1 //===-- Mips16ISelLowering.h - Mips16 DAG Lowering Interface ----*- C++ -*-===//
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 // Subclass of MipsTargetLowering specialized for mips16.
11 //
12 //===----------------------------------------------------------------------===//
13 #include "Mips16ISelLowering.h"
14 #include "MCTargetDesc/MipsBaseInfo.h"
15 #include "Mips16HardFloatInfo.h"
16 #include "MipsMachineFunction.h"
17 #include "MipsRegisterInfo.h"
18 #include "MipsTargetMachine.h"
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/CodeGen/MachineInstrBuilder.h"
21 #include "llvm/Support/CommandLine.h"
22 #include "llvm/Target/TargetInstrInfo.h"
23 #include <string>
24 
25 using namespace llvm;
26 
27 #define DEBUG_TYPE "mips-lower"
28 
29 static cl::opt<bool> DontExpandCondPseudos16(
30   "mips16-dont-expand-cond-pseudo",
31   cl::init(false),
32   cl::desc("Don't expand conditional move related "
33            "pseudos for Mips 16"),
34   cl::Hidden);
35 
36 namespace {
37 struct Mips16Libcall {
38   RTLIB::Libcall Libcall;
39   const char *Name;
40 
operator <__anon1351efc40111::Mips16Libcall41   bool operator<(const Mips16Libcall &RHS) const {
42     return std::strcmp(Name, RHS.Name) < 0;
43   }
44 };
45 
46 struct Mips16IntrinsicHelperType{
47   const char* Name;
48   const char* Helper;
49 
operator <__anon1351efc40111::Mips16IntrinsicHelperType50   bool operator<(const Mips16IntrinsicHelperType &RHS) const {
51     return std::strcmp(Name, RHS.Name) < 0;
52   }
operator ==__anon1351efc40111::Mips16IntrinsicHelperType53   bool operator==(const Mips16IntrinsicHelperType &RHS) const {
54     return std::strcmp(Name, RHS.Name) == 0;
55   }
56 };
57 }
58 
59 // Libcalls for which no helper is generated. Sorted by name for binary search.
60 static const Mips16Libcall HardFloatLibCalls[] = {
61   { RTLIB::ADD_F64, "__mips16_adddf3" },
62   { RTLIB::ADD_F32, "__mips16_addsf3" },
63   { RTLIB::DIV_F64, "__mips16_divdf3" },
64   { RTLIB::DIV_F32, "__mips16_divsf3" },
65   { RTLIB::OEQ_F64, "__mips16_eqdf2" },
66   { RTLIB::OEQ_F32, "__mips16_eqsf2" },
67   { RTLIB::FPEXT_F32_F64, "__mips16_extendsfdf2" },
68   { RTLIB::FPTOSINT_F64_I32, "__mips16_fix_truncdfsi" },
69   { RTLIB::FPTOSINT_F32_I32, "__mips16_fix_truncsfsi" },
70   { RTLIB::SINTTOFP_I32_F64, "__mips16_floatsidf" },
71   { RTLIB::SINTTOFP_I32_F32, "__mips16_floatsisf" },
72   { RTLIB::UINTTOFP_I32_F64, "__mips16_floatunsidf" },
73   { RTLIB::UINTTOFP_I32_F32, "__mips16_floatunsisf" },
74   { RTLIB::OGE_F64, "__mips16_gedf2" },
75   { RTLIB::OGE_F32, "__mips16_gesf2" },
76   { RTLIB::OGT_F64, "__mips16_gtdf2" },
77   { RTLIB::OGT_F32, "__mips16_gtsf2" },
78   { RTLIB::OLE_F64, "__mips16_ledf2" },
79   { RTLIB::OLE_F32, "__mips16_lesf2" },
80   { RTLIB::OLT_F64, "__mips16_ltdf2" },
81   { RTLIB::OLT_F32, "__mips16_ltsf2" },
82   { RTLIB::MUL_F64, "__mips16_muldf3" },
83   { RTLIB::MUL_F32, "__mips16_mulsf3" },
84   { RTLIB::UNE_F64, "__mips16_nedf2" },
85   { RTLIB::UNE_F32, "__mips16_nesf2" },
86   { RTLIB::UNKNOWN_LIBCALL, "__mips16_ret_dc" }, // No associated libcall.
87   { RTLIB::UNKNOWN_LIBCALL, "__mips16_ret_df" }, // No associated libcall.
88   { RTLIB::UNKNOWN_LIBCALL, "__mips16_ret_sc" }, // No associated libcall.
89   { RTLIB::UNKNOWN_LIBCALL, "__mips16_ret_sf" }, // No associated libcall.
90   { RTLIB::SUB_F64, "__mips16_subdf3" },
91   { RTLIB::SUB_F32, "__mips16_subsf3" },
92   { RTLIB::FPROUND_F64_F32, "__mips16_truncdfsf2" },
93   { RTLIB::UO_F64, "__mips16_unorddf2" },
94   { RTLIB::UO_F32, "__mips16_unordsf2" }
95 };
96 
97 static const Mips16IntrinsicHelperType Mips16IntrinsicHelper[] = {
98   {"__fixunsdfsi", "__mips16_call_stub_2" },
99   {"ceil",  "__mips16_call_stub_df_2"},
100   {"ceilf", "__mips16_call_stub_sf_1"},
101   {"copysign",  "__mips16_call_stub_df_10"},
102   {"copysignf", "__mips16_call_stub_sf_5"},
103   {"cos",  "__mips16_call_stub_df_2"},
104   {"cosf", "__mips16_call_stub_sf_1"},
105   {"exp2",  "__mips16_call_stub_df_2"},
106   {"exp2f", "__mips16_call_stub_sf_1"},
107   {"floor",  "__mips16_call_stub_df_2"},
108   {"floorf", "__mips16_call_stub_sf_1"},
109   {"log2",  "__mips16_call_stub_df_2"},
110   {"log2f", "__mips16_call_stub_sf_1"},
111   {"nearbyint",  "__mips16_call_stub_df_2"},
112   {"nearbyintf", "__mips16_call_stub_sf_1"},
113   {"rint",  "__mips16_call_stub_df_2"},
114   {"rintf", "__mips16_call_stub_sf_1"},
115   {"sin",  "__mips16_call_stub_df_2"},
116   {"sinf", "__mips16_call_stub_sf_1"},
117   {"sqrt",  "__mips16_call_stub_df_2"},
118   {"sqrtf", "__mips16_call_stub_sf_1"},
119   {"trunc",  "__mips16_call_stub_df_2"},
120   {"truncf", "__mips16_call_stub_sf_1"},
121 };
122 
Mips16TargetLowering(const MipsTargetMachine & TM,const MipsSubtarget & STI)123 Mips16TargetLowering::Mips16TargetLowering(const MipsTargetMachine &TM,
124                                            const MipsSubtarget &STI)
125     : MipsTargetLowering(TM, STI) {
126 
127   // Set up the register classes
128   addRegisterClass(MVT::i32, &Mips::CPU16RegsRegClass);
129 
130   if (!TM.Options.UseSoftFloat)
131     setMips16HardFloatLibCalls();
132 
133   setOperationAction(ISD::ATOMIC_FENCE,       MVT::Other, Expand);
134   setOperationAction(ISD::ATOMIC_CMP_SWAP,    MVT::i32,   Expand);
135   setOperationAction(ISD::ATOMIC_SWAP,        MVT::i32,   Expand);
136   setOperationAction(ISD::ATOMIC_LOAD_ADD,    MVT::i32,   Expand);
137   setOperationAction(ISD::ATOMIC_LOAD_SUB,    MVT::i32,   Expand);
138   setOperationAction(ISD::ATOMIC_LOAD_AND,    MVT::i32,   Expand);
139   setOperationAction(ISD::ATOMIC_LOAD_OR,     MVT::i32,   Expand);
140   setOperationAction(ISD::ATOMIC_LOAD_XOR,    MVT::i32,   Expand);
141   setOperationAction(ISD::ATOMIC_LOAD_NAND,   MVT::i32,   Expand);
142   setOperationAction(ISD::ATOMIC_LOAD_MIN,    MVT::i32,   Expand);
143   setOperationAction(ISD::ATOMIC_LOAD_MAX,    MVT::i32,   Expand);
144   setOperationAction(ISD::ATOMIC_LOAD_UMIN,   MVT::i32,   Expand);
145   setOperationAction(ISD::ATOMIC_LOAD_UMAX,   MVT::i32,   Expand);
146 
147   setOperationAction(ISD::ROTR, MVT::i32,  Expand);
148   setOperationAction(ISD::ROTR, MVT::i64,  Expand);
149   setOperationAction(ISD::BSWAP, MVT::i32, Expand);
150   setOperationAction(ISD::BSWAP, MVT::i64, Expand);
151 
152   computeRegisterProperties(STI.getRegisterInfo());
153 }
154 
155 const MipsTargetLowering *
createMips16TargetLowering(const MipsTargetMachine & TM,const MipsSubtarget & STI)156 llvm::createMips16TargetLowering(const MipsTargetMachine &TM,
157                                  const MipsSubtarget &STI) {
158   return new Mips16TargetLowering(TM, STI);
159 }
160 
161 bool
allowsMisalignedMemoryAccesses(EVT VT,unsigned,unsigned,bool * Fast) const162 Mips16TargetLowering::allowsMisalignedMemoryAccesses(EVT VT,
163                                                      unsigned,
164                                                      unsigned,
165                                                      bool *Fast) const {
166   return false;
167 }
168 
169 MachineBasicBlock *
EmitInstrWithCustomInserter(MachineInstr * MI,MachineBasicBlock * BB) const170 Mips16TargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
171                                                   MachineBasicBlock *BB) const {
172   switch (MI->getOpcode()) {
173   default:
174     return MipsTargetLowering::EmitInstrWithCustomInserter(MI, BB);
175   case Mips::SelBeqZ:
176     return emitSel16(Mips::BeqzRxImm16, MI, BB);
177   case Mips::SelBneZ:
178     return emitSel16(Mips::BnezRxImm16, MI, BB);
179   case Mips::SelTBteqZCmpi:
180     return emitSeliT16(Mips::Bteqz16, Mips::CmpiRxImmX16, MI, BB);
181   case Mips::SelTBteqZSlti:
182     return emitSeliT16(Mips::Bteqz16, Mips::SltiRxImmX16, MI, BB);
183   case Mips::SelTBteqZSltiu:
184     return emitSeliT16(Mips::Bteqz16, Mips::SltiuRxImmX16, MI, BB);
185   case Mips::SelTBtneZCmpi:
186     return emitSeliT16(Mips::Btnez16, Mips::CmpiRxImmX16, MI, BB);
187   case Mips::SelTBtneZSlti:
188     return emitSeliT16(Mips::Btnez16, Mips::SltiRxImmX16, MI, BB);
189   case Mips::SelTBtneZSltiu:
190     return emitSeliT16(Mips::Btnez16, Mips::SltiuRxImmX16, MI, BB);
191   case Mips::SelTBteqZCmp:
192     return emitSelT16(Mips::Bteqz16, Mips::CmpRxRy16, MI, BB);
193   case Mips::SelTBteqZSlt:
194     return emitSelT16(Mips::Bteqz16, Mips::SltRxRy16, MI, BB);
195   case Mips::SelTBteqZSltu:
196     return emitSelT16(Mips::Bteqz16, Mips::SltuRxRy16, MI, BB);
197   case Mips::SelTBtneZCmp:
198     return emitSelT16(Mips::Btnez16, Mips::CmpRxRy16, MI, BB);
199   case Mips::SelTBtneZSlt:
200     return emitSelT16(Mips::Btnez16, Mips::SltRxRy16, MI, BB);
201   case Mips::SelTBtneZSltu:
202     return emitSelT16(Mips::Btnez16, Mips::SltuRxRy16, MI, BB);
203   case Mips::BteqzT8CmpX16:
204     return emitFEXT_T8I816_ins(Mips::Bteqz16, Mips::CmpRxRy16, MI, BB);
205   case Mips::BteqzT8SltX16:
206     return emitFEXT_T8I816_ins(Mips::Bteqz16, Mips::SltRxRy16, MI, BB);
207   case Mips::BteqzT8SltuX16:
208     // TBD: figure out a way to get this or remove the instruction
209     // altogether.
210     return emitFEXT_T8I816_ins(Mips::Bteqz16, Mips::SltuRxRy16, MI, BB);
211   case Mips::BtnezT8CmpX16:
212     return emitFEXT_T8I816_ins(Mips::Btnez16, Mips::CmpRxRy16, MI, BB);
213   case Mips::BtnezT8SltX16:
214     return emitFEXT_T8I816_ins(Mips::Btnez16, Mips::SltRxRy16, MI, BB);
215   case Mips::BtnezT8SltuX16:
216     // TBD: figure out a way to get this or remove the instruction
217     // altogether.
218     return emitFEXT_T8I816_ins(Mips::Btnez16, Mips::SltuRxRy16, MI, BB);
219   case Mips::BteqzT8CmpiX16: return emitFEXT_T8I8I16_ins(
220     Mips::Bteqz16, Mips::CmpiRxImm16, Mips::CmpiRxImmX16, false, MI, BB);
221   case Mips::BteqzT8SltiX16: return emitFEXT_T8I8I16_ins(
222     Mips::Bteqz16, Mips::SltiRxImm16, Mips::SltiRxImmX16, true, MI, BB);
223   case Mips::BteqzT8SltiuX16: return emitFEXT_T8I8I16_ins(
224     Mips::Bteqz16, Mips::SltiuRxImm16, Mips::SltiuRxImmX16, false, MI, BB);
225   case Mips::BtnezT8CmpiX16: return emitFEXT_T8I8I16_ins(
226     Mips::Btnez16, Mips::CmpiRxImm16, Mips::CmpiRxImmX16, false, MI, BB);
227   case Mips::BtnezT8SltiX16: return emitFEXT_T8I8I16_ins(
228     Mips::Btnez16, Mips::SltiRxImm16, Mips::SltiRxImmX16, true, MI, BB);
229   case Mips::BtnezT8SltiuX16: return emitFEXT_T8I8I16_ins(
230     Mips::Btnez16, Mips::SltiuRxImm16, Mips::SltiuRxImmX16, false, MI, BB);
231     break;
232   case Mips::SltCCRxRy16:
233     return emitFEXT_CCRX16_ins(Mips::SltRxRy16, MI, BB);
234     break;
235   case Mips::SltiCCRxImmX16:
236     return emitFEXT_CCRXI16_ins
237       (Mips::SltiRxImm16, Mips::SltiRxImmX16, MI, BB);
238   case Mips::SltiuCCRxImmX16:
239     return emitFEXT_CCRXI16_ins
240       (Mips::SltiuRxImm16, Mips::SltiuRxImmX16, MI, BB);
241   case Mips::SltuCCRxRy16:
242     return emitFEXT_CCRX16_ins
243       (Mips::SltuRxRy16, MI, BB);
244   }
245 }
246 
isEligibleForTailCallOptimization(const CCState & CCInfo,unsigned NextStackOffset,const MipsFunctionInfo & FI) const247 bool Mips16TargetLowering::isEligibleForTailCallOptimization(
248     const CCState &CCInfo, unsigned NextStackOffset,
249     const MipsFunctionInfo &FI) const {
250   // No tail call optimization for mips16.
251   return false;
252 }
253 
setMips16HardFloatLibCalls()254 void Mips16TargetLowering::setMips16HardFloatLibCalls() {
255   for (unsigned I = 0; I != array_lengthof(HardFloatLibCalls); ++I) {
256     assert((I == 0 || HardFloatLibCalls[I - 1] < HardFloatLibCalls[I]) &&
257            "Array not sorted!");
258     if (HardFloatLibCalls[I].Libcall != RTLIB::UNKNOWN_LIBCALL)
259       setLibcallName(HardFloatLibCalls[I].Libcall, HardFloatLibCalls[I].Name);
260   }
261 
262   setLibcallName(RTLIB::O_F64, "__mips16_unorddf2");
263   setLibcallName(RTLIB::O_F32, "__mips16_unordsf2");
264 }
265 
266 //
267 // The Mips16 hard float is a crazy quilt inherited from gcc. I have a much
268 // cleaner way to do all of this but it will have to wait until the traditional
269 // gcc mechanism is completed.
270 //
271 // For Pic, in order for Mips16 code to call Mips32 code which according the abi
272 // have either arguments or returned values placed in floating point registers,
273 // we use a set of helper functions. (This includes functions which return type
274 //  complex which on Mips are returned in a pair of floating point registers).
275 //
276 // This is an encoding that we inherited from gcc.
277 // In Mips traditional O32, N32 ABI, floating point numbers are passed in
278 // floating point argument registers 1,2 only when the first and optionally
279 // the second arguments are float (sf) or double (df).
280 // For Mips16 we are only concerned with the situations where floating point
281 // arguments are being passed in floating point registers by the ABI, because
282 // Mips16 mode code cannot execute floating point instructions to load those
283 // values and hence helper functions are needed.
284 // The possibilities are (), (sf), (sf, sf), (sf, df), (df), (df, sf), (df, df)
285 // the helper function suffixs for these are:
286 //                        0,  1,    5,        9,         2,   6,        10
287 // this suffix can then be calculated as follows:
288 // for a given argument Arg:
289 //     Arg1x, Arg2x = 1 :  Arg is sf
290 //                    2 :  Arg is df
291 //                    0:   Arg is neither sf or df
292 // So this stub is the string for number Arg1x + Arg2x*4.
293 // However not all numbers between 0 and 10 are possible, we check anyway and
294 // assert if the impossible exists.
295 //
296 
getMips16HelperFunctionStubNumber(ArgListTy & Args) const297 unsigned int Mips16TargetLowering::getMips16HelperFunctionStubNumber
298   (ArgListTy &Args) const {
299   unsigned int resultNum = 0;
300   if (Args.size() >= 1) {
301     Type *t = Args[0].Ty;
302     if (t->isFloatTy()) {
303       resultNum = 1;
304     }
305     else if (t->isDoubleTy()) {
306       resultNum = 2;
307     }
308   }
309   if (resultNum) {
310     if (Args.size() >=2) {
311       Type *t = Args[1].Ty;
312       if (t->isFloatTy()) {
313         resultNum += 4;
314       }
315       else if (t->isDoubleTy()) {
316         resultNum += 8;
317       }
318     }
319   }
320   return resultNum;
321 }
322 
323 //
324 // Prefixes are attached to stub numbers depending on the return type.
325 // return type: float  sf_
326 //              double df_
327 //              single complex sc_
328 //              double complext dc_
329 //              others  NO PREFIX
330 //
331 //
332 // The full name of a helper function is__mips16_call_stub +
333 //    return type dependent prefix + stub number
334 //
335 // FIXME: This is something that probably should be in a different source file
336 // and perhaps done differently but my main purpose is to not waste runtime
337 // on something that we can enumerate in the source. Another possibility is
338 // to have a python script to generate these mapping tables. This will do
339 // for now. There are a whole series of helper function mapping arrays, one
340 // for each return type class as outlined above. There there are 11 possible
341 // entries. Ones with 0 are ones which should never be selected.
342 //
343 // All the arrays are similar except for ones which return neither
344 // sf, df, sc, dc, in which we only care about ones which have sf or df as a
345 // first parameter.
346 //
347 #define P_ "__mips16_call_stub_"
348 #define MAX_STUB_NUMBER 10
349 #define T1 P "1", P "2", 0, 0, P "5", P "6", 0, 0, P "9", P "10"
350 #define T P "0" , T1
351 #define P P_
352 static char const * vMips16Helper[MAX_STUB_NUMBER+1] =
353   {nullptr, T1 };
354 #undef P
355 #define P P_ "sf_"
356 static char const * sfMips16Helper[MAX_STUB_NUMBER+1] =
357   { T };
358 #undef P
359 #define P P_ "df_"
360 static char const * dfMips16Helper[MAX_STUB_NUMBER+1] =
361   { T };
362 #undef P
363 #define P P_ "sc_"
364 static char const * scMips16Helper[MAX_STUB_NUMBER+1] =
365   { T };
366 #undef P
367 #define P P_ "dc_"
368 static char const * dcMips16Helper[MAX_STUB_NUMBER+1] =
369   { T };
370 #undef P
371 #undef P_
372 
373 
374 const char* Mips16TargetLowering::
getMips16HelperFunction(Type * RetTy,ArgListTy & Args,bool & needHelper) const375   getMips16HelperFunction
376     (Type* RetTy, ArgListTy &Args, bool &needHelper) const {
377   const unsigned int stubNum = getMips16HelperFunctionStubNumber(Args);
378 #ifndef NDEBUG
379   const unsigned int maxStubNum = 10;
380   assert(stubNum <= maxStubNum);
381   const bool validStubNum[maxStubNum+1] =
382     {true, true, true, false, false, true, true, false, false, true, true};
383   assert(validStubNum[stubNum]);
384 #endif
385   const char *result;
386   if (RetTy->isFloatTy()) {
387     result = sfMips16Helper[stubNum];
388   }
389   else if (RetTy ->isDoubleTy()) {
390     result = dfMips16Helper[stubNum];
391   }
392   else if (RetTy->isStructTy()) {
393     // check if it's complex
394     if (RetTy->getNumContainedTypes() == 2) {
395       if ((RetTy->getContainedType(0)->isFloatTy()) &&
396           (RetTy->getContainedType(1)->isFloatTy())) {
397         result = scMips16Helper[stubNum];
398       }
399       else if ((RetTy->getContainedType(0)->isDoubleTy()) &&
400                (RetTy->getContainedType(1)->isDoubleTy())) {
401         result = dcMips16Helper[stubNum];
402       }
403       else {
404         llvm_unreachable("Uncovered condition");
405       }
406     }
407     else {
408       llvm_unreachable("Uncovered condition");
409     }
410   }
411   else {
412     if (stubNum == 0) {
413       needHelper = false;
414       return "";
415     }
416     result = vMips16Helper[stubNum];
417   }
418   needHelper = true;
419   return result;
420 }
421 
422 void Mips16TargetLowering::
getOpndList(SmallVectorImpl<SDValue> & Ops,std::deque<std::pair<unsigned,SDValue>> & RegsToPass,bool IsPICCall,bool GlobalOrExternal,bool InternalLinkage,bool IsCallReloc,CallLoweringInfo & CLI,SDValue Callee,SDValue Chain) const423 getOpndList(SmallVectorImpl<SDValue> &Ops,
424             std::deque< std::pair<unsigned, SDValue> > &RegsToPass,
425             bool IsPICCall, bool GlobalOrExternal, bool InternalLinkage,
426             bool IsCallReloc, CallLoweringInfo &CLI, SDValue Callee,
427             SDValue Chain) const {
428   SelectionDAG &DAG = CLI.DAG;
429   MachineFunction &MF = DAG.getMachineFunction();
430   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
431   const char* Mips16HelperFunction = nullptr;
432   bool NeedMips16Helper = false;
433 
434   if (Subtarget.inMips16HardFloat()) {
435     //
436     // currently we don't have symbols tagged with the mips16 or mips32
437     // qualifier so we will assume that we don't know what kind it is.
438     // and generate the helper
439     //
440     bool LookupHelper = true;
441     if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(CLI.Callee)) {
442       Mips16Libcall Find = { RTLIB::UNKNOWN_LIBCALL, S->getSymbol() };
443 
444       if (std::binary_search(std::begin(HardFloatLibCalls),
445                              std::end(HardFloatLibCalls), Find))
446         LookupHelper = false;
447       else {
448         const char *Symbol = S->getSymbol();
449         Mips16IntrinsicHelperType IntrinsicFind = { Symbol, "" };
450         const Mips16HardFloatInfo::FuncSignature *Signature =
451             Mips16HardFloatInfo::findFuncSignature(Symbol);
452         if (!IsPICCall && (Signature && (FuncInfo->StubsNeeded.find(Symbol) ==
453                                          FuncInfo->StubsNeeded.end()))) {
454           FuncInfo->StubsNeeded[Symbol] = Signature;
455           //
456           // S2 is normally saved if the stub is for a function which
457           // returns a float or double value and is not otherwise. This is
458           // because more work is required after the function the stub
459           // is calling completes, and so the stub cannot directly return
460           // and the stub has no stack space to store the return address so
461           // S2 is used for that purpose.
462           // In order to take advantage of not saving S2, we need to also
463           // optimize the call in the stub and this requires some further
464           // functionality in MipsAsmPrinter which we don't have yet.
465           // So for now we always save S2. The optimization will be done
466           // in a follow-on patch.
467           //
468           if (1 || (Signature->RetSig != Mips16HardFloatInfo::NoFPRet))
469             FuncInfo->setSaveS2();
470         }
471         // one more look at list of intrinsics
472         const Mips16IntrinsicHelperType *Helper =
473             std::lower_bound(std::begin(Mips16IntrinsicHelper),
474                              std::end(Mips16IntrinsicHelper), IntrinsicFind);
475         if (Helper != std::end(Mips16IntrinsicHelper) &&
476             *Helper == IntrinsicFind) {
477           Mips16HelperFunction = Helper->Helper;
478           NeedMips16Helper = true;
479           LookupHelper = false;
480         }
481 
482       }
483     } else if (GlobalAddressSDNode *G =
484                    dyn_cast<GlobalAddressSDNode>(CLI.Callee)) {
485       Mips16Libcall Find = { RTLIB::UNKNOWN_LIBCALL,
486                              G->getGlobal()->getName().data() };
487 
488       if (std::binary_search(std::begin(HardFloatLibCalls),
489                              std::end(HardFloatLibCalls), Find))
490         LookupHelper = false;
491     }
492     if (LookupHelper)
493       Mips16HelperFunction =
494         getMips16HelperFunction(CLI.RetTy, CLI.getArgs(), NeedMips16Helper);
495   }
496 
497   SDValue JumpTarget = Callee;
498 
499   // T9 should contain the address of the callee function if
500   // -relocation-model=pic or it is an indirect call.
501   if (IsPICCall || !GlobalOrExternal) {
502     unsigned V0Reg = Mips::V0;
503     if (NeedMips16Helper) {
504       RegsToPass.push_front(std::make_pair(V0Reg, Callee));
505       JumpTarget = DAG.getExternalSymbol(Mips16HelperFunction, getPointerTy());
506       ExternalSymbolSDNode *S = cast<ExternalSymbolSDNode>(JumpTarget);
507       JumpTarget = getAddrGlobal(S, CLI.DL, JumpTarget.getValueType(), DAG,
508                                  MipsII::MO_GOT, Chain,
509                                  FuncInfo->callPtrInfo(S->getSymbol()));
510     } else
511       RegsToPass.push_front(std::make_pair((unsigned)Mips::T9, Callee));
512   }
513 
514   Ops.push_back(JumpTarget);
515 
516   MipsTargetLowering::getOpndList(Ops, RegsToPass, IsPICCall, GlobalOrExternal,
517                                   InternalLinkage, IsCallReloc, CLI, Callee,
518                                   Chain);
519 }
520 
521 MachineBasicBlock *Mips16TargetLowering::
emitSel16(unsigned Opc,MachineInstr * MI,MachineBasicBlock * BB) const522 emitSel16(unsigned Opc, MachineInstr *MI, MachineBasicBlock *BB) const {
523   if (DontExpandCondPseudos16)
524     return BB;
525   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
526   DebugLoc DL = MI->getDebugLoc();
527   // To "insert" a SELECT_CC instruction, we actually have to insert the
528   // diamond control-flow pattern.  The incoming instruction knows the
529   // destination vreg to set, the condition code register to branch on, the
530   // true/false values to select between, and a branch opcode to use.
531   const BasicBlock *LLVM_BB = BB->getBasicBlock();
532   MachineFunction::iterator It = BB;
533   ++It;
534 
535   //  thisMBB:
536   //  ...
537   //   TrueVal = ...
538   //   setcc r1, r2, r3
539   //   bNE   r1, r0, copy1MBB
540   //   fallthrough --> copy0MBB
541   MachineBasicBlock *thisMBB  = BB;
542   MachineFunction *F = BB->getParent();
543   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
544   MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
545   F->insert(It, copy0MBB);
546   F->insert(It, sinkMBB);
547 
548   // Transfer the remainder of BB and its successor edges to sinkMBB.
549   sinkMBB->splice(sinkMBB->begin(), BB,
550                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
551   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
552 
553   // Next, add the true and fallthrough blocks as its successors.
554   BB->addSuccessor(copy0MBB);
555   BB->addSuccessor(sinkMBB);
556 
557   BuildMI(BB, DL, TII->get(Opc)).addReg(MI->getOperand(3).getReg())
558     .addMBB(sinkMBB);
559 
560   //  copy0MBB:
561   //   %FalseValue = ...
562   //   # fallthrough to sinkMBB
563   BB = copy0MBB;
564 
565   // Update machine-CFG edges
566   BB->addSuccessor(sinkMBB);
567 
568   //  sinkMBB:
569   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
570   //  ...
571   BB = sinkMBB;
572 
573   BuildMI(*BB, BB->begin(), DL,
574           TII->get(Mips::PHI), MI->getOperand(0).getReg())
575     .addReg(MI->getOperand(1).getReg()).addMBB(thisMBB)
576     .addReg(MI->getOperand(2).getReg()).addMBB(copy0MBB);
577 
578   MI->eraseFromParent();   // The pseudo instruction is gone now.
579   return BB;
580 }
581 
582 MachineBasicBlock *
emitSelT16(unsigned Opc1,unsigned Opc2,MachineInstr * MI,MachineBasicBlock * BB) const583 Mips16TargetLowering::emitSelT16(unsigned Opc1, unsigned Opc2, MachineInstr *MI,
584                                  MachineBasicBlock *BB) const {
585   if (DontExpandCondPseudos16)
586     return BB;
587   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
588   DebugLoc DL = MI->getDebugLoc();
589   // To "insert" a SELECT_CC instruction, we actually have to insert the
590   // diamond control-flow pattern.  The incoming instruction knows the
591   // destination vreg to set, the condition code register to branch on, the
592   // true/false values to select between, and a branch opcode to use.
593   const BasicBlock *LLVM_BB = BB->getBasicBlock();
594   MachineFunction::iterator It = BB;
595   ++It;
596 
597   //  thisMBB:
598   //  ...
599   //   TrueVal = ...
600   //   setcc r1, r2, r3
601   //   bNE   r1, r0, copy1MBB
602   //   fallthrough --> copy0MBB
603   MachineBasicBlock *thisMBB  = BB;
604   MachineFunction *F = BB->getParent();
605   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
606   MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
607   F->insert(It, copy0MBB);
608   F->insert(It, sinkMBB);
609 
610   // Transfer the remainder of BB and its successor edges to sinkMBB.
611   sinkMBB->splice(sinkMBB->begin(), BB,
612                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
613   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
614 
615   // Next, add the true and fallthrough blocks as its successors.
616   BB->addSuccessor(copy0MBB);
617   BB->addSuccessor(sinkMBB);
618 
619   BuildMI(BB, DL, TII->get(Opc2)).addReg(MI->getOperand(3).getReg())
620     .addReg(MI->getOperand(4).getReg());
621   BuildMI(BB, DL, TII->get(Opc1)).addMBB(sinkMBB);
622 
623   //  copy0MBB:
624   //   %FalseValue = ...
625   //   # fallthrough to sinkMBB
626   BB = copy0MBB;
627 
628   // Update machine-CFG edges
629   BB->addSuccessor(sinkMBB);
630 
631   //  sinkMBB:
632   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
633   //  ...
634   BB = sinkMBB;
635 
636   BuildMI(*BB, BB->begin(), DL,
637           TII->get(Mips::PHI), MI->getOperand(0).getReg())
638     .addReg(MI->getOperand(1).getReg()).addMBB(thisMBB)
639     .addReg(MI->getOperand(2).getReg()).addMBB(copy0MBB);
640 
641   MI->eraseFromParent();   // The pseudo instruction is gone now.
642   return BB;
643 
644 }
645 
646 MachineBasicBlock *
emitSeliT16(unsigned Opc1,unsigned Opc2,MachineInstr * MI,MachineBasicBlock * BB) const647 Mips16TargetLowering::emitSeliT16(unsigned Opc1, unsigned Opc2,
648                                   MachineInstr *MI,
649                                   MachineBasicBlock *BB) const {
650   if (DontExpandCondPseudos16)
651     return BB;
652   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
653   DebugLoc DL = MI->getDebugLoc();
654   // To "insert" a SELECT_CC instruction, we actually have to insert the
655   // diamond control-flow pattern.  The incoming instruction knows the
656   // destination vreg to set, the condition code register to branch on, the
657   // true/false values to select between, and a branch opcode to use.
658   const BasicBlock *LLVM_BB = BB->getBasicBlock();
659   MachineFunction::iterator It = BB;
660   ++It;
661 
662   //  thisMBB:
663   //  ...
664   //   TrueVal = ...
665   //   setcc r1, r2, r3
666   //   bNE   r1, r0, copy1MBB
667   //   fallthrough --> copy0MBB
668   MachineBasicBlock *thisMBB  = BB;
669   MachineFunction *F = BB->getParent();
670   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
671   MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
672   F->insert(It, copy0MBB);
673   F->insert(It, sinkMBB);
674 
675   // Transfer the remainder of BB and its successor edges to sinkMBB.
676   sinkMBB->splice(sinkMBB->begin(), BB,
677                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
678   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
679 
680   // Next, add the true and fallthrough blocks as its successors.
681   BB->addSuccessor(copy0MBB);
682   BB->addSuccessor(sinkMBB);
683 
684   BuildMI(BB, DL, TII->get(Opc2)).addReg(MI->getOperand(3).getReg())
685     .addImm(MI->getOperand(4).getImm());
686   BuildMI(BB, DL, TII->get(Opc1)).addMBB(sinkMBB);
687 
688   //  copy0MBB:
689   //   %FalseValue = ...
690   //   # fallthrough to sinkMBB
691   BB = copy0MBB;
692 
693   // Update machine-CFG edges
694   BB->addSuccessor(sinkMBB);
695 
696   //  sinkMBB:
697   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
698   //  ...
699   BB = sinkMBB;
700 
701   BuildMI(*BB, BB->begin(), DL,
702           TII->get(Mips::PHI), MI->getOperand(0).getReg())
703     .addReg(MI->getOperand(1).getReg()).addMBB(thisMBB)
704     .addReg(MI->getOperand(2).getReg()).addMBB(copy0MBB);
705 
706   MI->eraseFromParent();   // The pseudo instruction is gone now.
707   return BB;
708 
709 }
710 
711 MachineBasicBlock *
emitFEXT_T8I816_ins(unsigned BtOpc,unsigned CmpOpc,MachineInstr * MI,MachineBasicBlock * BB) const712 Mips16TargetLowering::emitFEXT_T8I816_ins(unsigned BtOpc, unsigned CmpOpc,
713                                           MachineInstr *MI,
714                                           MachineBasicBlock *BB) const {
715   if (DontExpandCondPseudos16)
716     return BB;
717   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
718   unsigned regX = MI->getOperand(0).getReg();
719   unsigned regY = MI->getOperand(1).getReg();
720   MachineBasicBlock *target = MI->getOperand(2).getMBB();
721   BuildMI(*BB, MI, MI->getDebugLoc(), TII->get(CmpOpc)).addReg(regX)
722     .addReg(regY);
723   BuildMI(*BB, MI, MI->getDebugLoc(), TII->get(BtOpc)).addMBB(target);
724   MI->eraseFromParent();   // The pseudo instruction is gone now.
725   return BB;
726 }
727 
emitFEXT_T8I8I16_ins(unsigned BtOpc,unsigned CmpiOpc,unsigned CmpiXOpc,bool ImmSigned,MachineInstr * MI,MachineBasicBlock * BB) const728 MachineBasicBlock *Mips16TargetLowering::emitFEXT_T8I8I16_ins(
729     unsigned BtOpc, unsigned CmpiOpc, unsigned CmpiXOpc, bool ImmSigned,
730     MachineInstr *MI, MachineBasicBlock *BB) const {
731   if (DontExpandCondPseudos16)
732     return BB;
733   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
734   unsigned regX = MI->getOperand(0).getReg();
735   int64_t imm = MI->getOperand(1).getImm();
736   MachineBasicBlock *target = MI->getOperand(2).getMBB();
737   unsigned CmpOpc;
738   if (isUInt<8>(imm))
739     CmpOpc = CmpiOpc;
740   else if ((!ImmSigned && isUInt<16>(imm)) ||
741            (ImmSigned && isInt<16>(imm)))
742     CmpOpc = CmpiXOpc;
743   else
744     llvm_unreachable("immediate field not usable");
745   BuildMI(*BB, MI, MI->getDebugLoc(), TII->get(CmpOpc)).addReg(regX)
746     .addImm(imm);
747   BuildMI(*BB, MI, MI->getDebugLoc(), TII->get(BtOpc)).addMBB(target);
748   MI->eraseFromParent();   // The pseudo instruction is gone now.
749   return BB;
750 }
751 
Mips16WhichOp8uOr16simm(unsigned shortOp,unsigned longOp,int64_t Imm)752 static unsigned Mips16WhichOp8uOr16simm
753   (unsigned shortOp, unsigned longOp, int64_t Imm) {
754   if (isUInt<8>(Imm))
755     return shortOp;
756   else if (isInt<16>(Imm))
757     return longOp;
758   else
759     llvm_unreachable("immediate field not usable");
760 }
761 
762 MachineBasicBlock *
emitFEXT_CCRX16_ins(unsigned SltOpc,MachineInstr * MI,MachineBasicBlock * BB) const763 Mips16TargetLowering::emitFEXT_CCRX16_ins(unsigned SltOpc, MachineInstr *MI,
764                                           MachineBasicBlock *BB) const {
765   if (DontExpandCondPseudos16)
766     return BB;
767   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
768   unsigned CC = MI->getOperand(0).getReg();
769   unsigned regX = MI->getOperand(1).getReg();
770   unsigned regY = MI->getOperand(2).getReg();
771   BuildMI(*BB, MI, MI->getDebugLoc(), TII->get(SltOpc)).addReg(regX).addReg(
772       regY);
773   BuildMI(*BB, MI, MI->getDebugLoc(),
774           TII->get(Mips::MoveR3216), CC).addReg(Mips::T8);
775   MI->eraseFromParent();   // The pseudo instruction is gone now.
776   return BB;
777 }
778 
779 MachineBasicBlock *
emitFEXT_CCRXI16_ins(unsigned SltiOpc,unsigned SltiXOpc,MachineInstr * MI,MachineBasicBlock * BB) const780 Mips16TargetLowering::emitFEXT_CCRXI16_ins(unsigned SltiOpc, unsigned SltiXOpc,
781                                            MachineInstr *MI,
782                                            MachineBasicBlock *BB) const {
783   if (DontExpandCondPseudos16)
784     return BB;
785   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
786   unsigned CC = MI->getOperand(0).getReg();
787   unsigned regX = MI->getOperand(1).getReg();
788   int64_t Imm = MI->getOperand(2).getImm();
789   unsigned SltOpc = Mips16WhichOp8uOr16simm(SltiOpc, SltiXOpc, Imm);
790   BuildMI(*BB, MI, MI->getDebugLoc(),
791           TII->get(SltOpc)).addReg(regX).addImm(Imm);
792   BuildMI(*BB, MI, MI->getDebugLoc(),
793           TII->get(Mips::MoveR3216), CC).addReg(Mips::T8);
794   MI->eraseFromParent();   // The pseudo instruction is gone now.
795   return BB;
796 
797 }
798