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/Support/Compiler.h"
30 #include "llvm/Support/Debug.h"
31 #include "llvm/Support/MathExtras.h"
39 //===--------------------------------------------------------------------===//
40 /// AlphaDAGToDAGISel - Alpha specific code to select Alpha machine
41 /// instructions for SelectionDAG operations.
42 class AlphaDAGToDAGISel : public SelectionDAGISel {
43 AlphaTargetLowering AlphaLowering;
45 static const int64_t IMM_LOW = -32768;
46 static const int64_t IMM_HIGH = 32767;
47 static const int64_t IMM_MULT = 65536;
48 static const int64_t IMM_FULLHIGH = IMM_HIGH + IMM_HIGH * IMM_MULT;
49 static const int64_t IMM_FULLLOW = IMM_LOW + IMM_LOW * IMM_MULT;
51 static int64_t get_ldah16(int64_t x) {
52 int64_t y = x / IMM_MULT;
53 if (x % IMM_MULT > IMM_HIGH)
58 static int64_t get_lda16(int64_t x) {
59 return x - get_ldah16(x) * IMM_MULT;
62 /// get_zapImm - Return a zap mask if X is a valid immediate for a zapnot
63 /// instruction (if not, return 0). Note that this code accepts partial
64 /// zap masks. For example (and LHS, 1) is a valid zap, as long we know
65 /// that the bits 1-7 of LHS are already zero. If LHS is non-null, we are
66 /// in checking mode. If LHS is null, we assume that the mask has already
67 /// been validated before.
68 uint64_t get_zapImm(SDValue LHS, uint64_t Constant) {
69 uint64_t BitsToCheck = 0;
71 for (unsigned i = 0; i != 8; ++i) {
72 if (((Constant >> 8*i) & 0xFF) == 0) {
76 if (((Constant >> 8*i) & 0xFF) == 0xFF) {
77 // If the entire byte is set, zapnot the byte.
78 } else if (LHS.Val == 0) {
79 // Otherwise, if the mask was previously validated, we know its okay
80 // to zapnot this entire byte even though all the bits aren't set.
82 // Otherwise we don't know that the it's okay to zapnot this entire
83 // byte. Only do this iff we can prove that the missing bits are
84 // already null, so the bytezap doesn't need to really null them.
85 BitsToCheck |= ~Constant & (0xFF << 8*i);
90 // If there are missing bits in a byte (for example, X & 0xEF00), check to
91 // see if the missing bits (0x1000) are already known zero if not, the zap
92 // isn't okay to do, as it won't clear all the required bits.
94 !CurDAG->MaskedValueIsZero(LHS,
95 APInt(LHS.getValueSizeInBits(),
102 static uint64_t get_zapImm(uint64_t x) {
104 for(int i = 0; i != 8; ++i) {
105 if ((x & 0x00FF) == 0x00FF)
107 else if ((x & 0x00FF) != 0)
115 static uint64_t getNearPower2(uint64_t x) {
117 unsigned at = CountLeadingZeros_64(x);
118 uint64_t complow = 1 << (63 - at);
119 uint64_t comphigh = 1 << (64 - at);
120 //cerr << x << ":" << complow << ":" << comphigh << "\n";
121 if (abs(complow - x) <= abs(comphigh - x))
127 static bool chkRemNearPower2(uint64_t x, uint64_t r, bool swap) {
128 uint64_t y = getNearPower2(x);
135 static bool isFPZ(SDValue N) {
136 ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(N);
137 return (CN && (CN->getValueAPF().isZero()));
139 static bool isFPZn(SDValue N) {
140 ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(N);
141 return (CN && CN->getValueAPF().isNegZero());
143 static bool isFPZp(SDValue N) {
144 ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(N);
145 return (CN && CN->getValueAPF().isPosZero());
149 explicit AlphaDAGToDAGISel(AlphaTargetMachine &TM)
150 : SelectionDAGISel(AlphaLowering),
151 AlphaLowering(*TM.getTargetLowering())
154 /// getI64Imm - Return a target constant with the specified value, of type
156 inline SDValue getI64Imm(int64_t Imm) {
157 return CurDAG->getTargetConstant(Imm, MVT::i64);
160 // Select - Convert the specified operand from a target-independent to a
161 // target-specific node if it hasn't already been changed.
162 SDNode *Select(SDValue Op);
164 /// InstructionSelect - This callback is invoked by
165 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
166 virtual void InstructionSelect(SelectionDAG &DAG);
168 virtual const char *getPassName() const {
169 return "Alpha DAG->DAG Pattern Instruction Selection";
172 /// SelectInlineAsmMemoryOperand - Implement addressing mode selection for
173 /// inline asm expressions.
174 virtual bool SelectInlineAsmMemoryOperand(const SDValue &Op,
176 std::vector<SDValue> &OutOps,
179 switch (ConstraintCode) {
180 default: return true;
187 OutOps.push_back(Op0);
191 // Include the pieces autogenerated from the target description.
192 #include "AlphaGenDAGISel.inc"
195 SDValue getGlobalBaseReg();
196 SDValue getGlobalRetAddr();
197 void SelectCALL(SDValue Op);
202 /// getGlobalBaseReg - Output the instructions required to put the
203 /// GOT address into a register.
205 SDValue AlphaDAGToDAGISel::getGlobalBaseReg() {
207 for(MachineRegisterInfo::livein_iterator ii = RegInfo->livein_begin(),
208 ee = RegInfo->livein_end(); ii != ee; ++ii)
209 if (ii->first == Alpha::R29) {
213 assert(GP && "GOT PTR not in liveins");
214 return CurDAG->getCopyFromReg(CurDAG->getEntryNode(),
218 /// getRASaveReg - Grab the return address
220 SDValue AlphaDAGToDAGISel::getGlobalRetAddr() {
222 for(MachineRegisterInfo::livein_iterator ii = RegInfo->livein_begin(),
223 ee = RegInfo->livein_end(); ii != ee; ++ii)
224 if (ii->first == Alpha::R26) {
228 assert(RA && "RA PTR not in liveins");
229 return CurDAG->getCopyFromReg(CurDAG->getEntryNode(),
233 /// InstructionSelect - This callback is invoked by
234 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
235 void AlphaDAGToDAGISel::InstructionSelect(SelectionDAG &DAG) {
238 // Select target instructions for the DAG.
239 DAG.setRoot(SelectRoot(DAG.getRoot()));
240 DAG.RemoveDeadNodes();
243 // Select - Convert the specified operand from a target-independent to a
244 // target-specific node if it hasn't already been changed.
245 SDNode *AlphaDAGToDAGISel::Select(SDValue Op) {
247 if (N->isMachineOpcode()) {
248 return NULL; // Already selected.
251 switch (N->getOpcode()) {
257 case ISD::FrameIndex: {
258 int FI = cast<FrameIndexSDNode>(N)->getIndex();
259 return CurDAG->SelectNodeTo(N, Alpha::LDA, MVT::i64,
260 CurDAG->getTargetFrameIndex(FI, MVT::i32),
263 case ISD::GLOBAL_OFFSET_TABLE: {
264 SDValue Result = getGlobalBaseReg();
265 ReplaceUses(Op, Result);
268 case AlphaISD::GlobalRetAddr: {
269 SDValue Result = getGlobalRetAddr();
270 ReplaceUses(Op, Result);
274 case AlphaISD::DivCall: {
275 SDValue Chain = CurDAG->getEntryNode();
276 SDValue N0 = Op.getOperand(0);
277 SDValue N1 = Op.getOperand(1);
278 SDValue N2 = Op.getOperand(2);
282 Chain = CurDAG->getCopyToReg(Chain, Alpha::R24, N1,
284 Chain = CurDAG->getCopyToReg(Chain, Alpha::R25, N2,
286 Chain = CurDAG->getCopyToReg(Chain, Alpha::R27, N0,
289 CurDAG->getTargetNode(Alpha::JSRs, MVT::Other, MVT::Flag,
290 Chain, Chain.getValue(1));
291 Chain = CurDAG->getCopyFromReg(Chain, Alpha::R27, MVT::i64,
293 return CurDAG->SelectNodeTo(N, Alpha::BISr, MVT::i64, Chain, Chain);
296 case ISD::READCYCLECOUNTER: {
297 SDValue Chain = N->getOperand(0);
298 AddToISelQueue(Chain); //Select chain
299 return CurDAG->getTargetNode(Alpha::RPCC, MVT::i64, MVT::Other,
303 case ISD::Constant: {
304 uint64_t uval = cast<ConstantSDNode>(N)->getValue();
307 SDValue Result = CurDAG->getCopyFromReg(CurDAG->getEntryNode(),
308 Alpha::R31, MVT::i64);
309 ReplaceUses(Op, Result);
313 int64_t val = (int64_t)uval;
314 int32_t val32 = (int32_t)val;
315 if (val <= IMM_HIGH + IMM_HIGH * IMM_MULT &&
316 val >= IMM_LOW + IMM_LOW * IMM_MULT)
317 break; //(LDAH (LDA))
318 if ((uval >> 32) == 0 && //empty upper bits
319 val32 <= IMM_HIGH + IMM_HIGH * IMM_MULT)
320 // val32 >= IMM_LOW + IMM_LOW * IMM_MULT) //always true
321 break; //(zext (LDAH (LDA)))
322 //Else use the constant pool
323 ConstantInt *C = ConstantInt::get(Type::Int64Ty, uval);
324 SDValue CPI = CurDAG->getTargetConstantPool(C, MVT::i64);
325 SDNode *Tmp = CurDAG->getTargetNode(Alpha::LDAHr, MVT::i64, CPI,
327 return CurDAG->SelectNodeTo(N, Alpha::LDQr, MVT::i64, MVT::Other,
328 CPI, SDValue(Tmp, 0), CurDAG->getEntryNode());
330 case ISD::TargetConstantFP: {
331 ConstantFPSDNode *CN = cast<ConstantFPSDNode>(N);
332 bool isDouble = N->getValueType(0) == MVT::f64;
333 MVT T = isDouble ? MVT::f64 : MVT::f32;
334 if (CN->getValueAPF().isPosZero()) {
335 return CurDAG->SelectNodeTo(N, isDouble ? Alpha::CPYST : Alpha::CPYSS,
336 T, CurDAG->getRegister(Alpha::F31, T),
337 CurDAG->getRegister(Alpha::F31, T));
338 } else if (CN->getValueAPF().isNegZero()) {
339 return CurDAG->SelectNodeTo(N, isDouble ? Alpha::CPYSNT : Alpha::CPYSNS,
340 T, CurDAG->getRegister(Alpha::F31, T),
341 CurDAG->getRegister(Alpha::F31, T));
349 if (N->getOperand(0).Val->getValueType(0).isFloatingPoint()) {
350 ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(2))->get();
352 unsigned Opc = Alpha::WTF;
356 default: DEBUG(N->dump(CurDAG)); assert(0 && "Unknown FP comparison!");
357 case ISD::SETEQ: case ISD::SETOEQ: case ISD::SETUEQ:
358 Opc = Alpha::CMPTEQ; break;
359 case ISD::SETLT: case ISD::SETOLT: case ISD::SETULT:
360 Opc = Alpha::CMPTLT; break;
361 case ISD::SETLE: case ISD::SETOLE: case ISD::SETULE:
362 Opc = Alpha::CMPTLE; break;
363 case ISD::SETGT: case ISD::SETOGT: case ISD::SETUGT:
364 Opc = Alpha::CMPTLT; rev = true; break;
365 case ISD::SETGE: case ISD::SETOGE: case ISD::SETUGE:
366 Opc = Alpha::CMPTLE; rev = true; break;
367 case ISD::SETNE: case ISD::SETONE: case ISD::SETUNE:
368 Opc = Alpha::CMPTEQ; inv = true; break;
370 Opc = Alpha::CMPTUN; inv = true; break;
372 Opc = Alpha::CMPTUN; break;
374 SDValue tmp1 = N->getOperand(rev?1:0);
375 SDValue tmp2 = N->getOperand(rev?0:1);
376 AddToISelQueue(tmp1);
377 AddToISelQueue(tmp2);
378 SDNode *cmp = CurDAG->getTargetNode(Opc, MVT::f64, tmp1, tmp2);
380 cmp = CurDAG->getTargetNode(Alpha::CMPTEQ, MVT::f64, SDValue(cmp, 0),
381 CurDAG->getRegister(Alpha::F31, MVT::f64));
383 case ISD::SETUEQ: case ISD::SETULT: case ISD::SETULE:
384 case ISD::SETUNE: case ISD::SETUGT: case ISD::SETUGE:
386 SDNode* cmp2 = CurDAG->getTargetNode(Alpha::CMPTUN, MVT::f64,
388 cmp = CurDAG->getTargetNode(Alpha::ADDT, MVT::f64,
389 SDValue(cmp2, 0), SDValue(cmp, 0));
395 SDNode* LD = CurDAG->getTargetNode(Alpha::FTOIT, MVT::i64, SDValue(cmp, 0));
396 return CurDAG->getTargetNode(Alpha::CMPULT, MVT::i64,
397 CurDAG->getRegister(Alpha::R31, MVT::i64),
403 if (N->getValueType(0).isFloatingPoint() &&
404 (N->getOperand(0).getOpcode() != ISD::SETCC ||
405 !N->getOperand(0).getOperand(1).getValueType().isFloatingPoint())) {
406 //This should be the condition not covered by the Patterns
407 //FIXME: Don't have SelectCode die, but rather return something testable
408 // so that things like this can be caught in fall though code
410 bool isDouble = N->getValueType(0) == MVT::f64;
411 SDValue cond = N->getOperand(0);
412 SDValue TV = N->getOperand(1);
413 SDValue FV = N->getOperand(2);
414 AddToISelQueue(cond);
418 SDNode* LD = CurDAG->getTargetNode(Alpha::ITOFT, MVT::f64, cond);
419 return CurDAG->getTargetNode(isDouble?Alpha::FCMOVNET:Alpha::FCMOVNES,
420 MVT::f64, FV, TV, SDValue(LD,0));
425 ConstantSDNode* SC = NULL;
426 ConstantSDNode* MC = NULL;
427 if (N->getOperand(0).getOpcode() == ISD::SRL &&
428 (MC = dyn_cast<ConstantSDNode>(N->getOperand(1))) &&
429 (SC = dyn_cast<ConstantSDNode>(N->getOperand(0).getOperand(1)))) {
430 uint64_t sval = SC->getValue();
431 uint64_t mval = MC->getValue();
432 // If the result is a zap, let the autogened stuff handle it.
433 if (get_zapImm(N->getOperand(0), mval))
435 // given mask X, and shift S, we want to see if there is any zap in the
436 // mask if we play around with the botton S bits
437 uint64_t dontcare = (~0ULL) >> (64 - sval);
438 uint64_t mask = mval << sval;
440 if (get_zapImm(mask | dontcare))
441 mask = mask | dontcare;
443 if (get_zapImm(mask)) {
444 AddToISelQueue(N->getOperand(0).getOperand(0));
446 SDValue(CurDAG->getTargetNode(Alpha::ZAPNOTi, MVT::i64,
447 N->getOperand(0).getOperand(0),
448 getI64Imm(get_zapImm(mask))), 0);
449 return CurDAG->getTargetNode(Alpha::SRLr, MVT::i64, Z,
458 return SelectCode(Op);
461 void AlphaDAGToDAGISel::SelectCALL(SDValue Op) {
462 //TODO: add flag stuff to prevent nondeturministic breakage!
465 SDValue Chain = N->getOperand(0);
466 SDValue Addr = N->getOperand(1);
467 SDValue InFlag(0,0); // Null incoming flag value.
468 AddToISelQueue(Chain);
470 std::vector<SDValue> CallOperands;
471 std::vector<MVT> TypeOperands;
474 for(int i = 2, e = N->getNumOperands(); i < e; ++i) {
475 TypeOperands.push_back(N->getOperand(i).getValueType());
476 AddToISelQueue(N->getOperand(i));
477 CallOperands.push_back(N->getOperand(i));
479 int count = N->getNumOperands() - 2;
481 static const unsigned args_int[] = {Alpha::R16, Alpha::R17, Alpha::R18,
482 Alpha::R19, Alpha::R20, Alpha::R21};
483 static const unsigned args_float[] = {Alpha::F16, Alpha::F17, Alpha::F18,
484 Alpha::F19, Alpha::F20, Alpha::F21};
486 for (int i = 6; i < count; ++i) {
487 unsigned Opc = Alpha::WTF;
488 if (TypeOperands[i].isInteger()) {
490 } else if (TypeOperands[i] == MVT::f32) {
492 } else if (TypeOperands[i] == MVT::f64) {
495 assert(0 && "Unknown operand");
497 SDValue Ops[] = { CallOperands[i], getI64Imm((i - 6) * 8),
498 CurDAG->getCopyFromReg(Chain, Alpha::R30, MVT::i64),
500 Chain = SDValue(CurDAG->getTargetNode(Opc, MVT::Other, Ops, 4), 0);
502 for (int i = 0; i < std::min(6, count); ++i) {
503 if (TypeOperands[i].isInteger()) {
504 Chain = CurDAG->getCopyToReg(Chain, args_int[i], CallOperands[i], InFlag);
505 InFlag = Chain.getValue(1);
506 } else if (TypeOperands[i] == MVT::f32 || TypeOperands[i] == MVT::f64) {
507 Chain = CurDAG->getCopyToReg(Chain, args_float[i], CallOperands[i], InFlag);
508 InFlag = Chain.getValue(1);
510 assert(0 && "Unknown operand");
513 // Finally, once everything is in registers to pass to the call, emit the
515 if (Addr.getOpcode() == AlphaISD::GPRelLo) {
516 SDValue GOT = getGlobalBaseReg();
517 Chain = CurDAG->getCopyToReg(Chain, Alpha::R29, GOT, InFlag);
518 InFlag = Chain.getValue(1);
519 Chain = SDValue(CurDAG->getTargetNode(Alpha::BSR, MVT::Other, MVT::Flag,
520 Addr.getOperand(0), Chain, InFlag), 0);
522 AddToISelQueue(Addr);
523 Chain = CurDAG->getCopyToReg(Chain, Alpha::R27, Addr, InFlag);
524 InFlag = Chain.getValue(1);
525 Chain = SDValue(CurDAG->getTargetNode(Alpha::JSR, MVT::Other, MVT::Flag,
528 InFlag = Chain.getValue(1);
530 std::vector<SDValue> CallResults;
532 switch (N->getValueType(0).getSimpleVT()) {
533 default: assert(0 && "Unexpected ret value!");
534 case MVT::Other: break;
536 Chain = CurDAG->getCopyFromReg(Chain, Alpha::R0, MVT::i64, InFlag).getValue(1);
537 CallResults.push_back(Chain.getValue(0));
540 Chain = CurDAG->getCopyFromReg(Chain, Alpha::F0, MVT::f32, InFlag).getValue(1);
541 CallResults.push_back(Chain.getValue(0));
544 Chain = CurDAG->getCopyFromReg(Chain, Alpha::F0, MVT::f64, InFlag).getValue(1);
545 CallResults.push_back(Chain.getValue(0));
549 CallResults.push_back(Chain);
550 for (unsigned i = 0, e = CallResults.size(); i != e; ++i)
551 ReplaceUses(Op.getValue(i), CallResults[i]);
555 /// createAlphaISelDag - This pass converts a legalized DAG into a
556 /// Alpha-specific DAG, ready for instruction scheduling.
558 FunctionPass *llvm::createAlphaISelDag(AlphaTargetMachine &TM) {
559 return new AlphaDAGToDAGISel(TM);