1 //===-- TargetLowering.cpp - Implement the TargetLowering class -----------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This implements the TargetLowering class.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Target/TargetLowering.h"
15 #include "llvm/Target/TargetSubtarget.h"
16 #include "llvm/Target/TargetData.h"
17 #include "llvm/Target/TargetMachine.h"
18 #include "llvm/Target/MRegisterInfo.h"
19 #include "llvm/DerivedTypes.h"
20 #include "llvm/CodeGen/SelectionDAG.h"
21 #include "llvm/ADT/StringExtras.h"
22 #include "llvm/ADT/STLExtras.h"
23 #include "llvm/Support/MathExtras.h"
24 #include "llvm/Target/TargetAsmInfo.h"
25 #include "llvm/CallingConv.h"
28 /// InitLibcallNames - Set default libcall names.
30 static void InitLibcallNames(const char **Names) {
31 Names[RTLIB::SHL_I32] = "__ashlsi3";
32 Names[RTLIB::SHL_I64] = "__ashldi3";
33 Names[RTLIB::SRL_I32] = "__lshrsi3";
34 Names[RTLIB::SRL_I64] = "__lshrdi3";
35 Names[RTLIB::SRA_I32] = "__ashrsi3";
36 Names[RTLIB::SRA_I64] = "__ashrdi3";
37 Names[RTLIB::MUL_I32] = "__mulsi3";
38 Names[RTLIB::MUL_I64] = "__muldi3";
39 Names[RTLIB::SDIV_I32] = "__divsi3";
40 Names[RTLIB::SDIV_I64] = "__divdi3";
41 Names[RTLIB::UDIV_I32] = "__udivsi3";
42 Names[RTLIB::UDIV_I64] = "__udivdi3";
43 Names[RTLIB::SREM_I32] = "__modsi3";
44 Names[RTLIB::SREM_I64] = "__moddi3";
45 Names[RTLIB::UREM_I32] = "__umodsi3";
46 Names[RTLIB::UREM_I64] = "__umoddi3";
47 Names[RTLIB::NEG_I32] = "__negsi2";
48 Names[RTLIB::NEG_I64] = "__negdi2";
49 Names[RTLIB::ADD_F32] = "__addsf3";
50 Names[RTLIB::ADD_F64] = "__adddf3";
51 Names[RTLIB::ADD_PPCF128] = "__gcc_qadd";
52 Names[RTLIB::SUB_F32] = "__subsf3";
53 Names[RTLIB::SUB_F64] = "__subdf3";
54 Names[RTLIB::SUB_PPCF128] = "__gcc_qsub";
55 Names[RTLIB::MUL_F32] = "__mulsf3";
56 Names[RTLIB::MUL_F64] = "__muldf3";
57 Names[RTLIB::MUL_PPCF128] = "__gcc_qmul";
58 Names[RTLIB::DIV_F32] = "__divsf3";
59 Names[RTLIB::DIV_F64] = "__divdf3";
60 Names[RTLIB::DIV_PPCF128] = "__gcc_qdiv";
61 Names[RTLIB::REM_F32] = "fmodf";
62 Names[RTLIB::REM_F64] = "fmod";
63 Names[RTLIB::REM_PPCF128] = "fmodl";
64 Names[RTLIB::NEG_F32] = "__negsf2";
65 Names[RTLIB::NEG_F64] = "__negdf2";
66 Names[RTLIB::POWI_F32] = "__powisf2";
67 Names[RTLIB::POWI_F64] = "__powidf2";
68 Names[RTLIB::POWI_F80] = "__powixf2";
69 Names[RTLIB::POWI_PPCF128] = "__powitf2";
70 Names[RTLIB::SQRT_F32] = "sqrtf";
71 Names[RTLIB::SQRT_F64] = "sqrt";
72 Names[RTLIB::SQRT_F80] = "sqrtl";
73 Names[RTLIB::SQRT_PPCF128] = "sqrtl";
74 Names[RTLIB::SIN_F32] = "sinf";
75 Names[RTLIB::SIN_F64] = "sin";
76 Names[RTLIB::COS_F32] = "cosf";
77 Names[RTLIB::COS_F64] = "cos";
78 Names[RTLIB::POW_F32] = "powf";
79 Names[RTLIB::POW_F64] = "pow";
80 Names[RTLIB::POW_F80] = "powl";
81 Names[RTLIB::POW_PPCF128] = "powl";
82 Names[RTLIB::FPEXT_F32_F64] = "__extendsfdf2";
83 Names[RTLIB::FPROUND_F64_F32] = "__truncdfsf2";
84 Names[RTLIB::FPTOSINT_F32_I32] = "__fixsfsi";
85 Names[RTLIB::FPTOSINT_F32_I64] = "__fixsfdi";
86 Names[RTLIB::FPTOSINT_F64_I32] = "__fixdfsi";
87 Names[RTLIB::FPTOSINT_F64_I64] = "__fixdfdi";
88 Names[RTLIB::FPTOSINT_F80_I64] = "__fixxfdi";
89 Names[RTLIB::FPTOSINT_PPCF128_I64] = "__fixtfdi";
90 Names[RTLIB::FPTOUINT_F32_I32] = "__fixunssfsi";
91 Names[RTLIB::FPTOUINT_F32_I64] = "__fixunssfdi";
92 Names[RTLIB::FPTOUINT_F64_I32] = "__fixunsdfsi";
93 Names[RTLIB::FPTOUINT_F64_I64] = "__fixunsdfdi";
94 Names[RTLIB::FPTOUINT_F80_I32] = "__fixunsxfsi";
95 Names[RTLIB::FPTOUINT_F80_I64] = "__fixunsxfdi";
96 Names[RTLIB::FPTOUINT_PPCF128_I64] = "__fixunstfdi";
97 Names[RTLIB::SINTTOFP_I32_F32] = "__floatsisf";
98 Names[RTLIB::SINTTOFP_I32_F64] = "__floatsidf";
99 Names[RTLIB::SINTTOFP_I64_F32] = "__floatdisf";
100 Names[RTLIB::SINTTOFP_I64_F64] = "__floatdidf";
101 Names[RTLIB::SINTTOFP_I64_F80] = "__floatdixf";
102 Names[RTLIB::SINTTOFP_I64_PPCF128] = "__floatditf";
103 Names[RTLIB::UINTTOFP_I32_F32] = "__floatunsisf";
104 Names[RTLIB::UINTTOFP_I32_F64] = "__floatunsidf";
105 Names[RTLIB::UINTTOFP_I64_F32] = "__floatundisf";
106 Names[RTLIB::UINTTOFP_I64_F64] = "__floatundidf";
107 Names[RTLIB::OEQ_F32] = "__eqsf2";
108 Names[RTLIB::OEQ_F64] = "__eqdf2";
109 Names[RTLIB::UNE_F32] = "__nesf2";
110 Names[RTLIB::UNE_F64] = "__nedf2";
111 Names[RTLIB::OGE_F32] = "__gesf2";
112 Names[RTLIB::OGE_F64] = "__gedf2";
113 Names[RTLIB::OLT_F32] = "__ltsf2";
114 Names[RTLIB::OLT_F64] = "__ltdf2";
115 Names[RTLIB::OLE_F32] = "__lesf2";
116 Names[RTLIB::OLE_F64] = "__ledf2";
117 Names[RTLIB::OGT_F32] = "__gtsf2";
118 Names[RTLIB::OGT_F64] = "__gtdf2";
119 Names[RTLIB::UO_F32] = "__unordsf2";
120 Names[RTLIB::UO_F64] = "__unorddf2";
121 Names[RTLIB::O_F32] = "__unordsf2";
122 Names[RTLIB::O_F64] = "__unorddf2";
125 /// InitCmpLibcallCCs - Set default comparison libcall CC.
127 static void InitCmpLibcallCCs(ISD::CondCode *CCs) {
128 memset(CCs, ISD::SETCC_INVALID, sizeof(ISD::CondCode)*RTLIB::UNKNOWN_LIBCALL);
129 CCs[RTLIB::OEQ_F32] = ISD::SETEQ;
130 CCs[RTLIB::OEQ_F64] = ISD::SETEQ;
131 CCs[RTLIB::UNE_F32] = ISD::SETNE;
132 CCs[RTLIB::UNE_F64] = ISD::SETNE;
133 CCs[RTLIB::OGE_F32] = ISD::SETGE;
134 CCs[RTLIB::OGE_F64] = ISD::SETGE;
135 CCs[RTLIB::OLT_F32] = ISD::SETLT;
136 CCs[RTLIB::OLT_F64] = ISD::SETLT;
137 CCs[RTLIB::OLE_F32] = ISD::SETLE;
138 CCs[RTLIB::OLE_F64] = ISD::SETLE;
139 CCs[RTLIB::OGT_F32] = ISD::SETGT;
140 CCs[RTLIB::OGT_F64] = ISD::SETGT;
141 CCs[RTLIB::UO_F32] = ISD::SETNE;
142 CCs[RTLIB::UO_F64] = ISD::SETNE;
143 CCs[RTLIB::O_F32] = ISD::SETEQ;
144 CCs[RTLIB::O_F64] = ISD::SETEQ;
147 TargetLowering::TargetLowering(TargetMachine &tm)
148 : TM(tm), TD(TM.getTargetData()) {
149 assert(ISD::BUILTIN_OP_END <= 156 &&
150 "Fixed size array in TargetLowering is not large enough!");
151 // All operations default to being supported.
152 memset(OpActions, 0, sizeof(OpActions));
153 memset(LoadXActions, 0, sizeof(LoadXActions));
154 memset(&StoreXActions, 0, sizeof(StoreXActions));
155 memset(&IndexedModeActions, 0, sizeof(IndexedModeActions));
156 memset(&ConvertActions, 0, sizeof(ConvertActions));
158 // Set default actions for various operations.
159 for (unsigned VT = 0; VT != (unsigned)MVT::LAST_VALUETYPE; ++VT) {
160 // Default all indexed load / store to expand.
161 for (unsigned IM = (unsigned)ISD::PRE_INC;
162 IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) {
163 setIndexedLoadAction(IM, (MVT::ValueType)VT, Expand);
164 setIndexedStoreAction(IM, (MVT::ValueType)VT, Expand);
167 // These operations default to expand.
168 setOperationAction(ISD::FGETSIGN, (MVT::ValueType)VT, Expand);
171 IsLittleEndian = TD->isLittleEndian();
172 UsesGlobalOffsetTable = false;
173 ShiftAmountTy = SetCCResultTy = PointerTy = getValueType(TD->getIntPtrType());
174 ShiftAmtHandling = Undefined;
175 memset(RegClassForVT, 0,MVT::LAST_VALUETYPE*sizeof(TargetRegisterClass*));
176 memset(TargetDAGCombineArray, 0, array_lengthof(TargetDAGCombineArray));
177 maxStoresPerMemset = maxStoresPerMemcpy = maxStoresPerMemmove = 8;
178 allowUnalignedMemoryAccesses = false;
179 UseUnderscoreSetJmp = false;
180 UseUnderscoreLongJmp = false;
181 SelectIsExpensive = false;
182 IntDivIsCheap = false;
183 Pow2DivIsCheap = false;
184 StackPointerRegisterToSaveRestore = 0;
185 ExceptionPointerRegister = 0;
186 ExceptionSelectorRegister = 0;
187 SetCCResultContents = UndefinedSetCCResult;
188 SchedPreferenceInfo = SchedulingForLatency;
190 JumpBufAlignment = 0;
191 IfCvtBlockSizeLimit = 2;
193 InitLibcallNames(LibcallRoutineNames);
194 InitCmpLibcallCCs(CmpLibcallCCs);
196 // Tell Legalize whether the assembler supports DEBUG_LOC.
197 if (!TM.getTargetAsmInfo()->hasDotLocAndDotFile())
198 setOperationAction(ISD::DEBUG_LOC, MVT::Other, Expand);
201 TargetLowering::~TargetLowering() {}
204 SDOperand TargetLowering::LowerMEMCPY(SDOperand Op, SelectionDAG &DAG) {
205 assert(getSubtarget() && "Subtarget not defined");
206 SDOperand ChainOp = Op.getOperand(0);
207 SDOperand DestOp = Op.getOperand(1);
208 SDOperand SourceOp = Op.getOperand(2);
209 SDOperand CountOp = Op.getOperand(3);
210 SDOperand AlignOp = Op.getOperand(4);
211 SDOperand AlwaysInlineOp = Op.getOperand(5);
213 bool AlwaysInline = (bool)cast<ConstantSDNode>(AlwaysInlineOp)->getValue();
214 unsigned Align = (unsigned)cast<ConstantSDNode>(AlignOp)->getValue();
215 if (Align == 0) Align = 1;
217 // If size is unknown, call memcpy.
218 ConstantSDNode *I = dyn_cast<ConstantSDNode>(CountOp);
220 assert(!AlwaysInline && "Cannot inline copy of unknown size");
221 return LowerMEMCPYCall(ChainOp, DestOp, SourceOp, CountOp, DAG);
224 // If not DWORD aligned or if size is more than threshold, then call memcpy.
225 // The libc version is likely to be faster for the following cases. It can
226 // use the address value and run time information about the CPU.
227 // With glibc 2.6.1 on a core 2, coping an array of 100M longs was 30% faster
228 unsigned Size = I->getValue();
230 (Size <= getSubtarget()->getMaxInlineSizeThreshold() &&
232 return LowerMEMCPYInline(ChainOp, DestOp, SourceOp, Size, Align, DAG);
233 return LowerMEMCPYCall(ChainOp, DestOp, SourceOp, CountOp, DAG);
237 SDOperand TargetLowering::LowerMEMCPYCall(SDOperand Chain,
242 MVT::ValueType IntPtr = getPointerTy();
243 TargetLowering::ArgListTy Args;
244 TargetLowering::ArgListEntry Entry;
245 Entry.Ty = getTargetData()->getIntPtrType();
246 Entry.Node = Dest; Args.push_back(Entry);
247 Entry.Node = Source; Args.push_back(Entry);
248 Entry.Node = Count; Args.push_back(Entry);
249 std::pair<SDOperand,SDOperand> CallResult =
250 LowerCallTo(Chain, Type::VoidTy, false, false, CallingConv::C, false,
251 DAG.getExternalSymbol("memcpy", IntPtr), Args, DAG);
252 return CallResult.second;
256 /// computeRegisterProperties - Once all of the register classes are added,
257 /// this allows us to compute derived properties we expose.
258 void TargetLowering::computeRegisterProperties() {
259 assert(MVT::LAST_VALUETYPE <= 32 &&
260 "Too many value types for ValueTypeActions to hold!");
262 // Everything defaults to needing one register.
263 for (unsigned i = 0; i != MVT::LAST_VALUETYPE; ++i) {
264 NumRegistersForVT[i] = 1;
265 RegisterTypeForVT[i] = TransformToType[i] = i;
267 // ...except isVoid, which doesn't need any registers.
268 NumRegistersForVT[MVT::isVoid] = 0;
270 // Find the largest integer register class.
271 unsigned LargestIntReg = MVT::i128;
272 for (; RegClassForVT[LargestIntReg] == 0; --LargestIntReg)
273 assert(LargestIntReg != MVT::i1 && "No integer registers defined!");
275 // Every integer value type larger than this largest register takes twice as
276 // many registers to represent as the previous ValueType.
277 for (MVT::ValueType ExpandedReg = LargestIntReg + 1;
278 MVT::isInteger(ExpandedReg); ++ExpandedReg) {
279 NumRegistersForVT[ExpandedReg] = 2*NumRegistersForVT[ExpandedReg-1];
280 RegisterTypeForVT[ExpandedReg] = LargestIntReg;
281 TransformToType[ExpandedReg] = ExpandedReg - 1;
282 ValueTypeActions.setTypeAction(ExpandedReg, Expand);
285 // Inspect all of the ValueType's smaller than the largest integer
286 // register to see which ones need promotion.
287 MVT::ValueType LegalIntReg = LargestIntReg;
288 for (MVT::ValueType IntReg = LargestIntReg - 1;
289 IntReg >= MVT::i1; --IntReg) {
290 if (isTypeLegal(IntReg)) {
291 LegalIntReg = IntReg;
293 RegisterTypeForVT[IntReg] = TransformToType[IntReg] = LegalIntReg;
294 ValueTypeActions.setTypeAction(IntReg, Promote);
298 // ppcf128 type is really two f64's.
299 if (!isTypeLegal(MVT::ppcf128)) {
300 NumRegistersForVT[MVT::ppcf128] = 2*NumRegistersForVT[MVT::f64];
301 RegisterTypeForVT[MVT::ppcf128] = MVT::f64;
302 TransformToType[MVT::ppcf128] = MVT::f64;
303 ValueTypeActions.setTypeAction(MVT::ppcf128, Expand);
306 // Decide how to handle f64. If the target does not have native f64 support,
307 // expand it to i64 and we will be generating soft float library calls.
308 if (!isTypeLegal(MVT::f64)) {
309 NumRegistersForVT[MVT::f64] = NumRegistersForVT[MVT::i64];
310 RegisterTypeForVT[MVT::f64] = RegisterTypeForVT[MVT::i64];
311 TransformToType[MVT::f64] = MVT::i64;
312 ValueTypeActions.setTypeAction(MVT::f64, Expand);
315 // Decide how to handle f32. If the target does not have native support for
316 // f32, promote it to f64 if it is legal. Otherwise, expand it to i32.
317 if (!isTypeLegal(MVT::f32)) {
318 if (isTypeLegal(MVT::f64)) {
319 NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::f64];
320 RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::f64];
321 TransformToType[MVT::f32] = MVT::f64;
322 ValueTypeActions.setTypeAction(MVT::f32, Promote);
324 NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::i32];
325 RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::i32];
326 TransformToType[MVT::f32] = MVT::i32;
327 ValueTypeActions.setTypeAction(MVT::f32, Expand);
331 // Loop over all of the vector value types to see which need transformations.
332 for (MVT::ValueType i = MVT::FIRST_VECTOR_VALUETYPE;
333 i <= MVT::LAST_VECTOR_VALUETYPE; ++i) {
334 if (!isTypeLegal(i)) {
335 MVT::ValueType IntermediateVT, RegisterVT;
336 unsigned NumIntermediates;
337 NumRegistersForVT[i] =
338 getVectorTypeBreakdown(i,
339 IntermediateVT, NumIntermediates,
341 RegisterTypeForVT[i] = RegisterVT;
342 TransformToType[i] = MVT::Other; // this isn't actually used
343 ValueTypeActions.setTypeAction(i, Expand);
348 const char *TargetLowering::getTargetNodeName(unsigned Opcode) const {
352 /// getVectorTypeBreakdown - Vector types are broken down into some number of
353 /// legal first class types. For example, MVT::v8f32 maps to 2 MVT::v4f32
354 /// with Altivec or SSE1, or 8 promoted MVT::f64 values with the X86 FP stack.
355 /// Similarly, MVT::v2i64 turns into 4 MVT::i32 values with both PPC and X86.
357 /// This method returns the number of registers needed, and the VT for each
358 /// register. It also returns the VT and quantity of the intermediate values
359 /// before they are promoted/expanded.
361 unsigned TargetLowering::getVectorTypeBreakdown(MVT::ValueType VT,
362 MVT::ValueType &IntermediateVT,
363 unsigned &NumIntermediates,
364 MVT::ValueType &RegisterVT) const {
365 // Figure out the right, legal destination reg to copy into.
366 unsigned NumElts = MVT::getVectorNumElements(VT);
367 MVT::ValueType EltTy = MVT::getVectorElementType(VT);
369 unsigned NumVectorRegs = 1;
371 // FIXME: We don't support non-power-of-2-sized vectors for now. Ideally we
372 // could break down into LHS/RHS like LegalizeDAG does.
373 if (!isPowerOf2_32(NumElts)) {
374 NumVectorRegs = NumElts;
378 // Divide the input until we get to a supported size. This will always
379 // end with a scalar if the target doesn't support vectors.
380 while (NumElts > 1 &&
381 !isTypeLegal(MVT::getVectorType(EltTy, NumElts))) {
386 NumIntermediates = NumVectorRegs;
388 MVT::ValueType NewVT = MVT::getVectorType(EltTy, NumElts);
389 if (!isTypeLegal(NewVT))
391 IntermediateVT = NewVT;
393 MVT::ValueType DestVT = getTypeToTransformTo(NewVT);
395 if (DestVT < NewVT) {
396 // Value is expanded, e.g. i64 -> i16.
397 return NumVectorRegs*(MVT::getSizeInBits(NewVT)/MVT::getSizeInBits(DestVT));
399 // Otherwise, promotion or legal types use the same number of registers as
400 // the vector decimated to the appropriate level.
401 return NumVectorRegs;
407 SDOperand TargetLowering::getPICJumpTableRelocBase(SDOperand Table,
408 SelectionDAG &DAG) const {
409 if (usesGlobalOffsetTable())
410 return DAG.getNode(ISD::GLOBAL_OFFSET_TABLE, getPointerTy());
414 //===----------------------------------------------------------------------===//
415 // Optimization Methods
416 //===----------------------------------------------------------------------===//
418 /// ShrinkDemandedConstant - Check to see if the specified operand of the
419 /// specified instruction is a constant integer. If so, check to see if there
420 /// are any bits set in the constant that are not demanded. If so, shrink the
421 /// constant and return true.
422 bool TargetLowering::TargetLoweringOpt::ShrinkDemandedConstant(SDOperand Op,
424 // FIXME: ISD::SELECT, ISD::SELECT_CC
425 switch(Op.getOpcode()) {
430 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1)))
431 if ((~Demanded & C->getValue()) != 0) {
432 MVT::ValueType VT = Op.getValueType();
433 SDOperand New = DAG.getNode(Op.getOpcode(), VT, Op.getOperand(0),
434 DAG.getConstant(Demanded & C->getValue(),
436 return CombineTo(Op, New);
443 /// SimplifyDemandedBits - Look at Op. At this point, we know that only the
444 /// DemandedMask bits of the result of Op are ever used downstream. If we can
445 /// use this information to simplify Op, create a new simplified DAG node and
446 /// return true, returning the original and new nodes in Old and New. Otherwise,
447 /// analyze the expression and return a mask of KnownOne and KnownZero bits for
448 /// the expression (used to simplify the caller). The KnownZero/One bits may
449 /// only be accurate for those bits in the DemandedMask.
450 bool TargetLowering::SimplifyDemandedBits(SDOperand Op, uint64_t DemandedMask,
453 TargetLoweringOpt &TLO,
454 unsigned Depth) const {
455 KnownZero = KnownOne = 0; // Don't know anything.
457 // The masks are not wide enough to represent this type! Should use APInt.
458 if (Op.getValueType() == MVT::i128)
461 // Other users may use these bits.
462 if (!Op.Val->hasOneUse()) {
464 // If not at the root, Just compute the KnownZero/KnownOne bits to
465 // simplify things downstream.
466 TLO.DAG.ComputeMaskedBits(Op, DemandedMask, KnownZero, KnownOne, Depth);
469 // If this is the root being simplified, allow it to have multiple uses,
470 // just set the DemandedMask to all bits.
471 DemandedMask = MVT::getIntVTBitMask(Op.getValueType());
472 } else if (DemandedMask == 0) {
473 // Not demanding any bits from Op.
474 if (Op.getOpcode() != ISD::UNDEF)
475 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::UNDEF, Op.getValueType()));
477 } else if (Depth == 6) { // Limit search depth.
481 uint64_t KnownZero2, KnownOne2, KnownZeroOut, KnownOneOut;
482 switch (Op.getOpcode()) {
484 // We know all of the bits for a constant!
485 KnownOne = cast<ConstantSDNode>(Op)->getValue() & DemandedMask;
486 KnownZero = ~KnownOne & DemandedMask;
487 return false; // Don't fall through, will infinitely loop.
489 // If the RHS is a constant, check to see if the LHS would be zero without
490 // using the bits from the RHS. Below, we use knowledge about the RHS to
491 // simplify the LHS, here we're using information from the LHS to simplify
493 if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
494 uint64_t LHSZero, LHSOne;
495 TLO.DAG.ComputeMaskedBits(Op.getOperand(0), DemandedMask,
496 LHSZero, LHSOne, Depth+1);
497 // If the LHS already has zeros where RHSC does, this and is dead.
498 if ((LHSZero & DemandedMask) == (~RHSC->getValue() & DemandedMask))
499 return TLO.CombineTo(Op, Op.getOperand(0));
500 // If any of the set bits in the RHS are known zero on the LHS, shrink
502 if (TLO.ShrinkDemandedConstant(Op, ~LHSZero & DemandedMask))
506 if (SimplifyDemandedBits(Op.getOperand(1), DemandedMask, KnownZero,
507 KnownOne, TLO, Depth+1))
509 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
510 if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask & ~KnownZero,
511 KnownZero2, KnownOne2, TLO, Depth+1))
513 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
515 // If all of the demanded bits are known one on one side, return the other.
516 // These bits cannot contribute to the result of the 'and'.
517 if ((DemandedMask & ~KnownZero2 & KnownOne)==(DemandedMask & ~KnownZero2))
518 return TLO.CombineTo(Op, Op.getOperand(0));
519 if ((DemandedMask & ~KnownZero & KnownOne2)==(DemandedMask & ~KnownZero))
520 return TLO.CombineTo(Op, Op.getOperand(1));
521 // If all of the demanded bits in the inputs are known zeros, return zero.
522 if ((DemandedMask & (KnownZero|KnownZero2)) == DemandedMask)
523 return TLO.CombineTo(Op, TLO.DAG.getConstant(0, Op.getValueType()));
524 // If the RHS is a constant, see if we can simplify it.
525 if (TLO.ShrinkDemandedConstant(Op, DemandedMask & ~KnownZero2))
528 // Output known-1 bits are only known if set in both the LHS & RHS.
529 KnownOne &= KnownOne2;
530 // Output known-0 are known to be clear if zero in either the LHS | RHS.
531 KnownZero |= KnownZero2;
534 if (SimplifyDemandedBits(Op.getOperand(1), DemandedMask, KnownZero,
535 KnownOne, TLO, Depth+1))
537 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
538 if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask & ~KnownOne,
539 KnownZero2, KnownOne2, TLO, Depth+1))
541 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
543 // If all of the demanded bits are known zero on one side, return the other.
544 // These bits cannot contribute to the result of the 'or'.
545 if ((DemandedMask & ~KnownOne2 & KnownZero) == (DemandedMask & ~KnownOne2))
546 return TLO.CombineTo(Op, Op.getOperand(0));
547 if ((DemandedMask & ~KnownOne & KnownZero2) == (DemandedMask & ~KnownOne))
548 return TLO.CombineTo(Op, Op.getOperand(1));
549 // If all of the potentially set bits on one side are known to be set on
550 // the other side, just use the 'other' side.
551 if ((DemandedMask & (~KnownZero) & KnownOne2) ==
552 (DemandedMask & (~KnownZero)))
553 return TLO.CombineTo(Op, Op.getOperand(0));
554 if ((DemandedMask & (~KnownZero2) & KnownOne) ==
555 (DemandedMask & (~KnownZero2)))
556 return TLO.CombineTo(Op, Op.getOperand(1));
557 // If the RHS is a constant, see if we can simplify it.
558 if (TLO.ShrinkDemandedConstant(Op, DemandedMask))
561 // Output known-0 bits are only known if clear in both the LHS & RHS.
562 KnownZero &= KnownZero2;
563 // Output known-1 are known to be set if set in either the LHS | RHS.
564 KnownOne |= KnownOne2;
567 if (SimplifyDemandedBits(Op.getOperand(1), DemandedMask, KnownZero,
568 KnownOne, TLO, Depth+1))
570 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
571 if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask, KnownZero2,
572 KnownOne2, TLO, Depth+1))
574 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
576 // If all of the demanded bits are known zero on one side, return the other.
577 // These bits cannot contribute to the result of the 'xor'.
578 if ((DemandedMask & KnownZero) == DemandedMask)
579 return TLO.CombineTo(Op, Op.getOperand(0));
580 if ((DemandedMask & KnownZero2) == DemandedMask)
581 return TLO.CombineTo(Op, Op.getOperand(1));
583 // If all of the unknown bits are known to be zero on one side or the other
584 // (but not both) turn this into an *inclusive* or.
585 // e.g. (A & C1)^(B & C2) -> (A & C1)|(B & C2) iff C1&C2 == 0
586 if ((DemandedMask & ~KnownZero & ~KnownZero2) == 0)
587 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::OR, Op.getValueType(),
591 // Output known-0 bits are known if clear or set in both the LHS & RHS.
592 KnownZeroOut = (KnownZero & KnownZero2) | (KnownOne & KnownOne2);
593 // Output known-1 are known to be set if set in only one of the LHS, RHS.
594 KnownOneOut = (KnownZero & KnownOne2) | (KnownOne & KnownZero2);
596 // If all of the demanded bits on one side are known, and all of the set
597 // bits on that side are also known to be set on the other side, turn this
598 // into an AND, as we know the bits will be cleared.
599 // e.g. (X | C1) ^ C2 --> (X | C1) & ~C2 iff (C1&C2) == C2
600 if ((DemandedMask & (KnownZero|KnownOne)) == DemandedMask) { // all known
601 if ((KnownOne & KnownOne2) == KnownOne) {
602 MVT::ValueType VT = Op.getValueType();
603 SDOperand ANDC = TLO.DAG.getConstant(~KnownOne & DemandedMask, VT);
604 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::AND, VT, Op.getOperand(0),
609 // If the RHS is a constant, see if we can simplify it.
610 // FIXME: for XOR, we prefer to force bits to 1 if they will make a -1.
611 if (TLO.ShrinkDemandedConstant(Op, DemandedMask))
614 KnownZero = KnownZeroOut;
615 KnownOne = KnownOneOut;
618 // If we know the result of a setcc has the top bits zero, use this info.
619 if (getSetCCResultContents() == TargetLowering::ZeroOrOneSetCCResult)
620 KnownZero |= (MVT::getIntVTBitMask(Op.getValueType()) ^ 1ULL);
623 if (SimplifyDemandedBits(Op.getOperand(2), DemandedMask, KnownZero,
624 KnownOne, TLO, Depth+1))
626 if (SimplifyDemandedBits(Op.getOperand(1), DemandedMask, KnownZero2,
627 KnownOne2, TLO, Depth+1))
629 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
630 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
632 // If the operands are constants, see if we can simplify them.
633 if (TLO.ShrinkDemandedConstant(Op, DemandedMask))
636 // Only known if known in both the LHS and RHS.
637 KnownOne &= KnownOne2;
638 KnownZero &= KnownZero2;
641 if (SimplifyDemandedBits(Op.getOperand(3), DemandedMask, KnownZero,
642 KnownOne, TLO, Depth+1))
644 if (SimplifyDemandedBits(Op.getOperand(2), DemandedMask, KnownZero2,
645 KnownOne2, TLO, Depth+1))
647 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
648 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
650 // If the operands are constants, see if we can simplify them.
651 if (TLO.ShrinkDemandedConstant(Op, DemandedMask))
654 // Only known if known in both the LHS and RHS.
655 KnownOne &= KnownOne2;
656 KnownZero &= KnownZero2;
659 if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
660 unsigned ShAmt = SA->getValue();
661 SDOperand InOp = Op.getOperand(0);
663 // If this is ((X >>u C1) << ShAmt), see if we can simplify this into a
664 // single shift. We can do this if the bottom bits (which are shifted
665 // out) are never demanded.
666 if (InOp.getOpcode() == ISD::SRL &&
667 isa<ConstantSDNode>(InOp.getOperand(1))) {
668 if (ShAmt && (DemandedMask & ((1ULL << ShAmt)-1)) == 0) {
669 unsigned C1 = cast<ConstantSDNode>(InOp.getOperand(1))->getValue();
670 unsigned Opc = ISD::SHL;
678 TLO.DAG.getConstant(Diff, Op.getOperand(1).getValueType());
679 MVT::ValueType VT = Op.getValueType();
680 return TLO.CombineTo(Op, TLO.DAG.getNode(Opc, VT,
681 InOp.getOperand(0), NewSA));
685 if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask >> ShAmt,
686 KnownZero, KnownOne, TLO, Depth+1))
688 KnownZero <<= SA->getValue();
689 KnownOne <<= SA->getValue();
690 KnownZero |= (1ULL << SA->getValue())-1; // low bits known zero.
694 if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
695 MVT::ValueType VT = Op.getValueType();
696 unsigned ShAmt = SA->getValue();
697 uint64_t TypeMask = MVT::getIntVTBitMask(VT);
698 unsigned VTSize = MVT::getSizeInBits(VT);
699 SDOperand InOp = Op.getOperand(0);
701 // If this is ((X << C1) >>u ShAmt), see if we can simplify this into a
702 // single shift. We can do this if the top bits (which are shifted out)
703 // are never demanded.
704 if (InOp.getOpcode() == ISD::SHL &&
705 isa<ConstantSDNode>(InOp.getOperand(1))) {
706 if (ShAmt && (DemandedMask & (~0ULL << (VTSize-ShAmt))) == 0) {
707 unsigned C1 = cast<ConstantSDNode>(InOp.getOperand(1))->getValue();
708 unsigned Opc = ISD::SRL;
716 TLO.DAG.getConstant(Diff, Op.getOperand(1).getValueType());
717 return TLO.CombineTo(Op, TLO.DAG.getNode(Opc, VT,
718 InOp.getOperand(0), NewSA));
722 // Compute the new bits that are at the top now.
723 if (SimplifyDemandedBits(InOp, (DemandedMask << ShAmt) & TypeMask,
724 KnownZero, KnownOne, TLO, Depth+1))
726 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
727 KnownZero &= TypeMask;
728 KnownOne &= TypeMask;
732 uint64_t HighBits = (1ULL << ShAmt)-1;
733 HighBits <<= VTSize - ShAmt;
734 KnownZero |= HighBits; // High bits known zero.
738 if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
739 MVT::ValueType VT = Op.getValueType();
740 unsigned ShAmt = SA->getValue();
742 // Compute the new bits that are at the top now.
743 uint64_t TypeMask = MVT::getIntVTBitMask(VT);
745 uint64_t InDemandedMask = (DemandedMask << ShAmt) & TypeMask;
747 // If any of the demanded bits are produced by the sign extension, we also
748 // demand the input sign bit.
749 uint64_t HighBits = (1ULL << ShAmt)-1;
750 HighBits <<= MVT::getSizeInBits(VT) - ShAmt;
751 if (HighBits & DemandedMask)
752 InDemandedMask |= MVT::getIntVTSignBit(VT);
754 if (SimplifyDemandedBits(Op.getOperand(0), InDemandedMask,
755 KnownZero, KnownOne, TLO, Depth+1))
757 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
758 KnownZero &= TypeMask;
759 KnownOne &= TypeMask;
763 // Handle the sign bits.
764 uint64_t SignBit = MVT::getIntVTSignBit(VT);
765 SignBit >>= ShAmt; // Adjust to where it is now in the mask.
767 // If the input sign bit is known to be zero, or if none of the top bits
768 // are demanded, turn this into an unsigned shift right.
769 if ((KnownZero & SignBit) || (HighBits & ~DemandedMask) == HighBits) {
770 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL, VT, Op.getOperand(0),
772 } else if (KnownOne & SignBit) { // New bits are known one.
773 KnownOne |= HighBits;
777 case ISD::SIGN_EXTEND_INREG: {
778 MVT::ValueType EVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
780 // Sign extension. Compute the demanded bits in the result that are not
781 // present in the input.
782 uint64_t NewBits = ~MVT::getIntVTBitMask(EVT) & DemandedMask;
784 // If none of the extended bits are demanded, eliminate the sextinreg.
786 return TLO.CombineTo(Op, Op.getOperand(0));
788 uint64_t InSignBit = MVT::getIntVTSignBit(EVT);
789 int64_t InputDemandedBits = DemandedMask & MVT::getIntVTBitMask(EVT);
791 // Since the sign extended bits are demanded, we know that the sign
793 InputDemandedBits |= InSignBit;
795 if (SimplifyDemandedBits(Op.getOperand(0), InputDemandedBits,
796 KnownZero, KnownOne, TLO, Depth+1))
798 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
800 // If the sign bit of the input is known set or clear, then we know the
801 // top bits of the result.
803 // If the input sign bit is known zero, convert this into a zero extension.
804 if (KnownZero & InSignBit)
805 return TLO.CombineTo(Op,
806 TLO.DAG.getZeroExtendInReg(Op.getOperand(0), EVT));
808 if (KnownOne & InSignBit) { // Input sign bit known set
810 KnownZero &= ~NewBits;
811 } else { // Input sign bit unknown
812 KnownZero &= ~NewBits;
813 KnownOne &= ~NewBits;
820 MVT::ValueType VT = Op.getValueType();
821 unsigned LowBits = Log2_32(MVT::getSizeInBits(VT))+1;
822 KnownZero = ~((1ULL << LowBits)-1) & MVT::getIntVTBitMask(VT);
827 if (ISD::isZEXTLoad(Op.Val)) {
828 LoadSDNode *LD = cast<LoadSDNode>(Op);
829 MVT::ValueType VT = LD->getLoadedVT();
830 KnownZero |= ~MVT::getIntVTBitMask(VT) & DemandedMask;
834 case ISD::ZERO_EXTEND: {
835 uint64_t InMask = MVT::getIntVTBitMask(Op.getOperand(0).getValueType());
837 // If none of the top bits are demanded, convert this into an any_extend.
838 uint64_t NewBits = (~InMask) & DemandedMask;
840 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ANY_EXTEND,
844 if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask & InMask,
845 KnownZero, KnownOne, TLO, Depth+1))
847 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
848 KnownZero |= NewBits;
851 case ISD::SIGN_EXTEND: {
852 MVT::ValueType InVT = Op.getOperand(0).getValueType();
853 uint64_t InMask = MVT::getIntVTBitMask(InVT);
854 uint64_t InSignBit = MVT::getIntVTSignBit(InVT);
855 uint64_t NewBits = (~InMask) & DemandedMask;
857 // If none of the top bits are demanded, convert this into an any_extend.
859 return TLO.CombineTo(Op,TLO.DAG.getNode(ISD::ANY_EXTEND,Op.getValueType(),
862 // Since some of the sign extended bits are demanded, we know that the sign
864 uint64_t InDemandedBits = DemandedMask & InMask;
865 InDemandedBits |= InSignBit;
867 if (SimplifyDemandedBits(Op.getOperand(0), InDemandedBits, KnownZero,
868 KnownOne, TLO, Depth+1))
871 // If the sign bit is known zero, convert this to a zero extend.
872 if (KnownZero & InSignBit)
873 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ZERO_EXTEND,
877 // If the sign bit is known one, the top bits match.
878 if (KnownOne & InSignBit) {
880 KnownZero &= ~NewBits;
881 } else { // Otherwise, top bits aren't known.
882 KnownOne &= ~NewBits;
883 KnownZero &= ~NewBits;
887 case ISD::ANY_EXTEND: {
888 uint64_t InMask = MVT::getIntVTBitMask(Op.getOperand(0).getValueType());
889 if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask & InMask,
890 KnownZero, KnownOne, TLO, Depth+1))
892 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
895 case ISD::TRUNCATE: {
896 // Simplify the input, using demanded bit information, and compute the known
897 // zero/one bits live out.
898 if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask,
899 KnownZero, KnownOne, TLO, Depth+1))
902 // If the input is only used by this truncate, see if we can shrink it based
903 // on the known demanded bits.
904 if (Op.getOperand(0).Val->hasOneUse()) {
905 SDOperand In = Op.getOperand(0);
906 switch (In.getOpcode()) {
909 // Shrink SRL by a constant if none of the high bits shifted in are
911 if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(In.getOperand(1))){
912 uint64_t HighBits = MVT::getIntVTBitMask(In.getValueType());
913 HighBits &= ~MVT::getIntVTBitMask(Op.getValueType());
914 HighBits >>= ShAmt->getValue();
916 if (ShAmt->getValue() < MVT::getSizeInBits(Op.getValueType()) &&
917 (DemandedMask & HighBits) == 0) {
918 // None of the shifted in bits are needed. Add a truncate of the
919 // shift input, then shift it.
920 SDOperand NewTrunc = TLO.DAG.getNode(ISD::TRUNCATE,
923 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL,Op.getValueType(),
924 NewTrunc, In.getOperand(1)));
931 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
932 uint64_t OutMask = MVT::getIntVTBitMask(Op.getValueType());
933 KnownZero &= OutMask;
937 case ISD::AssertZext: {
938 MVT::ValueType VT = cast<VTSDNode>(Op.getOperand(1))->getVT();
939 uint64_t InMask = MVT::getIntVTBitMask(VT);
940 if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask & InMask,
941 KnownZero, KnownOne, TLO, Depth+1))
943 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
944 KnownZero |= ~InMask & DemandedMask;
948 // All bits are zero except the low bit.
949 KnownZero = MVT::getIntVTBitMask(Op.getValueType()) ^ 1;
951 case ISD::BIT_CONVERT:
953 // If this is an FP->Int bitcast and if the sign bit is the only thing that
954 // is demanded, turn this into a FGETSIGN.
955 if (DemandedMask == MVT::getIntVTSignBit(Op.getValueType()) &&
956 MVT::isFloatingPoint(Op.getOperand(0).getValueType()) &&
957 !MVT::isVector(Op.getOperand(0).getValueType())) {
958 // Only do this xform if FGETSIGN is valid or if before legalize.
959 if (!TLO.AfterLegalize ||
960 isOperationLegal(ISD::FGETSIGN, Op.getValueType())) {
961 // Make a FGETSIGN + SHL to move the sign bit into the appropriate
962 // place. We expect the SHL to be eliminated by other optimizations.
963 SDOperand Sign = TLO.DAG.getNode(ISD::FGETSIGN, Op.getValueType(),
965 unsigned ShVal = MVT::getSizeInBits(Op.getValueType())-1;
966 SDOperand ShAmt = TLO.DAG.getConstant(ShVal, getShiftAmountTy());
967 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SHL, Op.getValueType(),
975 case ISD::INTRINSIC_WO_CHAIN:
976 case ISD::INTRINSIC_W_CHAIN:
977 case ISD::INTRINSIC_VOID:
978 // Just use ComputeMaskedBits to compute output bits.
979 TLO.DAG.ComputeMaskedBits(Op, DemandedMask, KnownZero, KnownOne, Depth);
983 // If we know the value of all of the demanded bits, return this as a
985 if ((DemandedMask & (KnownZero|KnownOne)) == DemandedMask)
986 return TLO.CombineTo(Op, TLO.DAG.getConstant(KnownOne, Op.getValueType()));
991 /// computeMaskedBitsForTargetNode - Determine which of the bits specified
992 /// in Mask are known to be either zero or one and return them in the
993 /// KnownZero/KnownOne bitsets.
994 void TargetLowering::computeMaskedBitsForTargetNode(const SDOperand Op,
998 const SelectionDAG &DAG,
999 unsigned Depth) const {
1000 assert((Op.getOpcode() >= ISD::BUILTIN_OP_END ||
1001 Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN ||
1002 Op.getOpcode() == ISD::INTRINSIC_W_CHAIN ||
1003 Op.getOpcode() == ISD::INTRINSIC_VOID) &&
1004 "Should use MaskedValueIsZero if you don't know whether Op"
1005 " is a target node!");
1010 /// ComputeNumSignBitsForTargetNode - This method can be implemented by
1011 /// targets that want to expose additional information about sign bits to the
1013 unsigned TargetLowering::ComputeNumSignBitsForTargetNode(SDOperand Op,
1014 unsigned Depth) const {
1015 assert((Op.getOpcode() >= ISD::BUILTIN_OP_END ||
1016 Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN ||
1017 Op.getOpcode() == ISD::INTRINSIC_W_CHAIN ||
1018 Op.getOpcode() == ISD::INTRINSIC_VOID) &&
1019 "Should use ComputeNumSignBits if you don't know whether Op"
1020 " is a target node!");
1025 /// SimplifySetCC - Try to simplify a setcc built with the specified operands
1026 /// and cc. If it is unable to simplify it, return a null SDOperand.
1028 TargetLowering::SimplifySetCC(MVT::ValueType VT, SDOperand N0, SDOperand N1,
1029 ISD::CondCode Cond, bool foldBooleans,
1030 DAGCombinerInfo &DCI) const {
1031 SelectionDAG &DAG = DCI.DAG;
1033 // These setcc operations always fold.
1037 case ISD::SETFALSE2: return DAG.getConstant(0, VT);
1039 case ISD::SETTRUE2: return DAG.getConstant(1, VT);
1042 if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val)) {
1043 uint64_t C1 = N1C->getValue();
1044 if (isa<ConstantSDNode>(N0.Val)) {
1045 return DAG.FoldSetCC(VT, N0, N1, Cond);
1047 // If the LHS is '(srl (ctlz x), 5)', the RHS is 0/1, and this is an
1048 // equality comparison, then we're just comparing whether X itself is
1050 if (N0.getOpcode() == ISD::SRL && (C1 == 0 || C1 == 1) &&
1051 N0.getOperand(0).getOpcode() == ISD::CTLZ &&
1052 N0.getOperand(1).getOpcode() == ISD::Constant) {
1053 unsigned ShAmt = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
1054 if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
1055 ShAmt == Log2_32(MVT::getSizeInBits(N0.getValueType()))) {
1056 if ((C1 == 0) == (Cond == ISD::SETEQ)) {
1057 // (srl (ctlz x), 5) == 0 -> X != 0
1058 // (srl (ctlz x), 5) != 1 -> X != 0
1061 // (srl (ctlz x), 5) != 0 -> X == 0
1062 // (srl (ctlz x), 5) == 1 -> X == 0
1065 SDOperand Zero = DAG.getConstant(0, N0.getValueType());
1066 return DAG.getSetCC(VT, N0.getOperand(0).getOperand(0),
1071 // If the LHS is a ZERO_EXTEND, perform the comparison on the input.
1072 if (N0.getOpcode() == ISD::ZERO_EXTEND) {
1073 unsigned InSize = MVT::getSizeInBits(N0.getOperand(0).getValueType());
1075 // If the comparison constant has bits in the upper part, the
1076 // zero-extended value could never match.
1077 if (C1 & (~0ULL << InSize)) {
1078 unsigned VSize = MVT::getSizeInBits(N0.getValueType());
1082 case ISD::SETEQ: return DAG.getConstant(0, VT);
1085 case ISD::SETNE: return DAG.getConstant(1, VT);
1088 // True if the sign bit of C1 is set.
1089 return DAG.getConstant((C1 & (1ULL << (VSize-1))) != 0, VT);
1092 // True if the sign bit of C1 isn't set.
1093 return DAG.getConstant((C1 & (1ULL << (VSize-1))) == 0, VT);
1099 // Otherwise, we can perform the comparison with the low bits.
1107 return DAG.getSetCC(VT, N0.getOperand(0),
1108 DAG.getConstant(C1, N0.getOperand(0).getValueType()),
1111 break; // todo, be more careful with signed comparisons
1113 } else if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
1114 (Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
1115 MVT::ValueType ExtSrcTy = cast<VTSDNode>(N0.getOperand(1))->getVT();
1116 unsigned ExtSrcTyBits = MVT::getSizeInBits(ExtSrcTy);
1117 MVT::ValueType ExtDstTy = N0.getValueType();
1118 unsigned ExtDstTyBits = MVT::getSizeInBits(ExtDstTy);
1120 // If the extended part has any inconsistent bits, it cannot ever
1121 // compare equal. In other words, they have to be all ones or all
1124 (~0ULL >> (64-ExtSrcTyBits)) & (~0ULL << (ExtDstTyBits-1));
1125 if ((C1 & ExtBits) != 0 && (C1 & ExtBits) != ExtBits)
1126 return DAG.getConstant(Cond == ISD::SETNE, VT);
1129 MVT::ValueType Op0Ty = N0.getOperand(0).getValueType();
1130 if (Op0Ty == ExtSrcTy) {
1131 ZextOp = N0.getOperand(0);
1133 int64_t Imm = ~0ULL >> (64-ExtSrcTyBits);
1134 ZextOp = DAG.getNode(ISD::AND, Op0Ty, N0.getOperand(0),
1135 DAG.getConstant(Imm, Op0Ty));
1137 if (!DCI.isCalledByLegalizer())
1138 DCI.AddToWorklist(ZextOp.Val);
1139 // Otherwise, make this a use of a zext.
1140 return DAG.getSetCC(VT, ZextOp,
1141 DAG.getConstant(C1 & (~0ULL>>(64-ExtSrcTyBits)),
1144 } else if ((N1C->getValue() == 0 || N1C->getValue() == 1) &&
1145 (Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
1147 // SETCC (SETCC), [0|1], [EQ|NE] -> SETCC
1148 if (N0.getOpcode() == ISD::SETCC) {
1149 bool TrueWhenTrue = (Cond == ISD::SETEQ) ^ (N1C->getValue() != 1);
1153 // Invert the condition.
1154 ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
1155 CC = ISD::getSetCCInverse(CC,
1156 MVT::isInteger(N0.getOperand(0).getValueType()));
1157 return DAG.getSetCC(VT, N0.getOperand(0), N0.getOperand(1), CC);
1160 if ((N0.getOpcode() == ISD::XOR ||
1161 (N0.getOpcode() == ISD::AND &&
1162 N0.getOperand(0).getOpcode() == ISD::XOR &&
1163 N0.getOperand(1) == N0.getOperand(0).getOperand(1))) &&
1164 isa<ConstantSDNode>(N0.getOperand(1)) &&
1165 cast<ConstantSDNode>(N0.getOperand(1))->getValue() == 1) {
1166 // If this is (X^1) == 0/1, swap the RHS and eliminate the xor. We
1167 // can only do this if the top bits are known zero.
1168 if (DAG.MaskedValueIsZero(N0,
1169 MVT::getIntVTBitMask(N0.getValueType())-1)){
1170 // Okay, get the un-inverted input value.
1172 if (N0.getOpcode() == ISD::XOR)
1173 Val = N0.getOperand(0);
1175 assert(N0.getOpcode() == ISD::AND &&
1176 N0.getOperand(0).getOpcode() == ISD::XOR);
1177 // ((X^1)&1)^1 -> X & 1
1178 Val = DAG.getNode(ISD::AND, N0.getValueType(),
1179 N0.getOperand(0).getOperand(0),
1182 return DAG.getSetCC(VT, Val, N1,
1183 Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ);
1188 uint64_t MinVal, MaxVal;
1189 unsigned OperandBitSize = MVT::getSizeInBits(N1C->getValueType(0));
1190 if (ISD::isSignedIntSetCC(Cond)) {
1191 MinVal = 1ULL << (OperandBitSize-1);
1192 if (OperandBitSize != 1) // Avoid X >> 64, which is undefined.
1193 MaxVal = ~0ULL >> (65-OperandBitSize);
1198 MaxVal = ~0ULL >> (64-OperandBitSize);
1201 // Canonicalize GE/LE comparisons to use GT/LT comparisons.
1202 if (Cond == ISD::SETGE || Cond == ISD::SETUGE) {
1203 if (C1 == MinVal) return DAG.getConstant(1, VT); // X >= MIN --> true
1204 --C1; // X >= C0 --> X > (C0-1)
1205 return DAG.getSetCC(VT, N0, DAG.getConstant(C1, N1.getValueType()),
1206 (Cond == ISD::SETGE) ? ISD::SETGT : ISD::SETUGT);
1209 if (Cond == ISD::SETLE || Cond == ISD::SETULE) {
1210 if (C1 == MaxVal) return DAG.getConstant(1, VT); // X <= MAX --> true
1211 ++C1; // X <= C0 --> X < (C0+1)
1212 return DAG.getSetCC(VT, N0, DAG.getConstant(C1, N1.getValueType()),
1213 (Cond == ISD::SETLE) ? ISD::SETLT : ISD::SETULT);
1216 if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal)
1217 return DAG.getConstant(0, VT); // X < MIN --> false
1218 if ((Cond == ISD::SETGE || Cond == ISD::SETUGE) && C1 == MinVal)
1219 return DAG.getConstant(1, VT); // X >= MIN --> true
1220 if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MaxVal)
1221 return DAG.getConstant(0, VT); // X > MAX --> false
1222 if ((Cond == ISD::SETLE || Cond == ISD::SETULE) && C1 == MaxVal)
1223 return DAG.getConstant(1, VT); // X <= MAX --> true
1225 // Canonicalize setgt X, Min --> setne X, Min
1226 if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MinVal)
1227 return DAG.getSetCC(VT, N0, N1, ISD::SETNE);
1228 // Canonicalize setlt X, Max --> setne X, Max
1229 if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MaxVal)
1230 return DAG.getSetCC(VT, N0, N1, ISD::SETNE);
1232 // If we have setult X, 1, turn it into seteq X, 0
1233 if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal+1)
1234 return DAG.getSetCC(VT, N0, DAG.getConstant(MinVal, N0.getValueType()),
1236 // If we have setugt X, Max-1, turn it into seteq X, Max
1237 else if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MaxVal-1)
1238 return DAG.getSetCC(VT, N0, DAG.getConstant(MaxVal, N0.getValueType()),
1241 // If we have "setcc X, C0", check to see if we can shrink the immediate
1244 // SETUGT X, SINTMAX -> SETLT X, 0
1245 if (Cond == ISD::SETUGT && OperandBitSize != 1 &&
1246 C1 == (~0ULL >> (65-OperandBitSize)))
1247 return DAG.getSetCC(VT, N0, DAG.getConstant(0, N1.getValueType()),
1250 // FIXME: Implement the rest of these.
1252 // Fold bit comparisons when we can.
1253 if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
1254 VT == N0.getValueType() && N0.getOpcode() == ISD::AND)
1255 if (ConstantSDNode *AndRHS =
1256 dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
1257 if (Cond == ISD::SETNE && C1 == 0) {// (X & 8) != 0 --> (X & 8) >> 3
1258 // Perform the xform if the AND RHS is a single bit.
1259 if (isPowerOf2_64(AndRHS->getValue())) {
1260 return DAG.getNode(ISD::SRL, VT, N0,
1261 DAG.getConstant(Log2_64(AndRHS->getValue()),
1262 getShiftAmountTy()));
1264 } else if (Cond == ISD::SETEQ && C1 == AndRHS->getValue()) {
1265 // (X & 8) == 8 --> (X & 8) >> 3
1266 // Perform the xform if C1 is a single bit.
1267 if (isPowerOf2_64(C1)) {
1268 return DAG.getNode(ISD::SRL, VT, N0,
1269 DAG.getConstant(Log2_64(C1), getShiftAmountTy()));
1274 } else if (isa<ConstantSDNode>(N0.Val)) {
1275 // Ensure that the constant occurs on the RHS.
1276 return DAG.getSetCC(VT, N1, N0, ISD::getSetCCSwappedOperands(Cond));
1279 if (isa<ConstantFPSDNode>(N0.Val)) {
1280 // Constant fold or commute setcc.
1281 SDOperand O = DAG.FoldSetCC(VT, N0, N1, Cond);
1282 if (O.Val) return O;
1286 // We can always fold X == X for integer setcc's.
1287 if (MVT::isInteger(N0.getValueType()))
1288 return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT);
1289 unsigned UOF = ISD::getUnorderedFlavor(Cond);
1290 if (UOF == 2) // FP operators that are undefined on NaNs.
1291 return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT);
1292 if (UOF == unsigned(ISD::isTrueWhenEqual(Cond)))
1293 return DAG.getConstant(UOF, VT);
1294 // Otherwise, we can't fold it. However, we can simplify it to SETUO/SETO
1295 // if it is not already.
1296 ISD::CondCode NewCond = UOF == 0 ? ISD::SETO : ISD::SETUO;
1297 if (NewCond != Cond)
1298 return DAG.getSetCC(VT, N0, N1, NewCond);
1301 if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
1302 MVT::isInteger(N0.getValueType())) {
1303 if (N0.getOpcode() == ISD::ADD || N0.getOpcode() == ISD::SUB ||
1304 N0.getOpcode() == ISD::XOR) {
1305 // Simplify (X+Y) == (X+Z) --> Y == Z
1306 if (N0.getOpcode() == N1.getOpcode()) {
1307 if (N0.getOperand(0) == N1.getOperand(0))
1308 return DAG.getSetCC(VT, N0.getOperand(1), N1.getOperand(1), Cond);
1309 if (N0.getOperand(1) == N1.getOperand(1))
1310 return DAG.getSetCC(VT, N0.getOperand(0), N1.getOperand(0), Cond);
1311 if (DAG.isCommutativeBinOp(N0.getOpcode())) {
1312 // If X op Y == Y op X, try other combinations.
1313 if (N0.getOperand(0) == N1.getOperand(1))
1314 return DAG.getSetCC(VT, N0.getOperand(1), N1.getOperand(0), Cond);
1315 if (N0.getOperand(1) == N1.getOperand(0))
1316 return DAG.getSetCC(VT, N0.getOperand(0), N1.getOperand(1), Cond);
1320 if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(N1)) {
1321 if (ConstantSDNode *LHSR = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
1322 // Turn (X+C1) == C2 --> X == C2-C1
1323 if (N0.getOpcode() == ISD::ADD && N0.Val->hasOneUse()) {
1324 return DAG.getSetCC(VT, N0.getOperand(0),
1325 DAG.getConstant(RHSC->getValue()-LHSR->getValue(),
1326 N0.getValueType()), Cond);
1329 // Turn (X^C1) == C2 into X == C1^C2 iff X&~C1 = 0.
1330 if (N0.getOpcode() == ISD::XOR)
1331 // If we know that all of the inverted bits are zero, don't bother
1332 // performing the inversion.
1333 if (DAG.MaskedValueIsZero(N0.getOperand(0), ~LHSR->getValue()))
1334 return DAG.getSetCC(VT, N0.getOperand(0),
1335 DAG.getConstant(LHSR->getValue()^RHSC->getValue(),
1336 N0.getValueType()), Cond);
1339 // Turn (C1-X) == C2 --> X == C1-C2
1340 if (ConstantSDNode *SUBC = dyn_cast<ConstantSDNode>(N0.getOperand(0))) {
1341 if (N0.getOpcode() == ISD::SUB && N0.Val->hasOneUse()) {
1342 return DAG.getSetCC(VT, N0.getOperand(1),
1343 DAG.getConstant(SUBC->getValue()-RHSC->getValue(),
1344 N0.getValueType()), Cond);
1349 // Simplify (X+Z) == X --> Z == 0
1350 if (N0.getOperand(0) == N1)
1351 return DAG.getSetCC(VT, N0.getOperand(1),
1352 DAG.getConstant(0, N0.getValueType()), Cond);
1353 if (N0.getOperand(1) == N1) {
1354 if (DAG.isCommutativeBinOp(N0.getOpcode()))
1355 return DAG.getSetCC(VT, N0.getOperand(0),
1356 DAG.getConstant(0, N0.getValueType()), Cond);
1357 else if (N0.Val->hasOneUse()) {
1358 assert(N0.getOpcode() == ISD::SUB && "Unexpected operation!");
1359 // (Z-X) == X --> Z == X<<1
1360 SDOperand SH = DAG.getNode(ISD::SHL, N1.getValueType(),
1362 DAG.getConstant(1, getShiftAmountTy()));
1363 if (!DCI.isCalledByLegalizer())
1364 DCI.AddToWorklist(SH.Val);
1365 return DAG.getSetCC(VT, N0.getOperand(0), SH, Cond);
1370 if (N1.getOpcode() == ISD::ADD || N1.getOpcode() == ISD::SUB ||
1371 N1.getOpcode() == ISD::XOR) {
1372 // Simplify X == (X+Z) --> Z == 0
1373 if (N1.getOperand(0) == N0) {
1374 return DAG.getSetCC(VT, N1.getOperand(1),
1375 DAG.getConstant(0, N1.getValueType()), Cond);
1376 } else if (N1.getOperand(1) == N0) {
1377 if (DAG.isCommutativeBinOp(N1.getOpcode())) {
1378 return DAG.getSetCC(VT, N1.getOperand(0),
1379 DAG.getConstant(0, N1.getValueType()), Cond);
1380 } else if (N1.Val->hasOneUse()) {
1381 assert(N1.getOpcode() == ISD::SUB && "Unexpected operation!");
1382 // X == (Z-X) --> X<<1 == Z
1383 SDOperand SH = DAG.getNode(ISD::SHL, N1.getValueType(), N0,
1384 DAG.getConstant(1, getShiftAmountTy()));
1385 if (!DCI.isCalledByLegalizer())
1386 DCI.AddToWorklist(SH.Val);
1387 return DAG.getSetCC(VT, SH, N1.getOperand(0), Cond);
1393 // Fold away ALL boolean setcc's.
1395 if (N0.getValueType() == MVT::i1 && foldBooleans) {
1397 default: assert(0 && "Unknown integer setcc!");
1398 case ISD::SETEQ: // X == Y -> (X^Y)^1
1399 Temp = DAG.getNode(ISD::XOR, MVT::i1, N0, N1);
1400 N0 = DAG.getNode(ISD::XOR, MVT::i1, Temp, DAG.getConstant(1, MVT::i1));
1401 if (!DCI.isCalledByLegalizer())
1402 DCI.AddToWorklist(Temp.Val);
1404 case ISD::SETNE: // X != Y --> (X^Y)
1405 N0 = DAG.getNode(ISD::XOR, MVT::i1, N0, N1);
1407 case ISD::SETGT: // X >s Y --> X == 0 & Y == 1 --> X^1 & Y
1408 case ISD::SETULT: // X <u Y --> X == 0 & Y == 1 --> X^1 & Y
1409 Temp = DAG.getNode(ISD::XOR, MVT::i1, N0, DAG.getConstant(1, MVT::i1));
1410 N0 = DAG.getNode(ISD::AND, MVT::i1, N1, Temp);
1411 if (!DCI.isCalledByLegalizer())
1412 DCI.AddToWorklist(Temp.Val);
1414 case ISD::SETLT: // X <s Y --> X == 1 & Y == 0 --> Y^1 & X
1415 case ISD::SETUGT: // X >u Y --> X == 1 & Y == 0 --> Y^1 & X
1416 Temp = DAG.getNode(ISD::XOR, MVT::i1, N1, DAG.getConstant(1, MVT::i1));
1417 N0 = DAG.getNode(ISD::AND, MVT::i1, N0, Temp);
1418 if (!DCI.isCalledByLegalizer())
1419 DCI.AddToWorklist(Temp.Val);
1421 case ISD::SETULE: // X <=u Y --> X == 0 | Y == 1 --> X^1 | Y
1422 case ISD::SETGE: // X >=s Y --> X == 0 | Y == 1 --> X^1 | Y
1423 Temp = DAG.getNode(ISD::XOR, MVT::i1, N0, DAG.getConstant(1, MVT::i1));
1424 N0 = DAG.getNode(ISD::OR, MVT::i1, N1, Temp);
1425 if (!DCI.isCalledByLegalizer())
1426 DCI.AddToWorklist(Temp.Val);
1428 case ISD::SETUGE: // X >=u Y --> X == 1 | Y == 0 --> Y^1 | X
1429 case ISD::SETLE: // X <=s Y --> X == 1 | Y == 0 --> Y^1 | X
1430 Temp = DAG.getNode(ISD::XOR, MVT::i1, N1, DAG.getConstant(1, MVT::i1));
1431 N0 = DAG.getNode(ISD::OR, MVT::i1, N0, Temp);
1434 if (VT != MVT::i1) {
1435 if (!DCI.isCalledByLegalizer())
1436 DCI.AddToWorklist(N0.Val);
1437 // FIXME: If running after legalize, we probably can't do this.
1438 N0 = DAG.getNode(ISD::ZERO_EXTEND, VT, N0);
1443 // Could not fold it.
1447 SDOperand TargetLowering::
1448 PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const {
1449 // Default implementation: no optimization.
1453 //===----------------------------------------------------------------------===//
1454 // Inline Assembler Implementation Methods
1455 //===----------------------------------------------------------------------===//
1457 TargetLowering::ConstraintType
1458 TargetLowering::getConstraintType(const std::string &Constraint) const {
1459 // FIXME: lots more standard ones to handle.
1460 if (Constraint.size() == 1) {
1461 switch (Constraint[0]) {
1463 case 'r': return C_RegisterClass;
1465 case 'o': // offsetable
1466 case 'V': // not offsetable
1468 case 'i': // Simple Integer or Relocatable Constant
1469 case 'n': // Simple Integer
1470 case 's': // Relocatable Constant
1471 case 'X': // Allow ANY value.
1472 case 'I': // Target registers.
1484 if (Constraint.size() > 1 && Constraint[0] == '{' &&
1485 Constraint[Constraint.size()-1] == '}')
1490 /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
1491 /// vector. If it is invalid, don't add anything to Ops.
1492 void TargetLowering::LowerAsmOperandForConstraint(SDOperand Op,
1493 char ConstraintLetter,
1494 std::vector<SDOperand> &Ops,
1495 SelectionDAG &DAG) {
1496 switch (ConstraintLetter) {
1498 case 'X': // Allows any operand; labels (basic block) use this.
1499 if (Op.getOpcode() == ISD::BasicBlock) {
1504 case 'i': // Simple Integer or Relocatable Constant
1505 case 'n': // Simple Integer
1506 case 's': { // Relocatable Constant
1507 // These operands are interested in values of the form (GV+C), where C may
1508 // be folded in as an offset of GV, or it may be explicitly added. Also, it
1509 // is possible and fine if either GV or C are missing.
1510 ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op);
1511 GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(Op);
1513 // If we have "(add GV, C)", pull out GV/C
1514 if (Op.getOpcode() == ISD::ADD) {
1515 C = dyn_cast<ConstantSDNode>(Op.getOperand(1));
1516 GA = dyn_cast<GlobalAddressSDNode>(Op.getOperand(0));
1517 if (C == 0 || GA == 0) {
1518 C = dyn_cast<ConstantSDNode>(Op.getOperand(0));
1519 GA = dyn_cast<GlobalAddressSDNode>(Op.getOperand(1));
1521 if (C == 0 || GA == 0)
1525 // If we find a valid operand, map to the TargetXXX version so that the
1526 // value itself doesn't get selected.
1527 if (GA) { // Either &GV or &GV+C
1528 if (ConstraintLetter != 'n') {
1529 int64_t Offs = GA->getOffset();
1530 if (C) Offs += C->getValue();
1531 Ops.push_back(DAG.getTargetGlobalAddress(GA->getGlobal(),
1532 Op.getValueType(), Offs));
1536 if (C) { // just C, no GV.
1537 // Simple constants are not allowed for 's'.
1538 if (ConstraintLetter != 's') {
1539 Ops.push_back(DAG.getTargetConstant(C->getValue(), Op.getValueType()));
1548 std::vector<unsigned> TargetLowering::
1549 getRegClassForInlineAsmConstraint(const std::string &Constraint,
1550 MVT::ValueType VT) const {
1551 return std::vector<unsigned>();
1555 std::pair<unsigned, const TargetRegisterClass*> TargetLowering::
1556 getRegForInlineAsmConstraint(const std::string &Constraint,
1557 MVT::ValueType VT) const {
1558 if (Constraint[0] != '{')
1559 return std::pair<unsigned, const TargetRegisterClass*>(0, 0);
1560 assert(*(Constraint.end()-1) == '}' && "Not a brace enclosed constraint?");
1562 // Remove the braces from around the name.
1563 std::string RegName(Constraint.begin()+1, Constraint.end()-1);
1565 // Figure out which register class contains this reg.
1566 const MRegisterInfo *RI = TM.getRegisterInfo();
1567 for (MRegisterInfo::regclass_iterator RCI = RI->regclass_begin(),
1568 E = RI->regclass_end(); RCI != E; ++RCI) {
1569 const TargetRegisterClass *RC = *RCI;
1571 // If none of the the value types for this register class are valid, we
1572 // can't use it. For example, 64-bit reg classes on 32-bit targets.
1573 bool isLegal = false;
1574 for (TargetRegisterClass::vt_iterator I = RC->vt_begin(), E = RC->vt_end();
1576 if (isTypeLegal(*I)) {
1582 if (!isLegal) continue;
1584 for (TargetRegisterClass::iterator I = RC->begin(), E = RC->end();
1586 if (StringsEqualNoCase(RegName, RI->get(*I).Name))
1587 return std::make_pair(*I, RC);
1591 return std::pair<unsigned, const TargetRegisterClass*>(0, 0);
1594 //===----------------------------------------------------------------------===//
1595 // Loop Strength Reduction hooks
1596 //===----------------------------------------------------------------------===//
1598 /// isLegalAddressingMode - Return true if the addressing mode represented
1599 /// by AM is legal for this target, for a load/store of the specified type.
1600 bool TargetLowering::isLegalAddressingMode(const AddrMode &AM,
1601 const Type *Ty) const {
1602 // The default implementation of this implements a conservative RISCy, r+r and
1605 // Allows a sign-extended 16-bit immediate field.
1606 if (AM.BaseOffs <= -(1LL << 16) || AM.BaseOffs >= (1LL << 16)-1)
1609 // No global is ever allowed as a base.
1613 // Only support r+r,
1615 case 0: // "r+i" or just "i", depending on HasBaseReg.
1618 if (AM.HasBaseReg && AM.BaseOffs) // "r+r+i" is not allowed.
1620 // Otherwise we have r+r or r+i.
1623 if (AM.HasBaseReg || AM.BaseOffs) // 2*r+r or 2*r+i is not allowed.
1625 // Allow 2*r as r+r.
1632 // Magic for divide replacement
1635 int64_t m; // magic number
1636 int64_t s; // shift amount
1640 uint64_t m; // magic number
1641 int64_t a; // add indicator
1642 int64_t s; // shift amount
1645 /// magic - calculate the magic numbers required to codegen an integer sdiv as
1646 /// a sequence of multiply and shifts. Requires that the divisor not be 0, 1,
1648 static ms magic32(int32_t d) {
1650 uint32_t ad, anc, delta, q1, r1, q2, r2, t;
1651 const uint32_t two31 = 0x80000000U;
1655 t = two31 + ((uint32_t)d >> 31);
1656 anc = t - 1 - t%ad; // absolute value of nc
1657 p = 31; // initialize p
1658 q1 = two31/anc; // initialize q1 = 2p/abs(nc)
1659 r1 = two31 - q1*anc; // initialize r1 = rem(2p,abs(nc))
1660 q2 = two31/ad; // initialize q2 = 2p/abs(d)
1661 r2 = two31 - q2*ad; // initialize r2 = rem(2p,abs(d))
1664 q1 = 2*q1; // update q1 = 2p/abs(nc)
1665 r1 = 2*r1; // update r1 = rem(2p/abs(nc))
1666 if (r1 >= anc) { // must be unsigned comparison
1670 q2 = 2*q2; // update q2 = 2p/abs(d)
1671 r2 = 2*r2; // update r2 = rem(2p/abs(d))
1672 if (r2 >= ad) { // must be unsigned comparison
1677 } while (q1 < delta || (q1 == delta && r1 == 0));
1679 mag.m = (int32_t)(q2 + 1); // make sure to sign extend
1680 if (d < 0) mag.m = -mag.m; // resulting magic number
1681 mag.s = p - 32; // resulting shift
1685 /// magicu - calculate the magic numbers required to codegen an integer udiv as
1686 /// a sequence of multiply, add and shifts. Requires that the divisor not be 0.
1687 static mu magicu32(uint32_t d) {
1689 uint32_t nc, delta, q1, r1, q2, r2;
1691 magu.a = 0; // initialize "add" indicator
1693 p = 31; // initialize p
1694 q1 = 0x80000000/nc; // initialize q1 = 2p/nc
1695 r1 = 0x80000000 - q1*nc; // initialize r1 = rem(2p,nc)
1696 q2 = 0x7FFFFFFF/d; // initialize q2 = (2p-1)/d
1697 r2 = 0x7FFFFFFF - q2*d; // initialize r2 = rem((2p-1),d)
1700 if (r1 >= nc - r1 ) {
1701 q1 = 2*q1 + 1; // update q1
1702 r1 = 2*r1 - nc; // update r1
1705 q1 = 2*q1; // update q1
1706 r1 = 2*r1; // update r1
1708 if (r2 + 1 >= d - r2) {
1709 if (q2 >= 0x7FFFFFFF) magu.a = 1;
1710 q2 = 2*q2 + 1; // update q2
1711 r2 = 2*r2 + 1 - d; // update r2
1714 if (q2 >= 0x80000000) magu.a = 1;
1715 q2 = 2*q2; // update q2
1716 r2 = 2*r2 + 1; // update r2
1719 } while (p < 64 && (q1 < delta || (q1 == delta && r1 == 0)));
1720 magu.m = q2 + 1; // resulting magic number
1721 magu.s = p - 32; // resulting shift
1725 /// magic - calculate the magic numbers required to codegen an integer sdiv as
1726 /// a sequence of multiply and shifts. Requires that the divisor not be 0, 1,
1728 static ms magic64(int64_t d) {
1730 uint64_t ad, anc, delta, q1, r1, q2, r2, t;
1731 const uint64_t two63 = 9223372036854775808ULL; // 2^63
1734 ad = d >= 0 ? d : -d;
1735 t = two63 + ((uint64_t)d >> 63);
1736 anc = t - 1 - t%ad; // absolute value of nc
1737 p = 63; // initialize p
1738 q1 = two63/anc; // initialize q1 = 2p/abs(nc)
1739 r1 = two63 - q1*anc; // initialize r1 = rem(2p,abs(nc))
1740 q2 = two63/ad; // initialize q2 = 2p/abs(d)
1741 r2 = two63 - q2*ad; // initialize r2 = rem(2p,abs(d))
1744 q1 = 2*q1; // update q1 = 2p/abs(nc)
1745 r1 = 2*r1; // update r1 = rem(2p/abs(nc))
1746 if (r1 >= anc) { // must be unsigned comparison
1750 q2 = 2*q2; // update q2 = 2p/abs(d)
1751 r2 = 2*r2; // update r2 = rem(2p/abs(d))
1752 if (r2 >= ad) { // must be unsigned comparison
1757 } while (q1 < delta || (q1 == delta && r1 == 0));
1760 if (d < 0) mag.m = -mag.m; // resulting magic number
1761 mag.s = p - 64; // resulting shift
1765 /// magicu - calculate the magic numbers required to codegen an integer udiv as
1766 /// a sequence of multiply, add and shifts. Requires that the divisor not be 0.
1767 static mu magicu64(uint64_t d)
1770 uint64_t nc, delta, q1, r1, q2, r2;
1772 magu.a = 0; // initialize "add" indicator
1774 p = 63; // initialize p
1775 q1 = 0x8000000000000000ull/nc; // initialize q1 = 2p/nc
1776 r1 = 0x8000000000000000ull - q1*nc; // initialize r1 = rem(2p,nc)
1777 q2 = 0x7FFFFFFFFFFFFFFFull/d; // initialize q2 = (2p-1)/d
1778 r2 = 0x7FFFFFFFFFFFFFFFull - q2*d; // initialize r2 = rem((2p-1),d)
1781 if (r1 >= nc - r1 ) {
1782 q1 = 2*q1 + 1; // update q1
1783 r1 = 2*r1 - nc; // update r1
1786 q1 = 2*q1; // update q1
1787 r1 = 2*r1; // update r1
1789 if (r2 + 1 >= d - r2) {
1790 if (q2 >= 0x7FFFFFFFFFFFFFFFull) magu.a = 1;
1791 q2 = 2*q2 + 1; // update q2
1792 r2 = 2*r2 + 1 - d; // update r2
1795 if (q2 >= 0x8000000000000000ull) magu.a = 1;
1796 q2 = 2*q2; // update q2
1797 r2 = 2*r2 + 1; // update r2
1800 } while (p < 128 && (q1 < delta || (q1 == delta && r1 == 0)));
1801 magu.m = q2 + 1; // resulting magic number
1802 magu.s = p - 64; // resulting shift
1806 /// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant,
1807 /// return a DAG expression to select that will generate the same value by
1808 /// multiplying by a magic number. See:
1809 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
1810 SDOperand TargetLowering::BuildSDIV(SDNode *N, SelectionDAG &DAG,
1811 std::vector<SDNode*>* Created) const {
1812 MVT::ValueType VT = N->getValueType(0);
1814 // Check to see if we can do this.
1815 if (!isTypeLegal(VT) || (VT != MVT::i32 && VT != MVT::i64))
1816 return SDOperand(); // BuildSDIV only operates on i32 or i64
1818 int64_t d = cast<ConstantSDNode>(N->getOperand(1))->getSignExtended();
1819 ms magics = (VT == MVT::i32) ? magic32(d) : magic64(d);
1821 // Multiply the numerator (operand 0) by the magic value
1823 if (isOperationLegal(ISD::MULHS, VT))
1824 Q = DAG.getNode(ISD::MULHS, VT, N->getOperand(0),
1825 DAG.getConstant(magics.m, VT));
1826 else if (isOperationLegal(ISD::SMUL_LOHI, VT))
1827 Q = SDOperand(DAG.getNode(ISD::SMUL_LOHI, DAG.getVTList(VT, VT),
1829 DAG.getConstant(magics.m, VT)).Val, 1);
1831 return SDOperand(); // No mulhs or equvialent
1832 // If d > 0 and m < 0, add the numerator
1833 if (d > 0 && magics.m < 0) {
1834 Q = DAG.getNode(ISD::ADD, VT, Q, N->getOperand(0));
1836 Created->push_back(Q.Val);
1838 // If d < 0 and m > 0, subtract the numerator.
1839 if (d < 0 && magics.m > 0) {
1840 Q = DAG.getNode(ISD::SUB, VT, Q, N->getOperand(0));
1842 Created->push_back(Q.Val);
1844 // Shift right algebraic if shift value is nonzero
1846 Q = DAG.getNode(ISD::SRA, VT, Q,
1847 DAG.getConstant(magics.s, getShiftAmountTy()));
1849 Created->push_back(Q.Val);
1851 // Extract the sign bit and add it to the quotient
1853 DAG.getNode(ISD::SRL, VT, Q, DAG.getConstant(MVT::getSizeInBits(VT)-1,
1854 getShiftAmountTy()));
1856 Created->push_back(T.Val);
1857 return DAG.getNode(ISD::ADD, VT, Q, T);
1860 /// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant,
1861 /// return a DAG expression to select that will generate the same value by
1862 /// multiplying by a magic number. See:
1863 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
1864 SDOperand TargetLowering::BuildUDIV(SDNode *N, SelectionDAG &DAG,
1865 std::vector<SDNode*>* Created) const {
1866 MVT::ValueType VT = N->getValueType(0);
1868 // Check to see if we can do this.
1869 if (!isTypeLegal(VT) || (VT != MVT::i32 && VT != MVT::i64))
1870 return SDOperand(); // BuildUDIV only operates on i32 or i64
1872 uint64_t d = cast<ConstantSDNode>(N->getOperand(1))->getValue();
1873 mu magics = (VT == MVT::i32) ? magicu32(d) : magicu64(d);
1875 // Multiply the numerator (operand 0) by the magic value
1877 if (isOperationLegal(ISD::MULHU, VT))
1878 Q = DAG.getNode(ISD::MULHU, VT, N->getOperand(0),
1879 DAG.getConstant(magics.m, VT));
1880 else if (isOperationLegal(ISD::UMUL_LOHI, VT))
1881 Q = SDOperand(DAG.getNode(ISD::UMUL_LOHI, DAG.getVTList(VT, VT),
1883 DAG.getConstant(magics.m, VT)).Val, 1);
1885 return SDOperand(); // No mulhu or equvialent
1887 Created->push_back(Q.Val);
1889 if (magics.a == 0) {
1890 return DAG.getNode(ISD::SRL, VT, Q,
1891 DAG.getConstant(magics.s, getShiftAmountTy()));
1893 SDOperand NPQ = DAG.getNode(ISD::SUB, VT, N->getOperand(0), Q);
1895 Created->push_back(NPQ.Val);
1896 NPQ = DAG.getNode(ISD::SRL, VT, NPQ,
1897 DAG.getConstant(1, getShiftAmountTy()));
1899 Created->push_back(NPQ.Val);
1900 NPQ = DAG.getNode(ISD::ADD, VT, NPQ, Q);
1902 Created->push_back(NPQ.Val);
1903 return DAG.getNode(ISD::SRL, VT, NPQ,
1904 DAG.getConstant(magics.s-1, getShiftAmountTy()));