Newer
Older
clc5q
committed
SMP_msg("DEBUG: Setting DEF for: ");
clc5q
committed
SMP_msg("\n");
this->Defs.SetRef(TempOp);
}
} // end for (OpNum = 0; ...)
if (this->IsRegClearIdiom()) {
// Something like xor eax,eax clears eax but does not really
// use eax. It is the same as mov eax,0 and we don't want to
// extend the prior def-use chain for eax to this instruction
// by treating the instruction as xor eax,eax. Instead, we
// build the DEF and USE lists and RTL as if it were mov eax,0.
op_t ImmOp = InitOp;
ImmOp.value = 0;
SetOperandWidthToProcessorWidth(ImmOp);
this->Uses.SetRef(ImmOp, NUMERIC);
return;
}
// 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
op_t TempOp = this->SMPcmd.Operands[OpNum];
if (MDKnownOperandType(TempOp)) {
clc5q
committed
SMP_msg("DEBUG: Setting USE for: ");
clc5q
committed
SMP_msg("\n");
this->Uses.SetRef(TempOp);
}
} // end for (OpNum = 0; ...)
return;
} // end of SMPInstr::BuildSMPDefUseLists()
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
// Declare a branch/jump to be a tail call, clean up def/use lists.
void SMPInstr::SetTailCall(void) {
this->booleans1 |= INSTR_SET_TAIL_CALL;
if (this->type == COND_BRANCH) {
this->SetCondTailCall();
}
else {
this->ResetCondTailCall();
}
this->CallTarget = this->FarBranchTarget;
this->type = RETURN;
this->GetBlock()->SetReturns(true);
// We want to add the caller-saved registers to the USEs and DEFs lists
this->MDAddRegDef(R_ax, false);
this->MDAddRegDef(R_cx, false);
this->MDAddRegDef(R_dx, false);
this->MDAddRegUse(R_ax, false);
this->MDAddRegUse(R_cx, false);
this->MDAddRegUse(R_dx, false);
} // end of SMPInstr::SetTailCall()
// record original Lea instruction [pseudo-]memory operand.
void SMPInstr::SetLeaMemUseOp(op_t NewLeaOperand) {
if (NULL != this->BasicBlock) {
this->GetBlock()->GetFunc()->AddLeaOperand(this->GetAddr(), NewLeaOperand);
}
return;
}
// If DefReg is not already in the DEF list, add a DEF for it.
void SMPInstr::MDAddRegDef(ushort DefReg, bool Shown, SMPOperandType Type) {
op_t TempDef = InitOp;
TempDef.type = o_reg;
TempDef.reg = DefReg;
if (Shown)
TempDef.set_showed();
else
TempDef.clr_showed();
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 Shown, SMPOperandType Type) {
op_t TempUse = InitOp;
TempUse.type = o_reg;
TempUse.reg = UseReg;
if (Shown)
TempUse.set_showed();
else
TempUse.clr_showed();
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;
SMPOperandType RefType;
unsigned short opcode = this->SMPcmd.itype;
int BaseReg;
int IndexReg;
ushort ScaleFactor;
ea_t displacement;
bool UseFP = true;
bool HasIndexReg = false;
bool leaInst = (NN_lea == opcode);
bool DebugFlag = (this->GetAddr() == 0x8086177);
clc5q
committed
SMP_msg("DEBUG: Fixing up DEF-USE lists for debug location\n");
#if SMP_BASEREG_POINTER_TYPE
// Some instructions are analyzed outside of any function or block when fixing up
// the IDB, so we have to assume the block and func pointers might be NULL.
if ((NULL != this->BasicBlock) && (NULL != this->BasicBlock->GetFunc()))
UseFP = this->BasicBlock->GetFunc()->UsesFramePointer();
#endif
if (DebugFlag) {
clc5q
committed
SMP_msg("DEBUG: UseFP = %d\n", UseFP);
for (OpNum = 0; OpNum < UA_MAXOP; ++OpNum) {
op_t Opnd = SMPcmd.Operands[OpNum];
if ((Opnd.type == o_phrase) || (Opnd.type == o_displ) || (Opnd.type == o_mem)) {
MDExtractAddressFields(Opnd, BaseReg, IndexReg, ScaleFactor, displacement);
SingleAddressReg = ((0 == displacement)
&& ((R_none == BaseReg) || (R_none == IndexReg)));
if (R_none != IndexReg) {
op_t IndexOpnd = Opnd; // Init to current operand field values
IndexOpnd.type = o_reg; // Change type and reg fields
IndexOpnd.reg = (ushort) IndexReg;
IndexOpnd.hasSIB = 0;
IndexOpnd.set_showed();
if (0 == ScaleFactor)
this->Uses.SetRef(IndexOpnd);
else { // scaling == shift ==> NUMERIC
HasIndexReg = true;
this->Uses.SetRef(IndexOpnd, NUMERIC);
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 = (ushort) BaseReg;
BaseOpnd.set_showed();
RefType = UNINIT;
#if SMP_BASEREG_POINTER_TYPE
// R_sp and R_bp will get type STACKPTR in SMPInstr::SetImmedTypes().
// Other registers used as base registers should get their USEs as
// base registers typed as POINTER, which might get refined later
// to STACKPTR, GLOBALPTR, HEAPPTR, etc.
// NOTE: the NN_lea opcode is often used without a true base register.
// E.g. lea eax,[eax+eax+5] is an x86 idiom for eax:=eax*2+5, which
// could not be done in one instruction without using the addressing
// modes of the machine to do the arithmetic. We don't want to set the
// USE of EAX to POINTER in this case, so we will conservatively skip
// all lea instructions here.
// We cannot be sure that a register is truly a base register unless
// there is also an index register. E.g. with reg+displacement, we
// could have memaddr+indexreg or basereg+offset, depending on what
// the displacement is. The exception is if there is no offset and only
// one addressing register, e.g. mov eax,[ebx].
if (BaseOpnd.is_reg(MD_STACK_POINTER_REG) || (UseFP && BaseOpnd.is_reg(MD_FRAME_POINTER_REG))
|| leaInst || (!HasIndexReg && !SingleAddressReg)) {
#endif
this->Uses.SetRef(BaseOpnd, RefType);
} // end if R_none != BaseReg
} // end if (o_phrase or o_displ operand)
} // end for (all operands)
// The lea (load effective address) instruction looks as if it has
// a memory USE: lea ebx,[edx+esi]
// However, this instruction is really just: ebx := edx+esi
// Now that the above code has inserted the "addressing" registers
// into the USE list, we should remove the "memory USE".
if (leaInst) {
set<DefOrUse, LessDefUse>::iterator CurrUse;
for (CurrUse = this->GetFirstUse(); CurrUse != this->GetLastUse(); ++CurrUse) {
op_t UseOp = CurrUse->GetOp();
if ((o_mem <= UseOp.type) && (o_displ >= UseOp.type)) {
this->EraseUse(CurrUse);
this->USEMemOp = InitOp;
break;
}
}
}
// Next, handle repeat prefices in the instructions. The Intel REPE/REPZ prefix
// is just the text printed for SCAS/CMPS instructions that have a REP prefix.
// Only two distinct prefix codes are actually defined: REP and REPNE/REPNZ, and
// REPNE/REPNZ only applies to SCAS and CMPS instructions.
bool HasRepPrefix = (0 != (this->SMPcmd.auxpref & aux_rep));
bool HasRepnePrefix = (0 != (this->SMPcmd.auxpref & aux_repne));
if (HasRepPrefix && HasRepnePrefix)
SMP_msg("REP and REPNE both present at %lx %s\n", (unsigned long) this->GetAddr(), DisAsmText.GetDisAsm(this->GetAddr()));
if (HasRepPrefix || HasRepnePrefix) {
// All repeating instructions use ECX as the countdown register.
op_t BaseOpnd = InitOp;
BaseOpnd.type = o_reg; // Change type and reg fields
BaseOpnd.reg = R_cx;
BaseOpnd.clr_showed();
this->Defs.SetRef(BaseOpnd, NUMERIC);
this->Uses.SetRef(BaseOpnd, NUMERIC);
if ((opcode == NN_cmps) || (opcode == NN_scas) || (opcode == NN_movs) || (opcode == NN_stos)) {
// ESI and EDI are USEd and DEFed to point to source and dest strings for CMPS/MOVS.
// Only EDI is involved with SCAS/STOS.
op_t BaseOpnd = InitOp;
BaseOpnd.type = o_reg; // Change type and reg fields
BaseOpnd.clr_showed();
if ((opcode == NN_cmps) || (opcode == NN_movs)) {
BaseOpnd.reg = R_si;
this->Defs.SetRef(BaseOpnd, POINTER);
this->Uses.SetRef(BaseOpnd, POINTER);
}
BaseOpnd.reg = R_di;
this->Defs.SetRef(BaseOpnd, POINTER);
this->Uses.SetRef(BaseOpnd, POINTER);
else if ((NN_loopw <= opcode) && (NN_loopqne >= opcode)) {
op_t LoopCounterOp = InitOp;
LoopCounterOp.type = o_reg;
LoopCounterOp.reg = R_cx;
this->Defs.SetRef(LoopCounterOp, NUMERIC);
this->Uses.SetRef(LoopCounterOp, NUMERIC);
}
// Now, handle special instruction categories that have implicit operands.
if (NN_cmpxchg == opcode) {
// 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, false);
} // 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, false);
this->MDAddRegUse(R_sp, false);
// We always reference [esp+0] or [esp-4], so add it to the DEF or USE list.
op_t StackOp = InitOp;
StackOp.type = o_displ;
StackOp.reg = R_sp;
SetOperandWidthToProcessorWidth(StackOp);
if (this->MDIsPopInstr()) {
StackOp.addr = 0; // [ESP+0]
this->Uses.SetRef(StackOp); // USE
}
else {
StackOp.addr = (ea_t) -STARS_ISA_Bytewidth; // [ESP-4]
this->Defs.SetRef(StackOp); // DEF
}
clc5q
committed
else if ((this->type == CALL) || (this->type == INDIR_CALL) || this->IsTailCall()) {
// We want to add the caller-saved registers to the USEs and DEFs lists
this->MDAddRegDef(R_ax, false);
this->MDAddRegDef(R_cx, false);
this->MDAddRegDef(R_dx, false);
this->MDAddRegUse(R_ax, false);
this->MDAddRegUse(R_cx, false);
this->MDAddRegUse(R_dx, false);
#if 1
if (this->MDIsInterruptCall()) {
#endif
this->MDAddRegDef(R_bx, false);
this->MDAddRegUse(R_bx, false);
this->MDAddRegDef(R_si, false);
this->MDAddRegUse(R_si, false);
}
#endif
else if (this->MDIsEnterInstr() || this->MDIsLeaveInstr()) {
// Entire function prologue or epilogue microcoded.
this->MDAddRegDef(MD_STACK_POINTER_REG, false);
this->MDAddRegUse(MD_STACK_POINTER_REG, false);
this->MDAddRegDef(MD_FRAME_POINTER_REG, false);
this->MDAddRegUse(MD_FRAME_POINTER_REG, false);
else if ((opcode == NN_maskmovq) || (opcode == NN_maskmovdqu)) {
else if (8 == this->GetOptType()) {
// This category implicitly writes to EDX:EAX.
this->MDAddRegDef(R_dx, false);
this->MDAddRegDef(R_ax, false);
} // 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).
for (OpNum = 0; OpNum < UA_MAXOP; ++OpNum) {
op_t TempUse = this->SMPcmd.Operands[OpNum];
if (!TempUse.showed()) { // hidden operand
if (TempUse.is_reg(R_ax)) { // not R_al, so it is not 8 bits
if ((NN_div == this->SMPcmd.itype) || (NN_idiv == this->SMPcmd.itype)) {
this->MDAddRegUse(R_dx, false);
}
this->MDAddRegDef(R_ax, false);
this->MDAddRegDef(R_dx, false);
}
}
}
} // end else if (7 == OptType)
#if 0
// The floating point instructions in type categories 14 and 15 often USE and DEF
// the floating point register stack, e.g. pushing a value onto that stack is a
// massive copy downward of stack locations. We don't really care about the USE of
// the stack if the value being pushed came from elsewhere than the stack. For example,
// an "fld" opcode pushes its source onto the stack. We build RTLs with a simple
// move structure, but the RTL building can be fooled by seeing two "source" operands
// in the USE list.
if ((14 == SMPTypeCategory[this->SMPcmd.itype])
|| (15 == SMPTypeCategory[this->SMPcmd.itype])) {
}
#endif
clc5q
committed
#if 0 // Not true for LOOP instructions that use only the ECX counter register.
if (this->type == COND_BRANCH) {
assert(SMPUsesFlags[opcode]);
clc5q
committed
#endif
// The return value register EAX is not quite like a caller-save or callee-save
// register (technically, it is caller-save). Within a callee, it might appear
// that EAX has become dead by the time a return instruction is reached, but
// the USE that would make it not dead is in the caller. To prevent type inference
// from mistakenly thinking that all USEs of EAX have been seen in the callee,
// we add EAX to the USE list for all return instructions, as well as for all
// tail calls, which are essentially returns in terms of data flow analysis.
// This USE of EAX will always be of type UNINIT unless its DEF has a known type
// that propagates to it. Thus, it will prevent an invalid back inference of the
// DEF type from "all" USE types that are visible in the callee; even if they
// were all NUMERIC, this return USE will be UNINIT and inhibit the invalid
// type inference. EAX could be loaded with a pointer from memory, for example,
// and USEd only in a comparison instruction, making it falsely appear to be
// a NUMERIC, without this extra USE at the return instruction.
// Because some of the library functions pass values around in EBX, EDI, etc.,
// we will add these general purpose registers to the USE list for returns
// in order to prevent erroneous analyses of dead registers or unused
// metadata.
if ((this->type == RETURN) || this->IsTailCall()) {
this->MDAddRegUse(R_ax, false);
this->MDAddRegUse(R_bx, false);
this->MDAddRegUse(R_cx, false);
this->MDAddRegUse(R_dx, false);
this->MDAddRegUse(MD_FRAME_POINTER_REG, false);
this->MDAddRegUse(R_si, false);
this->MDAddRegUse(R_di, false);
}
clc5q
committed
// Next, add the flags register to the DEFs and USEs for those instructions that
// are marked as defining or using flags.
if (!this->IsDefsFlags() && SMPDefsFlags[opcode]) {
this->MDAddRegDef(X86_FLAGS_REG, false);
this->SetDefsFlags();
if (!this->IsUsesFlags() && SMPUsesFlags[opcode]) {
this->MDAddRegUse(X86_FLAGS_REG, false);
this->SetUsesFlags();
}
if (this->IsNop()) {
// Clear the DEFs and USEs for no-ops.
// These include machine idioms for no-ops, e.g. mov esi,esi
// or xchg ax,ax or lea esi,[esi].
this->Defs.clear();
this->Uses.clear();
this->MoveSource = InitOp;
this->DEFMemOp = InitOp;
this->USEMemOp = InitOp;
this->OptType = 1;
}
#endif
clc5q
committed
SMP_msg("DEBUG after MDFixupDefUseLists:\n");
return;
} // end of SMPInstr::MDFixupDefUseLists()
// If we can definitely identify which part of the addressing expression
// used in MemOp is the POINTER type, and it is not a STACKPTR or GLOBALPTR
// immediate, set the USE type for that register to POINTER and return true.
// If we can find definite NUMERIC addressing registers that are not already
// typed as NUMERIC, set their USE types to NUMERIC and return true.
bool SMPInstr::MDFindPointerUse(op_t MemOp, bool UseFP) {
bool changed = false;
int BaseReg;
int IndexReg;
op_t BaseOp = InitOp;
op_t IndexOp = InitOp;
SMPOperandType BaseType = UNKNOWN;
SMPOperandType IndexType = UNKNOWN;
ushort ScaleFactor;
ea_t offset;
set<DefOrUse, LessDefUse>::iterator BaseIter;
set<DefOrUse, LessDefUse>::iterator IndexIter;
if (NN_lea == this->SMPcmd.itype)
return false; // lea instruction really has no memory operands
if (NN_fnop == this->SMPcmd.itype)
return false; // SSA marker instruction
MDExtractAddressFields(MemOp, BaseReg, IndexReg, ScaleFactor, offset);
if (R_none != IndexReg) {
IndexOp.type = o_reg;
IndexOp.reg = MDCanonicalizeSubReg((ushort) IndexReg);
IndexOp.dtyp = STARS_ISA_dtyp; // Canonical reg width
IndexIter = this->FindUse(IndexOp);
assert(IndexIter != this->GetLastUse());
IndexType = IndexIter->GetType();
}
if (R_none != BaseReg) {
BaseOp.type = o_reg;
BaseOp.reg = MDCanonicalizeSubReg((ushort) BaseReg);
BaseOp.dtyp = STARS_ISA_dtyp; // Canonical reg width
BaseIter = this->FindUse(BaseOp);
assert(BaseIter != this->GetLastUse());
BaseType = BaseIter->GetType();
}
if (MDIsStackPtrReg(BaseReg, UseFP)) {
if ((R_none != IndexReg) && (!IsNumeric(IndexType))) {
// We have an indexed access into the stack frame.
// Set IndexReg USE type to NUMERIC.
changed = true;
IndexIter = this->SetUseType(IndexOp, NUMERIC);
assert(IndexIter != this->GetLastUse());
}
return changed; // stack accesses will get STACKPTR type in SetImmedTypes()
}
if (MDIsStackPtrReg(IndexReg, UseFP)) {
if ((R_none != BaseReg) && (!IsNumeric(BaseType))) {
// We have an indexed access into the stack frame.
// Set BaseReg USE type to NUMERIC.
// Note that BaseReg is really an IndexReg and vice versa.
changed = true;
BaseIter = this->SetUseType(BaseOp, NUMERIC);
assert(BaseIter != this->GetLastUse());
clc5q
committed
SMP_msg("WARNING: BaseReg is index, IndexReg is base: %s\n",
DisAsmText.GetDisAsm(this->GetAddr()));
}
return changed; // stack accesses will get STACKPTR type in SetImmedTypes()
}
if (IsImmedGlobalAddress(offset)) {
if ((R_none != IndexReg) && (!IsNumeric(IndexType))) {
// We have an indexed access into a global.
// Set IndexReg USE type to NUMERIC.
changed = true;
IndexIter = this->SetUseType(IndexOp, NUMERIC);
assert(IndexIter != this->GetLastUse());
}
if ((R_none != BaseReg) && (!IsNumeric(BaseType))) {
// We have an indexed access into a global.
// Set BaseReg USE type to NUMERIC.
// Note that BaseReg is really an index register.
changed = true;
BaseIter = this->SetUseType(BaseOp, NUMERIC);
assert(BaseIter != this->GetLastUse());
clc5q
committed
SMP_msg("WARNING: BaseReg used as index: %s\n", DisAsmText.GetDisAsm(this->GetAddr()));
clc5q
committed
return changed; // global immediate is handled in SetImmedTypes()
// At this point, we must have a base address in a register, not used
// to directly address the stack or a global.
if ((0 < ScaleFactor) || (R_none == IndexReg)) {
// IndexReg is scaled, meaning it is NUMERIC, so BaseReg must
// be a POINTER; or IndexReg is not present, so BaseReg is the
// only possible holder of an address.
if (R_none != BaseReg) {
if (UNINIT == BaseIter->GetType()) {
changed = true;
BaseIter = this->SetUseType(BaseOp, POINTER);
assert(BaseIter != this->GetLastUse());
}
}
}
else if (R_none == BaseReg) {
// We have an unscaled IndexReg and no BaseReg and offset was
// not a global offset, so IndexReg must be a POINTER.
if (R_none != IndexReg) {
changed = true;
IndexIter = this->SetUseType(IndexOp, POINTER);
assert(IndexIter != this->GetLastUse());
}
}
}
else { // We have BaseReg and an unscaled IndexReg.
// The only hope for typing something like [ebx+edx] is for
// one register to already be typed NUMERIC, in which case
// the other one must be a POINTER, or if one register is
// already POINTER, then the other one must be NUMERIC.
if (IsNumeric(BaseType)) {
if (UNINIT == IndexType) {
// Set to POINTER or PROF_POINTER
changed = true;
IndexIter = this->SetUseType(IndexOp, POINTER);
assert(IndexIter != this->GetLastUse());
}
else if (IsNumeric(IndexType)) {
SMP_msg("ERROR: BaseReg and IndexReg both NUMERIC at %lx: %s\n",
(unsigned long) this->address, DisAsmText.GetDisAsm(this->GetAddr()));
}
}
else { // BaseReg was not NUMERIC
if (UNINIT == BaseType) { // BaseReg is UNINIT
if (IsNumeric(IndexType)) {
changed = true;
BaseIter = this->SetUseType(BaseOp, POINTER);
assert(BaseIter != this->GetLastUse());
}
else if (IsDataPtr(IndexType)) {
// IndexReg is POINTER, so make BaseReg NUMERIC.
changed = true;
BaseIter = this->SetUseType(BaseOp, NUMERIC);
assert(BaseIter != this->GetLastUse());
}
}
else if (IsDataPtr(BaseType)) {
// BaseReg was a pointer type. IndexReg must be NUMERIC.
if (UNINIT == IndexType) {
changed = true;
IndexIter = this->SetUseType(IndexOp, NUMERIC);
assert(IndexIter != this->GetLastUse());
}
else if (IsDataPtr(IndexType)) {
SMP_msg("ERROR: BaseReg and IndexReg both POINTER at %lx: %s\n",
(unsigned long) this->address, DisAsmText.GetDisAsm(this->GetAddr()));
}
}
}
}
return changed;
} // end of SMPInstr::MDFindPointerUse()
clc5q
committed
// Are all DEFs typed to something besides UNINIT?
bool SMPInstr::AllDEFsTyped(void) {
if (this->AreDEFsTyped()) {
return true;
}
clc5q
committed
bool FoundUNINIT = false;
set<DefOrUse, LessDefUse>::iterator DefIter;
for (DefIter = this->GetFirstDef(); DefIter != this->GetLastDef(); ++DefIter) {
if (IsEqType(UNINIT, DefIter->GetType())) {
FoundUNINIT = true;
break;
}
}
if (!FoundUNINIT) {
this->SetDEFsTyped();
}
clc5q
committed
return (!FoundUNINIT);
} // end of SMPInstr::AllDEFsTyped()
// Are all USEs typed to something besides UNINIT?
bool SMPInstr::AllUSEsTyped(void) {
if (this->AreUSEsTyped()) {
return true;
}
clc5q
committed
bool FoundUNINIT = false;
set<DefOrUse, LessDefUse>::iterator UseIter;
for (UseIter = this->GetFirstUse(); UseIter != this->GetLastUse(); ++UseIter) {
if (IsEqType(UNINIT, UseIter->GetType())) {
FoundUNINIT = true;
break;
}
}
if (!FoundUNINIT) {
this->SetUSEsTyped();
}
clc5q
committed
return (!FoundUNINIT);
} // end of SMPInstr::AllUSEsTyped()
// Return true if UseOp is a USE reg, not just an address reg in a memory USE
clc5q
committed
bool SMPInstr::IsNonAddressReg(op_t UseOp) const {
bool FoundUse = false;
ushort SearchReg = MDCanonicalizeSubReg(UseOp.reg);
for (size_t OpNum = 0; OpNum < UA_MAXOP; ++OpNum) {
op_t Opnd = this->SMPcmd.Operands[OpNum];
if (this->features & UseMacros[OpNum]) { // USE
if (Opnd.type == o_reg) {
ushort TestReg = MDCanonicalizeSubReg(Opnd.reg);
if (TestReg == SearchReg) {
FoundUse = true;
break;
}
}
}
}
return FoundUse;
} // end of SMPInstr::IsNonAddressReg()
uval_t SMPInstr::MDGetShiftCount(void) const {
uval_t ShiftCount = 0;
if (this->MDIsShiftOrRotate()) {
SMPRegTransfer *CurrRT = this->RTL.GetRT(0);
assert(CurrRT->HasRightSubTree());
CurrRT = CurrRT->GetRightTree();
op_t ShiftCountOp = CurrRT->GetRightOperand();
if (o_imm == ShiftCountOp.type) {
ShiftCount = ShiftCountOp.value;
}
}
return ShiftCount;
} // end of SMPInstr::MDGetShiftCount()
clc5q
committed
// RTL shows DEF operand is subreg.
bool SMPInstr::IsReducedWidthDef(void) const {
SMPRegTransfer *CurrRT = this->RTL.GetRT(0);
op_t DefOp = CurrRT->GetLeftOperand();
return ((o_void != DefOp.type) && (DefOp.dtyp < 2));
}
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
// Is a sub-register of UseOp used as a shift counter in the RTL?
// For example, UseOp could be ECX on an x86 machine, and CL
// could be used as a shift or rotate counter.
bool SMPInstr::IsSubRegUsedAsShiftCount(op_t UseOp) {
bool ShiftCounter = false;
if ((o_reg == UseOp.type) && this->MDIsShiftOrRotate()) {
SMPRegTransfer *CurrRT = this->RTL.GetRT(0);
assert(CurrRT->HasRightSubTree());
CurrRT = CurrRT->GetRightTree();
op_t ShiftCountOp = CurrRT->GetRightOperand();
if (o_reg == ShiftCountOp.type) {
ushort UseReg = UseOp.reg;
ushort ShiftCountReg = ShiftCountOp.reg;
ushort WideUseReg = MDCanonicalizeSubReg(UseReg);
ushort WideShiftCountReg = MDCanonicalizeSubReg(ShiftCountReg);
if ((UseReg != ShiftCountReg) && (WideUseReg == WideShiftCountReg)) {
// Registers were not equal, but their canonical enclosing
// registers are equal. Because shift counters that are not
// immediate are the 8-bit subregister in x86 (MD here !!!!!!)
// it must be that the ShiftCountReg is a subreg of UseReg.
// This is the condition we are looking for.
ShiftCounter = true;
}
}
}
return ShiftCounter;
} // end of SMPInstr::IsSubRegUsedAsShiftCount()
// Does UseOp ultimately come from a small positive constant?
bool SMPInstr::IsOpSourceSmallPositiveConstant(op_t UseOp, int UseSSANum) {
bool UseFP = this->GetBlock()->GetFunc()->UsesFramePointer();
if ((UseSSANum == -1) || (!MDIsDataFlowOpnd(UseOp, UseFP))) {
clc5q
committed
return false;
}
clc5q
committed
bool FoundSmallConst = false;
bool RegDef = (o_reg == UseOp.type);
bool LocalName = this->GetBlock()->IsLocalName(UseOp);
clc5q
committed
bool IndirectMemAccess = MDIsIndirectMemoryOpnd(UseOp, UseFP);
bool AboveStackFrame = (!RegDef && !IndirectMemAccess && (this->GetBlock()->GetFunc()->WritesAboveLocalFrame(UseOp, this->AreDefsNormalized())));
ea_t UseAddr = this->GetAddr();
ea_t FirstFuncAddr = this->GetBlock()->GetFunc()->GetFirstFuncAddr();
clc5q
committed
ea_t UseDefAddr = this->GetBlock()->GetDefAddrFromUseAddr(UseOp, UseAddr, UseSSANum, LocalName);
bool UpExposedUse = (UseDefAddr == (this->GetBlock()->GetFirstAddr() - 1));
clc5q
committed
if (!LocalName && !AboveStackFrame && !IndirectMemAccess && ((UseDefAddr == BADADDR) || UpExposedUse)) {
// Try to find in the function level.
UseDefAddr = this->GetBlock()->GetFunc()->GetGlobalDefAddr(UseOp, UseSSANum);
}
if ((UseDefAddr == (FirstFuncAddr - 1)) || AboveStackFrame
clc5q
committed
|| (UseDefAddr == BADADDR) || IndirectMemAccess) {
// Cannot search for general memory DEFs; must be stack or register.
// FirstFuncAddr - 1 signifies the pseudo-inst to hold DEFs of regs
// that are LiveIn to the function; pseudo-inst is not a bitwise not.
// First block addr - 1 is pseudo-location that indicates live-in, UpExposed,
// and LocalName means we will not find a DEF anywhere besides this block.
// AboveStackFrame means an incoming arg, whose DEF will not be seen.
clc5q
committed
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
else if (UseDefAddr < this->GetBlock()->GetFunc()->GetNumBlocks()) {
// A block number was returned. That means the DEF is in a Phi Function.
// We could trace all Phi USEs and see if all of them come from small constants
// but we only need one of the Phi USEs to come from
// a small constant to potentially lead to a false positive numeric error. We
// will recurse on all Phi USEs, declaring success if we find a single one of them
// to come from a small constant.
size_t BlockNum = (size_t) UseDefAddr;
assert(!LocalName);
SMPBasicBlock *PhiDefBlock = this->GetBlock()->GetFunc()->GetBlockByNum(BlockNum);
assert(NULL != PhiDefBlock);
if (!PhiDefBlock->IsProcessed()) { // Prevent infinite recursion
set<SMPPhiFunction, LessPhi>::iterator DefPhiIter = PhiDefBlock->FindPhi(UseOp);
assert(DefPhiIter != PhiDefBlock->GetLastPhi());
size_t PhiListSize = DefPhiIter->GetPhiListSize();
PhiDefBlock->SetProcessed(true); // Prevent infinite recursion
for (size_t UseIndex = 0; UseIndex < PhiListSize; ++UseIndex) {
int PhiUseSSANum = DefPhiIter->GetUseSSANum(UseIndex);
if (this->IsOpSourceSmallPositiveConstant(UseOp, PhiUseSSANum)) {
FoundSmallConst = true; // only one success on all Phi USEs is needed
break;
}
}
}
}
else {
bool ValueFound;
uval_t ConstValue;
SMPInstr *DefInst = this->GetBlock()->GetFunc()->GetInstFromAddr(UseDefAddr);
if (DefInst->MDIsSimpleAssignment(ValueFound, ConstValue)) {
FoundSmallConst = (ValueFound && (ConstValue <= 2));
if (!FoundSmallConst && !ValueFound && DefInst->MDIsMoveInstr()) {
// We have a non-immediate move. Trace back through move source to find small const.
op_t CopyUseOp = DefInst->GetMoveSource();
CanonicalizeOpnd(CopyUseOp);
set<DefOrUse, LessDefUse>::iterator UseIter = DefInst->FindUse(CopyUseOp);
assert(UseIter != DefInst->GetLastUse());
int CopyUseSSANum = UseIter->GetSSANum();
FoundSmallConst = DefInst->IsOpSourceSmallPositiveConstant(CopyUseOp, CopyUseSSANum);
}
}
}
return FoundSmallConst;
} // end of SMPInstr::IsOpSourceSmallPositiveConstant()
// Does UseOp ultimately come from a bitwise not instruction?
bool SMPInstr::IsOpSourceBitwiseNot(op_t UseOp, int UseSSANum) {
bool UseFP = this->GetBlock()->GetFunc()->UsesFramePointer();
if ((UseSSANum == -1) || (!MDIsDataFlowOpnd(UseOp, UseFP))) {
return false;
}
bool FoundBitwiseNotInst = false;
bool RegDef = (o_reg == UseOp.type);
bool LocalName = this->GetBlock()->IsLocalName(UseOp);
clc5q
committed
bool IndirectMemAccess = MDIsIndirectMemoryOpnd(UseOp, UseFP);
bool AboveStackFrame = (!RegDef && !IndirectMemAccess && (this->GetBlock()->GetFunc()->WritesAboveLocalFrame(UseOp, this->AreDefsNormalized())));
ea_t UseAddr = this->GetAddr();
ea_t FirstFuncAddr = this->GetBlock()->GetFunc()->GetFirstFuncAddr();
ea_t UseDefAddr = this->GetBlock()->GetDefAddrFromUseAddr(UseOp, UseAddr, UseSSANum, LocalName);
bool UpExposedUse = (UseDefAddr == (this->GetBlock()->GetFirstAddr() - 1));
if (!LocalName && !AboveStackFrame && !IndirectMemAccess && ((UseDefAddr == BADADDR) || UpExposedUse)) {
// Try to find in the function level.
UseDefAddr = this->GetBlock()->GetFunc()->GetGlobalDefAddr(UseOp, UseSSANum);
}
if ((UseDefAddr == (FirstFuncAddr - 1)) || AboveStackFrame
|| (UseDefAddr == BADADDR) || IndirectMemAccess) {
// Cannot search for general memory DEFs; must be stack or register.
// FirstFuncAddr - 1 signifies the pseudo-inst to hold DEFs of regs
// that are LiveIn to the function; pseudo-inst is not a bitwise not.
// First block addr - 1 is pseudo-location that indicates live-in, UpExposed,
// and LocalName means we will not find a DEF anywhere besides this block.
// AboveStackFrame means an incoming arg, whose DEF will not be seen.
FoundBitwiseNotInst = false;
}
else if (UseDefAddr < this->GetBlock()->GetFunc()->GetNumBlocks()) {
// A block number was returned. That means the DEF is in a Phi Function.
clc5q
committed
// We could trace all Phi USEs and see if all of them come from bitwise nots
// but we only need one of the Phi USEs to come from
clc5q
committed
// a bitwise not to potentially lead to a false positive numeric error. We
// will recurse on all Phi USEs, declaring success if we find a single one of them
clc5q
committed
// to come from a bitwise not.
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
size_t BlockNum = (size_t) UseDefAddr;
assert(!LocalName);
SMPBasicBlock *PhiDefBlock = this->GetBlock()->GetFunc()->GetBlockByNum(BlockNum);
assert(NULL != PhiDefBlock);
if (!PhiDefBlock->IsProcessed()) { // Prevent infinite recursion
set<SMPPhiFunction, LessPhi>::iterator DefPhiIter = PhiDefBlock->FindPhi(UseOp);
assert(DefPhiIter != PhiDefBlock->GetLastPhi());
size_t PhiListSize = DefPhiIter->GetPhiListSize();
PhiDefBlock->SetProcessed(true); // Prevent infinite recursion
for (size_t UseIndex = 0; UseIndex < PhiListSize; ++UseIndex) {
int PhiUseSSANum = DefPhiIter->GetUseSSANum(UseIndex);
if (this->IsOpSourceBitwiseNot(UseOp, PhiUseSSANum)) {
FoundBitwiseNotInst = true; // only one success on all Phi USEs is needed
break;
}
}
}
}
else {
SMPInstr *DefInst = this->GetBlock()->GetFunc()->GetInstFromAddr(UseDefAddr);
if (DefInst->MDIsBitwiseNotOpcode()) {
FoundBitwiseNotInst = true;
}
else if (DefInst->MDIsMoveInstr()) {
op_t MoveUseOp = DefInst->GetMoveSource();
clc5q
committed
if (MDIsDataFlowOpnd(MoveUseOp, UseFP)) { // pattern is simple; don't try to follow through non-stack memory
CanonicalizeOpnd(MoveUseOp);
set<DefOrUse, LessDefUse>::iterator MoveUseIter = DefInst->FindUse(MoveUseOp);
assert(MoveUseIter != DefInst->GetLastUse());
int MoveUseSSANum = MoveUseIter->GetSSANum();
FoundBitwiseNotInst = DefInst->IsOpSourceBitwiseNot(MoveUseOp, MoveUseSSANum); // recurse
}
}
else {
// Not a move, not a bitwise not. We must return false.
FoundBitwiseNotInst = false;
}
}
return FoundBitwiseNotInst;
} // end of SMPInstr::IsOpSourceBitwiseNot()
clc5q
committed
// Does UseOp ultimately come from a set-condition-code instruction?
bool SMPInstr::IsOpSourceConditionCode(op_t UseOp, int UseSSANum) {
bool UseFP = this->GetBlock()->GetFunc()->UsesFramePointer();
if ((UseSSANum == -1) || (!MDIsDataFlowOpnd(UseOp, UseFP))) {
clc5q
committed
return false;
}
clc5q
committed
bool FoundConditionalSetInst = false;
clc5q
committed
bool RegDef = (o_reg == UseOp.type);
clc5q
committed
bool LocalName = this->GetBlock()->IsLocalName(UseOp);
clc5q
committed
bool IndirectMemAccess = MDIsIndirectMemoryOpnd(UseOp, UseFP);
bool AboveStackFrame = (!RegDef && !IndirectMemAccess && (this->GetBlock()->GetFunc()->WritesAboveLocalFrame(UseOp, this->AreDefsNormalized())));
clc5q
committed
ea_t UseAddr = this->GetAddr();
ea_t FirstFuncAddr = this->GetBlock()->GetFunc()->GetFirstFuncAddr();
clc5q
committed
ea_t UseDefAddr = this->GetBlock()->GetDefAddrFromUseAddr(UseOp, UseAddr, UseSSANum, LocalName);
bool UpExposedUse = (UseDefAddr == (this->GetBlock()->GetFirstAddr() - 1));
clc5q
committed
clc5q
committed
if (!LocalName && !AboveStackFrame && !IndirectMemAccess && ((UseDefAddr == BADADDR) || UpExposedUse)) {
// Try to find in the function level.
UseDefAddr = this->GetBlock()->GetFunc()->GetGlobalDefAddr(UseOp, UseSSANum);
}
if ((UseDefAddr == (FirstFuncAddr - 1)) || AboveStackFrame
clc5q
committed
|| (UseDefAddr == BADADDR) || IndirectMemAccess) {
// Cannot search for general memory DEFs; must be stack or register.
// FirstFuncAddr - 1 signifies the pseudo-inst to hold DEFs of regs
clc5q
committed
// that are LiveIn to the function; pseudo-inst is not a bitwise not.
// First block addr - 1 is pseudo-location that indicates live-in, UpExposed,
// and LocalName means we will not find a DEF anywhere besides this block.
// AboveStackFrame means an incoming arg, whose DEF will not be seen.
FoundConditionalSetInst = false;
}
else if (UseDefAddr < this->GetBlock()->GetFunc()->GetNumBlocks()) {
// A block number was returned. That means the DEF is in a Phi Function.
// We could trace all Phi USEs and see if all of them come from condition codes
// but we only need one of the Phi USEs to come from
// a condition code to potentially lead to a false positive numeric error. We
// will recurse on all Phi USEs, declaring success if we find a single one of them
// to come from a condition code.
size_t BlockNum = (size_t) UseDefAddr;
assert(!LocalName);
SMPBasicBlock *PhiDefBlock = this->GetBlock()->GetFunc()->GetBlockByNum(BlockNum);
assert(NULL != PhiDefBlock);
if (!PhiDefBlock->IsProcessed()) { // Prevent infinite recursion
set<SMPPhiFunction, LessPhi>::iterator DefPhiIter = PhiDefBlock->FindPhi(UseOp);
assert(DefPhiIter != PhiDefBlock->GetLastPhi());
size_t PhiListSize = DefPhiIter->GetPhiListSize();
PhiDefBlock->SetProcessed(true); // Prevent infinite recursion
for (size_t UseIndex = 0; UseIndex < PhiListSize; ++UseIndex) {
int PhiUseSSANum = DefPhiIter->GetUseSSANum(UseIndex);
if (this->IsOpSourceConditionCode(UseOp, PhiUseSSANum)) {
FoundConditionalSetInst = true; // only one success on all Phi USEs is needed
break;
}
}
}
}
else {
SMPInstr *DefInst = this->GetBlock()->GetFunc()->GetInstFromAddr(UseDefAddr);
if (DefInst->MDIsAnySetValue()) {
FoundConditionalSetInst = true;
clc5q
committed
}
else if (DefInst->MDIsMoveInstr()) {
op_t MoveUseOp = DefInst->GetMoveSource();
clc5q
committed
if (MDIsDataFlowOpnd(MoveUseOp, UseFP)) { // pattern is simple; don't try to follow through non-stack memory
CanonicalizeOpnd(MoveUseOp);
set<DefOrUse, LessDefUse>::iterator MoveUseIter = DefInst->FindUse(MoveUseOp);
assert(MoveUseIter != DefInst->GetLastUse());
int MoveUseSSANum = MoveUseIter->GetSSANum();
FoundConditionalSetInst = DefInst->IsOpSourceConditionCode(MoveUseOp, MoveUseSSANum); // recurse
clc5q
committed
}
}
else {
// Not a move, not a condition code transfer. We must return false.
FoundConditionalSetInst = false;
}
}
return FoundConditionalSetInst;
} // end of SMPInstr::IsOpSourceConditionCode()
// Does UseOp ultimately come from a move-with-zero-extension instruction?
bool SMPInstr::IsOpSourceZeroExtendedMove(op_t UseOp, int UseSSANum, bool TruncationCheck) {
bool UseFP = this->GetBlock()->GetFunc()->UsesFramePointer();
if ((UseSSANum == -1) || (!MDIsDataFlowOpnd(UseOp, UseFP))) {
clc5q
committed
return false;
}
bool FoundMoveZX = false;
clc5q
committed
bool RegDef = (o_reg == UseOp.type);
bool LocalName = this->GetBlock()->IsLocalName(UseOp);
clc5q
committed
bool IndirectMemAccess = MDIsIndirectMemoryOpnd(UseOp, UseFP);
bool AboveStackFrame = (!RegDef && !IndirectMemAccess && (this->GetBlock()->GetFunc()->WritesAboveLocalFrame(UseOp, this->AreDefsNormalized())));
ea_t UseAddr = this->GetAddr();
ea_t FirstFuncAddr = this->GetBlock()->GetFunc()->GetFirstFuncAddr();
clc5q
committed
ea_t UseDefAddr = this->GetBlock()->GetDefAddrFromUseAddr(UseOp, UseAddr, UseSSANum, LocalName);
bool UpExposedUse = (UseDefAddr == (this->GetBlock()->GetFirstAddr() - 1));
clc5q
committed
if (!LocalName && !AboveStackFrame && !IndirectMemAccess && ((UseDefAddr == BADADDR) || UpExposedUse)) {
// Try to find in the function level.
UseDefAddr = this->GetBlock()->GetFunc()->GetGlobalDefAddr(UseOp, UseSSANum);
}
if ((UseDefAddr == (FirstFuncAddr - 1)) || AboveStackFrame
clc5q
committed
|| (UseDefAddr == BADADDR) || IndirectMemAccess) {
// Cannot search for general memory DEFs; must be stack or register.
// FirstFuncAddr - 1 signifies the pseudo-inst to hold DEFs of regs
clc5q
committed
// that are LiveIn to the function; pseudo-inst is not a bitwise not.
// First block addr - 1 is pseudo-location that indicates live-in, UpExposed,
// and LocalName means we will not find a DEF anywhere besides this block.
// AboveStackFrame means an incoming arg, whose DEF will not be seen.
FoundMoveZX = false;
}
else if (UseDefAddr < this->GetBlock()->GetFunc()->GetNumBlocks()) {
// A block number was returned. That means the DEF is in a Phi Function.
// We could trace all Phi USEs and see if all of them come from zero-extended
// moves into the UseOp register, but we only need one of the Phi USEs to come from
// a zero-extended move to potentially lead to a false positive numeric error. We
// will recurse on all Phi USEs, declaring success if we find a single one of them
// to come from a zero-extended move.
size_t BlockNum = (size_t) UseDefAddr;
assert(!LocalName);
SMPBasicBlock *PhiDefBlock = this->GetBlock()->GetFunc()->GetBlockByNum(BlockNum);
assert(NULL != PhiDefBlock);
if (!PhiDefBlock->IsProcessed()) { // Prevent infinite recursion
set<SMPPhiFunction, LessPhi>::iterator DefPhiIter = PhiDefBlock->FindPhi(UseOp);
assert(DefPhiIter != PhiDefBlock->GetLastPhi());
size_t PhiListSize = DefPhiIter->GetPhiListSize();
PhiDefBlock->SetProcessed(true); // Prevent infinite recursion
for (size_t UseIndex = 0; UseIndex < PhiListSize; ++UseIndex) {
int PhiUseSSANum = DefPhiIter->GetUseSSANum(UseIndex);
if (this->IsOpSourceZeroExtendedMove(UseOp, PhiUseSSANum, TruncationCheck)) {
FoundMoveZX = true; // only one success on all Phi USEs is needed
break;
clc5q
committed
}
}
}
}
else {
SMPInstr *DefInst = this->GetBlock()->GetFunc()->GetInstFromAddr(UseDefAddr);
unsigned short SignMask;
if (DefInst->MDIsSignedLoad(SignMask)) {
FoundMoveZX = (FG_MASK_UNSIGNED == SignMask);
}
else if (DefInst->MDIsMoveInstr()) {
op_t MoveUseOp = DefInst->GetMoveSource();
clc5q
committed
if (MDIsDataFlowOpnd(MoveUseOp, UseFP)) { // pattern is simple; don't try to follow through non-stack memory
CanonicalizeOpnd(MoveUseOp);