1 //===-- TargetLowering.cpp - Implement the TargetLowering class -----------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // 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_F80] = "__addxf3";
52 Names[RTLIB::ADD_PPCF128] = "__gcc_qadd";
53 Names[RTLIB::SUB_F32] = "__subsf3";
54 Names[RTLIB::SUB_F64] = "__subdf3";
55 Names[RTLIB::SUB_F80] = "__subxf3";
56 Names[RTLIB::SUB_PPCF128] = "__gcc_qsub";
57 Names[RTLIB::MUL_F32] = "__mulsf3";
58 Names[RTLIB::MUL_F64] = "__muldf3";
59 Names[RTLIB::MUL_F80] = "__mulxf3";
60 Names[RTLIB::MUL_PPCF128] = "__gcc_qmul";
61 Names[RTLIB::DIV_F32] = "__divsf3";
62 Names[RTLIB::DIV_F64] = "__divdf3";
63 Names[RTLIB::DIV_F80] = "__divxf3";
64 Names[RTLIB::DIV_PPCF128] = "__gcc_qdiv";
65 Names[RTLIB::REM_F32] = "fmodf";
66 Names[RTLIB::REM_F64] = "fmod";
67 Names[RTLIB::REM_F80] = "fmodl";
68 Names[RTLIB::REM_PPCF128] = "fmodl";
69 Names[RTLIB::POWI_F32] = "__powisf2";
70 Names[RTLIB::POWI_F64] = "__powidf2";
71 Names[RTLIB::POWI_F80] = "__powixf2";
72 Names[RTLIB::POWI_PPCF128] = "__powitf2";
73 Names[RTLIB::SQRT_F32] = "sqrtf";
74 Names[RTLIB::SQRT_F64] = "sqrt";
75 Names[RTLIB::SQRT_F80] = "sqrtl";
76 Names[RTLIB::SQRT_PPCF128] = "sqrtl";
77 Names[RTLIB::SIN_F32] = "sinf";
78 Names[RTLIB::SIN_F64] = "sin";
79 Names[RTLIB::SIN_F80] = "sinl";
80 Names[RTLIB::SIN_PPCF128] = "sinl";
81 Names[RTLIB::COS_F32] = "cosf";
82 Names[RTLIB::COS_F64] = "cos";
83 Names[RTLIB::COS_F80] = "cosl";
84 Names[RTLIB::COS_PPCF128] = "cosl";
85 Names[RTLIB::POW_F32] = "powf";
86 Names[RTLIB::POW_F64] = "pow";
87 Names[RTLIB::POW_F80] = "powl";
88 Names[RTLIB::POW_PPCF128] = "powl";
89 Names[RTLIB::FPEXT_F32_F64] = "__extendsfdf2";
90 Names[RTLIB::FPROUND_F64_F32] = "__truncdfsf2";
91 Names[RTLIB::FPTOSINT_F32_I32] = "__fixsfsi";
92 Names[RTLIB::FPTOSINT_F32_I64] = "__fixsfdi";
93 Names[RTLIB::FPTOSINT_F64_I32] = "__fixdfsi";
94 Names[RTLIB::FPTOSINT_F64_I64] = "__fixdfdi";
95 Names[RTLIB::FPTOSINT_F80_I64] = "__fixxfdi";
96 Names[RTLIB::FPTOSINT_PPCF128_I64] = "__fixtfdi";
97 Names[RTLIB::FPTOUINT_F32_I32] = "__fixunssfsi";
98 Names[RTLIB::FPTOUINT_F32_I64] = "__fixunssfdi";
99 Names[RTLIB::FPTOUINT_F64_I32] = "__fixunsdfsi";
100 Names[RTLIB::FPTOUINT_F64_I64] = "__fixunsdfdi";
101 Names[RTLIB::FPTOUINT_F80_I32] = "__fixunsxfsi";
102 Names[RTLIB::FPTOUINT_F80_I64] = "__fixunsxfdi";
103 Names[RTLIB::FPTOUINT_PPCF128_I64] = "__fixunstfdi";
104 Names[RTLIB::SINTTOFP_I32_F32] = "__floatsisf";
105 Names[RTLIB::SINTTOFP_I32_F64] = "__floatsidf";
106 Names[RTLIB::SINTTOFP_I64_F32] = "__floatdisf";
107 Names[RTLIB::SINTTOFP_I64_F64] = "__floatdidf";
108 Names[RTLIB::SINTTOFP_I64_F80] = "__floatdixf";
109 Names[RTLIB::SINTTOFP_I64_PPCF128] = "__floatditf";
110 Names[RTLIB::UINTTOFP_I32_F32] = "__floatunsisf";
111 Names[RTLIB::UINTTOFP_I32_F64] = "__floatunsidf";
112 Names[RTLIB::UINTTOFP_I64_F32] = "__floatundisf";
113 Names[RTLIB::UINTTOFP_I64_F64] = "__floatundidf";
114 Names[RTLIB::OEQ_F32] = "__eqsf2";
115 Names[RTLIB::OEQ_F64] = "__eqdf2";
116 Names[RTLIB::UNE_F32] = "__nesf2";
117 Names[RTLIB::UNE_F64] = "__nedf2";
118 Names[RTLIB::OGE_F32] = "__gesf2";
119 Names[RTLIB::OGE_F64] = "__gedf2";
120 Names[RTLIB::OLT_F32] = "__ltsf2";
121 Names[RTLIB::OLT_F64] = "__ltdf2";
122 Names[RTLIB::OLE_F32] = "__lesf2";
123 Names[RTLIB::OLE_F64] = "__ledf2";
124 Names[RTLIB::OGT_F32] = "__gtsf2";
125 Names[RTLIB::OGT_F64] = "__gtdf2";
126 Names[RTLIB::UO_F32] = "__unordsf2";
127 Names[RTLIB::UO_F64] = "__unorddf2";
128 Names[RTLIB::O_F32] = "__unordsf2";
129 Names[RTLIB::O_F64] = "__unorddf2";
132 /// InitCmpLibcallCCs - Set default comparison libcall CC.
134 static void InitCmpLibcallCCs(ISD::CondCode *CCs) {
135 memset(CCs, ISD::SETCC_INVALID, sizeof(ISD::CondCode)*RTLIB::UNKNOWN_LIBCALL);
136 CCs[RTLIB::OEQ_F32] = ISD::SETEQ;
137 CCs[RTLIB::OEQ_F64] = ISD::SETEQ;
138 CCs[RTLIB::UNE_F32] = ISD::SETNE;
139 CCs[RTLIB::UNE_F64] = ISD::SETNE;
140 CCs[RTLIB::OGE_F32] = ISD::SETGE;
141 CCs[RTLIB::OGE_F64] = ISD::SETGE;
142 CCs[RTLIB::OLT_F32] = ISD::SETLT;
143 CCs[RTLIB::OLT_F64] = ISD::SETLT;
144 CCs[RTLIB::OLE_F32] = ISD::SETLE;
145 CCs[RTLIB::OLE_F64] = ISD::SETLE;
146 CCs[RTLIB::OGT_F32] = ISD::SETGT;
147 CCs[RTLIB::OGT_F64] = ISD::SETGT;
148 CCs[RTLIB::UO_F32] = ISD::SETNE;
149 CCs[RTLIB::UO_F64] = ISD::SETNE;
150 CCs[RTLIB::O_F32] = ISD::SETEQ;
151 CCs[RTLIB::O_F64] = ISD::SETEQ;
154 TargetLowering::TargetLowering(TargetMachine &tm)
155 : TM(tm), TD(TM.getTargetData()) {
156 assert(ISD::BUILTIN_OP_END <= 156 &&
157 "Fixed size array in TargetLowering is not large enough!");
158 // All operations default to being supported.
159 memset(OpActions, 0, sizeof(OpActions));
160 memset(LoadXActions, 0, sizeof(LoadXActions));
161 memset(TruncStoreActions, 0, sizeof(TruncStoreActions));
162 memset(IndexedModeActions, 0, sizeof(IndexedModeActions));
163 memset(ConvertActions, 0, sizeof(ConvertActions));
165 // Set default actions for various operations.
166 for (unsigned VT = 0; VT != (unsigned)MVT::LAST_VALUETYPE; ++VT) {
167 // Default all indexed load / store to expand.
168 for (unsigned IM = (unsigned)ISD::PRE_INC;
169 IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) {
170 setIndexedLoadAction(IM, (MVT::ValueType)VT, Expand);
171 setIndexedStoreAction(IM, (MVT::ValueType)VT, Expand);
174 // These operations default to expand.
175 setOperationAction(ISD::FGETSIGN, (MVT::ValueType)VT, Expand);
178 // Default ISD::TRAP to expand (which turns it into abort).
179 setOperationAction(ISD::TRAP, MVT::Other, Expand);
181 IsLittleEndian = TD->isLittleEndian();
182 UsesGlobalOffsetTable = false;
183 ShiftAmountTy = SetCCResultTy = PointerTy = getValueType(TD->getIntPtrType());
184 ShiftAmtHandling = Undefined;
185 memset(RegClassForVT, 0,MVT::LAST_VALUETYPE*sizeof(TargetRegisterClass*));
186 memset(TargetDAGCombineArray, 0, array_lengthof(TargetDAGCombineArray));
187 maxStoresPerMemset = maxStoresPerMemcpy = maxStoresPerMemmove = 8;
188 allowUnalignedMemoryAccesses = false;
189 UseUnderscoreSetJmp = false;
190 UseUnderscoreLongJmp = false;
191 SelectIsExpensive = false;
192 IntDivIsCheap = false;
193 Pow2DivIsCheap = false;
194 StackPointerRegisterToSaveRestore = 0;
195 ExceptionPointerRegister = 0;
196 ExceptionSelectorRegister = 0;
197 SetCCResultContents = UndefinedSetCCResult;
198 SchedPreferenceInfo = SchedulingForLatency;
200 JumpBufAlignment = 0;
201 IfCvtBlockSizeLimit = 2;
203 InitLibcallNames(LibcallRoutineNames);
204 InitCmpLibcallCCs(CmpLibcallCCs);
206 // Tell Legalize whether the assembler supports DEBUG_LOC.
207 if (!TM.getTargetAsmInfo()->hasDotLocAndDotFile())
208 setOperationAction(ISD::DEBUG_LOC, MVT::Other, Expand);
211 TargetLowering::~TargetLowering() {}
214 SDOperand TargetLowering::LowerMEMCPY(SDOperand Op, SelectionDAG &DAG) {
215 assert(getSubtarget() && "Subtarget not defined");
216 SDOperand ChainOp = Op.getOperand(0);
217 SDOperand DestOp = Op.getOperand(1);
218 SDOperand SourceOp = Op.getOperand(2);
219 SDOperand CountOp = Op.getOperand(3);
220 SDOperand AlignOp = Op.getOperand(4);
221 SDOperand AlwaysInlineOp = Op.getOperand(5);
223 bool AlwaysInline = (bool)cast<ConstantSDNode>(AlwaysInlineOp)->getValue();
224 unsigned Align = (unsigned)cast<ConstantSDNode>(AlignOp)->getValue();
225 if (Align == 0) Align = 1;
227 // If size is unknown, call memcpy.
228 ConstantSDNode *I = dyn_cast<ConstantSDNode>(CountOp);
230 assert(!AlwaysInline && "Cannot inline copy of unknown size");
231 return LowerMEMCPYCall(ChainOp, DestOp, SourceOp, CountOp, DAG);
234 // If not DWORD aligned or if size is more than threshold, then call memcpy.
235 // The libc version is likely to be faster for the following cases. It can
236 // use the address value and run time information about the CPU.
237 // With glibc 2.6.1 on a core 2, coping an array of 100M longs was 30% faster
238 unsigned Size = I->getValue();
240 (Size <= getSubtarget()->getMaxInlineSizeThreshold() &&
242 return LowerMEMCPYInline(ChainOp, DestOp, SourceOp, Size, Align, DAG);
243 return LowerMEMCPYCall(ChainOp, DestOp, SourceOp, CountOp, DAG);
247 SDOperand TargetLowering::LowerMEMCPYCall(SDOperand Chain,
252 MVT::ValueType IntPtr = getPointerTy();
253 TargetLowering::ArgListTy Args;
254 TargetLowering::ArgListEntry Entry;
255 Entry.Ty = getTargetData()->getIntPtrType();
256 Entry.Node = Dest; Args.push_back(Entry);
257 Entry.Node = Source; Args.push_back(Entry);
258 Entry.Node = Count; Args.push_back(Entry);
259 std::pair<SDOperand,SDOperand> CallResult =
260 LowerCallTo(Chain, Type::VoidTy, false, false, CallingConv::C, false,
261 DAG.getExternalSymbol("memcpy", IntPtr), Args, DAG);
262 return CallResult.second;
266 /// computeRegisterProperties - Once all of the register classes are added,
267 /// this allows us to compute derived properties we expose.
268 void TargetLowering::computeRegisterProperties() {
269 assert(MVT::LAST_VALUETYPE <= 32 &&
270 "Too many value types for ValueTypeActions to hold!");
272 // Everything defaults to needing one register.
273 for (unsigned i = 0; i != MVT::LAST_VALUETYPE; ++i) {
274 NumRegistersForVT[i] = 1;
275 RegisterTypeForVT[i] = TransformToType[i] = i;
277 // ...except isVoid, which doesn't need any registers.
278 NumRegistersForVT[MVT::isVoid] = 0;
280 // Find the largest integer register class.
281 unsigned LargestIntReg = MVT::i128;
282 for (; RegClassForVT[LargestIntReg] == 0; --LargestIntReg)
283 assert(LargestIntReg != MVT::i1 && "No integer registers defined!");
285 // Every integer value type larger than this largest register takes twice as
286 // many registers to represent as the previous ValueType.
287 for (MVT::ValueType ExpandedReg = LargestIntReg + 1;
288 MVT::isInteger(ExpandedReg); ++ExpandedReg) {
289 NumRegistersForVT[ExpandedReg] = 2*NumRegistersForVT[ExpandedReg-1];
290 RegisterTypeForVT[ExpandedReg] = LargestIntReg;
291 TransformToType[ExpandedReg] = ExpandedReg - 1;
292 ValueTypeActions.setTypeAction(ExpandedReg, Expand);
295 // Inspect all of the ValueType's smaller than the largest integer
296 // register to see which ones need promotion.
297 MVT::ValueType LegalIntReg = LargestIntReg;
298 for (MVT::ValueType IntReg = LargestIntReg - 1;
299 IntReg >= MVT::i1; --IntReg) {
300 if (isTypeLegal(IntReg)) {
301 LegalIntReg = IntReg;
303 RegisterTypeForVT[IntReg] = TransformToType[IntReg] = LegalIntReg;
304 ValueTypeActions.setTypeAction(IntReg, Promote);
308 // ppcf128 type is really two f64's.
309 if (!isTypeLegal(MVT::ppcf128)) {
310 NumRegistersForVT[MVT::ppcf128] = 2*NumRegistersForVT[MVT::f64];
311 RegisterTypeForVT[MVT::ppcf128] = MVT::f64;
312 TransformToType[MVT::ppcf128] = MVT::f64;
313 ValueTypeActions.setTypeAction(MVT::ppcf128, Expand);
316 // Decide how to handle f64. If the target does not have native f64 support,
317 // expand it to i64 and we will be generating soft float library calls.
318 if (!isTypeLegal(MVT::f64)) {
319 NumRegistersForVT[MVT::f64] = NumRegistersForVT[MVT::i64];
320 RegisterTypeForVT[MVT::f64] = RegisterTypeForVT[MVT::i64];
321 TransformToType[MVT::f64] = MVT::i64;
322 ValueTypeActions.setTypeAction(MVT::f64, Expand);
325 // Decide how to handle f32. If the target does not have native support for
326 // f32, promote it to f64 if it is legal. Otherwise, expand it to i32.
327 if (!isTypeLegal(MVT::f32)) {
328 if (isTypeLegal(MVT::f64)) {
329 NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::f64];
330 RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::f64];
331 TransformToType[MVT::f32] = MVT::f64;
332 ValueTypeActions.setTypeAction(MVT::f32, Promote);
334 NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::i32];
335 RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::i32];
336 TransformToType[MVT::f32] = MVT::i32;
337 ValueTypeActions.setTypeAction(MVT::f32, Expand);
341 // Loop over all of the vector value types to see which need transformations.
342 for (MVT::ValueType i = MVT::FIRST_VECTOR_VALUETYPE;
343 i <= MVT::LAST_VECTOR_VALUETYPE; ++i) {
344 if (!isTypeLegal(i)) {
345 MVT::ValueType IntermediateVT, RegisterVT;
346 unsigned NumIntermediates;
347 NumRegistersForVT[i] =
348 getVectorTypeBreakdown(i,
349 IntermediateVT, NumIntermediates,
351 RegisterTypeForVT[i] = RegisterVT;
352 TransformToType[i] = MVT::Other; // this isn't actually used
353 ValueTypeActions.setTypeAction(i, Expand);
358 const char *TargetLowering::getTargetNodeName(unsigned Opcode) const {
362 /// getVectorTypeBreakdown - Vector types are broken down into some number of
363 /// legal first class types. For example, MVT::v8f32 maps to 2 MVT::v4f32
364 /// with Altivec or SSE1, or 8 promoted MVT::f64 values with the X86 FP stack.
365 /// Similarly, MVT::v2i64 turns into 4 MVT::i32 values with both PPC and X86.
367 /// This method returns the number of registers needed, and the VT for each
368 /// register. It also returns the VT and quantity of the intermediate values
369 /// before they are promoted/expanded.
371 unsigned TargetLowering::getVectorTypeBreakdown(MVT::ValueType VT,
372 MVT::ValueType &IntermediateVT,
373 unsigned &NumIntermediates,
374 MVT::ValueType &RegisterVT) const {
375 // Figure out the right, legal destination reg to copy into.
376 unsigned NumElts = MVT::getVectorNumElements(VT);
377 MVT::ValueType EltTy = MVT::getVectorElementType(VT);
379 unsigned NumVectorRegs = 1;
381 // FIXME: We don't support non-power-of-2-sized vectors for now. Ideally we
382 // could break down into LHS/RHS like LegalizeDAG does.
383 if (!isPowerOf2_32(NumElts)) {
384 NumVectorRegs = NumElts;
388 // Divide the input until we get to a supported size. This will always
389 // end with a scalar if the target doesn't support vectors.
390 while (NumElts > 1 &&
391 !isTypeLegal(MVT::getVectorType(EltTy, NumElts))) {
396 NumIntermediates = NumVectorRegs;
398 MVT::ValueType NewVT = MVT::getVectorType(EltTy, NumElts);
399 if (!isTypeLegal(NewVT))
401 IntermediateVT = NewVT;
403 MVT::ValueType DestVT = getTypeToTransformTo(NewVT);
405 if (DestVT < NewVT) {
406 // Value is expanded, e.g. i64 -> i16.
407 return NumVectorRegs*(MVT::getSizeInBits(NewVT)/MVT::getSizeInBits(DestVT));
409 // Otherwise, promotion or legal types use the same number of registers as
410 // the vector decimated to the appropriate level.
411 return NumVectorRegs;
417 SDOperand TargetLowering::getPICJumpTableRelocBase(SDOperand Table,
418 SelectionDAG &DAG) const {
419 if (usesGlobalOffsetTable())
420 return DAG.getNode(ISD::GLOBAL_OFFSET_TABLE, getPointerTy());
424 //===----------------------------------------------------------------------===//
425 // Optimization Methods
426 //===----------------------------------------------------------------------===//
428 /// ShrinkDemandedConstant - Check to see if the specified operand of the
429 /// specified instruction is a constant integer. If so, check to see if there
430 /// are any bits set in the constant that are not demanded. If so, shrink the
431 /// constant and return true.
432 bool TargetLowering::TargetLoweringOpt::ShrinkDemandedConstant(SDOperand Op,
434 // FIXME: ISD::SELECT, ISD::SELECT_CC
435 switch(Op.getOpcode()) {
440 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1)))
441 if ((~Demanded & C->getValue()) != 0) {
442 MVT::ValueType VT = Op.getValueType();
443 SDOperand New = DAG.getNode(Op.getOpcode(), VT, Op.getOperand(0),
444 DAG.getConstant(Demanded & C->getValue(),
446 return CombineTo(Op, New);
453 /// SimplifyDemandedBits - Look at Op. At this point, we know that only the
454 /// DemandedMask bits of the result of Op are ever used downstream. If we can
455 /// use this information to simplify Op, create a new simplified DAG node and
456 /// return true, returning the original and new nodes in Old and New. Otherwise,
457 /// analyze the expression and return a mask of KnownOne and KnownZero bits for
458 /// the expression (used to simplify the caller). The KnownZero/One bits may
459 /// only be accurate for those bits in the DemandedMask.
460 bool TargetLowering::SimplifyDemandedBits(SDOperand Op, uint64_t DemandedMask,
463 TargetLoweringOpt &TLO,
464 unsigned Depth) const {
465 KnownZero = KnownOne = 0; // Don't know anything.
467 // The masks are not wide enough to represent this type! Should use APInt.
468 if (Op.getValueType() == MVT::i128)
471 // Other users may use these bits.
472 if (!Op.Val->hasOneUse()) {
474 // If not at the root, Just compute the KnownZero/KnownOne bits to
475 // simplify things downstream.
476 TLO.DAG.ComputeMaskedBits(Op, DemandedMask, KnownZero, KnownOne, Depth);
479 // If this is the root being simplified, allow it to have multiple uses,
480 // just set the DemandedMask to all bits.
481 DemandedMask = MVT::getIntVTBitMask(Op.getValueType());
482 } else if (DemandedMask == 0) {
483 // Not demanding any bits from Op.
484 if (Op.getOpcode() != ISD::UNDEF)
485 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::UNDEF, Op.getValueType()));
487 } else if (Depth == 6) { // Limit search depth.
491 uint64_t KnownZero2, KnownOne2, KnownZeroOut, KnownOneOut;
492 switch (Op.getOpcode()) {
494 // We know all of the bits for a constant!
495 KnownOne = cast<ConstantSDNode>(Op)->getValue() & DemandedMask;
496 KnownZero = ~KnownOne & DemandedMask;
497 return false; // Don't fall through, will infinitely loop.
499 // If the RHS is a constant, check to see if the LHS would be zero without
500 // using the bits from the RHS. Below, we use knowledge about the RHS to
501 // simplify the LHS, here we're using information from the LHS to simplify
503 if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
504 uint64_t LHSZero, LHSOne;
505 TLO.DAG.ComputeMaskedBits(Op.getOperand(0), DemandedMask,
506 LHSZero, LHSOne, Depth+1);
507 // If the LHS already has zeros where RHSC does, this and is dead.
508 if ((LHSZero & DemandedMask) == (~RHSC->getValue() & DemandedMask))
509 return TLO.CombineTo(Op, Op.getOperand(0));
510 // If any of the set bits in the RHS are known zero on the LHS, shrink
512 if (TLO.ShrinkDemandedConstant(Op, ~LHSZero & DemandedMask))
516 if (SimplifyDemandedBits(Op.getOperand(1), DemandedMask, KnownZero,
517 KnownOne, TLO, Depth+1))
519 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
520 if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask & ~KnownZero,
521 KnownZero2, KnownOne2, TLO, Depth+1))
523 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
525 // If all of the demanded bits are known one on one side, return the other.
526 // These bits cannot contribute to the result of the 'and'.
527 if ((DemandedMask & ~KnownZero2 & KnownOne)==(DemandedMask & ~KnownZero2))
528 return TLO.CombineTo(Op, Op.getOperand(0));
529 if ((DemandedMask & ~KnownZero & KnownOne2)==(DemandedMask & ~KnownZero))
530 return TLO.CombineTo(Op, Op.getOperand(1));
531 // If all of the demanded bits in the inputs are known zeros, return zero.
532 if ((DemandedMask & (KnownZero|KnownZero2)) == DemandedMask)
533 return TLO.CombineTo(Op, TLO.DAG.getConstant(0, Op.getValueType()));
534 // If the RHS is a constant, see if we can simplify it.
535 if (TLO.ShrinkDemandedConstant(Op, DemandedMask & ~KnownZero2))
538 // Output known-1 bits are only known if set in both the LHS & RHS.
539 KnownOne &= KnownOne2;
540 // Output known-0 are known to be clear if zero in either the LHS | RHS.
541 KnownZero |= KnownZero2;
544 if (SimplifyDemandedBits(Op.getOperand(1), DemandedMask, KnownZero,
545 KnownOne, TLO, Depth+1))
547 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
548 if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask & ~KnownOne,
549 KnownZero2, KnownOne2, TLO, Depth+1))
551 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
553 // If all of the demanded bits are known zero on one side, return the other.
554 // These bits cannot contribute to the result of the 'or'.
555 if ((DemandedMask & ~KnownOne2 & KnownZero) == (DemandedMask & ~KnownOne2))
556 return TLO.CombineTo(Op, Op.getOperand(0));
557 if ((DemandedMask & ~KnownOne & KnownZero2) == (DemandedMask & ~KnownOne))
558 return TLO.CombineTo(Op, Op.getOperand(1));
559 // If all of the potentially set bits on one side are known to be set on
560 // the other side, just use the 'other' side.
561 if ((DemandedMask & (~KnownZero) & KnownOne2) ==
562 (DemandedMask & (~KnownZero)))
563 return TLO.CombineTo(Op, Op.getOperand(0));
564 if ((DemandedMask & (~KnownZero2) & KnownOne) ==
565 (DemandedMask & (~KnownZero2)))
566 return TLO.CombineTo(Op, Op.getOperand(1));
567 // If the RHS is a constant, see if we can simplify it.
568 if (TLO.ShrinkDemandedConstant(Op, DemandedMask))
571 // Output known-0 bits are only known if clear in both the LHS & RHS.
572 KnownZero &= KnownZero2;
573 // Output known-1 are known to be set if set in either the LHS | RHS.
574 KnownOne |= KnownOne2;
577 if (SimplifyDemandedBits(Op.getOperand(1), DemandedMask, KnownZero,
578 KnownOne, TLO, Depth+1))
580 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
581 if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask, KnownZero2,
582 KnownOne2, TLO, Depth+1))
584 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
586 // If all of the demanded bits are known zero on one side, return the other.
587 // These bits cannot contribute to the result of the 'xor'.
588 if ((DemandedMask & KnownZero) == DemandedMask)
589 return TLO.CombineTo(Op, Op.getOperand(0));
590 if ((DemandedMask & KnownZero2) == DemandedMask)
591 return TLO.CombineTo(Op, Op.getOperand(1));
593 // If all of the unknown bits are known to be zero on one side or the other
594 // (but not both) turn this into an *inclusive* or.
595 // e.g. (A & C1)^(B & C2) -> (A & C1)|(B & C2) iff C1&C2 == 0
596 if ((DemandedMask & ~KnownZero & ~KnownZero2) == 0)
597 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::OR, Op.getValueType(),
601 // Output known-0 bits are known if clear or set in both the LHS & RHS.
602 KnownZeroOut = (KnownZero & KnownZero2) | (KnownOne & KnownOne2);
603 // Output known-1 are known to be set if set in only one of the LHS, RHS.
604 KnownOneOut = (KnownZero & KnownOne2) | (KnownOne & KnownZero2);
606 // If all of the demanded bits on one side are known, and all of the set
607 // bits on that side are also known to be set on the other side, turn this
608 // into an AND, as we know the bits will be cleared.
609 // e.g. (X | C1) ^ C2 --> (X | C1) & ~C2 iff (C1&C2) == C2
610 if ((DemandedMask & (KnownZero|KnownOne)) == DemandedMask) { // all known
611 if ((KnownOne & KnownOne2) == KnownOne) {
612 MVT::ValueType VT = Op.getValueType();
613 SDOperand ANDC = TLO.DAG.getConstant(~KnownOne & DemandedMask, VT);
614 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::AND, VT, Op.getOperand(0),
619 // If the RHS is a constant, see if we can simplify it.
620 // FIXME: for XOR, we prefer to force bits to 1 if they will make a -1.
621 if (TLO.ShrinkDemandedConstant(Op, DemandedMask))
624 KnownZero = KnownZeroOut;
625 KnownOne = KnownOneOut;
628 // If we know the result of a setcc has the top bits zero, use this info.
629 if (getSetCCResultContents() == TargetLowering::ZeroOrOneSetCCResult)
630 KnownZero |= (MVT::getIntVTBitMask(Op.getValueType()) ^ 1ULL);
633 if (SimplifyDemandedBits(Op.getOperand(2), DemandedMask, KnownZero,
634 KnownOne, TLO, Depth+1))
636 if (SimplifyDemandedBits(Op.getOperand(1), DemandedMask, KnownZero2,
637 KnownOne2, TLO, Depth+1))
639 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
640 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
642 // If the operands are constants, see if we can simplify them.
643 if (TLO.ShrinkDemandedConstant(Op, DemandedMask))
646 // Only known if known in both the LHS and RHS.
647 KnownOne &= KnownOne2;
648 KnownZero &= KnownZero2;
651 if (SimplifyDemandedBits(Op.getOperand(3), DemandedMask, KnownZero,
652 KnownOne, TLO, Depth+1))
654 if (SimplifyDemandedBits(Op.getOperand(2), DemandedMask, KnownZero2,
655 KnownOne2, TLO, Depth+1))
657 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
658 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
660 // If the operands are constants, see if we can simplify them.
661 if (TLO.ShrinkDemandedConstant(Op, DemandedMask))
664 // Only known if known in both the LHS and RHS.
665 KnownOne &= KnownOne2;
666 KnownZero &= KnownZero2;
669 if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
670 unsigned ShAmt = SA->getValue();
671 SDOperand InOp = Op.getOperand(0);
673 // If this is ((X >>u C1) << ShAmt), see if we can simplify this into a
674 // single shift. We can do this if the bottom bits (which are shifted
675 // out) are never demanded.
676 if (InOp.getOpcode() == ISD::SRL &&
677 isa<ConstantSDNode>(InOp.getOperand(1))) {
678 if (ShAmt && (DemandedMask & ((1ULL << ShAmt)-1)) == 0) {
679 unsigned C1 = cast<ConstantSDNode>(InOp.getOperand(1))->getValue();
680 unsigned Opc = ISD::SHL;
688 TLO.DAG.getConstant(Diff, Op.getOperand(1).getValueType());
689 MVT::ValueType VT = Op.getValueType();
690 return TLO.CombineTo(Op, TLO.DAG.getNode(Opc, VT,
691 InOp.getOperand(0), NewSA));
695 if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask >> ShAmt,
696 KnownZero, KnownOne, TLO, Depth+1))
698 KnownZero <<= SA->getValue();
699 KnownOne <<= SA->getValue();
700 KnownZero |= (1ULL << SA->getValue())-1; // low bits known zero.
704 if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
705 MVT::ValueType VT = Op.getValueType();
706 unsigned ShAmt = SA->getValue();
707 uint64_t TypeMask = MVT::getIntVTBitMask(VT);
708 unsigned VTSize = MVT::getSizeInBits(VT);
709 SDOperand InOp = Op.getOperand(0);
711 // If this is ((X << C1) >>u ShAmt), see if we can simplify this into a
712 // single shift. We can do this if the top bits (which are shifted out)
713 // are never demanded.
714 if (InOp.getOpcode() == ISD::SHL &&
715 isa<ConstantSDNode>(InOp.getOperand(1))) {
716 if (ShAmt && (DemandedMask & (~0ULL << (VTSize-ShAmt))) == 0) {
717 unsigned C1 = cast<ConstantSDNode>(InOp.getOperand(1))->getValue();
718 unsigned Opc = ISD::SRL;
726 TLO.DAG.getConstant(Diff, Op.getOperand(1).getValueType());
727 return TLO.CombineTo(Op, TLO.DAG.getNode(Opc, VT,
728 InOp.getOperand(0), NewSA));
732 // Compute the new bits that are at the top now.
733 if (SimplifyDemandedBits(InOp, (DemandedMask << ShAmt) & TypeMask,
734 KnownZero, KnownOne, TLO, Depth+1))
736 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
737 KnownZero &= TypeMask;
738 KnownOne &= TypeMask;
742 uint64_t HighBits = (1ULL << ShAmt)-1;
743 HighBits <<= VTSize - ShAmt;
744 KnownZero |= HighBits; // High bits known zero.
748 if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
749 MVT::ValueType VT = Op.getValueType();
750 unsigned ShAmt = SA->getValue();
752 // Compute the new bits that are at the top now.
753 uint64_t TypeMask = MVT::getIntVTBitMask(VT);
755 uint64_t InDemandedMask = (DemandedMask << ShAmt) & TypeMask;
757 // If any of the demanded bits are produced by the sign extension, we also
758 // demand the input sign bit.
759 uint64_t HighBits = (1ULL << ShAmt)-1;
760 HighBits <<= MVT::getSizeInBits(VT) - ShAmt;
761 if (HighBits & DemandedMask)
762 InDemandedMask |= MVT::getIntVTSignBit(VT);
764 if (SimplifyDemandedBits(Op.getOperand(0), InDemandedMask,
765 KnownZero, KnownOne, TLO, Depth+1))
767 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
768 KnownZero &= TypeMask;
769 KnownOne &= TypeMask;
773 // Handle the sign bits.
774 uint64_t SignBit = MVT::getIntVTSignBit(VT);
775 SignBit >>= ShAmt; // Adjust to where it is now in the mask.
777 // If the input sign bit is known to be zero, or if none of the top bits
778 // are demanded, turn this into an unsigned shift right.
779 if ((KnownZero & SignBit) || (HighBits & ~DemandedMask) == HighBits) {
780 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL, VT, Op.getOperand(0),
782 } else if (KnownOne & SignBit) { // New bits are known one.
783 KnownOne |= HighBits;
787 case ISD::SIGN_EXTEND_INREG: {
788 MVT::ValueType EVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
790 // Sign extension. Compute the demanded bits in the result that are not
791 // present in the input.
792 uint64_t NewBits = ~MVT::getIntVTBitMask(EVT) & DemandedMask;
794 // If none of the extended bits are demanded, eliminate the sextinreg.
796 return TLO.CombineTo(Op, Op.getOperand(0));
798 uint64_t InSignBit = MVT::getIntVTSignBit(EVT);
799 int64_t InputDemandedBits = DemandedMask & MVT::getIntVTBitMask(EVT);
801 // Since the sign extended bits are demanded, we know that the sign
803 InputDemandedBits |= InSignBit;
805 if (SimplifyDemandedBits(Op.getOperand(0), InputDemandedBits,
806 KnownZero, KnownOne, TLO, Depth+1))
808 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
810 // If the sign bit of the input is known set or clear, then we know the
811 // top bits of the result.
813 // If the input sign bit is known zero, convert this into a zero extension.
814 if (KnownZero & InSignBit)
815 return TLO.CombineTo(Op,
816 TLO.DAG.getZeroExtendInReg(Op.getOperand(0), EVT));
818 if (KnownOne & InSignBit) { // Input sign bit known set
820 KnownZero &= ~NewBits;
821 } else { // Input sign bit unknown
822 KnownZero &= ~NewBits;
823 KnownOne &= ~NewBits;
830 MVT::ValueType VT = Op.getValueType();
831 unsigned LowBits = Log2_32(MVT::getSizeInBits(VT))+1;
832 KnownZero = ~((1ULL << LowBits)-1) & MVT::getIntVTBitMask(VT);
837 if (ISD::isZEXTLoad(Op.Val)) {
838 LoadSDNode *LD = cast<LoadSDNode>(Op);
839 MVT::ValueType VT = LD->getLoadedVT();
840 KnownZero |= ~MVT::getIntVTBitMask(VT) & DemandedMask;
844 case ISD::ZERO_EXTEND: {
845 uint64_t InMask = MVT::getIntVTBitMask(Op.getOperand(0).getValueType());
847 // If none of the top bits are demanded, convert this into an any_extend.
848 uint64_t NewBits = (~InMask) & DemandedMask;
850 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ANY_EXTEND,
854 if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask & InMask,
855 KnownZero, KnownOne, TLO, Depth+1))
857 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
858 KnownZero |= NewBits;
861 case ISD::SIGN_EXTEND: {
862 MVT::ValueType InVT = Op.getOperand(0).getValueType();
863 uint64_t InMask = MVT::getIntVTBitMask(InVT);
864 uint64_t InSignBit = MVT::getIntVTSignBit(InVT);
865 uint64_t NewBits = (~InMask) & DemandedMask;
867 // If none of the top bits are demanded, convert this into an any_extend.
869 return TLO.CombineTo(Op,TLO.DAG.getNode(ISD::ANY_EXTEND,Op.getValueType(),
872 // Since some of the sign extended bits are demanded, we know that the sign
874 uint64_t InDemandedBits = DemandedMask & InMask;
875 InDemandedBits |= InSignBit;
877 if (SimplifyDemandedBits(Op.getOperand(0), InDemandedBits, KnownZero,
878 KnownOne, TLO, Depth+1))
881 // If the sign bit is known zero, convert this to a zero extend.
882 if (KnownZero & InSignBit)
883 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ZERO_EXTEND,
887 // If the sign bit is known one, the top bits match.
888 if (KnownOne & InSignBit) {
890 KnownZero &= ~NewBits;
891 } else { // Otherwise, top bits aren't known.
892 KnownOne &= ~NewBits;
893 KnownZero &= ~NewBits;
897 case ISD::ANY_EXTEND: {
898 uint64_t InMask = MVT::getIntVTBitMask(Op.getOperand(0).getValueType());
899 if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask & InMask,
900 KnownZero, KnownOne, TLO, Depth+1))
902 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
905 case ISD::TRUNCATE: {
906 // Simplify the input, using demanded bit information, and compute the known
907 // zero/one bits live out.
908 if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask,
909 KnownZero, KnownOne, TLO, Depth+1))
912 // If the input is only used by this truncate, see if we can shrink it based
913 // on the known demanded bits.
914 if (Op.getOperand(0).Val->hasOneUse()) {
915 SDOperand In = Op.getOperand(0);
916 switch (In.getOpcode()) {
919 // Shrink SRL by a constant if none of the high bits shifted in are
921 if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(In.getOperand(1))){
922 uint64_t HighBits = MVT::getIntVTBitMask(In.getValueType());
923 HighBits &= ~MVT::getIntVTBitMask(Op.getValueType());
924 HighBits >>= ShAmt->getValue();
926 if (ShAmt->getValue() < MVT::getSizeInBits(Op.getValueType()) &&
927 (DemandedMask & HighBits) == 0) {
928 // None of the shifted in bits are needed. Add a truncate of the
929 // shift input, then shift it.
930 SDOperand NewTrunc = TLO.DAG.getNode(ISD::TRUNCATE,
933 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL,Op.getValueType(),
934 NewTrunc, In.getOperand(1)));
941 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
942 uint64_t OutMask = MVT::getIntVTBitMask(Op.getValueType());
943 KnownZero &= OutMask;
947 case ISD::AssertZext: {
948 MVT::ValueType VT = cast<VTSDNode>(Op.getOperand(1))->getVT();
949 uint64_t InMask = MVT::getIntVTBitMask(VT);
950 if (SimplifyDemandedBits(Op.getOperand(0), DemandedMask & InMask,
951 KnownZero, KnownOne, TLO, Depth+1))
953 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
954 KnownZero |= ~InMask & DemandedMask;
958 // All bits are zero except the low bit.
959 KnownZero = MVT::getIntVTBitMask(Op.getValueType()) ^ 1;
961 case ISD::BIT_CONVERT:
963 // If this is an FP->Int bitcast and if the sign bit is the only thing that
964 // is demanded, turn this into a FGETSIGN.
965 if (DemandedMask == MVT::getIntVTSignBit(Op.getValueType()) &&
966 MVT::isFloatingPoint(Op.getOperand(0).getValueType()) &&
967 !MVT::isVector(Op.getOperand(0).getValueType())) {
968 // Only do this xform if FGETSIGN is valid or if before legalize.
969 if (!TLO.AfterLegalize ||
970 isOperationLegal(ISD::FGETSIGN, Op.getValueType())) {
971 // Make a FGETSIGN + SHL to move the sign bit into the appropriate
972 // place. We expect the SHL to be eliminated by other optimizations.
973 SDOperand Sign = TLO.DAG.getNode(ISD::FGETSIGN, Op.getValueType(),
975 unsigned ShVal = MVT::getSizeInBits(Op.getValueType())-1;
976 SDOperand ShAmt = TLO.DAG.getConstant(ShVal, getShiftAmountTy());
977 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SHL, Op.getValueType(),
985 case ISD::INTRINSIC_WO_CHAIN:
986 case ISD::INTRINSIC_W_CHAIN:
987 case ISD::INTRINSIC_VOID:
988 // Just use ComputeMaskedBits to compute output bits.
989 TLO.DAG.ComputeMaskedBits(Op, DemandedMask, KnownZero, KnownOne, Depth);
993 // If we know the value of all of the demanded bits, return this as a
995 if ((DemandedMask & (KnownZero|KnownOne)) == DemandedMask)
996 return TLO.CombineTo(Op, TLO.DAG.getConstant(KnownOne, Op.getValueType()));
1001 /// computeMaskedBitsForTargetNode - Determine which of the bits specified
1002 /// in Mask are known to be either zero or one and return them in the
1003 /// KnownZero/KnownOne bitsets.
1004 void TargetLowering::computeMaskedBitsForTargetNode(const SDOperand Op,
1006 uint64_t &KnownZero,
1008 const SelectionDAG &DAG,
1009 unsigned Depth) const {
1010 assert((Op.getOpcode() >= ISD::BUILTIN_OP_END ||
1011 Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN ||
1012 Op.getOpcode() == ISD::INTRINSIC_W_CHAIN ||
1013 Op.getOpcode() == ISD::INTRINSIC_VOID) &&
1014 "Should use MaskedValueIsZero if you don't know whether Op"
1015 " is a target node!");
1020 /// ComputeNumSignBitsForTargetNode - This method can be implemented by
1021 /// targets that want to expose additional information about sign bits to the
1023 unsigned TargetLowering::ComputeNumSignBitsForTargetNode(SDOperand Op,
1024 unsigned Depth) const {
1025 assert((Op.getOpcode() >= ISD::BUILTIN_OP_END ||
1026 Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN ||
1027 Op.getOpcode() == ISD::INTRINSIC_W_CHAIN ||
1028 Op.getOpcode() == ISD::INTRINSIC_VOID) &&
1029 "Should use ComputeNumSignBits if you don't know whether Op"
1030 " is a target node!");
1035 /// SimplifySetCC - Try to simplify a setcc built with the specified operands
1036 /// and cc. If it is unable to simplify it, return a null SDOperand.
1038 TargetLowering::SimplifySetCC(MVT::ValueType VT, SDOperand N0, SDOperand N1,
1039 ISD::CondCode Cond, bool foldBooleans,
1040 DAGCombinerInfo &DCI) const {
1041 SelectionDAG &DAG = DCI.DAG;
1043 // These setcc operations always fold.
1047 case ISD::SETFALSE2: return DAG.getConstant(0, VT);
1049 case ISD::SETTRUE2: return DAG.getConstant(1, VT);
1052 if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val)) {
1053 uint64_t C1 = N1C->getValue();
1054 if (isa<ConstantSDNode>(N0.Val)) {
1055 return DAG.FoldSetCC(VT, N0, N1, Cond);
1057 // If the LHS is '(srl (ctlz x), 5)', the RHS is 0/1, and this is an
1058 // equality comparison, then we're just comparing whether X itself is
1060 if (N0.getOpcode() == ISD::SRL && (C1 == 0 || C1 == 1) &&
1061 N0.getOperand(0).getOpcode() == ISD::CTLZ &&
1062 N0.getOperand(1).getOpcode() == ISD::Constant) {
1063 unsigned ShAmt = cast<ConstantSDNode>(N0.getOperand(1))->getValue();
1064 if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
1065 ShAmt == Log2_32(MVT::getSizeInBits(N0.getValueType()))) {
1066 if ((C1 == 0) == (Cond == ISD::SETEQ)) {
1067 // (srl (ctlz x), 5) == 0 -> X != 0
1068 // (srl (ctlz x), 5) != 1 -> X != 0
1071 // (srl (ctlz x), 5) != 0 -> X == 0
1072 // (srl (ctlz x), 5) == 1 -> X == 0
1075 SDOperand Zero = DAG.getConstant(0, N0.getValueType());
1076 return DAG.getSetCC(VT, N0.getOperand(0).getOperand(0),
1081 // If the LHS is a ZERO_EXTEND, perform the comparison on the input.
1082 if (N0.getOpcode() == ISD::ZERO_EXTEND) {
1083 unsigned InSize = MVT::getSizeInBits(N0.getOperand(0).getValueType());
1085 // If the comparison constant has bits in the upper part, the
1086 // zero-extended value could never match.
1087 if (C1 & (~0ULL << InSize)) {
1088 unsigned VSize = MVT::getSizeInBits(N0.getValueType());
1092 case ISD::SETEQ: return DAG.getConstant(0, VT);
1095 case ISD::SETNE: return DAG.getConstant(1, VT);
1098 // True if the sign bit of C1 is set.
1099 return DAG.getConstant((C1 & (1ULL << (VSize-1))) != 0, VT);
1102 // True if the sign bit of C1 isn't set.
1103 return DAG.getConstant((C1 & (1ULL << (VSize-1))) == 0, VT);
1109 // Otherwise, we can perform the comparison with the low bits.
1117 return DAG.getSetCC(VT, N0.getOperand(0),
1118 DAG.getConstant(C1, N0.getOperand(0).getValueType()),
1121 break; // todo, be more careful with signed comparisons
1123 } else if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
1124 (Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
1125 MVT::ValueType ExtSrcTy = cast<VTSDNode>(N0.getOperand(1))->getVT();
1126 unsigned ExtSrcTyBits = MVT::getSizeInBits(ExtSrcTy);
1127 MVT::ValueType ExtDstTy = N0.getValueType();
1128 unsigned ExtDstTyBits = MVT::getSizeInBits(ExtDstTy);
1130 // If the extended part has any inconsistent bits, it cannot ever
1131 // compare equal. In other words, they have to be all ones or all
1134 (~0ULL >> (64-ExtSrcTyBits)) & (~0ULL << (ExtDstTyBits-1));
1135 if ((C1 & ExtBits) != 0 && (C1 & ExtBits) != ExtBits)
1136 return DAG.getConstant(Cond == ISD::SETNE, VT);
1139 MVT::ValueType Op0Ty = N0.getOperand(0).getValueType();
1140 if (Op0Ty == ExtSrcTy) {
1141 ZextOp = N0.getOperand(0);
1143 int64_t Imm = ~0ULL >> (64-ExtSrcTyBits);
1144 ZextOp = DAG.getNode(ISD::AND, Op0Ty, N0.getOperand(0),
1145 DAG.getConstant(Imm, Op0Ty));
1147 if (!DCI.isCalledByLegalizer())
1148 DCI.AddToWorklist(ZextOp.Val);
1149 // Otherwise, make this a use of a zext.
1150 return DAG.getSetCC(VT, ZextOp,
1151 DAG.getConstant(C1 & (~0ULL>>(64-ExtSrcTyBits)),
1154 } else if ((N1C->getValue() == 0 || N1C->getValue() == 1) &&
1155 (Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
1157 // SETCC (SETCC), [0|1], [EQ|NE] -> SETCC
1158 if (N0.getOpcode() == ISD::SETCC) {
1159 bool TrueWhenTrue = (Cond == ISD::SETEQ) ^ (N1C->getValue() != 1);
1163 // Invert the condition.
1164 ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
1165 CC = ISD::getSetCCInverse(CC,
1166 MVT::isInteger(N0.getOperand(0).getValueType()));
1167 return DAG.getSetCC(VT, N0.getOperand(0), N0.getOperand(1), CC);
1170 if ((N0.getOpcode() == ISD::XOR ||
1171 (N0.getOpcode() == ISD::AND &&
1172 N0.getOperand(0).getOpcode() == ISD::XOR &&
1173 N0.getOperand(1) == N0.getOperand(0).getOperand(1))) &&
1174 isa<ConstantSDNode>(N0.getOperand(1)) &&
1175 cast<ConstantSDNode>(N0.getOperand(1))->getValue() == 1) {
1176 // If this is (X^1) == 0/1, swap the RHS and eliminate the xor. We
1177 // can only do this if the top bits are known zero.
1178 if (DAG.MaskedValueIsZero(N0,
1179 MVT::getIntVTBitMask(N0.getValueType())-1)){
1180 // Okay, get the un-inverted input value.
1182 if (N0.getOpcode() == ISD::XOR)
1183 Val = N0.getOperand(0);
1185 assert(N0.getOpcode() == ISD::AND &&
1186 N0.getOperand(0).getOpcode() == ISD::XOR);
1187 // ((X^1)&1)^1 -> X & 1
1188 Val = DAG.getNode(ISD::AND, N0.getValueType(),
1189 N0.getOperand(0).getOperand(0),
1192 return DAG.getSetCC(VT, Val, N1,
1193 Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ);
1198 uint64_t MinVal, MaxVal;
1199 unsigned OperandBitSize = MVT::getSizeInBits(N1C->getValueType(0));
1200 if (ISD::isSignedIntSetCC(Cond)) {
1201 MinVal = 1ULL << (OperandBitSize-1);
1202 if (OperandBitSize != 1) // Avoid X >> 64, which is undefined.
1203 MaxVal = ~0ULL >> (65-OperandBitSize);
1208 MaxVal = ~0ULL >> (64-OperandBitSize);
1211 // Canonicalize GE/LE comparisons to use GT/LT comparisons.
1212 if (Cond == ISD::SETGE || Cond == ISD::SETUGE) {
1213 if (C1 == MinVal) return DAG.getConstant(1, VT); // X >= MIN --> true
1214 --C1; // X >= C0 --> X > (C0-1)
1215 return DAG.getSetCC(VT, N0, DAG.getConstant(C1, N1.getValueType()),
1216 (Cond == ISD::SETGE) ? ISD::SETGT : ISD::SETUGT);
1219 if (Cond == ISD::SETLE || Cond == ISD::SETULE) {
1220 if (C1 == MaxVal) return DAG.getConstant(1, VT); // X <= MAX --> true
1221 ++C1; // X <= C0 --> X < (C0+1)
1222 return DAG.getSetCC(VT, N0, DAG.getConstant(C1, N1.getValueType()),
1223 (Cond == ISD::SETLE) ? ISD::SETLT : ISD::SETULT);
1226 if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal)
1227 return DAG.getConstant(0, VT); // X < MIN --> false
1228 if ((Cond == ISD::SETGE || Cond == ISD::SETUGE) && C1 == MinVal)
1229 return DAG.getConstant(1, VT); // X >= MIN --> true
1230 if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MaxVal)
1231 return DAG.getConstant(0, VT); // X > MAX --> false
1232 if ((Cond == ISD::SETLE || Cond == ISD::SETULE) && C1 == MaxVal)
1233 return DAG.getConstant(1, VT); // X <= MAX --> true
1235 // Canonicalize setgt X, Min --> setne X, Min
1236 if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MinVal)
1237 return DAG.getSetCC(VT, N0, N1, ISD::SETNE);
1238 // Canonicalize setlt X, Max --> setne X, Max
1239 if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MaxVal)
1240 return DAG.getSetCC(VT, N0, N1, ISD::SETNE);
1242 // If we have setult X, 1, turn it into seteq X, 0
1243 if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal+1)
1244 return DAG.getSetCC(VT, N0, DAG.getConstant(MinVal, N0.getValueType()),
1246 // If we have setugt X, Max-1, turn it into seteq X, Max
1247 else if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MaxVal-1)
1248 return DAG.getSetCC(VT, N0, DAG.getConstant(MaxVal, N0.getValueType()),
1251 // If we have "setcc X, C0", check to see if we can shrink the immediate
1254 // SETUGT X, SINTMAX -> SETLT X, 0
1255 if (Cond == ISD::SETUGT && OperandBitSize != 1 &&
1256 C1 == (~0ULL >> (65-OperandBitSize)))
1257 return DAG.getSetCC(VT, N0, DAG.getConstant(0, N1.getValueType()),
1260 // FIXME: Implement the rest of these.
1262 // Fold bit comparisons when we can.
1263 if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
1264 VT == N0.getValueType() && N0.getOpcode() == ISD::AND)
1265 if (ConstantSDNode *AndRHS =
1266 dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
1267 if (Cond == ISD::SETNE && C1 == 0) {// (X & 8) != 0 --> (X & 8) >> 3
1268 // Perform the xform if the AND RHS is a single bit.
1269 if (isPowerOf2_64(AndRHS->getValue())) {
1270 return DAG.getNode(ISD::SRL, VT, N0,
1271 DAG.getConstant(Log2_64(AndRHS->getValue()),
1272 getShiftAmountTy()));
1274 } else if (Cond == ISD::SETEQ && C1 == AndRHS->getValue()) {
1275 // (X & 8) == 8 --> (X & 8) >> 3
1276 // Perform the xform if C1 is a single bit.
1277 if (isPowerOf2_64(C1)) {
1278 return DAG.getNode(ISD::SRL, VT, N0,
1279 DAG.getConstant(Log2_64(C1), getShiftAmountTy()));
1284 } else if (isa<ConstantSDNode>(N0.Val)) {
1285 // Ensure that the constant occurs on the RHS.
1286 return DAG.getSetCC(VT, N1, N0, ISD::getSetCCSwappedOperands(Cond));
1289 if (isa<ConstantFPSDNode>(N0.Val)) {
1290 // Constant fold or commute setcc.
1291 SDOperand O = DAG.FoldSetCC(VT, N0, N1, Cond);
1292 if (O.Val) return O;
1293 } else if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1.Val)) {
1294 // If the RHS of an FP comparison is a constant, simplify it away in
1296 if (CFP->getValueAPF().isNaN()) {
1297 // If an operand is known to be a nan, we can fold it.
1298 switch (ISD::getUnorderedFlavor(Cond)) {
1299 default: assert(0 && "Unknown flavor!");
1300 case 0: // Known false.
1301 return DAG.getConstant(0, VT);
1302 case 1: // Known true.
1303 return DAG.getConstant(1, VT);
1304 case 2: // Undefined.
1305 return DAG.getNode(ISD::UNDEF, VT);
1309 // Otherwise, we know the RHS is not a NaN. Simplify the node to drop the
1310 // constant if knowing that the operand is non-nan is enough. We prefer to
1311 // have SETO(x,x) instead of SETO(x, 0.0) because this avoids having to
1313 if (Cond == ISD::SETO || Cond == ISD::SETUO)
1314 return DAG.getSetCC(VT, N0, N0, Cond);
1318 // We can always fold X == X for integer setcc's.
1319 if (MVT::isInteger(N0.getValueType()))
1320 return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT);
1321 unsigned UOF = ISD::getUnorderedFlavor(Cond);
1322 if (UOF == 2) // FP operators that are undefined on NaNs.
1323 return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT);
1324 if (UOF == unsigned(ISD::isTrueWhenEqual(Cond)))
1325 return DAG.getConstant(UOF, VT);
1326 // Otherwise, we can't fold it. However, we can simplify it to SETUO/SETO
1327 // if it is not already.
1328 ISD::CondCode NewCond = UOF == 0 ? ISD::SETO : ISD::SETUO;
1329 if (NewCond != Cond)
1330 return DAG.getSetCC(VT, N0, N1, NewCond);
1333 if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
1334 MVT::isInteger(N0.getValueType())) {
1335 if (N0.getOpcode() == ISD::ADD || N0.getOpcode() == ISD::SUB ||
1336 N0.getOpcode() == ISD::XOR) {
1337 // Simplify (X+Y) == (X+Z) --> Y == Z
1338 if (N0.getOpcode() == N1.getOpcode()) {
1339 if (N0.getOperand(0) == N1.getOperand(0))
1340 return DAG.getSetCC(VT, N0.getOperand(1), N1.getOperand(1), Cond);
1341 if (N0.getOperand(1) == N1.getOperand(1))
1342 return DAG.getSetCC(VT, N0.getOperand(0), N1.getOperand(0), Cond);
1343 if (DAG.isCommutativeBinOp(N0.getOpcode())) {
1344 // If X op Y == Y op X, try other combinations.
1345 if (N0.getOperand(0) == N1.getOperand(1))
1346 return DAG.getSetCC(VT, N0.getOperand(1), N1.getOperand(0), Cond);
1347 if (N0.getOperand(1) == N1.getOperand(0))
1348 return DAG.getSetCC(VT, N0.getOperand(0), N1.getOperand(1), Cond);
1352 if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(N1)) {
1353 if (ConstantSDNode *LHSR = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
1354 // Turn (X+C1) == C2 --> X == C2-C1
1355 if (N0.getOpcode() == ISD::ADD && N0.Val->hasOneUse()) {
1356 return DAG.getSetCC(VT, N0.getOperand(0),
1357 DAG.getConstant(RHSC->getValue()-LHSR->getValue(),
1358 N0.getValueType()), Cond);
1361 // Turn (X^C1) == C2 into X == C1^C2 iff X&~C1 = 0.
1362 if (N0.getOpcode() == ISD::XOR)
1363 // If we know that all of the inverted bits are zero, don't bother
1364 // performing the inversion.
1365 if (DAG.MaskedValueIsZero(N0.getOperand(0), ~LHSR->getValue()))
1366 return DAG.getSetCC(VT, N0.getOperand(0),
1367 DAG.getConstant(LHSR->getValue()^RHSC->getValue(),
1368 N0.getValueType()), Cond);
1371 // Turn (C1-X) == C2 --> X == C1-C2
1372 if (ConstantSDNode *SUBC = dyn_cast<ConstantSDNode>(N0.getOperand(0))) {
1373 if (N0.getOpcode() == ISD::SUB && N0.Val->hasOneUse()) {
1374 return DAG.getSetCC(VT, N0.getOperand(1),
1375 DAG.getConstant(SUBC->getValue()-RHSC->getValue(),
1376 N0.getValueType()), Cond);
1381 // Simplify (X+Z) == X --> Z == 0
1382 if (N0.getOperand(0) == N1)
1383 return DAG.getSetCC(VT, N0.getOperand(1),
1384 DAG.getConstant(0, N0.getValueType()), Cond);
1385 if (N0.getOperand(1) == N1) {
1386 if (DAG.isCommutativeBinOp(N0.getOpcode()))
1387 return DAG.getSetCC(VT, N0.getOperand(0),
1388 DAG.getConstant(0, N0.getValueType()), Cond);
1389 else if (N0.Val->hasOneUse()) {
1390 assert(N0.getOpcode() == ISD::SUB && "Unexpected operation!");
1391 // (Z-X) == X --> Z == X<<1
1392 SDOperand SH = DAG.getNode(ISD::SHL, N1.getValueType(),
1394 DAG.getConstant(1, getShiftAmountTy()));
1395 if (!DCI.isCalledByLegalizer())
1396 DCI.AddToWorklist(SH.Val);
1397 return DAG.getSetCC(VT, N0.getOperand(0), SH, Cond);
1402 if (N1.getOpcode() == ISD::ADD || N1.getOpcode() == ISD::SUB ||
1403 N1.getOpcode() == ISD::XOR) {
1404 // Simplify X == (X+Z) --> Z == 0
1405 if (N1.getOperand(0) == N0) {
1406 return DAG.getSetCC(VT, N1.getOperand(1),
1407 DAG.getConstant(0, N1.getValueType()), Cond);
1408 } else if (N1.getOperand(1) == N0) {
1409 if (DAG.isCommutativeBinOp(N1.getOpcode())) {
1410 return DAG.getSetCC(VT, N1.getOperand(0),
1411 DAG.getConstant(0, N1.getValueType()), Cond);
1412 } else if (N1.Val->hasOneUse()) {
1413 assert(N1.getOpcode() == ISD::SUB && "Unexpected operation!");
1414 // X == (Z-X) --> X<<1 == Z
1415 SDOperand SH = DAG.getNode(ISD::SHL, N1.getValueType(), N0,
1416 DAG.getConstant(1, getShiftAmountTy()));
1417 if (!DCI.isCalledByLegalizer())
1418 DCI.AddToWorklist(SH.Val);
1419 return DAG.getSetCC(VT, SH, N1.getOperand(0), Cond);
1425 // Fold away ALL boolean setcc's.
1427 if (N0.getValueType() == MVT::i1 && foldBooleans) {
1429 default: assert(0 && "Unknown integer setcc!");
1430 case ISD::SETEQ: // X == Y -> (X^Y)^1
1431 Temp = DAG.getNode(ISD::XOR, MVT::i1, N0, N1);
1432 N0 = DAG.getNode(ISD::XOR, MVT::i1, Temp, DAG.getConstant(1, MVT::i1));
1433 if (!DCI.isCalledByLegalizer())
1434 DCI.AddToWorklist(Temp.Val);
1436 case ISD::SETNE: // X != Y --> (X^Y)
1437 N0 = DAG.getNode(ISD::XOR, MVT::i1, N0, N1);
1439 case ISD::SETGT: // X >s Y --> X == 0 & Y == 1 --> X^1 & Y
1440 case ISD::SETULT: // X <u Y --> X == 0 & Y == 1 --> X^1 & Y
1441 Temp = DAG.getNode(ISD::XOR, MVT::i1, N0, DAG.getConstant(1, MVT::i1));
1442 N0 = DAG.getNode(ISD::AND, MVT::i1, N1, Temp);
1443 if (!DCI.isCalledByLegalizer())
1444 DCI.AddToWorklist(Temp.Val);
1446 case ISD::SETLT: // X <s Y --> X == 1 & Y == 0 --> Y^1 & X
1447 case ISD::SETUGT: // X >u Y --> X == 1 & Y == 0 --> Y^1 & X
1448 Temp = DAG.getNode(ISD::XOR, MVT::i1, N1, DAG.getConstant(1, MVT::i1));
1449 N0 = DAG.getNode(ISD::AND, MVT::i1, N0, Temp);
1450 if (!DCI.isCalledByLegalizer())
1451 DCI.AddToWorklist(Temp.Val);
1453 case ISD::SETULE: // X <=u Y --> X == 0 | Y == 1 --> X^1 | Y
1454 case ISD::SETGE: // X >=s Y --> X == 0 | Y == 1 --> X^1 | Y
1455 Temp = DAG.getNode(ISD::XOR, MVT::i1, N0, DAG.getConstant(1, MVT::i1));
1456 N0 = DAG.getNode(ISD::OR, MVT::i1, N1, Temp);
1457 if (!DCI.isCalledByLegalizer())
1458 DCI.AddToWorklist(Temp.Val);
1460 case ISD::SETUGE: // X >=u Y --> X == 1 | Y == 0 --> Y^1 | X
1461 case ISD::SETLE: // X <=s Y --> X == 1 | Y == 0 --> Y^1 | X
1462 Temp = DAG.getNode(ISD::XOR, MVT::i1, N1, DAG.getConstant(1, MVT::i1));
1463 N0 = DAG.getNode(ISD::OR, MVT::i1, N0, Temp);
1466 if (VT != MVT::i1) {
1467 if (!DCI.isCalledByLegalizer())
1468 DCI.AddToWorklist(N0.Val);
1469 // FIXME: If running after legalize, we probably can't do this.
1470 N0 = DAG.getNode(ISD::ZERO_EXTEND, VT, N0);
1475 // Could not fold it.
1479 SDOperand TargetLowering::
1480 PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const {
1481 // Default implementation: no optimization.
1485 //===----------------------------------------------------------------------===//
1486 // Inline Assembler Implementation Methods
1487 //===----------------------------------------------------------------------===//
1489 TargetLowering::ConstraintType
1490 TargetLowering::getConstraintType(const std::string &Constraint) const {
1491 // FIXME: lots more standard ones to handle.
1492 if (Constraint.size() == 1) {
1493 switch (Constraint[0]) {
1495 case 'r': return C_RegisterClass;
1497 case 'o': // offsetable
1498 case 'V': // not offsetable
1500 case 'i': // Simple Integer or Relocatable Constant
1501 case 'n': // Simple Integer
1502 case 's': // Relocatable Constant
1503 case 'X': // Allow ANY value.
1504 case 'I': // Target registers.
1516 if (Constraint.size() > 1 && Constraint[0] == '{' &&
1517 Constraint[Constraint.size()-1] == '}')
1522 /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
1523 /// vector. If it is invalid, don't add anything to Ops.
1524 void TargetLowering::LowerAsmOperandForConstraint(SDOperand Op,
1525 char ConstraintLetter,
1526 std::vector<SDOperand> &Ops,
1527 SelectionDAG &DAG) {
1528 switch (ConstraintLetter) {
1530 case 'X': // Allows any operand; labels (basic block) use this.
1531 if (Op.getOpcode() == ISD::BasicBlock) {
1536 case 'i': // Simple Integer or Relocatable Constant
1537 case 'n': // Simple Integer
1538 case 's': { // Relocatable Constant
1539 // These operands are interested in values of the form (GV+C), where C may
1540 // be folded in as an offset of GV, or it may be explicitly added. Also, it
1541 // is possible and fine if either GV or C are missing.
1542 ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op);
1543 GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(Op);
1545 // If we have "(add GV, C)", pull out GV/C
1546 if (Op.getOpcode() == ISD::ADD) {
1547 C = dyn_cast<ConstantSDNode>(Op.getOperand(1));
1548 GA = dyn_cast<GlobalAddressSDNode>(Op.getOperand(0));
1549 if (C == 0 || GA == 0) {
1550 C = dyn_cast<ConstantSDNode>(Op.getOperand(0));
1551 GA = dyn_cast<GlobalAddressSDNode>(Op.getOperand(1));
1553 if (C == 0 || GA == 0)
1557 // If we find a valid operand, map to the TargetXXX version so that the
1558 // value itself doesn't get selected.
1559 if (GA) { // Either &GV or &GV+C
1560 if (ConstraintLetter != 'n') {
1561 int64_t Offs = GA->getOffset();
1562 if (C) Offs += C->getValue();
1563 Ops.push_back(DAG.getTargetGlobalAddress(GA->getGlobal(),
1564 Op.getValueType(), Offs));
1568 if (C) { // just C, no GV.
1569 // Simple constants are not allowed for 's'.
1570 if (ConstraintLetter != 's') {
1571 Ops.push_back(DAG.getTargetConstant(C->getValue(), Op.getValueType()));
1580 std::vector<unsigned> TargetLowering::
1581 getRegClassForInlineAsmConstraint(const std::string &Constraint,
1582 MVT::ValueType VT) const {
1583 return std::vector<unsigned>();
1587 std::pair<unsigned, const TargetRegisterClass*> TargetLowering::
1588 getRegForInlineAsmConstraint(const std::string &Constraint,
1589 MVT::ValueType VT) const {
1590 if (Constraint[0] != '{')
1591 return std::pair<unsigned, const TargetRegisterClass*>(0, 0);
1592 assert(*(Constraint.end()-1) == '}' && "Not a brace enclosed constraint?");
1594 // Remove the braces from around the name.
1595 std::string RegName(Constraint.begin()+1, Constraint.end()-1);
1597 // Figure out which register class contains this reg.
1598 const MRegisterInfo *RI = TM.getRegisterInfo();
1599 for (MRegisterInfo::regclass_iterator RCI = RI->regclass_begin(),
1600 E = RI->regclass_end(); RCI != E; ++RCI) {
1601 const TargetRegisterClass *RC = *RCI;
1603 // If none of the the value types for this register class are valid, we
1604 // can't use it. For example, 64-bit reg classes on 32-bit targets.
1605 bool isLegal = false;
1606 for (TargetRegisterClass::vt_iterator I = RC->vt_begin(), E = RC->vt_end();
1608 if (isTypeLegal(*I)) {
1614 if (!isLegal) continue;
1616 for (TargetRegisterClass::iterator I = RC->begin(), E = RC->end();
1618 if (StringsEqualNoCase(RegName, RI->get(*I).Name))
1619 return std::make_pair(*I, RC);
1623 return std::pair<unsigned, const TargetRegisterClass*>(0, 0);
1626 //===----------------------------------------------------------------------===//
1627 // Loop Strength Reduction hooks
1628 //===----------------------------------------------------------------------===//
1630 /// isLegalAddressingMode - Return true if the addressing mode represented
1631 /// by AM is legal for this target, for a load/store of the specified type.
1632 bool TargetLowering::isLegalAddressingMode(const AddrMode &AM,
1633 const Type *Ty) const {
1634 // The default implementation of this implements a conservative RISCy, r+r and
1637 // Allows a sign-extended 16-bit immediate field.
1638 if (AM.BaseOffs <= -(1LL << 16) || AM.BaseOffs >= (1LL << 16)-1)
1641 // No global is ever allowed as a base.
1645 // Only support r+r,
1647 case 0: // "r+i" or just "i", depending on HasBaseReg.
1650 if (AM.HasBaseReg && AM.BaseOffs) // "r+r+i" is not allowed.
1652 // Otherwise we have r+r or r+i.
1655 if (AM.HasBaseReg || AM.BaseOffs) // 2*r+r or 2*r+i is not allowed.
1657 // Allow 2*r as r+r.
1664 // Magic for divide replacement
1667 int64_t m; // magic number
1668 int64_t s; // shift amount
1672 uint64_t m; // magic number
1673 int64_t a; // add indicator
1674 int64_t s; // shift amount
1677 /// magic - calculate the magic numbers required to codegen an integer sdiv as
1678 /// a sequence of multiply and shifts. Requires that the divisor not be 0, 1,
1680 static ms magic32(int32_t d) {
1682 uint32_t ad, anc, delta, q1, r1, q2, r2, t;
1683 const uint32_t two31 = 0x80000000U;
1687 t = two31 + ((uint32_t)d >> 31);
1688 anc = t - 1 - t%ad; // absolute value of nc
1689 p = 31; // initialize p
1690 q1 = two31/anc; // initialize q1 = 2p/abs(nc)
1691 r1 = two31 - q1*anc; // initialize r1 = rem(2p,abs(nc))
1692 q2 = two31/ad; // initialize q2 = 2p/abs(d)
1693 r2 = two31 - q2*ad; // initialize r2 = rem(2p,abs(d))
1696 q1 = 2*q1; // update q1 = 2p/abs(nc)
1697 r1 = 2*r1; // update r1 = rem(2p/abs(nc))
1698 if (r1 >= anc) { // must be unsigned comparison
1702 q2 = 2*q2; // update q2 = 2p/abs(d)
1703 r2 = 2*r2; // update r2 = rem(2p/abs(d))
1704 if (r2 >= ad) { // must be unsigned comparison
1709 } while (q1 < delta || (q1 == delta && r1 == 0));
1711 mag.m = (int32_t)(q2 + 1); // make sure to sign extend
1712 if (d < 0) mag.m = -mag.m; // resulting magic number
1713 mag.s = p - 32; // resulting shift
1717 /// magicu - calculate the magic numbers required to codegen an integer udiv as
1718 /// a sequence of multiply, add and shifts. Requires that the divisor not be 0.
1719 static mu magicu32(uint32_t d) {
1721 uint32_t nc, delta, q1, r1, q2, r2;
1723 magu.a = 0; // initialize "add" indicator
1725 p = 31; // initialize p
1726 q1 = 0x80000000/nc; // initialize q1 = 2p/nc
1727 r1 = 0x80000000 - q1*nc; // initialize r1 = rem(2p,nc)
1728 q2 = 0x7FFFFFFF/d; // initialize q2 = (2p-1)/d
1729 r2 = 0x7FFFFFFF - q2*d; // initialize r2 = rem((2p-1),d)
1732 if (r1 >= nc - r1 ) {
1733 q1 = 2*q1 + 1; // update q1
1734 r1 = 2*r1 - nc; // update r1
1737 q1 = 2*q1; // update q1
1738 r1 = 2*r1; // update r1
1740 if (r2 + 1 >= d - r2) {
1741 if (q2 >= 0x7FFFFFFF) magu.a = 1;
1742 q2 = 2*q2 + 1; // update q2
1743 r2 = 2*r2 + 1 - d; // update r2
1746 if (q2 >= 0x80000000) magu.a = 1;
1747 q2 = 2*q2; // update q2
1748 r2 = 2*r2 + 1; // update r2
1751 } while (p < 64 && (q1 < delta || (q1 == delta && r1 == 0)));
1752 magu.m = q2 + 1; // resulting magic number
1753 magu.s = p - 32; // resulting shift
1757 /// magic - calculate the magic numbers required to codegen an integer sdiv as
1758 /// a sequence of multiply and shifts. Requires that the divisor not be 0, 1,
1760 static ms magic64(int64_t d) {
1762 uint64_t ad, anc, delta, q1, r1, q2, r2, t;
1763 const uint64_t two63 = 9223372036854775808ULL; // 2^63
1766 ad = d >= 0 ? d : -d;
1767 t = two63 + ((uint64_t)d >> 63);
1768 anc = t - 1 - t%ad; // absolute value of nc
1769 p = 63; // initialize p
1770 q1 = two63/anc; // initialize q1 = 2p/abs(nc)
1771 r1 = two63 - q1*anc; // initialize r1 = rem(2p,abs(nc))
1772 q2 = two63/ad; // initialize q2 = 2p/abs(d)
1773 r2 = two63 - q2*ad; // initialize r2 = rem(2p,abs(d))
1776 q1 = 2*q1; // update q1 = 2p/abs(nc)
1777 r1 = 2*r1; // update r1 = rem(2p/abs(nc))
1778 if (r1 >= anc) { // must be unsigned comparison
1782 q2 = 2*q2; // update q2 = 2p/abs(d)
1783 r2 = 2*r2; // update r2 = rem(2p/abs(d))
1784 if (r2 >= ad) { // must be unsigned comparison
1789 } while (q1 < delta || (q1 == delta && r1 == 0));
1792 if (d < 0) mag.m = -mag.m; // resulting magic number
1793 mag.s = p - 64; // resulting shift
1797 /// magicu - calculate the magic numbers required to codegen an integer udiv as
1798 /// a sequence of multiply, add and shifts. Requires that the divisor not be 0.
1799 static mu magicu64(uint64_t d)
1802 uint64_t nc, delta, q1, r1, q2, r2;
1804 magu.a = 0; // initialize "add" indicator
1806 p = 63; // initialize p
1807 q1 = 0x8000000000000000ull/nc; // initialize q1 = 2p/nc
1808 r1 = 0x8000000000000000ull - q1*nc; // initialize r1 = rem(2p,nc)
1809 q2 = 0x7FFFFFFFFFFFFFFFull/d; // initialize q2 = (2p-1)/d
1810 r2 = 0x7FFFFFFFFFFFFFFFull - q2*d; // initialize r2 = rem((2p-1),d)
1813 if (r1 >= nc - r1 ) {
1814 q1 = 2*q1 + 1; // update q1
1815 r1 = 2*r1 - nc; // update r1
1818 q1 = 2*q1; // update q1
1819 r1 = 2*r1; // update r1
1821 if (r2 + 1 >= d - r2) {
1822 if (q2 >= 0x7FFFFFFFFFFFFFFFull) magu.a = 1;
1823 q2 = 2*q2 + 1; // update q2
1824 r2 = 2*r2 + 1 - d; // update r2
1827 if (q2 >= 0x8000000000000000ull) magu.a = 1;
1828 q2 = 2*q2; // update q2
1829 r2 = 2*r2 + 1; // update r2
1832 } while (p < 128 && (q1 < delta || (q1 == delta && r1 == 0)));
1833 magu.m = q2 + 1; // resulting magic number
1834 magu.s = p - 64; // resulting shift
1838 /// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant,
1839 /// return a DAG expression to select that will generate the same value by
1840 /// multiplying by a magic number. See:
1841 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
1842 SDOperand TargetLowering::BuildSDIV(SDNode *N, SelectionDAG &DAG,
1843 std::vector<SDNode*>* Created) const {
1844 MVT::ValueType VT = N->getValueType(0);
1846 // Check to see if we can do this.
1847 if (!isTypeLegal(VT) || (VT != MVT::i32 && VT != MVT::i64))
1848 return SDOperand(); // BuildSDIV only operates on i32 or i64
1850 int64_t d = cast<ConstantSDNode>(N->getOperand(1))->getSignExtended();
1851 ms magics = (VT == MVT::i32) ? magic32(d) : magic64(d);
1853 // Multiply the numerator (operand 0) by the magic value
1855 if (isOperationLegal(ISD::MULHS, VT))
1856 Q = DAG.getNode(ISD::MULHS, VT, N->getOperand(0),
1857 DAG.getConstant(magics.m, VT));
1858 else if (isOperationLegal(ISD::SMUL_LOHI, VT))
1859 Q = SDOperand(DAG.getNode(ISD::SMUL_LOHI, DAG.getVTList(VT, VT),
1861 DAG.getConstant(magics.m, VT)).Val, 1);
1863 return SDOperand(); // No mulhs or equvialent
1864 // If d > 0 and m < 0, add the numerator
1865 if (d > 0 && magics.m < 0) {
1866 Q = DAG.getNode(ISD::ADD, VT, Q, N->getOperand(0));
1868 Created->push_back(Q.Val);
1870 // If d < 0 and m > 0, subtract the numerator.
1871 if (d < 0 && magics.m > 0) {
1872 Q = DAG.getNode(ISD::SUB, VT, Q, N->getOperand(0));
1874 Created->push_back(Q.Val);
1876 // Shift right algebraic if shift value is nonzero
1878 Q = DAG.getNode(ISD::SRA, VT, Q,
1879 DAG.getConstant(magics.s, getShiftAmountTy()));
1881 Created->push_back(Q.Val);
1883 // Extract the sign bit and add it to the quotient
1885 DAG.getNode(ISD::SRL, VT, Q, DAG.getConstant(MVT::getSizeInBits(VT)-1,
1886 getShiftAmountTy()));
1888 Created->push_back(T.Val);
1889 return DAG.getNode(ISD::ADD, VT, Q, T);
1892 /// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant,
1893 /// return a DAG expression to select that will generate the same value by
1894 /// multiplying by a magic number. See:
1895 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
1896 SDOperand TargetLowering::BuildUDIV(SDNode *N, SelectionDAG &DAG,
1897 std::vector<SDNode*>* Created) const {
1898 MVT::ValueType VT = N->getValueType(0);
1900 // Check to see if we can do this.
1901 if (!isTypeLegal(VT) || (VT != MVT::i32 && VT != MVT::i64))
1902 return SDOperand(); // BuildUDIV only operates on i32 or i64
1904 uint64_t d = cast<ConstantSDNode>(N->getOperand(1))->getValue();
1905 mu magics = (VT == MVT::i32) ? magicu32(d) : magicu64(d);
1907 // Multiply the numerator (operand 0) by the magic value
1909 if (isOperationLegal(ISD::MULHU, VT))
1910 Q = DAG.getNode(ISD::MULHU, VT, N->getOperand(0),
1911 DAG.getConstant(magics.m, VT));
1912 else if (isOperationLegal(ISD::UMUL_LOHI, VT))
1913 Q = SDOperand(DAG.getNode(ISD::UMUL_LOHI, DAG.getVTList(VT, VT),
1915 DAG.getConstant(magics.m, VT)).Val, 1);
1917 return SDOperand(); // No mulhu or equvialent
1919 Created->push_back(Q.Val);
1921 if (magics.a == 0) {
1922 return DAG.getNode(ISD::SRL, VT, Q,
1923 DAG.getConstant(magics.s, getShiftAmountTy()));
1925 SDOperand NPQ = DAG.getNode(ISD::SUB, VT, N->getOperand(0), Q);
1927 Created->push_back(NPQ.Val);
1928 NPQ = DAG.getNode(ISD::SRL, VT, NPQ,
1929 DAG.getConstant(1, getShiftAmountTy()));
1931 Created->push_back(NPQ.Val);
1932 NPQ = DAG.getNode(ISD::ADD, VT, NPQ, Q);
1934 Created->push_back(NPQ.Val);
1935 return DAG.getNode(ISD::SRL, VT, NPQ,
1936 DAG.getConstant(magics.s-1, getShiftAmountTy()));