1 //===-- MBlazeISelLowering.cpp - MBlaze DAG Lowering Implementation -------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines the interfaces that MBlaze uses to lower LLVM code into a
11 // selection DAG.
12 //
13 //===----------------------------------------------------------------------===//
14
15 #define DEBUG_TYPE "mblaze-lower"
16 #include "MBlazeISelLowering.h"
17 #include "MBlazeMachineFunction.h"
18 #include "MBlazeSubtarget.h"
19 #include "MBlazeTargetMachine.h"
20 #include "MBlazeTargetObjectFile.h"
21 #include "llvm/CodeGen/CallingConvLower.h"
22 #include "llvm/CodeGen/MachineFrameInfo.h"
23 #include "llvm/CodeGen/MachineFunction.h"
24 #include "llvm/CodeGen/MachineInstrBuilder.h"
25 #include "llvm/CodeGen/MachineRegisterInfo.h"
26 #include "llvm/CodeGen/SelectionDAGISel.h"
27 #include "llvm/CodeGen/ValueTypes.h"
28 #include "llvm/IR/CallingConv.h"
29 #include "llvm/IR/DerivedTypes.h"
30 #include "llvm/IR/Function.h"
31 #include "llvm/IR/GlobalVariable.h"
32 #include "llvm/IR/Intrinsics.h"
33 #include "llvm/Support/Debug.h"
34 #include "llvm/Support/ErrorHandling.h"
35 #include "llvm/Support/raw_ostream.h"
36 using namespace llvm;
37
38 static bool CC_MBlaze_AssignReg(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
39 CCValAssign::LocInfo &LocInfo,
40 ISD::ArgFlagsTy &ArgFlags,
41 CCState &State);
42
getTargetNodeName(unsigned Opcode) const43 const char *MBlazeTargetLowering::getTargetNodeName(unsigned Opcode) const {
44 switch (Opcode) {
45 case MBlazeISD::JmpLink : return "MBlazeISD::JmpLink";
46 case MBlazeISD::GPRel : return "MBlazeISD::GPRel";
47 case MBlazeISD::Wrap : return "MBlazeISD::Wrap";
48 case MBlazeISD::ICmp : return "MBlazeISD::ICmp";
49 case MBlazeISD::Ret : return "MBlazeISD::Ret";
50 case MBlazeISD::Select_CC : return "MBlazeISD::Select_CC";
51 default : return NULL;
52 }
53 }
54
MBlazeTargetLowering(MBlazeTargetMachine & TM)55 MBlazeTargetLowering::MBlazeTargetLowering(MBlazeTargetMachine &TM)
56 : TargetLowering(TM, new MBlazeTargetObjectFile()) {
57 Subtarget = &TM.getSubtarget<MBlazeSubtarget>();
58
59 // MBlaze does not have i1 type, so use i32 for
60 // setcc operations results (slt, sgt, ...).
61 setBooleanContents(ZeroOrOneBooleanContent);
62 setBooleanVectorContents(ZeroOrOneBooleanContent); // FIXME: Is this correct?
63
64 // Set up the register classes
65 addRegisterClass(MVT::i32, &MBlaze::GPRRegClass);
66 if (Subtarget->hasFPU()) {
67 addRegisterClass(MVT::f32, &MBlaze::GPRRegClass);
68 setOperationAction(ISD::ConstantFP, MVT::f32, Legal);
69 }
70
71 // Floating point operations which are not supported
72 setOperationAction(ISD::FREM, MVT::f32, Expand);
73 setOperationAction(ISD::FMA, MVT::f32, Expand);
74 setOperationAction(ISD::UINT_TO_FP, MVT::i8, Expand);
75 setOperationAction(ISD::UINT_TO_FP, MVT::i16, Expand);
76 setOperationAction(ISD::UINT_TO_FP, MVT::i32, Expand);
77 setOperationAction(ISD::FP_TO_UINT, MVT::i32, Expand);
78 setOperationAction(ISD::FP_ROUND, MVT::f32, Expand);
79 setOperationAction(ISD::FP_ROUND, MVT::f64, Expand);
80 setOperationAction(ISD::FCOPYSIGN, MVT::f32, Expand);
81 setOperationAction(ISD::FCOPYSIGN, MVT::f64, Expand);
82 setOperationAction(ISD::FSIN, MVT::f32, Expand);
83 setOperationAction(ISD::FCOS, MVT::f32, Expand);
84 setOperationAction(ISD::FSINCOS, MVT::f32, Expand);
85 setOperationAction(ISD::FPOWI, MVT::f32, Expand);
86 setOperationAction(ISD::FPOW, MVT::f32, Expand);
87 setOperationAction(ISD::FLOG, MVT::f32, Expand);
88 setOperationAction(ISD::FLOG2, MVT::f32, Expand);
89 setOperationAction(ISD::FLOG10, MVT::f32, Expand);
90 setOperationAction(ISD::FEXP, MVT::f32, Expand);
91
92 // Load extented operations for i1 types must be promoted
93 setLoadExtAction(ISD::EXTLOAD, MVT::i1, Promote);
94 setLoadExtAction(ISD::ZEXTLOAD, MVT::i1, Promote);
95 setLoadExtAction(ISD::SEXTLOAD, MVT::i1, Promote);
96
97 // Sign extended loads must be expanded
98 setLoadExtAction(ISD::SEXTLOAD, MVT::i8, Expand);
99 setLoadExtAction(ISD::SEXTLOAD, MVT::i16, Expand);
100
101 // MBlaze has no REM or DIVREM operations.
102 setOperationAction(ISD::UREM, MVT::i32, Expand);
103 setOperationAction(ISD::SREM, MVT::i32, Expand);
104 setOperationAction(ISD::SDIVREM, MVT::i32, Expand);
105 setOperationAction(ISD::UDIVREM, MVT::i32, Expand);
106
107 // If the processor doesn't support multiply then expand it
108 if (!Subtarget->hasMul()) {
109 setOperationAction(ISD::MUL, MVT::i32, Expand);
110 }
111
112 // If the processor doesn't support 64-bit multiply then expand
113 if (!Subtarget->hasMul() || !Subtarget->hasMul64()) {
114 setOperationAction(ISD::MULHS, MVT::i32, Expand);
115 setOperationAction(ISD::MULHS, MVT::i64, Expand);
116 setOperationAction(ISD::MULHU, MVT::i32, Expand);
117 setOperationAction(ISD::MULHU, MVT::i64, Expand);
118 }
119
120 // If the processor doesn't support division then expand
121 if (!Subtarget->hasDiv()) {
122 setOperationAction(ISD::UDIV, MVT::i32, Expand);
123 setOperationAction(ISD::SDIV, MVT::i32, Expand);
124 }
125
126 // Expand unsupported conversions
127 setOperationAction(ISD::BITCAST, MVT::f32, Expand);
128 setOperationAction(ISD::BITCAST, MVT::i32, Expand);
129
130 // Expand SELECT_CC
131 setOperationAction(ISD::SELECT_CC, MVT::Other, Expand);
132
133 // MBlaze doesn't have MUL_LOHI
134 setOperationAction(ISD::SMUL_LOHI, MVT::i32, Expand);
135 setOperationAction(ISD::UMUL_LOHI, MVT::i32, Expand);
136 setOperationAction(ISD::SMUL_LOHI, MVT::i64, Expand);
137 setOperationAction(ISD::UMUL_LOHI, MVT::i64, Expand);
138
139 // Used by legalize types to correctly generate the setcc result.
140 // Without this, every float setcc comes with a AND/OR with the result,
141 // we don't want this, since the fpcmp result goes to a flag register,
142 // which is used implicitly by brcond and select operations.
143 AddPromotedToType(ISD::SETCC, MVT::i1, MVT::i32);
144 AddPromotedToType(ISD::SELECT, MVT::i1, MVT::i32);
145 AddPromotedToType(ISD::SELECT_CC, MVT::i1, MVT::i32);
146
147 // MBlaze Custom Operations
148 setOperationAction(ISD::GlobalAddress, MVT::i32, Custom);
149 setOperationAction(ISD::GlobalTLSAddress, MVT::i32, Custom);
150 setOperationAction(ISD::JumpTable, MVT::i32, Custom);
151 setOperationAction(ISD::ConstantPool, MVT::i32, Custom);
152
153 // Variable Argument support
154 setOperationAction(ISD::VASTART, MVT::Other, Custom);
155 setOperationAction(ISD::VAEND, MVT::Other, Expand);
156 setOperationAction(ISD::VAARG, MVT::Other, Expand);
157 setOperationAction(ISD::VACOPY, MVT::Other, Expand);
158
159
160 // Operations not directly supported by MBlaze.
161 setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Expand);
162 setOperationAction(ISD::BR_JT, MVT::Other, Expand);
163 setOperationAction(ISD::BR_CC, MVT::f32, Expand);
164 setOperationAction(ISD::BR_CC, MVT::i32, Expand);
165 setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand);
166 setOperationAction(ISD::ROTL, MVT::i32, Expand);
167 setOperationAction(ISD::ROTR, MVT::i32, Expand);
168 setOperationAction(ISD::SHL_PARTS, MVT::i32, Expand);
169 setOperationAction(ISD::SRA_PARTS, MVT::i32, Expand);
170 setOperationAction(ISD::SRL_PARTS, MVT::i32, Expand);
171 setOperationAction(ISD::CTLZ, MVT::i32, Expand);
172 setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i32, Expand);
173 setOperationAction(ISD::CTTZ, MVT::i32, Expand);
174 setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i32, Expand);
175 setOperationAction(ISD::CTPOP, MVT::i32, Expand);
176 setOperationAction(ISD::BSWAP, MVT::i32, Expand);
177
178 // We don't have line number support yet.
179 setOperationAction(ISD::EH_LABEL, MVT::Other, Expand);
180
181 // Use the default for now
182 setOperationAction(ISD::STACKSAVE, MVT::Other, Expand);
183 setOperationAction(ISD::STACKRESTORE, MVT::Other, Expand);
184
185 // MBlaze doesn't have extending float->double load/store
186 setLoadExtAction(ISD::EXTLOAD, MVT::f32, Expand);
187 setTruncStoreAction(MVT::f64, MVT::f32, Expand);
188
189 setMinFunctionAlignment(2);
190
191 setStackPointerRegisterToSaveRestore(MBlaze::R1);
192 computeRegisterProperties();
193 }
194
getSetCCResultType(EVT VT) const195 EVT MBlazeTargetLowering::getSetCCResultType(EVT VT) const {
196 return MVT::i32;
197 }
198
LowerOperation(SDValue Op,SelectionDAG & DAG) const199 SDValue MBlazeTargetLowering::LowerOperation(SDValue Op,
200 SelectionDAG &DAG) const {
201 switch (Op.getOpcode())
202 {
203 case ISD::ConstantPool: return LowerConstantPool(Op, DAG);
204 case ISD::GlobalAddress: return LowerGlobalAddress(Op, DAG);
205 case ISD::GlobalTLSAddress: return LowerGlobalTLSAddress(Op, DAG);
206 case ISD::JumpTable: return LowerJumpTable(Op, DAG);
207 case ISD::SELECT_CC: return LowerSELECT_CC(Op, DAG);
208 case ISD::VASTART: return LowerVASTART(Op, DAG);
209 }
210 return SDValue();
211 }
212
213 //===----------------------------------------------------------------------===//
214 // Lower helper functions
215 //===----------------------------------------------------------------------===//
216 MachineBasicBlock*
EmitInstrWithCustomInserter(MachineInstr * MI,MachineBasicBlock * MBB) const217 MBlazeTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
218 MachineBasicBlock *MBB)
219 const {
220 switch (MI->getOpcode()) {
221 default: llvm_unreachable("Unexpected instr type to insert");
222
223 case MBlaze::ShiftRL:
224 case MBlaze::ShiftRA:
225 case MBlaze::ShiftL:
226 return EmitCustomShift(MI, MBB);
227
228 case MBlaze::Select_FCC:
229 case MBlaze::Select_CC:
230 return EmitCustomSelect(MI, MBB);
231
232 case MBlaze::CAS32:
233 case MBlaze::SWP32:
234 case MBlaze::LAA32:
235 case MBlaze::LAS32:
236 case MBlaze::LAD32:
237 case MBlaze::LAO32:
238 case MBlaze::LAX32:
239 case MBlaze::LAN32:
240 return EmitCustomAtomic(MI, MBB);
241
242 case MBlaze::MEMBARRIER:
243 // The Microblaze does not need memory barriers. Just delete the pseudo
244 // instruction and finish.
245 MI->eraseFromParent();
246 return MBB;
247 }
248 }
249
250 MachineBasicBlock*
EmitCustomShift(MachineInstr * MI,MachineBasicBlock * MBB) const251 MBlazeTargetLowering::EmitCustomShift(MachineInstr *MI,
252 MachineBasicBlock *MBB) const {
253 const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
254 DebugLoc dl = MI->getDebugLoc();
255
256 // To "insert" a shift left instruction, we actually have to insert a
257 // simple loop. The incoming instruction knows the destination vreg to
258 // set, the source vreg to operate over and the shift amount.
259 const BasicBlock *LLVM_BB = MBB->getBasicBlock();
260 MachineFunction::iterator It = MBB;
261 ++It;
262
263 // start:
264 // andi samt, samt, 31
265 // beqid samt, finish
266 // add dst, src, r0
267 // loop:
268 // addik samt, samt, -1
269 // sra dst, dst
270 // bneid samt, loop
271 // nop
272 // finish:
273 MachineFunction *F = MBB->getParent();
274 MachineRegisterInfo &R = F->getRegInfo();
275 MachineBasicBlock *loop = F->CreateMachineBasicBlock(LLVM_BB);
276 MachineBasicBlock *finish = F->CreateMachineBasicBlock(LLVM_BB);
277 F->insert(It, loop);
278 F->insert(It, finish);
279
280 // Update machine-CFG edges by transferring adding all successors and
281 // remaining instructions from the current block to the new block which
282 // will contain the Phi node for the select.
283 finish->splice(finish->begin(), MBB,
284 llvm::next(MachineBasicBlock::iterator(MI)),
285 MBB->end());
286 finish->transferSuccessorsAndUpdatePHIs(MBB);
287
288 // Add the true and fallthrough blocks as its successors.
289 MBB->addSuccessor(loop);
290 MBB->addSuccessor(finish);
291
292 // Next, add the finish block as a successor of the loop block
293 loop->addSuccessor(finish);
294 loop->addSuccessor(loop);
295
296 unsigned IAMT = R.createVirtualRegister(&MBlaze::GPRRegClass);
297 BuildMI(MBB, dl, TII->get(MBlaze::ANDI), IAMT)
298 .addReg(MI->getOperand(2).getReg())
299 .addImm(31);
300
301 unsigned IVAL = R.createVirtualRegister(&MBlaze::GPRRegClass);
302 BuildMI(MBB, dl, TII->get(MBlaze::ADDIK), IVAL)
303 .addReg(MI->getOperand(1).getReg())
304 .addImm(0);
305
306 BuildMI(MBB, dl, TII->get(MBlaze::BEQID))
307 .addReg(IAMT)
308 .addMBB(finish);
309
310 unsigned DST = R.createVirtualRegister(&MBlaze::GPRRegClass);
311 unsigned NDST = R.createVirtualRegister(&MBlaze::GPRRegClass);
312 BuildMI(loop, dl, TII->get(MBlaze::PHI), DST)
313 .addReg(IVAL).addMBB(MBB)
314 .addReg(NDST).addMBB(loop);
315
316 unsigned SAMT = R.createVirtualRegister(&MBlaze::GPRRegClass);
317 unsigned NAMT = R.createVirtualRegister(&MBlaze::GPRRegClass);
318 BuildMI(loop, dl, TII->get(MBlaze::PHI), SAMT)
319 .addReg(IAMT).addMBB(MBB)
320 .addReg(NAMT).addMBB(loop);
321
322 if (MI->getOpcode() == MBlaze::ShiftL)
323 BuildMI(loop, dl, TII->get(MBlaze::ADD), NDST).addReg(DST).addReg(DST);
324 else if (MI->getOpcode() == MBlaze::ShiftRA)
325 BuildMI(loop, dl, TII->get(MBlaze::SRA), NDST).addReg(DST);
326 else if (MI->getOpcode() == MBlaze::ShiftRL)
327 BuildMI(loop, dl, TII->get(MBlaze::SRL), NDST).addReg(DST);
328 else
329 llvm_unreachable("Cannot lower unknown shift instruction");
330
331 BuildMI(loop, dl, TII->get(MBlaze::ADDIK), NAMT)
332 .addReg(SAMT)
333 .addImm(-1);
334
335 BuildMI(loop, dl, TII->get(MBlaze::BNEID))
336 .addReg(NAMT)
337 .addMBB(loop);
338
339 BuildMI(*finish, finish->begin(), dl,
340 TII->get(MBlaze::PHI), MI->getOperand(0).getReg())
341 .addReg(IVAL).addMBB(MBB)
342 .addReg(NDST).addMBB(loop);
343
344 // The pseudo instruction is no longer needed so remove it
345 MI->eraseFromParent();
346 return finish;
347 }
348
349 MachineBasicBlock*
EmitCustomSelect(MachineInstr * MI,MachineBasicBlock * MBB) const350 MBlazeTargetLowering::EmitCustomSelect(MachineInstr *MI,
351 MachineBasicBlock *MBB) const {
352 const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
353 DebugLoc dl = MI->getDebugLoc();
354
355 // To "insert" a SELECT_CC instruction, we actually have to insert the
356 // diamond control-flow pattern. The incoming instruction knows the
357 // destination vreg to set, the condition code register to branch on, the
358 // true/false values to select between, and a branch opcode to use.
359 const BasicBlock *LLVM_BB = MBB->getBasicBlock();
360 MachineFunction::iterator It = MBB;
361 ++It;
362
363 // thisMBB:
364 // ...
365 // TrueVal = ...
366 // setcc r1, r2, r3
367 // bNE r1, r0, copy1MBB
368 // fallthrough --> copy0MBB
369 MachineFunction *F = MBB->getParent();
370 MachineBasicBlock *flsBB = F->CreateMachineBasicBlock(LLVM_BB);
371 MachineBasicBlock *dneBB = F->CreateMachineBasicBlock(LLVM_BB);
372
373 unsigned Opc;
374 switch (MI->getOperand(4).getImm()) {
375 default: llvm_unreachable("Unknown branch condition");
376 case MBlazeCC::EQ: Opc = MBlaze::BEQID; break;
377 case MBlazeCC::NE: Opc = MBlaze::BNEID; break;
378 case MBlazeCC::GT: Opc = MBlaze::BGTID; break;
379 case MBlazeCC::LT: Opc = MBlaze::BLTID; break;
380 case MBlazeCC::GE: Opc = MBlaze::BGEID; break;
381 case MBlazeCC::LE: Opc = MBlaze::BLEID; break;
382 }
383
384 F->insert(It, flsBB);
385 F->insert(It, dneBB);
386
387 // Transfer the remainder of MBB and its successor edges to dneBB.
388 dneBB->splice(dneBB->begin(), MBB,
389 llvm::next(MachineBasicBlock::iterator(MI)),
390 MBB->end());
391 dneBB->transferSuccessorsAndUpdatePHIs(MBB);
392
393 MBB->addSuccessor(flsBB);
394 MBB->addSuccessor(dneBB);
395 flsBB->addSuccessor(dneBB);
396
397 BuildMI(MBB, dl, TII->get(Opc))
398 .addReg(MI->getOperand(3).getReg())
399 .addMBB(dneBB);
400
401 // sinkMBB:
402 // %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ]
403 // ...
404 //BuildMI(dneBB, dl, TII->get(MBlaze::PHI), MI->getOperand(0).getReg())
405 // .addReg(MI->getOperand(1).getReg()).addMBB(flsBB)
406 // .addReg(MI->getOperand(2).getReg()).addMBB(BB);
407
408 BuildMI(*dneBB, dneBB->begin(), dl,
409 TII->get(MBlaze::PHI), MI->getOperand(0).getReg())
410 .addReg(MI->getOperand(2).getReg()).addMBB(flsBB)
411 .addReg(MI->getOperand(1).getReg()).addMBB(MBB);
412
413 MI->eraseFromParent(); // The pseudo instruction is gone now.
414 return dneBB;
415 }
416
417 MachineBasicBlock*
EmitCustomAtomic(MachineInstr * MI,MachineBasicBlock * MBB) const418 MBlazeTargetLowering::EmitCustomAtomic(MachineInstr *MI,
419 MachineBasicBlock *MBB) const {
420 const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
421 DebugLoc dl = MI->getDebugLoc();
422
423 // All atomic instructions on the Microblaze are implemented using the
424 // load-linked / store-conditional style atomic instruction sequences.
425 // Thus, all operations will look something like the following:
426 //
427 // start:
428 // lwx RV, RP, 0
429 // <do stuff>
430 // swx RV, RP, 0
431 // addic RC, R0, 0
432 // bneid RC, start
433 //
434 // exit:
435 //
436 // To "insert" a shift left instruction, we actually have to insert a
437 // simple loop. The incoming instruction knows the destination vreg to
438 // set, the source vreg to operate over and the shift amount.
439 const BasicBlock *LLVM_BB = MBB->getBasicBlock();
440 MachineFunction::iterator It = MBB;
441 ++It;
442
443 // start:
444 // andi samt, samt, 31
445 // beqid samt, finish
446 // add dst, src, r0
447 // loop:
448 // addik samt, samt, -1
449 // sra dst, dst
450 // bneid samt, loop
451 // nop
452 // finish:
453 MachineFunction *F = MBB->getParent();
454 MachineRegisterInfo &R = F->getRegInfo();
455
456 // Create the start and exit basic blocks for the atomic operation
457 MachineBasicBlock *start = F->CreateMachineBasicBlock(LLVM_BB);
458 MachineBasicBlock *exit = F->CreateMachineBasicBlock(LLVM_BB);
459 F->insert(It, start);
460 F->insert(It, exit);
461
462 // Update machine-CFG edges by transferring adding all successors and
463 // remaining instructions from the current block to the new block which
464 // will contain the Phi node for the select.
465 exit->splice(exit->begin(), MBB, llvm::next(MachineBasicBlock::iterator(MI)),
466 MBB->end());
467 exit->transferSuccessorsAndUpdatePHIs(MBB);
468
469 // Add the fallthrough block as its successors.
470 MBB->addSuccessor(start);
471
472 BuildMI(start, dl, TII->get(MBlaze::LWX), MI->getOperand(0).getReg())
473 .addReg(MI->getOperand(1).getReg())
474 .addReg(MBlaze::R0);
475
476 MachineBasicBlock *final = start;
477 unsigned finalReg = 0;
478
479 switch (MI->getOpcode()) {
480 default: llvm_unreachable("Cannot lower unknown atomic instruction!");
481
482 case MBlaze::SWP32:
483 finalReg = MI->getOperand(2).getReg();
484 start->addSuccessor(exit);
485 start->addSuccessor(start);
486 break;
487
488 case MBlaze::LAN32:
489 case MBlaze::LAX32:
490 case MBlaze::LAO32:
491 case MBlaze::LAD32:
492 case MBlaze::LAS32:
493 case MBlaze::LAA32: {
494 unsigned opcode = 0;
495 switch (MI->getOpcode()) {
496 default: llvm_unreachable("Cannot lower unknown atomic load!");
497 case MBlaze::LAA32: opcode = MBlaze::ADDIK; break;
498 case MBlaze::LAS32: opcode = MBlaze::RSUBIK; break;
499 case MBlaze::LAD32: opcode = MBlaze::AND; break;
500 case MBlaze::LAO32: opcode = MBlaze::OR; break;
501 case MBlaze::LAX32: opcode = MBlaze::XOR; break;
502 case MBlaze::LAN32: opcode = MBlaze::AND; break;
503 }
504
505 finalReg = R.createVirtualRegister(&MBlaze::GPRRegClass);
506 start->addSuccessor(exit);
507 start->addSuccessor(start);
508
509 BuildMI(start, dl, TII->get(opcode), finalReg)
510 .addReg(MI->getOperand(0).getReg())
511 .addReg(MI->getOperand(2).getReg());
512
513 if (MI->getOpcode() == MBlaze::LAN32) {
514 unsigned tmp = finalReg;
515 finalReg = R.createVirtualRegister(&MBlaze::GPRRegClass);
516 BuildMI(start, dl, TII->get(MBlaze::XORI), finalReg)
517 .addReg(tmp)
518 .addImm(-1);
519 }
520 break;
521 }
522
523 case MBlaze::CAS32: {
524 finalReg = MI->getOperand(3).getReg();
525 final = F->CreateMachineBasicBlock(LLVM_BB);
526
527 F->insert(It, final);
528 start->addSuccessor(exit);
529 start->addSuccessor(final);
530 final->addSuccessor(exit);
531 final->addSuccessor(start);
532
533 unsigned CMP = R.createVirtualRegister(&MBlaze::GPRRegClass);
534 BuildMI(start, dl, TII->get(MBlaze::CMP), CMP)
535 .addReg(MI->getOperand(0).getReg())
536 .addReg(MI->getOperand(2).getReg());
537
538 BuildMI(start, dl, TII->get(MBlaze::BNEID))
539 .addReg(CMP)
540 .addMBB(exit);
541
542 final->moveAfter(start);
543 exit->moveAfter(final);
544 break;
545 }
546 }
547
548 unsigned CHK = R.createVirtualRegister(&MBlaze::GPRRegClass);
549 BuildMI(final, dl, TII->get(MBlaze::SWX))
550 .addReg(finalReg)
551 .addReg(MI->getOperand(1).getReg())
552 .addReg(MBlaze::R0);
553
554 BuildMI(final, dl, TII->get(MBlaze::ADDIC), CHK)
555 .addReg(MBlaze::R0)
556 .addImm(0);
557
558 BuildMI(final, dl, TII->get(MBlaze::BNEID))
559 .addReg(CHK)
560 .addMBB(start);
561
562 // The pseudo instruction is no longer needed so remove it
563 MI->eraseFromParent();
564 return exit;
565 }
566
567 //===----------------------------------------------------------------------===//
568 // Misc Lower Operation implementation
569 //===----------------------------------------------------------------------===//
570 //
571
LowerSELECT_CC(SDValue Op,SelectionDAG & DAG) const572 SDValue MBlazeTargetLowering::LowerSELECT_CC(SDValue Op,
573 SelectionDAG &DAG) const {
574 SDValue LHS = Op.getOperand(0);
575 SDValue RHS = Op.getOperand(1);
576 SDValue TrueVal = Op.getOperand(2);
577 SDValue FalseVal = Op.getOperand(3);
578 DebugLoc dl = Op.getDebugLoc();
579 unsigned Opc;
580
581 SDValue CompareFlag;
582 if (LHS.getValueType() == MVT::i32) {
583 Opc = MBlazeISD::Select_CC;
584 CompareFlag = DAG.getNode(MBlazeISD::ICmp, dl, MVT::i32, LHS, RHS)
585 .getValue(1);
586 } else {
587 llvm_unreachable("Cannot lower select_cc with unknown type");
588 }
589
590 return DAG.getNode(Opc, dl, TrueVal.getValueType(), TrueVal, FalseVal,
591 CompareFlag);
592 }
593
594 SDValue MBlazeTargetLowering::
LowerGlobalAddress(SDValue Op,SelectionDAG & DAG) const595 LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const {
596 // FIXME there isn't actually debug info here
597 DebugLoc dl = Op.getDebugLoc();
598 const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
599 SDValue GA = DAG.getTargetGlobalAddress(GV, dl, MVT::i32);
600
601 return DAG.getNode(MBlazeISD::Wrap, dl, MVT::i32, GA);
602 }
603
604 SDValue MBlazeTargetLowering::
LowerGlobalTLSAddress(SDValue Op,SelectionDAG & DAG) const605 LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const {
606 llvm_unreachable("TLS not implemented for MicroBlaze.");
607 }
608
609 SDValue MBlazeTargetLowering::
LowerJumpTable(SDValue Op,SelectionDAG & DAG) const610 LowerJumpTable(SDValue Op, SelectionDAG &DAG) const {
611 SDValue ResNode;
612 SDValue HiPart;
613 // FIXME there isn't actually debug info here
614 DebugLoc dl = Op.getDebugLoc();
615
616 EVT PtrVT = Op.getValueType();
617 JumpTableSDNode *JT = cast<JumpTableSDNode>(Op);
618
619 SDValue JTI = DAG.getTargetJumpTable(JT->getIndex(), PtrVT, 0);
620 return DAG.getNode(MBlazeISD::Wrap, dl, MVT::i32, JTI);
621 }
622
623 SDValue MBlazeTargetLowering::
LowerConstantPool(SDValue Op,SelectionDAG & DAG) const624 LowerConstantPool(SDValue Op, SelectionDAG &DAG) const {
625 SDValue ResNode;
626 ConstantPoolSDNode *N = cast<ConstantPoolSDNode>(Op);
627 const Constant *C = N->getConstVal();
628 DebugLoc dl = Op.getDebugLoc();
629
630 SDValue CP = DAG.getTargetConstantPool(C, MVT::i32, N->getAlignment(),
631 N->getOffset(), 0);
632 return DAG.getNode(MBlazeISD::Wrap, dl, MVT::i32, CP);
633 }
634
LowerVASTART(SDValue Op,SelectionDAG & DAG) const635 SDValue MBlazeTargetLowering::LowerVASTART(SDValue Op,
636 SelectionDAG &DAG) const {
637 MachineFunction &MF = DAG.getMachineFunction();
638 MBlazeFunctionInfo *FuncInfo = MF.getInfo<MBlazeFunctionInfo>();
639
640 DebugLoc dl = Op.getDebugLoc();
641 SDValue FI = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(),
642 getPointerTy());
643
644 // vastart just stores the address of the VarArgsFrameIndex slot into the
645 // memory location argument.
646 const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
647 return DAG.getStore(Op.getOperand(0), dl, FI, Op.getOperand(1),
648 MachinePointerInfo(SV),
649 false, false, 0);
650 }
651
652 //===----------------------------------------------------------------------===//
653 // Calling Convention Implementation
654 //===----------------------------------------------------------------------===//
655
656 #include "MBlazeGenCallingConv.inc"
657
CC_MBlaze_AssignReg(unsigned & ValNo,MVT & ValVT,MVT & LocVT,CCValAssign::LocInfo & LocInfo,ISD::ArgFlagsTy & ArgFlags,CCState & State)658 static bool CC_MBlaze_AssignReg(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
659 CCValAssign::LocInfo &LocInfo,
660 ISD::ArgFlagsTy &ArgFlags,
661 CCState &State) {
662 static const uint16_t ArgRegs[] = {
663 MBlaze::R5, MBlaze::R6, MBlaze::R7,
664 MBlaze::R8, MBlaze::R9, MBlaze::R10
665 };
666
667 const unsigned NumArgRegs = array_lengthof(ArgRegs);
668 unsigned Reg = State.AllocateReg(ArgRegs, NumArgRegs);
669 if (!Reg) return false;
670
671 unsigned SizeInBytes = ValVT.getSizeInBits() >> 3;
672 State.AllocateStack(SizeInBytes, SizeInBytes);
673 State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
674
675 return true;
676 }
677
678 //===----------------------------------------------------------------------===//
679 // Call Calling Convention Implementation
680 //===----------------------------------------------------------------------===//
681
682 /// LowerCall - functions arguments are copied from virtual regs to
683 /// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
684 /// TODO: isVarArg, isTailCall.
685 SDValue MBlazeTargetLowering::
LowerCall(TargetLowering::CallLoweringInfo & CLI,SmallVectorImpl<SDValue> & InVals) const686 LowerCall(TargetLowering::CallLoweringInfo &CLI,
687 SmallVectorImpl<SDValue> &InVals) const {
688 SelectionDAG &DAG = CLI.DAG;
689 DebugLoc &dl = CLI.DL;
690 SmallVector<ISD::OutputArg, 32> &Outs = CLI.Outs;
691 SmallVector<SDValue, 32> &OutVals = CLI.OutVals;
692 SmallVector<ISD::InputArg, 32> &Ins = CLI.Ins;
693 SDValue Chain = CLI.Chain;
694 SDValue Callee = CLI.Callee;
695 bool &isTailCall = CLI.IsTailCall;
696 CallingConv::ID CallConv = CLI.CallConv;
697 bool isVarArg = CLI.IsVarArg;
698
699 // MBlaze does not yet support tail call optimization
700 isTailCall = false;
701
702 // The MBlaze requires stack slots for arguments passed to var arg
703 // functions even if they are passed in registers.
704 bool needsRegArgSlots = isVarArg;
705
706 MachineFunction &MF = DAG.getMachineFunction();
707 MachineFrameInfo *MFI = MF.getFrameInfo();
708 const TargetFrameLowering &TFI = *MF.getTarget().getFrameLowering();
709
710 // Analyze operands of the call, assigning locations to each operand.
711 SmallVector<CCValAssign, 16> ArgLocs;
712 CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
713 getTargetMachine(), ArgLocs, *DAG.getContext());
714 CCInfo.AnalyzeCallOperands(Outs, CC_MBlaze);
715
716 // Get a count of how many bytes are to be pushed on the stack.
717 unsigned NumBytes = CCInfo.getNextStackOffset();
718
719 // Variable argument function calls require a minimum of 24-bytes of stack
720 if (isVarArg && NumBytes < 24) NumBytes = 24;
721
722 Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(NumBytes, true));
723
724 SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPass;
725 SmallVector<SDValue, 8> MemOpChains;
726
727 // Walk the register/memloc assignments, inserting copies/loads.
728 for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
729 CCValAssign &VA = ArgLocs[i];
730 MVT RegVT = VA.getLocVT();
731 SDValue Arg = OutVals[i];
732
733 // Promote the value if needed.
734 switch (VA.getLocInfo()) {
735 default: llvm_unreachable("Unknown loc info!");
736 case CCValAssign::Full: break;
737 case CCValAssign::SExt:
738 Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, RegVT, Arg);
739 break;
740 case CCValAssign::ZExt:
741 Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, RegVT, Arg);
742 break;
743 case CCValAssign::AExt:
744 Arg = DAG.getNode(ISD::ANY_EXTEND, dl, RegVT, Arg);
745 break;
746 }
747
748 // Arguments that can be passed on register must be kept at
749 // RegsToPass vector
750 if (VA.isRegLoc()) {
751 RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
752 } else {
753 // Register can't get to this point...
754 assert(VA.isMemLoc());
755
756 // Since we are alread passing values on the stack we don't
757 // need to worry about creating additional slots for the
758 // values passed via registers.
759 needsRegArgSlots = false;
760
761 // Create the frame index object for this incoming parameter
762 unsigned ArgSize = VA.getValVT().getSizeInBits()/8;
763 unsigned StackLoc = VA.getLocMemOffset() + 4;
764 int FI = MFI->CreateFixedObject(ArgSize, StackLoc, true);
765
766 SDValue PtrOff = DAG.getFrameIndex(FI,getPointerTy());
767
768 // emit ISD::STORE whichs stores the
769 // parameter value to a stack Location
770 MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff,
771 MachinePointerInfo(),
772 false, false, 0));
773 }
774 }
775
776 // If we need to reserve stack space for the arguments passed via registers
777 // then create a fixed stack object at the beginning of the stack.
778 if (needsRegArgSlots && TFI.hasReservedCallFrame(MF))
779 MFI->CreateFixedObject(28,0,true);
780
781 // Transform all store nodes into one single node because all store
782 // nodes are independent of each other.
783 if (!MemOpChains.empty())
784 Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
785 &MemOpChains[0], MemOpChains.size());
786
787 // Build a sequence of copy-to-reg nodes chained together with token
788 // chain and flag operands which copy the outgoing args into registers.
789 // The InFlag in necessary since all emitted instructions must be
790 // stuck together.
791 SDValue InFlag;
792 for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
793 Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
794 RegsToPass[i].second, InFlag);
795 InFlag = Chain.getValue(1);
796 }
797
798 // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
799 // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
800 // node so that legalize doesn't hack it.
801 if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
802 Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl,
803 getPointerTy(), 0, 0);
804 else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee))
805 Callee = DAG.getTargetExternalSymbol(S->getSymbol(),
806 getPointerTy(), 0);
807
808 // MBlazeJmpLink = #chain, #target_address, #opt_in_flags...
809 // = Chain, Callee, Reg#1, Reg#2, ...
810 //
811 // Returns a chain & a flag for retval copy to use.
812 SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
813 SmallVector<SDValue, 8> Ops;
814 Ops.push_back(Chain);
815 Ops.push_back(Callee);
816
817 // Add argument registers to the end of the list so that they are
818 // known live into the call.
819 for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
820 Ops.push_back(DAG.getRegister(RegsToPass[i].first,
821 RegsToPass[i].second.getValueType()));
822 }
823
824 if (InFlag.getNode())
825 Ops.push_back(InFlag);
826
827 Chain = DAG.getNode(MBlazeISD::JmpLink, dl, NodeTys, &Ops[0], Ops.size());
828 InFlag = Chain.getValue(1);
829
830 // Create the CALLSEQ_END node.
831 Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NumBytes, true),
832 DAG.getIntPtrConstant(0, true), InFlag);
833 if (!Ins.empty())
834 InFlag = Chain.getValue(1);
835
836 // Handle result values, copying them out of physregs into vregs that we
837 // return.
838 return LowerCallResult(Chain, InFlag, CallConv, isVarArg,
839 Ins, dl, DAG, InVals);
840 }
841
842 /// LowerCallResult - Lower the result values of a call into the
843 /// appropriate copies out of appropriate physical registers.
844 SDValue MBlazeTargetLowering::
LowerCallResult(SDValue Chain,SDValue InFlag,CallingConv::ID CallConv,bool isVarArg,const SmallVectorImpl<ISD::InputArg> & Ins,DebugLoc dl,SelectionDAG & DAG,SmallVectorImpl<SDValue> & InVals) const845 LowerCallResult(SDValue Chain, SDValue InFlag, CallingConv::ID CallConv,
846 bool isVarArg, const SmallVectorImpl<ISD::InputArg> &Ins,
847 DebugLoc dl, SelectionDAG &DAG,
848 SmallVectorImpl<SDValue> &InVals) const {
849 // Assign locations to each value returned by this call.
850 SmallVector<CCValAssign, 16> RVLocs;
851 CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
852 getTargetMachine(), RVLocs, *DAG.getContext());
853
854 CCInfo.AnalyzeCallResult(Ins, RetCC_MBlaze);
855
856 // Copy all of the result registers out of their specified physreg.
857 for (unsigned i = 0; i != RVLocs.size(); ++i) {
858 Chain = DAG.getCopyFromReg(Chain, dl, RVLocs[i].getLocReg(),
859 RVLocs[i].getValVT(), InFlag).getValue(1);
860 InFlag = Chain.getValue(2);
861 InVals.push_back(Chain.getValue(0));
862 }
863
864 return Chain;
865 }
866
867 //===----------------------------------------------------------------------===//
868 // Formal Arguments Calling Convention Implementation
869 //===----------------------------------------------------------------------===//
870
871 /// LowerFormalArguments - transform physical registers into
872 /// virtual registers and generate load operations for
873 /// arguments places on the stack.
874 SDValue MBlazeTargetLowering::
LowerFormalArguments(SDValue Chain,CallingConv::ID CallConv,bool isVarArg,const SmallVectorImpl<ISD::InputArg> & Ins,DebugLoc dl,SelectionDAG & DAG,SmallVectorImpl<SDValue> & InVals) const875 LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
876 const SmallVectorImpl<ISD::InputArg> &Ins,
877 DebugLoc dl, SelectionDAG &DAG,
878 SmallVectorImpl<SDValue> &InVals) const {
879 MachineFunction &MF = DAG.getMachineFunction();
880 MachineFrameInfo *MFI = MF.getFrameInfo();
881 MBlazeFunctionInfo *MBlazeFI = MF.getInfo<MBlazeFunctionInfo>();
882
883 unsigned StackReg = MF.getTarget().getRegisterInfo()->getFrameRegister(MF);
884 MBlazeFI->setVarArgsFrameIndex(0);
885
886 // Used with vargs to acumulate store chains.
887 std::vector<SDValue> OutChains;
888
889 // Keep track of the last register used for arguments
890 unsigned ArgRegEnd = 0;
891
892 // Assign locations to all of the incoming arguments.
893 SmallVector<CCValAssign, 16> ArgLocs;
894 CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
895 getTargetMachine(), ArgLocs, *DAG.getContext());
896
897 CCInfo.AnalyzeFormalArguments(Ins, CC_MBlaze);
898 SDValue StackPtr;
899
900 for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
901 CCValAssign &VA = ArgLocs[i];
902
903 // Arguments stored on registers
904 if (VA.isRegLoc()) {
905 MVT RegVT = VA.getLocVT();
906 ArgRegEnd = VA.getLocReg();
907 const TargetRegisterClass *RC;
908
909 if (RegVT == MVT::i32)
910 RC = &MBlaze::GPRRegClass;
911 else if (RegVT == MVT::f32)
912 RC = &MBlaze::GPRRegClass;
913 else
914 llvm_unreachable("RegVT not supported by LowerFormalArguments");
915
916 // Transform the arguments stored on
917 // physical registers into virtual ones
918 unsigned Reg = MF.addLiveIn(ArgRegEnd, RC);
919 SDValue ArgValue = DAG.getCopyFromReg(Chain, dl, Reg, RegVT);
920
921 // If this is an 8 or 16-bit value, it has been passed promoted
922 // to 32 bits. Insert an assert[sz]ext to capture this, then
923 // truncate to the right size. If if is a floating point value
924 // then convert to the correct type.
925 if (VA.getLocInfo() != CCValAssign::Full) {
926 unsigned Opcode = 0;
927 if (VA.getLocInfo() == CCValAssign::SExt)
928 Opcode = ISD::AssertSext;
929 else if (VA.getLocInfo() == CCValAssign::ZExt)
930 Opcode = ISD::AssertZext;
931 if (Opcode)
932 ArgValue = DAG.getNode(Opcode, dl, RegVT, ArgValue,
933 DAG.getValueType(VA.getValVT()));
934 ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue);
935 }
936
937 InVals.push_back(ArgValue);
938 } else { // VA.isRegLoc()
939 // sanity check
940 assert(VA.isMemLoc());
941
942 // The last argument is not a register
943 ArgRegEnd = 0;
944
945 // The stack pointer offset is relative to the caller stack frame.
946 // Since the real stack size is unknown here, a negative SPOffset
947 // is used so there's a way to adjust these offsets when the stack
948 // size get known (on EliminateFrameIndex). A dummy SPOffset is
949 // used instead of a direct negative address (which is recorded to
950 // be used on emitPrologue) to avoid mis-calc of the first stack
951 // offset on PEI::calculateFrameObjectOffsets.
952 // Arguments are always 32-bit.
953 unsigned ArgSize = VA.getLocVT().getSizeInBits()/8;
954 unsigned StackLoc = VA.getLocMemOffset() + 4;
955 int FI = MFI->CreateFixedObject(ArgSize, 0, true);
956 MBlazeFI->recordLoadArgsFI(FI, -StackLoc);
957 MBlazeFI->recordLiveIn(FI);
958
959 // Create load nodes to retrieve arguments from the stack
960 SDValue FIN = DAG.getFrameIndex(FI, getPointerTy());
961 InVals.push_back(DAG.getLoad(VA.getValVT(), dl, Chain, FIN,
962 MachinePointerInfo::getFixedStack(FI),
963 false, false, false, 0));
964 }
965 }
966
967 // To meet ABI, when VARARGS are passed on registers, the registers
968 // must have their values written to the caller stack frame. If the last
969 // argument was placed in the stack, there's no need to save any register.
970 if ((isVarArg) && ArgRegEnd) {
971 if (StackPtr.getNode() == 0)
972 StackPtr = DAG.getRegister(StackReg, getPointerTy());
973
974 // The last register argument that must be saved is MBlaze::R10
975 const TargetRegisterClass *RC = &MBlaze::GPRRegClass;
976
977 unsigned Begin = getMBlazeRegisterNumbering(MBlaze::R5);
978 unsigned Start = getMBlazeRegisterNumbering(ArgRegEnd+1);
979 unsigned End = getMBlazeRegisterNumbering(MBlaze::R10);
980 unsigned StackLoc = Start - Begin + 1;
981
982 for (; Start <= End; ++Start, ++StackLoc) {
983 unsigned Reg = getMBlazeRegisterFromNumbering(Start);
984 unsigned LiveReg = MF.addLiveIn(Reg, RC);
985 SDValue ArgValue = DAG.getCopyFromReg(Chain, dl, LiveReg, MVT::i32);
986
987 int FI = MFI->CreateFixedObject(4, 0, true);
988 MBlazeFI->recordStoreVarArgsFI(FI, -(StackLoc*4));
989 SDValue PtrOff = DAG.getFrameIndex(FI, getPointerTy());
990 OutChains.push_back(DAG.getStore(Chain, dl, ArgValue, PtrOff,
991 MachinePointerInfo(),
992 false, false, 0));
993
994 // Record the frame index of the first variable argument
995 // which is a value necessary to VASTART.
996 if (!MBlazeFI->getVarArgsFrameIndex())
997 MBlazeFI->setVarArgsFrameIndex(FI);
998 }
999 }
1000
1001 // All stores are grouped in one node to allow the matching between
1002 // the size of Ins and InVals. This only happens when on varg functions
1003 if (!OutChains.empty()) {
1004 OutChains.push_back(Chain);
1005 Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
1006 &OutChains[0], OutChains.size());
1007 }
1008
1009 return Chain;
1010 }
1011
1012 //===----------------------------------------------------------------------===//
1013 // Return Value Calling Convention Implementation
1014 //===----------------------------------------------------------------------===//
1015
1016 SDValue MBlazeTargetLowering::
LowerReturn(SDValue Chain,CallingConv::ID CallConv,bool isVarArg,const SmallVectorImpl<ISD::OutputArg> & Outs,const SmallVectorImpl<SDValue> & OutVals,DebugLoc dl,SelectionDAG & DAG) const1017 LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
1018 const SmallVectorImpl<ISD::OutputArg> &Outs,
1019 const SmallVectorImpl<SDValue> &OutVals,
1020 DebugLoc dl, SelectionDAG &DAG) const {
1021 // CCValAssign - represent the assignment of
1022 // the return value to a location
1023 SmallVector<CCValAssign, 16> RVLocs;
1024
1025 // CCState - Info about the registers and stack slot.
1026 CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
1027 getTargetMachine(), RVLocs, *DAG.getContext());
1028
1029 // Analize return values.
1030 CCInfo.AnalyzeReturn(Outs, RetCC_MBlaze);
1031
1032 SDValue Flag;
1033 SmallVector<SDValue, 4> RetOps(1, Chain);
1034
1035 // If this function is using the interrupt_handler calling convention
1036 // then use "rtid r14, 0" otherwise use "rtsd r15, 8"
1037 unsigned Ret = (CallConv == CallingConv::MBLAZE_INTR) ? MBlazeISD::IRet
1038 : MBlazeISD::Ret;
1039 unsigned Reg = (CallConv == CallingConv::MBLAZE_INTR) ? MBlaze::R14
1040 : MBlaze::R15;
1041 RetOps.push_back(DAG.getRegister(Reg, MVT::i32));
1042
1043
1044 // Copy the result values into the output registers.
1045 for (unsigned i = 0; i != RVLocs.size(); ++i) {
1046 CCValAssign &VA = RVLocs[i];
1047 assert(VA.isRegLoc() && "Can only return in registers!");
1048
1049 Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(),
1050 OutVals[i], Flag);
1051
1052 // guarantee that all emitted copies are
1053 // stuck together, avoiding something bad
1054 Flag = Chain.getValue(1);
1055 RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
1056 }
1057
1058 RetOps[0] = Chain; // Update chain.
1059
1060 // Add the flag if we have it.
1061 if (Flag.getNode())
1062 RetOps.push_back(Flag);
1063
1064 return DAG.getNode(Ret, dl, MVT::Other, &RetOps[0], RetOps.size());
1065 }
1066
1067 //===----------------------------------------------------------------------===//
1068 // MBlaze Inline Assembly Support
1069 //===----------------------------------------------------------------------===//
1070
1071 /// getConstraintType - Given a constraint letter, return the type of
1072 /// constraint it is for this target.
1073 MBlazeTargetLowering::ConstraintType MBlazeTargetLowering::
getConstraintType(const std::string & Constraint) const1074 getConstraintType(const std::string &Constraint) const
1075 {
1076 // MBlaze specific constrainy
1077 //
1078 // 'd' : An address register. Equivalent to r.
1079 // 'y' : Equivalent to r; retained for
1080 // backwards compatibility.
1081 // 'f' : Floating Point registers.
1082 if (Constraint.size() == 1) {
1083 switch (Constraint[0]) {
1084 default : break;
1085 case 'd':
1086 case 'y':
1087 case 'f':
1088 return C_RegisterClass;
1089 }
1090 }
1091 return TargetLowering::getConstraintType(Constraint);
1092 }
1093
1094 /// Examine constraint type and operand type and determine a weight value.
1095 /// This object must already have been set up with the operand type
1096 /// and the current alternative constraint selected.
1097 TargetLowering::ConstraintWeight
getSingleConstraintMatchWeight(AsmOperandInfo & info,const char * constraint) const1098 MBlazeTargetLowering::getSingleConstraintMatchWeight(
1099 AsmOperandInfo &info, const char *constraint) const {
1100 ConstraintWeight weight = CW_Invalid;
1101 Value *CallOperandVal = info.CallOperandVal;
1102 // If we don't have a value, we can't do a match,
1103 // but allow it at the lowest weight.
1104 if (CallOperandVal == NULL)
1105 return CW_Default;
1106 Type *type = CallOperandVal->getType();
1107 // Look at the constraint type.
1108 switch (*constraint) {
1109 default:
1110 weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint);
1111 break;
1112 case 'd':
1113 case 'y':
1114 if (type->isIntegerTy())
1115 weight = CW_Register;
1116 break;
1117 case 'f':
1118 if (type->isFloatTy())
1119 weight = CW_Register;
1120 break;
1121 }
1122 return weight;
1123 }
1124
1125 /// Given a register class constraint, like 'r', if this corresponds directly
1126 /// to an LLVM register class, return a register of 0 and the register class
1127 /// pointer.
1128 std::pair<unsigned, const TargetRegisterClass*> MBlazeTargetLowering::
getRegForInlineAsmConstraint(const std::string & Constraint,EVT VT) const1129 getRegForInlineAsmConstraint(const std::string &Constraint, EVT VT) const {
1130 if (Constraint.size() == 1) {
1131 switch (Constraint[0]) {
1132 case 'r':
1133 return std::make_pair(0U, &MBlaze::GPRRegClass);
1134 // TODO: These can't possibly be right, but match what was in
1135 // getRegClassForInlineAsmConstraint.
1136 case 'd':
1137 case 'y':
1138 case 'f':
1139 if (VT == MVT::f32)
1140 return std::make_pair(0U, &MBlaze::GPRRegClass);
1141 }
1142 }
1143 return TargetLowering::getRegForInlineAsmConstraint(Constraint, VT);
1144 }
1145
1146 bool MBlazeTargetLowering::
isOffsetFoldingLegal(const GlobalAddressSDNode * GA) const1147 isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
1148 // The MBlaze target isn't yet aware of offsets.
1149 return false;
1150 }
1151
isFPImmLegal(const APFloat & Imm,EVT VT) const1152 bool MBlazeTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const {
1153 return VT != MVT::f32;
1154 }
1155