1 //===-- AlphaISelDAGToDAG.cpp - Alpha pattern matching inst selector ------===//
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 file defines a pattern matching instruction selector for Alpha,
11 // converting from a legalized dag to a Alpha dag.
13 //===----------------------------------------------------------------------===//
16 #include "AlphaTargetMachine.h"
17 #include "AlphaISelLowering.h"
18 #include "llvm/CodeGen/MachineInstrBuilder.h"
19 #include "llvm/CodeGen/MachineFrameInfo.h"
20 #include "llvm/CodeGen/MachineFunction.h"
21 #include "llvm/CodeGen/MachineRegisterInfo.h"
22 #include "llvm/CodeGen/SelectionDAG.h"
23 #include "llvm/CodeGen/SelectionDAGISel.h"
24 #include "llvm/Target/TargetOptions.h"
25 #include "llvm/Constants.h"
26 #include "llvm/DerivedTypes.h"
27 #include "llvm/GlobalValue.h"
28 #include "llvm/Intrinsics.h"
29 #include "llvm/LLVMContext.h"
30 #include "llvm/Support/Compiler.h"
31 #include "llvm/Support/Debug.h"
32 #include "llvm/Support/ErrorHandling.h"
33 #include "llvm/Support/MathExtras.h"
34 #include "llvm/Support/raw_ostream.h"
40 //===--------------------------------------------------------------------===//
41 /// AlphaDAGToDAGISel - Alpha specific code to select Alpha machine
42 /// instructions for SelectionDAG operations.
43 class AlphaDAGToDAGISel : public SelectionDAGISel {
44 static const int64_t IMM_LOW = -32768;
45 static const int64_t IMM_HIGH = 32767;
46 static const int64_t IMM_MULT = 65536;
47 static const int64_t IMM_FULLHIGH = IMM_HIGH + IMM_HIGH * IMM_MULT;
48 static const int64_t IMM_FULLLOW = IMM_LOW + IMM_LOW * IMM_MULT;
50 static int64_t get_ldah16(int64_t x) {
51 int64_t y = x / IMM_MULT;
52 if (x % IMM_MULT > IMM_HIGH)
57 static int64_t get_lda16(int64_t x) {
58 return x - get_ldah16(x) * IMM_MULT;
61 /// get_zapImm - Return a zap mask if X is a valid immediate for a zapnot
62 /// instruction (if not, return 0). Note that this code accepts partial
63 /// zap masks. For example (and LHS, 1) is a valid zap, as long we know
64 /// that the bits 1-7 of LHS are already zero. If LHS is non-null, we are
65 /// in checking mode. If LHS is null, we assume that the mask has already
66 /// been validated before.
67 uint64_t get_zapImm(SDValue LHS, uint64_t Constant) {
68 uint64_t BitsToCheck = 0;
70 for (unsigned i = 0; i != 8; ++i) {
71 if (((Constant >> 8*i) & 0xFF) == 0) {
75 if (((Constant >> 8*i) & 0xFF) == 0xFF) {
76 // If the entire byte is set, zapnot the byte.
77 } else if (LHS.getNode() == 0) {
78 // Otherwise, if the mask was previously validated, we know its okay
79 // to zapnot this entire byte even though all the bits aren't set.
81 // Otherwise we don't know that the it's okay to zapnot this entire
82 // byte. Only do this iff we can prove that the missing bits are
83 // already null, so the bytezap doesn't need to really null them.
84 BitsToCheck |= ~Constant & (0xFF << 8*i);
89 // If there are missing bits in a byte (for example, X & 0xEF00), check to
90 // see if the missing bits (0x1000) are already known zero if not, the zap
91 // isn't okay to do, as it won't clear all the required bits.
93 !CurDAG->MaskedValueIsZero(LHS,
94 APInt(LHS.getValueSizeInBits(),
101 static uint64_t get_zapImm(uint64_t x) {
103 for(int i = 0; i != 8; ++i) {
104 if ((x & 0x00FF) == 0x00FF)
106 else if ((x & 0x00FF) != 0)
114 static uint64_t getNearPower2(uint64_t x) {
116 unsigned at = CountLeadingZeros_64(x);
117 uint64_t complow = 1 << (63 - at);
118 uint64_t comphigh = 1 << (64 - at);
119 //cerr << x << ":" << complow << ":" << comphigh << "\n";
120 if (abs64(complow - x) <= abs64(comphigh - x))
126 static bool chkRemNearPower2(uint64_t x, uint64_t r, bool swap) {
127 uint64_t y = getNearPower2(x);
134 static bool isFPZ(SDValue N) {
135 ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(N);
136 return (CN && (CN->getValueAPF().isZero()));
138 static bool isFPZn(SDValue N) {
139 ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(N);
140 return (CN && CN->getValueAPF().isNegZero());
142 static bool isFPZp(SDValue N) {
143 ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(N);
144 return (CN && CN->getValueAPF().isPosZero());
148 explicit AlphaDAGToDAGISel(AlphaTargetMachine &TM)
149 : SelectionDAGISel(TM)
152 /// getI64Imm - Return a target constant with the specified value, of type
154 inline SDValue getI64Imm(int64_t Imm) {
155 return CurDAG->getTargetConstant(Imm, MVT::i64);
158 // Select - Convert the specified operand from a target-independent to a
159 // target-specific node if it hasn't already been changed.
160 SDNode *Select(SDNode *N);
162 /// InstructionSelect - This callback is invoked by
163 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
164 virtual void InstructionSelect();
166 virtual const char *getPassName() const {
167 return "Alpha DAG->DAG Pattern Instruction Selection";
170 /// SelectInlineAsmMemoryOperand - Implement addressing mode selection for
171 /// inline asm expressions.
172 virtual bool SelectInlineAsmMemoryOperand(const SDValue &Op,
174 std::vector<SDValue> &OutOps) {
176 switch (ConstraintCode) {
177 default: return true;
183 OutOps.push_back(Op0);
187 // Include the pieces autogenerated from the target description.
188 #include "AlphaGenDAGISel.inc"
191 /// getTargetMachine - Return a reference to the TargetMachine, casted
192 /// to the target-specific type.
193 const AlphaTargetMachine &getTargetMachine() {
194 return static_cast<const AlphaTargetMachine &>(TM);
197 /// getInstrInfo - Return a reference to the TargetInstrInfo, casted
198 /// to the target-specific type.
199 const AlphaInstrInfo *getInstrInfo() {
200 return getTargetMachine().getInstrInfo();
203 SDNode *getGlobalBaseReg();
204 SDNode *getGlobalRetAddr();
205 void SelectCALL(SDNode *Op);
210 /// getGlobalBaseReg - Output the instructions required to put the
211 /// GOT address into a register.
213 SDNode *AlphaDAGToDAGISel::getGlobalBaseReg() {
214 unsigned GlobalBaseReg = getInstrInfo()->getGlobalBaseReg(MF);
215 return CurDAG->getRegister(GlobalBaseReg, TLI.getPointerTy()).getNode();
218 /// getGlobalRetAddr - Grab the return address.
220 SDNode *AlphaDAGToDAGISel::getGlobalRetAddr() {
221 unsigned GlobalRetAddr = getInstrInfo()->getGlobalRetAddr(MF);
222 return CurDAG->getRegister(GlobalRetAddr, TLI.getPointerTy()).getNode();
225 /// InstructionSelect - This callback is invoked by
226 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
227 void AlphaDAGToDAGISel::InstructionSelect() {
228 // Select target instructions for the DAG.
230 CurDAG->RemoveDeadNodes();
233 // Select - Convert the specified operand from a target-independent to a
234 // target-specific node if it hasn't already been changed.
235 SDNode *AlphaDAGToDAGISel::Select(SDNode *N) {
236 if (N->isMachineOpcode()) {
237 return NULL; // Already selected.
239 DebugLoc dl = N->getDebugLoc();
241 switch (N->getOpcode()) {
247 case ISD::FrameIndex: {
248 int FI = cast<FrameIndexSDNode>(N)->getIndex();
249 return CurDAG->SelectNodeTo(N, Alpha::LDA, MVT::i64,
250 CurDAG->getTargetFrameIndex(FI, MVT::i32),
253 case ISD::GLOBAL_OFFSET_TABLE:
254 return getGlobalBaseReg();
255 case AlphaISD::GlobalRetAddr:
256 return getGlobalRetAddr();
258 case AlphaISD::DivCall: {
259 SDValue Chain = CurDAG->getEntryNode();
260 SDValue N0 = N->getOperand(0);
261 SDValue N1 = N->getOperand(1);
262 SDValue N2 = N->getOperand(2);
263 Chain = CurDAG->getCopyToReg(Chain, dl, Alpha::R24, N1,
265 Chain = CurDAG->getCopyToReg(Chain, dl, Alpha::R25, N2,
267 Chain = CurDAG->getCopyToReg(Chain, dl, Alpha::R27, N0,
270 CurDAG->getMachineNode(Alpha::JSRs, dl, MVT::Other, MVT::Flag,
271 Chain, Chain.getValue(1));
272 Chain = CurDAG->getCopyFromReg(Chain, dl, Alpha::R27, MVT::i64,
274 return CurDAG->SelectNodeTo(N, Alpha::BISr, MVT::i64, Chain, Chain);
277 case ISD::READCYCLECOUNTER: {
278 SDValue Chain = N->getOperand(0);
279 return CurDAG->getMachineNode(Alpha::RPCC, dl, MVT::i64, MVT::Other,
283 case ISD::Constant: {
284 uint64_t uval = cast<ConstantSDNode>(N)->getZExtValue();
287 SDValue Result = CurDAG->getCopyFromReg(CurDAG->getEntryNode(), dl,
288 Alpha::R31, MVT::i64);
289 ReplaceUses(SDValue(N, 0), Result);
293 int64_t val = (int64_t)uval;
294 int32_t val32 = (int32_t)val;
295 if (val <= IMM_HIGH + IMM_HIGH * IMM_MULT &&
296 val >= IMM_LOW + IMM_LOW * IMM_MULT)
297 break; //(LDAH (LDA))
298 if ((uval >> 32) == 0 && //empty upper bits
299 val32 <= IMM_HIGH + IMM_HIGH * IMM_MULT)
300 // val32 >= IMM_LOW + IMM_LOW * IMM_MULT) //always true
301 break; //(zext (LDAH (LDA)))
302 //Else use the constant pool
303 ConstantInt *C = ConstantInt::get(
304 Type::getInt64Ty(*CurDAG->getContext()), uval);
305 SDValue CPI = CurDAG->getTargetConstantPool(C, MVT::i64);
306 SDNode *Tmp = CurDAG->getMachineNode(Alpha::LDAHr, dl, MVT::i64, CPI,
307 SDValue(getGlobalBaseReg(), 0));
308 return CurDAG->SelectNodeTo(N, Alpha::LDQr, MVT::i64, MVT::Other,
309 CPI, SDValue(Tmp, 0), CurDAG->getEntryNode());
311 case ISD::TargetConstantFP:
312 case ISD::ConstantFP: {
313 ConstantFPSDNode *CN = cast<ConstantFPSDNode>(N);
314 bool isDouble = N->getValueType(0) == MVT::f64;
315 EVT T = isDouble ? MVT::f64 : MVT::f32;
316 if (CN->getValueAPF().isPosZero()) {
317 return CurDAG->SelectNodeTo(N, isDouble ? Alpha::CPYST : Alpha::CPYSS,
318 T, CurDAG->getRegister(Alpha::F31, T),
319 CurDAG->getRegister(Alpha::F31, T));
320 } else if (CN->getValueAPF().isNegZero()) {
321 return CurDAG->SelectNodeTo(N, isDouble ? Alpha::CPYSNT : Alpha::CPYSNS,
322 T, CurDAG->getRegister(Alpha::F31, T),
323 CurDAG->getRegister(Alpha::F31, T));
325 llvm_report_error("Unhandled FP constant type");
331 if (N->getOperand(0).getNode()->getValueType(0).isFloatingPoint()) {
332 ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(2))->get();
334 unsigned Opc = Alpha::WTF;
338 default: DEBUG(N->dump(CurDAG)); llvm_unreachable("Unknown FP comparison!");
339 case ISD::SETEQ: case ISD::SETOEQ: case ISD::SETUEQ:
340 Opc = Alpha::CMPTEQ; break;
341 case ISD::SETLT: case ISD::SETOLT: case ISD::SETULT:
342 Opc = Alpha::CMPTLT; break;
343 case ISD::SETLE: case ISD::SETOLE: case ISD::SETULE:
344 Opc = Alpha::CMPTLE; break;
345 case ISD::SETGT: case ISD::SETOGT: case ISD::SETUGT:
346 Opc = Alpha::CMPTLT; rev = true; break;
347 case ISD::SETGE: case ISD::SETOGE: case ISD::SETUGE:
348 Opc = Alpha::CMPTLE; rev = true; break;
349 case ISD::SETNE: case ISD::SETONE: case ISD::SETUNE:
350 Opc = Alpha::CMPTEQ; inv = true; break;
352 Opc = Alpha::CMPTUN; inv = true; break;
354 Opc = Alpha::CMPTUN; break;
356 SDValue tmp1 = N->getOperand(rev?1:0);
357 SDValue tmp2 = N->getOperand(rev?0:1);
358 SDNode *cmp = CurDAG->getMachineNode(Opc, dl, MVT::f64, tmp1, tmp2);
360 cmp = CurDAG->getMachineNode(Alpha::CMPTEQ, dl,
361 MVT::f64, SDValue(cmp, 0),
362 CurDAG->getRegister(Alpha::F31, MVT::f64));
364 case ISD::SETUEQ: case ISD::SETULT: case ISD::SETULE:
365 case ISD::SETUNE: case ISD::SETUGT: case ISD::SETUGE:
367 SDNode* cmp2 = CurDAG->getMachineNode(Alpha::CMPTUN, dl, MVT::f64,
369 cmp = CurDAG->getMachineNode(Alpha::ADDT, dl, MVT::f64,
370 SDValue(cmp2, 0), SDValue(cmp, 0));
376 SDNode* LD = CurDAG->getMachineNode(Alpha::FTOIT, dl,
377 MVT::i64, SDValue(cmp, 0));
378 return CurDAG->getMachineNode(Alpha::CMPULT, dl, MVT::i64,
379 CurDAG->getRegister(Alpha::R31, MVT::i64),
385 ConstantSDNode* SC = NULL;
386 ConstantSDNode* MC = NULL;
387 if (N->getOperand(0).getOpcode() == ISD::SRL &&
388 (MC = dyn_cast<ConstantSDNode>(N->getOperand(1))) &&
389 (SC = dyn_cast<ConstantSDNode>(N->getOperand(0).getOperand(1)))) {
390 uint64_t sval = SC->getZExtValue();
391 uint64_t mval = MC->getZExtValue();
392 // If the result is a zap, let the autogened stuff handle it.
393 if (get_zapImm(N->getOperand(0), mval))
395 // given mask X, and shift S, we want to see if there is any zap in the
396 // mask if we play around with the botton S bits
397 uint64_t dontcare = (~0ULL) >> (64 - sval);
398 uint64_t mask = mval << sval;
400 if (get_zapImm(mask | dontcare))
401 mask = mask | dontcare;
403 if (get_zapImm(mask)) {
405 SDValue(CurDAG->getMachineNode(Alpha::ZAPNOTi, dl, MVT::i64,
406 N->getOperand(0).getOperand(0),
407 getI64Imm(get_zapImm(mask))), 0);
408 return CurDAG->getMachineNode(Alpha::SRLr, dl, MVT::i64, Z,
417 return SelectCode(N);
420 void AlphaDAGToDAGISel::SelectCALL(SDNode *N) {
421 //TODO: add flag stuff to prevent nondeturministic breakage!
423 SDValue Chain = N->getOperand(0);
424 SDValue Addr = N->getOperand(1);
425 SDValue InFlag = N->getOperand(N->getNumOperands() - 1);
426 DebugLoc dl = N->getDebugLoc();
428 if (Addr.getOpcode() == AlphaISD::GPRelLo) {
429 SDValue GOT = SDValue(getGlobalBaseReg(), 0);
430 Chain = CurDAG->getCopyToReg(Chain, dl, Alpha::R29, GOT, InFlag);
431 InFlag = Chain.getValue(1);
432 Chain = SDValue(CurDAG->getMachineNode(Alpha::BSR, dl, MVT::Other,
433 MVT::Flag, Addr.getOperand(0),
436 Chain = CurDAG->getCopyToReg(Chain, dl, Alpha::R27, Addr, InFlag);
437 InFlag = Chain.getValue(1);
438 Chain = SDValue(CurDAG->getMachineNode(Alpha::JSR, dl, MVT::Other,
439 MVT::Flag, Chain, InFlag), 0);
441 InFlag = Chain.getValue(1);
443 ReplaceUses(SDValue(N, 0), Chain);
444 ReplaceUses(SDValue(N, 1), InFlag);
448 /// createAlphaISelDag - This pass converts a legalized DAG into a
449 /// Alpha-specific DAG, ready for instruction scheduling.
451 FunctionPass *llvm::createAlphaISelDag(AlphaTargetMachine &TM) {
452 return new AlphaDAGToDAGISel(TM);