASSIGN operator.
			OperType = CurrRT->GetOperatorType();
			DefOp = CurrRT->GetLeftOperand();
			CurrDef = this->Defs.FindRef(DefOp);
			assert(CurrDef != this->GetLastDef()); // found it
			LeftType = CurrDef->GetType();
			if (CurrRT->HasRightSubTree()) {
				updated |= this->InferOperatorType(CurrRT->GetRightTree());
				RightType = CurrRT->GetRightTree()->GetOperatorType();
			}
			else {
				UseOp = CurrRT->GetRightOperand();
				if (o_void == UseOp.type) {
					SMP_msg("ERROR: void operand for SMP_ASSIGN in %s\n", DisAsmText.GetDisAsm(this->GetAddr()));
					return false;
				}
				else {
					CurrUse = this->Uses.FindRef(UseOp);
					if (CurrUse == this->GetLastUse()) {
						SMP_msg("WARNING: Adding missing USE of ");
						PrintOperand(UseOp);
						SMP_msg(" in %s\n", DisAsmText.GetDisAsm(this->GetAddr()));
						this->Uses.SetRef(UseOp);
						updated = true;
						break;
					}
					else {
						RightType = CurrUse->GetType();
					}
				}
			}

#if SMP_VERBOSE_DEBUG_INFER_TYPES
			if (DebugFlag) {
				SMP_msg("%x LeftType: %d OperatorType: %d RightType: %d\n", this->address, LeftType,
					OperType, RightType);
			}
#endif
			if ((UNINIT == RightType) && (UNINIT == LeftType)) {
				break;
			}
			else if (UNINIT == OperType) {
				// UNINIT SMP_ASSIGN operator, but either LeftType or RightType is not UNINIT.
				bool UpdatedOperType = false;
				if (UNINIT != RightType) {
					// We have to special case conditional moves. Only if both operands
					//  (the source and the prior value of the potential destination,
					//  which was added to the USE set by BuildMoveRTL()) agree in type
					//  can we propagate their common type to the operator and ultimately
					//  to the DEF.
					if ((!this->MDIsConditionalMoveInstr()) || this->Uses.TypesAgreeNoFlags()) {
						CurrRT->SetOperatorType(RightType, this);
						updated = true;
						OperType = RightType;
						UpdatedOperType = true;
					}
				}
				else { // LeftType must not be UNINIT
					CurrRT->SetOperatorType(LeftType, this);
					updated = true;
					UpdatedOperType = true;
				}
				// Speed up type propagation by passing the RightType/OperType to the Def
				//  on this iteration.
				if (UpdatedOperType) {
					// Propagate the new DEF type unless it is an indirect memory access.
					//  Future: Propagate until re-DEF of addressing register terminates
					//  the propagation. **!!**
					CurrDef = this->SetDefType(DefOp, OperType);
					LeftType = OperType;
					if (!MDIsIndirectMemoryOpnd(DefOp, this->BasicBlock->GetFunc()->UsesFramePointer())) {
						bool IsMemOp = (o_reg != DefOp.type);
						bool MemPropagate = MDIsStackAccessOpnd(DefOp, UseFP);
#if SMP_PROPAGATE_MEM_TYPES
						;
#else
						// Be conservative and only propagate register DEFs and SAFE stack locs.
						//  We can improve this in the future. **!!**
						MemPropagate = MemPropagate && SafeFunc;
#endif
						if ((o_reg == DefOp.type) || MemPropagate) {
							int SSANum = CurrDef->GetSSANum();
							if (this->BasicBlock->IsLocalName(DefOp)) {
								(void) this->BasicBlock->PropagateLocalDefType(DefOp, LeftType,
									this->GetAddr(), SSANum, IsMemOp);
							}
							else { // global name
								this->BasicBlock->GetFunc()->ResetProcessedBlocks(); // set Processed to false
								(void) this->BasicBlock->PropagateGlobalDefType(DefOp, LeftType,
									SSANum, IsMemOp);
							}
						}
					}
				}
				break;
			}
			else if (UNINIT == LeftType) {
				// SMP_ASSIGN operator has type, so propagate it.
				CurrDef = this->SetDefType(DefOp, OperType);
				LeftType = OperType;
				updated = true;
				// Propagate the new DEF type unless it is an indirect memory access.
				//  Future: Propagate until re-DEF of addressing register terminates
				//  the propagation. **!!**
				if (!MDIsIndirectMemoryOpnd(DefOp, this->BasicBlock->GetFunc()->UsesFramePointer())) {
					bool IsMemOp = (o_reg != DefOp.type);
					bool MemPropagate = MDIsStackAccessOpnd(DefOp, UseFP);
#if SMP_PROPAGATE_MEM_TYPES
					;
#else
					// Be conservative and only propagate register DEFs and SAFE stack locs.
					//  We can improve this in the future. **!!**
					MemPropagate = MemPropagate && SafeFunc;
#endif
					if ((o_reg == DefOp.type) || MemPropagate) {
						int SSANum = CurrDef->GetSSANum();
						if (this->BasicBlock->IsLocalName(DefOp)) {
							(void) this->BasicBlock->PropagateLocalDefType(DefOp, LeftType,
								this->GetAddr(), SSANum, IsMemOp);
						}
						else { // global name
							this->BasicBlock->GetFunc()->ResetProcessedBlocks(); // set Processed to false
							(void) this->BasicBlock->PropagateGlobalDefType(DefOp, LeftType,
								SSANum, IsMemOp);
						}
					}
				}
				break;
			}
			else if (UNINIT == RightType) {
				// SMP_ASSIGN operator has type, so propagate it.
				if (CurrRT->HasRightSubTree()) {
					CurrRT->GetRightTree()->SetOperatorType(OperType, this);
					updated = true;
					updated |= this->InferOperatorType(CurrRT->GetRightTree());
				}
				else {
					// For conditional moves, propagate to the pseudo-USE of the
					//  destination register as well as the source operand.
					if (this->MDIsConditionalMoveInstr()) {
						CurrUse = this->FindUse(DefOp);
						assert(CurrUse != this->GetLastUse());
						if (UNINIT == CurrUse->GetType())
							CurrUse = this->SetUseType(DefOp, OperType);
						else if (OperType != CurrUse->GetType()) {
							SMP_msg("WARNING: Avoiding lattice oscillation from type %d to %d at %x for: ",
								CurrUse->GetType(), OperType, this->address);
							PrintOperand(CurrUse->GetOp());
							SMP_msg("\n");
						}
					}
					CurrUse = this->SetUseType(UseOp, OperType);
					updated = true;
				}
				break;
			}
			break;

		default:
			SMP_msg("ERROR: Unknown operator %d at %x in %s\n", 
				CurrOp, this->GetAddr(), DisAsmText.GetDisAsm(this->GetAddr()));
			break;
	} // end switch on operator

	// Determine if type inference is finished for this register transfer.
	if (updated && (!TypeInferenceFinished)) {
		bool FinishedRight = false;
		bool FinishedLeft = false;
		bool FinishedOperator = (CurrRT->GetOperatorType() != UNINIT);
		if (FinishedOperator) {
			switch (CurrOp) {
				case SMP_INPUT:  // input from port
				case SMP_OUTPUT: // output to port
				case SMP_SIGN_EXTEND:
				case SMP_ZERO_EXTEND:
				case SMP_ADDRESS_OF: // take effective address
				case SMP_SYSTEM_OPERATION:   // for instructions such as CPUID, RDTSC, etc.; NUMERIC
				case SMP_BITWISE_NOT: // unary operator
				case SMP_NEGATE:    // unary negation
				case SMP_DECREMENT:
				case SMP_INCREMENT:
				case SMP_UNARY_NUMERIC_OPERATION:  // miscellaneous; produces NUMERIC result
				case SMP_UNARY_FLOATING_ARITHMETIC:  // all the same to our type system; all NUMERIC
					// Unary operators have no right operand.
					FinishedRight = true;
					break;

				default: // All binary operators come here
					if (CurrRT->HasRightSubTree()) {
						FinishedRight = CurrRT->GetRightTree()->IsTypeInferenceComplete();
					}
					else {
						UseOp = CurrRT->GetRightOperand();
						if (UseOp.type != o_void) {
							CurrUse = this->Uses.FindRef(UseOp);
							assert(CurrUse != this->GetLastUse());
							FinishedRight = (CurrUse->GetType() != UNINIT);
						}
						else { // if o_void, no further type inference on it is possible.
							FinishedRight = true;
						}
					}
					break;
			} // end switch on CurrOp
			if (FinishedRight) { // no point checking left op if right op is not finished
				DefOp = CurrRT->GetLeftOperand();
				if (DefOp.type != o_void) {
					if (SMP_ASSIGN == CurrOp) {
						CurrDef = this->Defs.FindRef(DefOp);
						assert(CurrDef != this->GetLastDef());
						FinishedLeft = (CurrDef->GetType() != UNINIT);
					}
					else { // not ASSIGN, so really a UseOp not DefOp
						CurrUse = this->Uses.FindRef(DefOp);
						assert(CurrUse != this->GetLastUse());
						FinishedLeft = (CurrUse->GetType() != UNINIT);
					}
				}
				else { // if o_void, no further type inference on it is possible.
					FinishedLeft = true;
				}
			}
			TypeInferenceFinished = (FinishedLeft && FinishedRight);
		} // end if (FinishedOperator)
	} // end if (updated && (!TypeInferenceFinished))
	if (TypeInferenceFinished) {
		CurrRT->SetTypeInferenceComplete();
	}
	return updated;
} // end of SMPInstr::InferOperatorType()

// Transfer function: Does operator propagate signedness of its operands to its result?
bool SMPInstr::DoesOperatorTransferSign(SMPoperator CurrOp) {
	bool transfer = false;

	switch (CurrOp) {
		case SMP_NULL_OPERATOR:
		case SMP_CALL:  // CALL instruction
		case SMP_INPUT:  // input from port
		case SMP_OUTPUT: // output to port
		case SMP_SYSTEM_OPERATION:   // for instructions such as CPUID, RDTSC, etc.; NUMERIC
			// No concept of signedness for some operators
			break;

		case SMP_ADDRESS_OF: // take effective address
		case SMP_U_LEFT_SHIFT: // unsigned left shift
		case SMP_U_RIGHT_SHIFT: // unsigned right shift
		case SMP_ROTATE_LEFT:
		case SMP_ROTATE_LEFT_CARRY: // rotate left through carry
		case SMP_ROTATE_RIGHT:
		case SMP_ROTATE_RIGHT_CARRY: // rotate right through carry
		case SMP_U_MULTIPLY:
		case SMP_U_DIVIDE:
		case SMP_U_REMAINDER:
		case SMP_ZERO_EXTEND:
		case SMP_BITWISE_NOT: // unary operator
		case SMP_BITWISE_XOR:
		case SMP_BITWISE_AND_NOT:
		case SMP_U_COMPARE: // unsigned compare (AND-based)
		case SMP_S_LEFT_SHIFT: // signed left shift
		case SMP_S_RIGHT_SHIFT: // signed right shift
		case SMP_S_MULTIPLY:
		case SMP_S_DIVIDE:
		case SMP_SIGN_EXTEND:
		case SMP_NEGATE:    // unary negation
		case SMP_S_COMPARE: // signed compare (subtraction-based)
		case SMP_LESS_THAN: // boolean test operators
		case SMP_GREATER_THAN:
		case SMP_LESS_EQUAL:
		case SMP_GREATER_EQUAL:
			// Inherently unsigned and signed operators force the signedness
			//  of their results, rather than propagating the signedness of
			//  their operands.
			break;

		case SMP_DECREMENT:
		case SMP_INCREMENT:
		case SMP_ADD:
		case SMP_ADD_CARRY:   // add with carry
		case SMP_SUBTRACT:
		case SMP_SUBTRACT_BORROW:  // subtract with borrow
		case SMP_ASSIGN:
		case SMP_BITWISE_AND:
		case SMP_BITWISE_OR:
		case SMP_EQUAL:
		case SMP_NOT_EQUAL:
		case SMP_LOGICAL_AND:
		case SMP_LOGICAL_OR:
		case SMP_UNARY_NUMERIC_OPERATION:  // miscellaneous; produces NUMERIC result
		case SMP_BINARY_NUMERIC_OPERATION:  // miscellaneous; produces NUMERIC result
			transfer = true;
			break;

		case SMP_UNARY_FLOATING_ARITHMETIC:  // all the same to our type system; all NUMERIC
		case SMP_BINARY_FLOATING_ARITHMETIC:  // all the same to our type system; all NUMERIC
		case SMP_REVERSE_SHIFT_U: // Shift right operand by bit count in left operand
		case SMP_SHUFFLE: // Shuffle bytes, words, etc. within destination operation per source mask
		case SMP_COMPARE_EQ_AND_SET: // Compare for equality and set fields to all 1's or all 0's
		case SMP_COMPARE_GT_AND_SET: // Compare for greater-than and set fields to all 1's or all 0's
		case SMP_PACK_S:  // Pack operands into extended-precision register, signed saturation for loss of precision
		case SMP_PACK_U:  // Pack operands into extended-precision register, unsigned saturation for loss of precision
		case SMP_AVERAGE_U: // Average of unsigned operands
		case SMP_MULTIPLY_AND_ADD: // multiply and add (or multiply and accumulate)
		case SMP_SUM_OF_DIFFS: // sum over two vectors of absolute values of differences of their elements
		case SMP_INTERLEAVE: // extended-precision interleaving of bytes or words or dwords etc.; NUMERIC
		case SMP_CONCATENATE:     // extended-precision concatenation; NUMERIC
			transfer = true;
			break;

		default:
			SMP_msg("ERROR: Unknown operator in %s\n", DisAsmText.GetDisAsm(this->GetAddr()));
			break;
	} // end switch on operator

	return transfer;
} // end of SMPInstr::DoesOperatorTransferSign()

// Initial inferences (if any) about FG info of operand based solely on the RTL operator type above it in RTL.