Skip to content
Snippets Groups Projects
SMPInstr.cpp 30.8 KiB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960
//
// SMPInstr.cpp
//
// This module performs the instruction level analyses needed for the
//   SMP project (Software Memory Protection).
//

#include <cstring>

#include <pro.h>
#include <assert.h>
#include <ida.hpp>
#include <idp.hpp>
#include <allins.hpp>
#include <auto.hpp>
#include <bytes.hpp>
#include <funcs.hpp>
#include <intel.hpp>
#include <loader.hpp>
#include <lines.hpp>
#include <name.hpp>

#include "SMPStaticAnalyzer.h"
#include "SMPDataFlowAnalysis.h"
#include "SMPInstr.h"

// Set to 1 for debugging output
#define SMP_DEBUG 1
#define SMP_DEBUG2 0   // verbose
#define SMP_DEBUG_XOR 0

static char *RegNames[R_of + 1] =
	{ "EAX", "ECX", "EDX", "EBX", "ESP", "EBP", "ESI", "EDI",
	  "R8", "R9", "R10", "R11", "R12", "R13", "R14", "R15",
	  "AL", "CL", "DL", "BL", "AH", "CH", "DH", "BH",
	  "SPL", "BPL", "SIL", "DIL", "EIP", "ES", "CS", "SS",
	  "DS", "FS", "GS", "CF", "ZF", "SF", "OF" 
	};

// Make the CF_CHG1 .. CF_CHG6 and CF_USE1..CF_USE6 macros more usable
//  by allowing us to pick them up with an array index.
static ulong DefMacros[UA_MAXOP] = {CF_CHG1, CF_CHG2, CF_CHG3, CF_CHG4, CF_CHG5, CF_CHG6};
static ulong UseMacros[UA_MAXOP] = {CF_USE1, CF_USE2, CF_USE3, CF_USE4, CF_USE5, CF_USE6};

// Text to be printed in each optimizing annotation explaining why
//  the annotation was emitted.
static char *OptExplanation[LAST_OPT_CATEGORY + 1] =
	{ "NoOpt", "NoMetaUpdate", "AlwaysNUM", "NUMVia2ndSrcIMMEDNUM",
	  "Always1stSrc", "1stSrcVia2ndSrcIMMEDNUM", "AlwaysPtr",
	  "AlwaysNUM", "AlwaysNUM", "NUMViaFPRegDest"
	};


// *****************************************************************
// Class SMPInstr
// *****************************************************************

// Constructor for instruction.
SMPInstr::SMPInstr(ea_t addr) {
	this->address = addr;
	this->analyzed = false;
	this->JumpTarget = false;
	return;
}

// Is the instruction the type that terminates a basic block?
bool SMPInstr::IsBasicBlockTerminator() const {
	return ((type == JUMP) || (type == COND_BRANCH)
			|| (type == INDIR_JUMP) || (type == RETURN));
}

// Is the destination operand a memory reference?
bool SMPInstr::HasDestMemoryOperand(void) const {
	bool MemDest = false;
	for (size_t index = 0; index < Defs.GetSize(); ++index) {
		optype_t CurrType = Defs.GetRef(index).GetOp().type;
		MemDest = ((CurrType == o_mem) || (CurrType == o_phrase) || (CurrType == o_displ));
		if (MemDest)
			break;
	}
	return MemDest;
} // end of SMPInstr::HasDestMemoryOperand()

// Is a source operand a memory reference?
bool SMPInstr::HasSourceMemoryOperand(void) const {
	bool MemSrc = false;
	for (size_t index = 0; index < Uses.GetSize(); ++index) {
		optype_t CurrType = Uses.GetRef(index).GetOp().type;
		MemSrc = ((CurrType == o_mem) || (CurrType == o_phrase)	|| (CurrType == o_displ));
		if (MemSrc)
			break;
	}
	return MemSrc;
} // end of SMPInstr::HasSourceMemoryOperand()

// Does the instruction whose flags are in F have a numeric type
//   as the second source operand?
// NOTE: We can only analyze immediate values now, using a heuristic
//   that values in the range +/- 8K are numeric and others are
//   probably addresses. When data flow analyses are implemented,
//   we will be able to analyze many non-immediate operands.
#define IMMEDNUM_LOWER -8191
#define IMMEDNUM_UPPER 8191
bool SMPInstr::IsSecondSrcOperandNumeric(flags_t F) const {
	bool SecondOpImm = (SMPcmd.Operands[1].type == o_imm);
	signed long TempImm;

	if (SecondOpImm) {
		TempImm = (signed long) SMPcmd.Operands[1].value;
	}

#if SMP_DEBUG
	if (SecondOpImm && (0 > TempImm)) {
#if 0
		msg("Negative immediate: %d Hex: %x ASM: %s\n", TempImm,
			SMPcmd.Operands[1].value, disasm);
#endif
	}
	else if ((!SecondOpImm) && (SMPcmd.Operands[1].type == o_imm)) {
		msg("Problem with flags on immediate src operand: %s\n", disasm);
	}
#endif

	return (SecondOpImm && (TempImm > IMMEDNUM_LOWER)
		&& (TempImm < IMMEDNUM_UPPER));
} // end of SMPInstr::IsSecondSrcOperandNumeric()

// DEBUG Print DEF and/or USE for an operand.
void PrintDefUse(ulong feature, int OpNum) {
	// CF_ macros number the operands from 1 to 6, while OpNum
	//  is a 0 to 5 index into the insn_t.Operands[] array.
	// OpNum == -1 is a signal that this is a DEF or USE or VarKillSet etc.
	//  operand and not an instruction operand.
	if (-1 == OpNum)
		return;
	switch (OpNum) {
		case 0:
			if (feature & CF_CHG1)
				msg(" DEF");
			if (feature & CF_USE1)
				msg(" USE");
			break;
		case 1:
			if (feature & CF_CHG2)
				msg(" DEF");
			if (feature & CF_USE2)
				msg(" USE");
			break;
		case 2:
			if (feature & CF_CHG3)
				msg(" DEF");
			if (feature & CF_USE3)
				msg(" USE");
			break;
		case 3:
			if (feature & CF_CHG4)
				msg(" DEF");
			if (feature & CF_USE4)
				msg(" USE");
			break;
		case 4:
			if (feature & CF_CHG5)
				msg(" DEF");
			if (feature & CF_USE5)
				msg(" USE");
			break;
		case 5:
			if (feature & CF_CHG6)
				msg(" DEF");
			if (feature & CF_USE6)
				msg(" USE");
			break;
	}
	return;
} // end PrintDefUse()

// DEBUG print SIB info for an operand.
void PrintSIB(op_t Opnd) {
	int BaseReg = sib_base(Opnd);
	short IndexReg = sib_index(Opnd);
	int ScaleFactor = sib_scale(Opnd);
#define NAME_LEN 5
	char BaseName[NAME_LEN] = {'N', 'o', 'n', 'e', '\0'};
	char IndexName[NAME_LEN] = {'N', 'o', 'n', 'e', '\0'};
#if 0
	if (BaseReg != R_bp) // SIB code for NO BASE REG
#endif
		qstrncpy(BaseName, RegNames[BaseReg], NAME_LEN - 1);

	if (IndexReg != R_sp) { // SIB code for NO INDEX REG
		qstrncpy(IndexName, RegNames[IndexReg], NAME_LEN -1);
	}
	msg(" Base %s Index %s Scale %d", BaseName, IndexName, ScaleFactor);
} // end PrintSIB()

// Debug: print one operand from an instruction or DEF or USE list.
void PrintOneOperand(op_t Opnd, ulong features, int OpNum) { 
	if (Opnd.type == o_void)
		return;
	else if (Opnd.type == o_mem) {
		msg(" Operand %d : memory : addr: %x", OpNum, Opnd.addr);
		PrintDefUse(features, OpNum);
		if (Opnd.hasSIB) { // has SIB info -- is this possible for o_mem?
			msg(" Found SIB byte for o_mem operand ");
			PrintSIB(Opnd);
		}
	}
	else if (Opnd.type == o_phrase) {
		msg(" Operand %d : memory phrase :", OpNum);
		PrintDefUse(features, OpNum);
		if (Opnd.hasSIB) { // has SIB info
			PrintSIB(Opnd);
		}
		else { // no SIB info
			ushort BaseReg = Opnd.phrase;
			msg(" reg %s", RegNames[BaseReg]);
		}
		if (Opnd.addr != 0) {
			msg(" \n WARNING: addr for o_phrase type: %d\n", Opnd.addr);
		}
	}
	else if (Opnd.type == o_displ) {
		msg(" Operand %d : memory displ :", OpNum);
		ea_t offset = Opnd.addr;
		PrintDefUse(features, OpNum);
		if (Opnd.hasSIB) {
			PrintSIB(Opnd);
			msg(" displ %d", offset);
		}
		else {
			ushort BaseReg = Opnd.reg;
			msg(" reg %s displ %d", RegNames[BaseReg], offset);
		}
	}
	else if (Opnd.type == o_reg) {
		msg(" Operand %d : register", OpNum);
		msg(" regno: %d", Opnd.reg);
		PrintDefUse(features, OpNum);
	}
	else if (Opnd.type == o_imm) {
		msg(" Operand %d : immed", OpNum);
		PrintDefUse(features, OpNum);
	}
	else if (Opnd.type == o_far) {
		msg(" Operand %d : FarPtrImmed", OpNum);
		msg(" addr: %x", Opnd.addr);
		PrintDefUse(features, OpNum);
	}
	else if (Opnd.type == o_near) {
		msg(" Operand %d : NearPtrImmed", OpNum);
		msg(" addr: %x", Opnd.addr);
		PrintDefUse(features, OpNum);
	}
	else {
		msg(" Operand %d : unknown", OpNum);
		PrintDefUse(features, OpNum);
	}
	if (!(Opnd.showed()))
		msg(" HIDDEN ");
	return;
} // end of PrintOneOperand()

// DEBUG print operands for Inst.
void SMPInstr::PrintOperands(void) const {
	op_t Opnd;
	for (int i = 0; i < UA_MAXOP; ++i) {
		Opnd = SMPcmd.Operands[i];
		PrintOneOperand(Opnd, this->features, i);
	}
	msg(" \n");
	return;
} // end of SMPInstr::PrintOperands()

// Print out the destination operand list for the instruction, given
//  the OptCategory for the instruction as a hint.
char * SMPInstr::DestString(int OptType) {
	static char DestList[MAXSTR] = { '\0', '\0' };
	int RegDestCount = 0;
	for (size_t DefIndex = 0; DefIndex < this->NumDefs(); ++DefIndex) {
		op_t DefOpnd = this->GetDef(DefIndex).GetOp();
		if (o_reg == DefOpnd.type) {
			ushort DestReg = DefOpnd.reg;
			if (0 == RegDestCount) {
				qstrncpy(DestList, RegNames[DestReg], 1 + strlen(RegNames[DestReg]));
			}
			else {
				qstrncat(DestList, " ", MAXSTR);
				qstrncat(DestList, RegNames[DestReg], MAXSTR);
			}
			++RegDestCount;
		}
	}
	if (0 >= RegDestCount) {
		msg("WARNING: No destination registers: %s\n", this->GetDisasm());
	}
	else {
		qstrncat(DestList, " ZZ ", MAXSTR);
	}
	return DestList;
} // end of SMPInstr::DestString()

// Equality operator for SMPInstr. Key field is address.
int SMPInstr::operator==(const SMPInstr &rhs) const {
	if (this->address != rhs.GetAddr())
		return 0;
	else
		return 1;
}

// Inequality operator for SMPInstr. Key field is address.
int SMPInstr::operator!=(const SMPInstr &rhs) const {
	return (this->address != rhs.GetAddr());
}

// Less than operator for sorting SMPInstr lists. Key field is address.
int SMPInstr::operator<(const SMPInstr &rhs) const {
	return (this->address < rhs.GetAddr());
}

// Less than or equal operator for sorting SMPInstr lists. Key field is address.
int SMPInstr::operator<=(const SMPInstr &rhs) const {
	return (this->address <= rhs.GetAddr());
}

#define MD_FIRST_ENTER_INSTR  NN_enterw
#define MD_LAST_ENTER_INSTR NN_enterq
// Is this instruction the one that allocates space on the
//  stack for the local variables?
bool SMPInstr::MDIsFrameAllocInstr(void) const {
	// The frame allocating instruction should look like:
	//   sub esp,48   or   add esp,-64   etc.
	if ((SMPcmd.itype == NN_sub) || (SMPcmd.itype == NN_add)) {
		if (Defs.GetRef(0).GetOp().is_reg(R_sp)) {
			// We know that an addition or subtraction is being
			//  performed on the stack pointer. This should not be
			//  possible within the prologue except at the stack
			//  frame allocation instruction, so return true. We
			//  could be more robust in this analysis in the future. **!!**
			// CAUTION: If a compiler allocates 64 bytes for locals
			//  and 16 bytes for outgoing arguments in a single
			//  instruction:  sub esp,80
			//  you cannot insist on finding sub esp,LocSize
			// To make this more robust, we are going to insist that
			//  an allocation of stack space is either performed by
			//  adding a negative immediate value, or by subtracting
			//  a positive immediate value. We will throw in, free of
			//  charge, a subtraction of a register, which is how alloca()
			//  usually allocates stack space.
			if (o_imm == Uses.GetRef(0).GetOp().type) {
				signed long TempImm = (signed long) Uses.GetRef(0).GetOp().value;
				if (((0 > TempImm) && (SMPcmd.itype == NN_add))
					|| ((0 < TempImm) && (SMPcmd.itype == NN_sub))) {
					return true;
				}
			}
			else if ((o_reg == Uses.GetRef(0).GetOp().type)
				&& (SMPcmd.itype == NN_sub)) { // alloca() ?
				return true;
			}
		}
	}
	else if ((SMPcmd.itype >= MD_FIRST_ENTER_INSTR) && (SMPcmd.itype <= MD_LAST_ENTER_INSTR)) {
		return true;
	}
	return false;
} // end of SMPInstr::MDIsFrameAllocInstr()

// Is this instruction in the epilogue the one that deallocates the local
//  vars region of the stack frame?
bool SMPInstr::MDIsFrameDeallocInstr(bool UseFP, asize_t LocalVarsSize) const {
	// The usual compiler idiom for the prologue on x86 is to
	//  deallocate the local var space with:   mov esp,ebp
	//  It could be  add esp,constant.  We can be tricked by
	//  add esp,constant when the constant is just the stack
	//  adjustment after a call. We will have to insist that
	//  the immediate operand have at least the value of
	//  LocalVarsSize for this second form, and that UseFP be true
	//  for the first form.
	if (UseFP && (this->SMPcmd.itype == NN_mov)
		&& (this->Defs.GetRef(0).GetOp().is_reg(R_sp))
		&& (this->Uses.GetRef(0).GetOp().is_reg(R_bp)))
		return true;
	else if ((this->SMPcmd.itype == NN_add)
		&& (this->Defs.GetRef(0).GetOp().is_reg(R_sp))
		&& (this->Uses.GetRef(1).GetOp().is_imm((uval_t) LocalVarsSize)))
		return true;
	else if ((this->SMPcmd.itype == NN_add)
		&& (this->Defs.GetRef(0).GetOp().is_reg(R_sp))
		&& (this->Uses.GetRef(1).GetOp().type == o_imm)) {
		msg("Used imprecise LocalVarsSize to find dealloc instr.\n");
		return true;
	}
	else if (NN_leave == this->SMPcmd.itype)
		return true;
	else
		return false;
} // end of SMPInstr::MDIsFrameDeallocInstr()

// Is instruction a no-op? There are 1-byte, 2-byte, etc versions of no-ops.
bool SMPInstr::MDIsNop(void) const {
	bool IsNop = false;
	ushort opcode = this->SMPcmd.itype;
	if (NN_nop == opcode)
		IsNop = true;
	else if (NN_mov == opcode) {
		if ((o_reg == this->SMPcmd.Operands[0].type) 
			&& this->SMPcmd.Operands[1].is_reg(this->SMPcmd.Operands[0].reg)) {
			// We have a register to register move with source == destination.
			IsNop = true;
		}
	}
	else if (NN_lea == opcode) {
		if ((o_reg == this->SMPcmd.Operands[0].type)
			&& (o_displ == this->SMPcmd.Operands[1].type)) {
			// We are looking for 6-byte no-ops like lea esi,[esi+0]
				ushort destreg = this->SMPcmd.Operands[0].reg;
				if ((this->SMPcmd.Operands[1].hasSIB)
					&& (destreg == (ushort) sib_base(this->SMPcmd.Operands[1]))) {
					IsNop = true;
				}
				else if (destreg == this->SMPcmd.Operands[1].reg) {
					IsNop = true;
				}
		}
	}
	return IsNop;
} // end of SMPInstr::MDIsNop()

// MACHINE DEPENDENT: Is instruction a return instruction?
bool SMPInstr::MDIsReturnInstr(void) const {
	return ((SMPcmd.itype == NN_retn) || (SMPcmd.itype == NN_retf));
}

// MACHINE DEPENDENT: Is instruction a POP instruction?
#define FIRST_POP_INST   NN_pop
#define LAST_POP_INST    NN_popfq
bool SMPInstr::MDIsPopInstr(void) const {
	return ((SMPcmd.itype >= FIRST_POP_INST)
			&& (SMPcmd.itype <= LAST_POP_INST));
}

// MACHINE DEPENDENT: Is instruction a PUSH instruction?
#define FIRST_PUSH_INST   NN_push
#define LAST_PUSH_INST    NN_pushfq
bool SMPInstr::MDIsPushInstr(void) const {
	return ((SMPcmd.itype >= FIRST_PUSH_INST)
			&& (SMPcmd.itype <= LAST_PUSH_INST));
}

// MACHINE DEPENDENT: Is instruction an ENTER instruction?
#define FIRST_ENTER_INST   NN_enterw
#define LAST_ENTER_INST    NN_enterq
bool SMPInstr::MDIsEnterInstr(void) const {
	return ((SMPcmd.itype >= FIRST_ENTER_INST)
			&& (SMPcmd.itype <= LAST_ENTER_INST));
}

// MACHINE DEPENDENT: Is instruction a LEAVE instruction?
#define FIRST_LEAVE_INST   NN_leavew
#define LAST_LEAVE_INST    NN_leaveq
bool SMPInstr::MDIsLeaveInstr(void) const {
	return ((SMPcmd.itype >= FIRST_LEAVE_INST)
			&& (SMPcmd.itype <= LAST_LEAVE_INST));
}

// MACHINE DEPENDENT: Does instruction use a callee-saved register?
bool SMPInstr::MDUsesCalleeSavedReg(void) const {
	for (size_t index = 0; index < this->Uses.GetSize(); ++index) {
		op_t CurrUse = this->GetUse(index).GetOp();
		if (CurrUse.is_reg(R_bp) || CurrUse.is_reg(R_si)
			|| CurrUse.is_reg(R_di) || CurrUse.is_reg(R_bx)) {
			return true;
		}
	}
	return false;
} // end of SMPInstr::MDUsesCalleeSavedReg()

// Is the instruction a register to register copy of a stack pointer or frame pointer
//  into a general purpose register (which mmStrata will now need to track as a stack 
//  relative pointer)?
bool SMPInstr::MDIsStackPointerCopy(bool UseFP) const {
	if ((this->OptType == 3) && (this->GetDef(0).GetOp().type == o_reg)
		&& (!(this->GetDef(0).GetOp().is_reg(R_sp)))) {
		if (UseFP) {
			if (this->GetUse(0).GetOp().is_reg(R_bp))
				// Move of base pointer EBP into a general register
				return true;
			else if ((this->GetUse(0).GetOp().is_reg(R_sp))
				&& !(this->GetDef(0).GetOp().is_reg(R_bp)))
				// Move of ESP into something besides a base pointer
				return true;
		}
		else if (this->GetUse(0).GetOp().is_reg(R_sp)) {
			// Move of ESP into a register; no base pointer used in this function
			return true;
		}
	}
	return false;
} // end of SMPInstr::MDIsStackPointerCopy()

// Is instruction a branch (conditional or unconditional) to a
//  code target that is not in the current chunk?
bool SMPInstr::IsBranchToFarChunk(void) const {
	func_t *CurrChunk = get_fchunk(this->address);
	bool FarBranch = false;
	if ((JUMP | COND_BRANCH) & this->GetDataFlowType()) {
		// Instruction is a direct branch, conditional or unconditional
		if (this->NumUses() > 0) {
			op_t JumpTarget = this->GetUse(0).GetOp();
			if ((o_near == JumpTarget.type) || (o_far == JumpTarget.type)) {
				// Branches to a code address
				func_t *TargetChunk = get_fchunk(JumpTarget.addr);
				// Is target address within the same chunk as the branch?
				FarBranch = (NULL == TargetChunk) || (CurrChunk->startEA != TargetChunk->startEA);
			}
		}
	}
	return FarBranch;
} // end of SMPInstr::IsBranchToFarChunk()

// Analyze the instruction and its operands.
void SMPInstr::Analyze(void) {
	if (this->analyzed)
		return;

	// Fill cmd structure with disassembly of instr
	ua_ana0(this->address);
	// Get the instr disassembly text.
	(void) generate_disasm_line(this->address, this->disasm, sizeof(this->disasm) - 1);
	// Remove interactive color-coding tags.
	tag_remove(this->disasm, this->disasm, 0);
	// Copy cmd to member variable SMPcmd.
	this->SMPcmd = cmd;
	// Get the canonical features into member variables features.
	this->features = cmd.get_canon_feature();

	// Record what type of instruction this is, simplified for the needs
	//  of data flow and type analysis.
	this->type = DFACategory[cmd.itype];
	// Record optimization category.
	this->OptType = OptCategory[cmd.itype];

	// Build the DEF and USE lists for the instruction.
	this->BuildSMPDefUseLists();
	// Fix up machine dependent quirks in the def and use lists.
	this->MDFixupDefUseLists();

	// Determine whether the instruction is a jump target by looking
	//  at its cross references and seeing if it has "TO" code xrefs.
	xrefblk_t xrefs;
	for (bool ok = xrefs.first_to(this->address, XREF_FAR); ok; ok = xrefs.next_to()) {
		if ((xrefs.from != 0) && (xrefs.iscode)) {
			this->JumpTarget = true;
			break;
		}
	}

	this->analyzed = true;
	return;
} // end of SMPInstr::Analyze()

// Fill the Defs and Uses private data members.
void SMPInstr::BuildSMPDefUseLists(void) {
	size_t OpNum;
	
	// Start with the Defs.
	for (OpNum = 0; OpNum < UA_MAXOP; ++OpNum) {
		if (this->features & DefMacros[OpNum]) { // DEF
			this->Defs.SetRef(this->SMPcmd.Operands[OpNum]);
		}
	} // end for (OpNum = 0; ...)

	// Now, do the Uses. Uses have special case operations, because
	//  any memory operand could have register uses in the addressing
	//  expression, and we must create Uses for those registers. For
	//  example:  mov eax,[ebx + esi*2 + 044Ch]
	//  This is a two-operand instruction with one def: eax. But
	//  there are three uses: [ebx + esi*2 + 044Ch], ebx, and esi.
	//  The first use is an op_t of type o_phrase (memory phrase),
	//  which can be copied from cmd.Operands[1]. Likewise, we just
	//  copy cmd.Operands[0] into the defs list. However, we must create
	//  op_t types for register ebx and register esi and append them
	//  to the Uses list. This is handled by the machine dependent
	//  method MDFixupDefUseLists().
	for (OpNum = 0; OpNum < UA_MAXOP; ++OpNum) {
		if (this->features & UseMacros[OpNum]) { // USE
			this->Uses.SetRef(this->SMPcmd.Operands[OpNum]);
		}
	} // end for (OpNum = 0; ...)

	return;
} // end of SMPInstr::BuildSMPDefUseLists()

// If DefReg is not already in the DEF list, add a DEF for it.
void SMPInstr::MDAddRegDef(ushort DefReg) {
	bool AlreadySet = false;
	for (size_t DefIndex = 0; DefIndex < this->NumDefs(); ++DefIndex) {
		if (this->GetDef(DefIndex).GetOp().is_reg(DefReg)) {
			AlreadySet = true;
			break;
		}
	}
	if (!AlreadySet) {
		op_t TempDef;
		TempDef.type = o_reg;
		TempDef.reg = DefReg;
		this->Defs.SetRef(TempDef);
	}
	return;
} // end of SMPInstr::MDAddRegDef()

// If UseReg is not already in the USE list, add a USE for it.
void SMPInstr::MDAddRegUse(ushort UseReg) {
	bool AlreadyUsed = false;
	for (size_t UseIndex = 0; UseIndex < this->NumUses(); ++UseIndex) {
		if (this->GetUse(UseIndex).GetOp().is_reg(UseReg)) {
			AlreadyUsed = true;
			break;
		}
	}
	if (!AlreadyUsed) {
		op_t TempUse;
		TempUse.type = o_reg;
		TempUse.reg = UseReg;
		this->Uses.SetRef(TempUse);
	}
	return;
} // end of SMPInstr::MDAddRegUse()

// Perform machine dependent ad hoc fixes to the def and use lists.
//  For example, some multiply and divide instructions in x86 implicitly
//  use and/or define register EDX. For memory phrase examples, see comment
//  in BuildSMPDefUseLists().
void SMPInstr::MDFixupDefUseLists(void) {
	// First, handle the uses hidden in memory addressing modes. Note that we do not
	//  care whether we are dealing with a memory destination operand or source
	//  operand, because register USEs, not DEFs, happen within the addressing expressions.
	size_t OpNum;
	for (OpNum = 0; OpNum < UA_MAXOP; ++OpNum) {
		op_t Opnd = SMPcmd.Operands[OpNum];
		if ((Opnd.type == o_phrase) || (Opnd.type == o_displ)) {
			if (Opnd.hasSIB) {
				int BaseReg = sib_base(Opnd);
				short IndexReg = sib_index(Opnd);
				if (R_none != BaseReg) {
					op_t BaseOpnd = Opnd; // Init to current operand field values
					BaseOpnd.type = o_reg; // Change type and reg fields
					BaseOpnd.reg = BaseReg;
					BaseOpnd.hasSIB = 0;
					this->Uses.SetRef(BaseOpnd);
				}
				if (R_none != IndexReg) { // Should we disallow R_sp here? **!!**
					op_t IndexOpnd = Opnd; // Init to current operand field values
					IndexOpnd.type = o_reg; // Change type and reg fields
					IndexOpnd.reg = IndexReg;
					IndexOpnd.hasSIB = 0;
					this->Uses.SetRef(IndexOpnd);
				}
			}
			else { // no SIB byte; can have base reg but no index reg
				ushort BaseReg = Opnd.reg;  // cannot be R_none for no SIB case
				op_t BaseOpnd = Opnd; // Init to current operand field values
				BaseOpnd.type = o_reg; // Change type and reg fields
				BaseOpnd.reg = BaseReg;
				BaseOpnd.hasSIB = 0;
				this->Uses.SetRef(BaseOpnd);
			}
		} // end if (o_phrase or o_displ operand)
	} // end for (all operands)

	// Now, handle special instruction categories that have implicit operands.
	if (NN_cmpxchg == SMPcmd.itype) {
		// x86 Compare and Exchange conditionally sets EAX. We must keep data flow analysis
		//  sound by declaring that EAX is always a DEF.
		this->MDAddRegDef(R_ax);
	} // end if NN_cmpxchg
	else if (this->MDIsPopInstr() || this->MDIsPushInstr() || this->MDIsReturnInstr()) {
		// IDA does not include the stack pointer in the DEFs or USEs.
		this->MDAddRegDef(R_sp);
		this->MDAddRegUse(R_sp);
	}
	else if (this->MDIsEnterInstr() || this->MDIsLeaveInstr()) {
		// Entire function prologue or epilogue microcoded.
		this->MDAddRegDef(R_sp);
		this->MDAddRegUse(R_sp);
		this->MDAddRegDef(R_bp);
		this->MDAddRegUse(R_bp);
	}
	else if (8 == this->GetOptType()) {
		// This category implicitly writes to EDX:EAX.
		this->MDAddRegDef(R_dx);
		this->MDAddRegDef(R_ax);
	} // end else if (8 == GetOptType)
	else if (7 == this->GetOptType()) {
		// Category 7 instructions sometimes write implicitly to EDX:EAX or DX:AX.
		//  DX is the same as EDX to IDA Pro (and SMP); ditto for EAX and AX.
		// DIV, IDIV, and MUL all have hidden EAX or AX operands (hidden in the IDA Pro
		//  sense, because they are not displayed in the disassembly text). For example:
		//  mul ebx means EDX:EAX <-- EAX*EBX, and mul bx means DX:AX <-- AX*BX. If the
		//  source operand is only 8 bits wide, there is room to hold the result in AX
		//  without using DX:  mul bl means AX <-- AL*BL.
		// IMUL has forms with a hidden EAX or AX operand and forms with no implicit
		//  operands:  imul ebx means EDX:EAX <-- EAX*EBX, but imul ebx,edx means that
		//  EBX*EDX gets truncated and the result placed in EBX (no hidden operands).
		bool HiddenEAXUse = false;
		for (size_t UseIndex = 0; UseIndex < this->NumUses(); ++UseIndex) {
			op_t TempUse = this->GetUse(UseIndex).GetOp();
			if (!TempUse.showed()) { // hidden operand
				if (TempUse.is_reg(R_ax)) { // not R_al, so it is not 8 bits
					this->MDAddRegUse(R_dx);
					this->MDAddRegDef(R_ax);
					this->MDAddRegDef(R_dx);
				}
			}
		}
	} // end else if (7 == OptType)
	return;
} // end of SMPInstr::MDFixupDefUseLists()

// Handle x86 opcode SIB byte annotations.
void SMPInstr::MDAnnotateSIBStackConstants(FILE *AnnotFile, op_t Opnd, ea_t offset, bool UseFP) {
	int BaseReg = sib_base(Opnd);
	short IndexReg = sib_index(Opnd);
	if (BaseReg == R_none) {
		msg("BaseReg of R_none at %x\n", this->address);
	}
	if (BaseReg == R_sp) { // ESP cannot be IndexReg
		// ESP-relative constant offset
		qfprintf(AnnotFile,
				"%x %d PTRIMMEDESP STACK %d displ %s\n",
				this->SMPcmd.ea, this->SMPcmd.size, offset, this->disasm);
	}
	else if (UseFP && ((IndexReg == R_bp) || (BaseReg == R_bp))) {
		// EBP-relative constant offset
		qfprintf(AnnotFile,
				"%x %d PTRIMMEDEBP STACK %d displ %s\n",
				this->SMPcmd.ea, this->SMPcmd.size, offset, this->disasm);
	}

	return;
} // end of MDAnnotateSIBStackConstants

// Emit annotations for constants used as ptr offsets from EBP or
//  ESP into the stack frame. Only pay attention to EBP-relative
//  offsets if EBP is being used as a frame pointer (UseFP == true).
void SMPInstr::AnnotateStackConstants(bool UseFP, FILE *AnnotFile) {
	op_t Opnd;
#if 0
	if (this->address == 0x80925f4) {
		msg("PROBLEM INSTRUCTION: \n");
		this->PrintOperands();
	}
#endif
	for (int i = 0; i < UA_MAXOP; ++i) {
		Opnd = SMPcmd.Operands[i];
		if (Opnd.type == o_displ) {
			ea_t offset = Opnd.addr;
			if (Opnd.hasSIB) {
				MDAnnotateSIBStackConstants(AnnotFile, Opnd, offset, UseFP);
			}
			else { // no SIB
				ushort BaseReg = Opnd.reg;
				if (BaseReg == R_sp) {
					// ESP-relative constant offset
					qfprintf(AnnotFile,
							"%x %d PTRIMMEDESP STACK %d displ %s\n",
							SMPcmd.ea, SMPcmd.size, offset, disasm);
				}
				else if (UseFP && (BaseReg == R_bp)) {
					// EBP-relative constant offset
					qfprintf(AnnotFile,
							"%x %d PTRIMMEDEBP STACK %d displ %s\n",
							SMPcmd.ea, SMPcmd.size, offset, disasm);
				}
			} // end if (Opnd.hasSIB) ... else ...
		} // end if (Opnd.type == o_displ) 
		else if (Opnd.type == o_phrase) {
			ea_t offset = 0; // mmStrata thinks [esp] is [esp+0]
			if (Opnd.hasSIB) {
				MDAnnotateSIBStackConstants(AnnotFile, Opnd, offset, UseFP);
			}
			else { // Something like [ecx]
				ushort BaseReg = Opnd.reg;
				if (BaseReg == R_sp) {
					// ESP-relative constant offset
					qfprintf(AnnotFile,
							"%x %d PTRIMMEDESP STACK %d displ %s\n",
							SMPcmd.ea, SMPcmd.size, offset, disasm);
				}
				else if (UseFP && (BaseReg == R_bp)) {
					// EBP-relative constant offset
					qfprintf(AnnotFile,
							"%x %d PTRIMMEDEBP STACK %d displ %s\n",
							SMPcmd.ea, SMPcmd.size, offset, disasm);
				}
			} // end if (Opnd.hasSIB) ... else ...
		} // end else if (Opnd.type == o_phrase)
	} // end for all operands

	// If we move a stack pointer or frame pointer into another register, we
	//  need to annotate the implicit zero offset, e.g. mov edi,esp == mov edi,esp+0
	//  and edi is becoming a stack pointer that mmStrata needs to track.
	if (this->MDIsStackPointerCopy(UseFP)) {
		if (UseFP && this->GetUse(0).GetOp().is_reg(R_bp)) {
			qfprintf(AnnotFile,	"%x %d PTRIMMEDEBP STACK 0 displ %s\n",
					SMPcmd.ea, SMPcmd.size, disasm);
		}
		else {
			qfprintf(AnnotFile,	"%x %d PTRIMMEDESP STACK 0 displ %s\n",
					SMPcmd.ea, SMPcmd.size, disasm);
		}
	}

	return;
} // end of SMPInstr::AnnotateStackConstants()

// Emit all annotations for the instruction.
void SMPInstr::EmitAnnotations(bool UseFP, bool AllocSeen, FILE *AnnotFile) {
	ea_t addr = this->address;
	flags_t InstrFlags = getFlags(addr);
	bool MemDest = this->HasDestMemoryOperand();
	bool MemSrc = this->HasSourceMemoryOperand();
	bool SecondSrcOperandNum = this->IsSecondSrcOperandNumeric(InstrFlags);

	++OptCount[OptType]; // keep count for debugging info

#if SMP_DEBUG_MEM
	if (MemDest || MemSrc) {
		msg("OptType: %d %s", OptType, disasm);
		this->PrintOperands();
	}
#endif

	// Emit appropriate optimization annotations.
	bool SDTInstrumentation = false;
	switch (OptType) {
		case 0:  // SDT will have to handle these
		{
#if SMP_DEBUG_TYPE0
			msg("OptType 0: %x  %s\n", addr, disasm);
#endif
			// mmStrata wants to suppress warnings on the PUSH
			//  instructions that precede the LocalVarsAllocInstr
			//  (i.e. the PUSHes of callee-saved regs).
			if (!AllocSeen && this->MDIsPushInstr()) {
				qfprintf(AnnotFile, "%x %d INSTR LOCAL NoWarn %s \n",
						addr, -3, disasm);
			}
			else {
				SDTInstrumentation = true;
			}
			break;
		}

		case 1:  // nothing for SDT to do
		{	qfprintf(AnnotFile, "%x %d INSTR LOCAL NoMetaUpdate %s \n",
					addr, -1, disasm);
			++AnnotationCount[OptType];
			break;
		}

		case 4:  // INC, DEC, etc.: no SDT work unless MemDest
		{	if (MemDest || MemSrc) {
				SDTInstrumentation = true;
				break;  // treat as category 0
	 		}
			qfprintf(AnnotFile, "%x %d INSTR LOCAL Always1stSrc %s \n",
					addr, -1, disasm);
			++AnnotationCount[OptType];
			break;
		}

		case 5: // ADD, etc.: If numeric 2nd src operand, no SDT work.
		{	if (MemDest || MemSrc) {
				SDTInstrumentation = true;
				break;  // treat as category 0
			}
			if (SecondSrcOperandNum) { // treat as category 1
				qfprintf(AnnotFile, "%x %d INSTR LOCAL %s %s \n",
						addr, -1, OptExplanation[OptType], disasm);
				++AnnotationCount[OptType];
			}
			break;
		}

		case 6: // Only OS code should include these; problem for SDT
		{	if (MemDest) {
				SDTInstrumentation = true;
				break;  // treat as category 0
			}
			qfprintf(AnnotFile, "%x %d INSTR LOCAL AlwaysPTR %s \n",
					addr, -OptType, disasm);
			++AnnotationCount[OptType];
			break;
		}

		case 8: // Implicitly writes to EDX:EAX, always numeric.
		{	qfprintf(AnnotFile, "%x %d INSTR LOCAL n EDX EAX ZZ %s %s \n",
					addr, -2, OptExplanation[OptType], disasm);
			++AnnotationCount[OptType];
			SDTInstrumentation = true;
			break;
		}

		case 9:  // Either writes to FP reg (cat. 1) or memory (cat. 0)
		{	if (MemDest) {
#if SMP_DEBUG
				// MemDest seems to happen too much.
				msg("Floating point MemDest: %s \n", disasm);
#endif
				SDTInstrumentation = true;
				break; // treat as category 0
			}
			qfprintf(AnnotFile, "%x %d INSTR LOCAL %s %s \n",
					addr, -1, OptExplanation[OptType], disasm);
			++AnnotationCount[OptType];
			break;
		}

		default: // 2,3,7: Optimization possibilities depend on operands
		{ 
#if SMP_DEBUG2
			if (OptType ==  3) {  // MOV instr class
				if (MemDest) {
					msg("MemDest on MOV: %s\n", disasm);
				}
				else if (!SecondSrcOperandNum) {
					msg("MOV: not 2nd op numeric: %s\n", disasm);
						this->PrintOperands();
				}
			}
#endif
			SDTInstrumentation = true;
			if (MemDest) {
#if SMP_DEBUG_XOR
				if (OptType == 2)
					msg("MemDest on OptType 2: %s\n", disasm);
#endif
				break;  // treat as category 0
			}
			if ((OptType == 2) || (OptType == 7) || SecondSrcOperandNum) {
				qfprintf(AnnotFile, "%x %d INSTR LOCAL n %s %s %s \n",
						addr, -2, this->DestString(OptType), 
						OptExplanation[OptType], disasm);
				++AnnotationCount[OptType];
			}
			break;
		}
	} // end switch (OptType)
	
	// If mmStrata is going to have to deal with the
	//  instruction, then we can annotate EBP and ESP
	//  relative constant offsets. If we have emitted
	//  an annotation of type -1, there is no point
	//  in telling mmStrata about these constants.
	if (SDTInstrumentation) {
		this->AnnotateStackConstants(UseFP, AnnotFile);
	}
	return;
} // end of SMPInstr::EmitAnnotations()