1//===-- MSP430ISelLowering.cpp - MSP430 DAG Lowering Implementation  ------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements the MSP430TargetLowering class.
10//
11//===----------------------------------------------------------------------===//
12
13#include "MSP430ISelLowering.h"
14#include "MSP430.h"
15#include "MSP430MachineFunctionInfo.h"
16#include "MSP430Subtarget.h"
17#include "MSP430TargetMachine.h"
18#include "llvm/CodeGen/CallingConvLower.h"
19#include "llvm/CodeGen/MachineFrameInfo.h"
20#include "llvm/CodeGen/MachineFunction.h"
21#include "llvm/CodeGen/MachineInstrBuilder.h"
22#include "llvm/CodeGen/MachineRegisterInfo.h"
23#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
24#include "llvm/CodeGen/ValueTypes.h"
25#include "llvm/IR/CallingConv.h"
26#include "llvm/IR/DerivedTypes.h"
27#include "llvm/IR/Function.h"
28#include "llvm/IR/GlobalAlias.h"
29#include "llvm/IR/GlobalVariable.h"
30#include "llvm/IR/Intrinsics.h"
31#include "llvm/Support/CommandLine.h"
32#include "llvm/Support/Debug.h"
33#include "llvm/Support/ErrorHandling.h"
34#include "llvm/Support/raw_ostream.h"
35using namespace llvm;
36
37#define DEBUG_TYPE "msp430-lower"
38
39static cl::opt<bool>MSP430NoLegalImmediate(
40  "msp430-no-legal-immediate", cl::Hidden,
41  cl::desc("Enable non legal immediates (for testing purposes only)"),
42  cl::init(false));
43
44MSP430TargetLowering::MSP430TargetLowering(const TargetMachine &TM,
45                                           const MSP430Subtarget &STI)
46    : TargetLowering(TM) {
47
48  // Set up the register classes.
49  addRegisterClass(MVT::i8,  &MSP430::GR8RegClass);
50  addRegisterClass(MVT::i16, &MSP430::GR16RegClass);
51
52  // Compute derived properties from the register classes
53  computeRegisterProperties(STI.getRegisterInfo());
54
55  // Provide all sorts of operation actions
56  setStackPointerRegisterToSaveRestore(MSP430::SP);
57  setBooleanContents(ZeroOrOneBooleanContent);
58  setBooleanVectorContents(ZeroOrOneBooleanContent); // FIXME: Is this correct?
59
60  // We have post-incremented loads / stores.
61  setIndexedLoadAction(ISD::POST_INC, MVT::i8, Legal);
62  setIndexedLoadAction(ISD::POST_INC, MVT::i16, Legal);
63
64  for (MVT VT : MVT::integer_valuetypes()) {
65    setLoadExtAction(ISD::EXTLOAD,  VT, MVT::i1,  Promote);
66    setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1,  Promote);
67    setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i1,  Promote);
68    setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i8,  Expand);
69    setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i16, Expand);
70  }
71
72  // We don't have any truncstores
73  setTruncStoreAction(MVT::i16, MVT::i8, Expand);
74
75  setOperationAction(ISD::SRA,              MVT::i8,    Custom);
76  setOperationAction(ISD::SHL,              MVT::i8,    Custom);
77  setOperationAction(ISD::SRL,              MVT::i8,    Custom);
78  setOperationAction(ISD::SRA,              MVT::i16,   Custom);
79  setOperationAction(ISD::SHL,              MVT::i16,   Custom);
80  setOperationAction(ISD::SRL,              MVT::i16,   Custom);
81  setOperationAction(ISD::ROTL,             MVT::i8,    Expand);
82  setOperationAction(ISD::ROTR,             MVT::i8,    Expand);
83  setOperationAction(ISD::ROTL,             MVT::i16,   Expand);
84  setOperationAction(ISD::ROTR,             MVT::i16,   Expand);
85  setOperationAction(ISD::GlobalAddress,    MVT::i16,   Custom);
86  setOperationAction(ISD::ExternalSymbol,   MVT::i16,   Custom);
87  setOperationAction(ISD::BlockAddress,     MVT::i16,   Custom);
88  setOperationAction(ISD::BR_JT,            MVT::Other, Expand);
89  setOperationAction(ISD::BR_CC,            MVT::i8,    Custom);
90  setOperationAction(ISD::BR_CC,            MVT::i16,   Custom);
91  setOperationAction(ISD::BRCOND,           MVT::Other, Expand);
92  setOperationAction(ISD::SETCC,            MVT::i8,    Custom);
93  setOperationAction(ISD::SETCC,            MVT::i16,   Custom);
94  setOperationAction(ISD::SELECT,           MVT::i8,    Expand);
95  setOperationAction(ISD::SELECT,           MVT::i16,   Expand);
96  setOperationAction(ISD::SELECT_CC,        MVT::i8,    Custom);
97  setOperationAction(ISD::SELECT_CC,        MVT::i16,   Custom);
98  setOperationAction(ISD::SIGN_EXTEND,      MVT::i16,   Custom);
99  setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i8, Expand);
100  setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i16, Expand);
101  setOperationAction(ISD::STACKSAVE,        MVT::Other, Expand);
102  setOperationAction(ISD::STACKRESTORE,     MVT::Other, Expand);
103
104  setOperationAction(ISD::CTTZ,             MVT::i8,    Expand);
105  setOperationAction(ISD::CTTZ,             MVT::i16,   Expand);
106  setOperationAction(ISD::CTLZ,             MVT::i8,    Expand);
107  setOperationAction(ISD::CTLZ,             MVT::i16,   Expand);
108  setOperationAction(ISD::CTPOP,            MVT::i8,    Expand);
109  setOperationAction(ISD::CTPOP,            MVT::i16,   Expand);
110
111  setOperationAction(ISD::SHL_PARTS,        MVT::i8,    Expand);
112  setOperationAction(ISD::SHL_PARTS,        MVT::i16,   Expand);
113  setOperationAction(ISD::SRL_PARTS,        MVT::i8,    Expand);
114  setOperationAction(ISD::SRL_PARTS,        MVT::i16,   Expand);
115  setOperationAction(ISD::SRA_PARTS,        MVT::i8,    Expand);
116  setOperationAction(ISD::SRA_PARTS,        MVT::i16,   Expand);
117
118  setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1,   Expand);
119
120  // FIXME: Implement efficiently multiplication by a constant
121  setOperationAction(ISD::MUL,              MVT::i8,    Promote);
122  setOperationAction(ISD::MULHS,            MVT::i8,    Promote);
123  setOperationAction(ISD::MULHU,            MVT::i8,    Promote);
124  setOperationAction(ISD::SMUL_LOHI,        MVT::i8,    Promote);
125  setOperationAction(ISD::UMUL_LOHI,        MVT::i8,    Promote);
126  setOperationAction(ISD::MUL,              MVT::i16,   LibCall);
127  setOperationAction(ISD::MULHS,            MVT::i16,   Expand);
128  setOperationAction(ISD::MULHU,            MVT::i16,   Expand);
129  setOperationAction(ISD::SMUL_LOHI,        MVT::i16,   Expand);
130  setOperationAction(ISD::UMUL_LOHI,        MVT::i16,   Expand);
131
132  setOperationAction(ISD::UDIV,             MVT::i8,    Promote);
133  setOperationAction(ISD::UDIVREM,          MVT::i8,    Promote);
134  setOperationAction(ISD::UREM,             MVT::i8,    Promote);
135  setOperationAction(ISD::SDIV,             MVT::i8,    Promote);
136  setOperationAction(ISD::SDIVREM,          MVT::i8,    Promote);
137  setOperationAction(ISD::SREM,             MVT::i8,    Promote);
138  setOperationAction(ISD::UDIV,             MVT::i16,   LibCall);
139  setOperationAction(ISD::UDIVREM,          MVT::i16,   Expand);
140  setOperationAction(ISD::UREM,             MVT::i16,   LibCall);
141  setOperationAction(ISD::SDIV,             MVT::i16,   LibCall);
142  setOperationAction(ISD::SDIVREM,          MVT::i16,   Expand);
143  setOperationAction(ISD::SREM,             MVT::i16,   LibCall);
144
145  // varargs support
146  setOperationAction(ISD::VASTART,          MVT::Other, Custom);
147  setOperationAction(ISD::VAARG,            MVT::Other, Expand);
148  setOperationAction(ISD::VAEND,            MVT::Other, Expand);
149  setOperationAction(ISD::VACOPY,           MVT::Other, Expand);
150  setOperationAction(ISD::JumpTable,        MVT::i16,   Custom);
151
152  // EABI Libcalls - EABI Section 6.2
153  const struct {
154    const RTLIB::Libcall Op;
155    const char * const Name;
156    const ISD::CondCode Cond;
157  } LibraryCalls[] = {
158    // Floating point conversions - EABI Table 6
159    { RTLIB::FPROUND_F64_F32,   "__mspabi_cvtdf",   ISD::SETCC_INVALID },
160    { RTLIB::FPEXT_F32_F64,     "__mspabi_cvtfd",   ISD::SETCC_INVALID },
161    // The following is NOT implemented in libgcc
162    //{ RTLIB::FPTOSINT_F64_I16,  "__mspabi_fixdi", ISD::SETCC_INVALID },
163    { RTLIB::FPTOSINT_F64_I32,  "__mspabi_fixdli",  ISD::SETCC_INVALID },
164    { RTLIB::FPTOSINT_F64_I64,  "__mspabi_fixdlli", ISD::SETCC_INVALID },
165    // The following is NOT implemented in libgcc
166    //{ RTLIB::FPTOUINT_F64_I16,  "__mspabi_fixdu", ISD::SETCC_INVALID },
167    { RTLIB::FPTOUINT_F64_I32,  "__mspabi_fixdul",  ISD::SETCC_INVALID },
168    { RTLIB::FPTOUINT_F64_I64,  "__mspabi_fixdull", ISD::SETCC_INVALID },
169    // The following is NOT implemented in libgcc
170    //{ RTLIB::FPTOSINT_F32_I16,  "__mspabi_fixfi", ISD::SETCC_INVALID },
171    { RTLIB::FPTOSINT_F32_I32,  "__mspabi_fixfli",  ISD::SETCC_INVALID },
172    { RTLIB::FPTOSINT_F32_I64,  "__mspabi_fixflli", ISD::SETCC_INVALID },
173    // The following is NOT implemented in libgcc
174    //{ RTLIB::FPTOUINT_F32_I16,  "__mspabi_fixfu", ISD::SETCC_INVALID },
175    { RTLIB::FPTOUINT_F32_I32,  "__mspabi_fixful",  ISD::SETCC_INVALID },
176    { RTLIB::FPTOUINT_F32_I64,  "__mspabi_fixfull", ISD::SETCC_INVALID },
177    // TODO The following IS implemented in libgcc
178    //{ RTLIB::SINTTOFP_I16_F64,  "__mspabi_fltid", ISD::SETCC_INVALID },
179    { RTLIB::SINTTOFP_I32_F64,  "__mspabi_fltlid",  ISD::SETCC_INVALID },
180    // TODO The following IS implemented in libgcc but is not in the EABI
181    { RTLIB::SINTTOFP_I64_F64,  "__mspabi_fltllid", ISD::SETCC_INVALID },
182    // TODO The following IS implemented in libgcc
183    //{ RTLIB::UINTTOFP_I16_F64,  "__mspabi_fltud", ISD::SETCC_INVALID },
184    { RTLIB::UINTTOFP_I32_F64,  "__mspabi_fltuld",  ISD::SETCC_INVALID },
185    // The following IS implemented in libgcc but is not in the EABI
186    { RTLIB::UINTTOFP_I64_F64,  "__mspabi_fltulld", ISD::SETCC_INVALID },
187    // TODO The following IS implemented in libgcc
188    //{ RTLIB::SINTTOFP_I16_F32,  "__mspabi_fltif", ISD::SETCC_INVALID },
189    { RTLIB::SINTTOFP_I32_F32,  "__mspabi_fltlif",  ISD::SETCC_INVALID },
190    // TODO The following IS implemented in libgcc but is not in the EABI
191    { RTLIB::SINTTOFP_I64_F32,  "__mspabi_fltllif", ISD::SETCC_INVALID },
192    // TODO The following IS implemented in libgcc
193    //{ RTLIB::UINTTOFP_I16_F32,  "__mspabi_fltuf", ISD::SETCC_INVALID },
194    { RTLIB::UINTTOFP_I32_F32,  "__mspabi_fltulf",  ISD::SETCC_INVALID },
195    // The following IS implemented in libgcc but is not in the EABI
196    { RTLIB::UINTTOFP_I64_F32,  "__mspabi_fltullf", ISD::SETCC_INVALID },
197
198    // Floating point comparisons - EABI Table 7
199    { RTLIB::OEQ_F64, "__mspabi_cmpd", ISD::SETEQ },
200    { RTLIB::UNE_F64, "__mspabi_cmpd", ISD::SETNE },
201    { RTLIB::OGE_F64, "__mspabi_cmpd", ISD::SETGE },
202    { RTLIB::OLT_F64, "__mspabi_cmpd", ISD::SETLT },
203    { RTLIB::OLE_F64, "__mspabi_cmpd", ISD::SETLE },
204    { RTLIB::OGT_F64, "__mspabi_cmpd", ISD::SETGT },
205    { RTLIB::OEQ_F32, "__mspabi_cmpf", ISD::SETEQ },
206    { RTLIB::UNE_F32, "__mspabi_cmpf", ISD::SETNE },
207    { RTLIB::OGE_F32, "__mspabi_cmpf", ISD::SETGE },
208    { RTLIB::OLT_F32, "__mspabi_cmpf", ISD::SETLT },
209    { RTLIB::OLE_F32, "__mspabi_cmpf", ISD::SETLE },
210    { RTLIB::OGT_F32, "__mspabi_cmpf", ISD::SETGT },
211
212    // Floating point arithmetic - EABI Table 8
213    { RTLIB::ADD_F64,  "__mspabi_addd", ISD::SETCC_INVALID },
214    { RTLIB::ADD_F32,  "__mspabi_addf", ISD::SETCC_INVALID },
215    { RTLIB::DIV_F64,  "__mspabi_divd", ISD::SETCC_INVALID },
216    { RTLIB::DIV_F32,  "__mspabi_divf", ISD::SETCC_INVALID },
217    { RTLIB::MUL_F64,  "__mspabi_mpyd", ISD::SETCC_INVALID },
218    { RTLIB::MUL_F32,  "__mspabi_mpyf", ISD::SETCC_INVALID },
219    { RTLIB::SUB_F64,  "__mspabi_subd", ISD::SETCC_INVALID },
220    { RTLIB::SUB_F32,  "__mspabi_subf", ISD::SETCC_INVALID },
221    // The following are NOT implemented in libgcc
222    // { RTLIB::NEG_F64,  "__mspabi_negd", ISD::SETCC_INVALID },
223    // { RTLIB::NEG_F32,  "__mspabi_negf", ISD::SETCC_INVALID },
224
225    // Universal Integer Operations - EABI Table 9
226    { RTLIB::SDIV_I16,   "__mspabi_divi", ISD::SETCC_INVALID },
227    { RTLIB::SDIV_I32,   "__mspabi_divli", ISD::SETCC_INVALID },
228    { RTLIB::SDIV_I64,   "__mspabi_divlli", ISD::SETCC_INVALID },
229    { RTLIB::UDIV_I16,   "__mspabi_divu", ISD::SETCC_INVALID },
230    { RTLIB::UDIV_I32,   "__mspabi_divul", ISD::SETCC_INVALID },
231    { RTLIB::UDIV_I64,   "__mspabi_divull", ISD::SETCC_INVALID },
232    { RTLIB::SREM_I16,   "__mspabi_remi", ISD::SETCC_INVALID },
233    { RTLIB::SREM_I32,   "__mspabi_remli", ISD::SETCC_INVALID },
234    { RTLIB::SREM_I64,   "__mspabi_remlli", ISD::SETCC_INVALID },
235    { RTLIB::UREM_I16,   "__mspabi_remu", ISD::SETCC_INVALID },
236    { RTLIB::UREM_I32,   "__mspabi_remul", ISD::SETCC_INVALID },
237    { RTLIB::UREM_I64,   "__mspabi_remull", ISD::SETCC_INVALID },
238
239    // Bitwise Operations - EABI Table 10
240    // TODO: __mspabi_[srli/srai/slli] ARE implemented in libgcc
241    { RTLIB::SRL_I32,    "__mspabi_srll", ISD::SETCC_INVALID },
242    { RTLIB::SRA_I32,    "__mspabi_sral", ISD::SETCC_INVALID },
243    { RTLIB::SHL_I32,    "__mspabi_slll", ISD::SETCC_INVALID },
244    // __mspabi_[srlll/srall/sllll/rlli/rlll] are NOT implemented in libgcc
245
246  };
247
248  for (const auto &LC : LibraryCalls) {
249    setLibcallName(LC.Op, LC.Name);
250    if (LC.Cond != ISD::SETCC_INVALID)
251      setCmpLibcallCC(LC.Op, LC.Cond);
252  }
253
254  if (STI.hasHWMult16()) {
255    const struct {
256      const RTLIB::Libcall Op;
257      const char * const Name;
258    } LibraryCalls[] = {
259      // Integer Multiply - EABI Table 9
260      { RTLIB::MUL_I16,   "__mspabi_mpyi_hw" },
261      { RTLIB::MUL_I32,   "__mspabi_mpyl_hw" },
262      { RTLIB::MUL_I64,   "__mspabi_mpyll_hw" },
263      // TODO The __mspabi_mpysl*_hw functions ARE implemented in libgcc
264      // TODO The __mspabi_mpyul*_hw functions ARE implemented in libgcc
265    };
266    for (const auto &LC : LibraryCalls) {
267      setLibcallName(LC.Op, LC.Name);
268    }
269  } else if (STI.hasHWMult32()) {
270    const struct {
271      const RTLIB::Libcall Op;
272      const char * const Name;
273    } LibraryCalls[] = {
274      // Integer Multiply - EABI Table 9
275      { RTLIB::MUL_I16,   "__mspabi_mpyi_hw" },
276      { RTLIB::MUL_I32,   "__mspabi_mpyl_hw32" },
277      { RTLIB::MUL_I64,   "__mspabi_mpyll_hw32" },
278      // TODO The __mspabi_mpysl*_hw32 functions ARE implemented in libgcc
279      // TODO The __mspabi_mpyul*_hw32 functions ARE implemented in libgcc
280    };
281    for (const auto &LC : LibraryCalls) {
282      setLibcallName(LC.Op, LC.Name);
283    }
284  } else if (STI.hasHWMultF5()) {
285    const struct {
286      const RTLIB::Libcall Op;
287      const char * const Name;
288    } LibraryCalls[] = {
289      // Integer Multiply - EABI Table 9
290      { RTLIB::MUL_I16,   "__mspabi_mpyi_f5hw" },
291      { RTLIB::MUL_I32,   "__mspabi_mpyl_f5hw" },
292      { RTLIB::MUL_I64,   "__mspabi_mpyll_f5hw" },
293      // TODO The __mspabi_mpysl*_f5hw functions ARE implemented in libgcc
294      // TODO The __mspabi_mpyul*_f5hw functions ARE implemented in libgcc
295    };
296    for (const auto &LC : LibraryCalls) {
297      setLibcallName(LC.Op, LC.Name);
298    }
299  } else { // NoHWMult
300    const struct {
301      const RTLIB::Libcall Op;
302      const char * const Name;
303    } LibraryCalls[] = {
304      // Integer Multiply - EABI Table 9
305      { RTLIB::MUL_I16,   "__mspabi_mpyi" },
306      { RTLIB::MUL_I32,   "__mspabi_mpyl" },
307      { RTLIB::MUL_I64,   "__mspabi_mpyll" },
308      // The __mspabi_mpysl* functions are NOT implemented in libgcc
309      // The __mspabi_mpyul* functions are NOT implemented in libgcc
310    };
311    for (const auto &LC : LibraryCalls) {
312      setLibcallName(LC.Op, LC.Name);
313    }
314    setLibcallCallingConv(RTLIB::MUL_I64, CallingConv::MSP430_BUILTIN);
315  }
316
317  // Several of the runtime library functions use a special calling conv
318  setLibcallCallingConv(RTLIB::UDIV_I64, CallingConv::MSP430_BUILTIN);
319  setLibcallCallingConv(RTLIB::UREM_I64, CallingConv::MSP430_BUILTIN);
320  setLibcallCallingConv(RTLIB::SDIV_I64, CallingConv::MSP430_BUILTIN);
321  setLibcallCallingConv(RTLIB::SREM_I64, CallingConv::MSP430_BUILTIN);
322  setLibcallCallingConv(RTLIB::ADD_F64, CallingConv::MSP430_BUILTIN);
323  setLibcallCallingConv(RTLIB::SUB_F64, CallingConv::MSP430_BUILTIN);
324  setLibcallCallingConv(RTLIB::MUL_F64, CallingConv::MSP430_BUILTIN);
325  setLibcallCallingConv(RTLIB::DIV_F64, CallingConv::MSP430_BUILTIN);
326  setLibcallCallingConv(RTLIB::OEQ_F64, CallingConv::MSP430_BUILTIN);
327  setLibcallCallingConv(RTLIB::UNE_F64, CallingConv::MSP430_BUILTIN);
328  setLibcallCallingConv(RTLIB::OGE_F64, CallingConv::MSP430_BUILTIN);
329  setLibcallCallingConv(RTLIB::OLT_F64, CallingConv::MSP430_BUILTIN);
330  setLibcallCallingConv(RTLIB::OLE_F64, CallingConv::MSP430_BUILTIN);
331  setLibcallCallingConv(RTLIB::OGT_F64, CallingConv::MSP430_BUILTIN);
332  // TODO: __mspabi_srall, __mspabi_srlll, __mspabi_sllll
333
334  setMinFunctionAlignment(Align(2));
335  setPrefFunctionAlignment(Align(2));
336  setMaxAtomicSizeInBitsSupported(0);
337}
338
339SDValue MSP430TargetLowering::LowerOperation(SDValue Op,
340                                             SelectionDAG &DAG) const {
341  switch (Op.getOpcode()) {
342  case ISD::SHL: // FALLTHROUGH
343  case ISD::SRL:
344  case ISD::SRA:              return LowerShifts(Op, DAG);
345  case ISD::GlobalAddress:    return LowerGlobalAddress(Op, DAG);
346  case ISD::BlockAddress:     return LowerBlockAddress(Op, DAG);
347  case ISD::ExternalSymbol:   return LowerExternalSymbol(Op, DAG);
348  case ISD::SETCC:            return LowerSETCC(Op, DAG);
349  case ISD::BR_CC:            return LowerBR_CC(Op, DAG);
350  case ISD::SELECT_CC:        return LowerSELECT_CC(Op, DAG);
351  case ISD::SIGN_EXTEND:      return LowerSIGN_EXTEND(Op, DAG);
352  case ISD::RETURNADDR:       return LowerRETURNADDR(Op, DAG);
353  case ISD::FRAMEADDR:        return LowerFRAMEADDR(Op, DAG);
354  case ISD::VASTART:          return LowerVASTART(Op, DAG);
355  case ISD::JumpTable:        return LowerJumpTable(Op, DAG);
356  default:
357    llvm_unreachable("unimplemented operand");
358  }
359}
360
361// Define non profitable transforms into shifts
362bool MSP430TargetLowering::shouldAvoidTransformToShift(EVT VT,
363                                                       unsigned Amount) const {
364  return !(Amount == 8 || Amount == 9 || Amount<=2);
365}
366
367// Implemented to verify test case assertions in
368// tests/codegen/msp430/shift-amount-threshold-b.ll
369bool MSP430TargetLowering::isLegalICmpImmediate(int64_t Immed) const {
370  if (MSP430NoLegalImmediate)
371    return Immed >= -32 && Immed < 32;
372  return TargetLowering::isLegalICmpImmediate(Immed);
373}
374
375//===----------------------------------------------------------------------===//
376//                       MSP430 Inline Assembly Support
377//===----------------------------------------------------------------------===//
378
379/// getConstraintType - Given a constraint letter, return the type of
380/// constraint it is for this target.
381TargetLowering::ConstraintType
382MSP430TargetLowering::getConstraintType(StringRef Constraint) const {
383  if (Constraint.size() == 1) {
384    switch (Constraint[0]) {
385    case 'r':
386      return C_RegisterClass;
387    default:
388      break;
389    }
390  }
391  return TargetLowering::getConstraintType(Constraint);
392}
393
394std::pair<unsigned, const TargetRegisterClass *>
395MSP430TargetLowering::getRegForInlineAsmConstraint(
396    const TargetRegisterInfo *TRI, StringRef Constraint, MVT VT) const {
397  if (Constraint.size() == 1) {
398    // GCC Constraint Letters
399    switch (Constraint[0]) {
400    default: break;
401    case 'r':   // GENERAL_REGS
402      if (VT == MVT::i8)
403        return std::make_pair(0U, &MSP430::GR8RegClass);
404
405      return std::make_pair(0U, &MSP430::GR16RegClass);
406    }
407  }
408
409  return TargetLowering::getRegForInlineAsmConstraint(TRI, Constraint, VT);
410}
411
412//===----------------------------------------------------------------------===//
413//                      Calling Convention Implementation
414//===----------------------------------------------------------------------===//
415
416#include "MSP430GenCallingConv.inc"
417
418/// For each argument in a function store the number of pieces it is composed
419/// of.
420template<typename ArgT>
421static void ParseFunctionArgs(const SmallVectorImpl<ArgT> &Args,
422                              SmallVectorImpl<unsigned> &Out) {
423  unsigned CurrentArgIndex;
424
425  if (Args.empty())
426    return;
427
428  CurrentArgIndex = Args[0].OrigArgIndex;
429  Out.push_back(0);
430
431  for (auto &Arg : Args) {
432    if (CurrentArgIndex == Arg.OrigArgIndex) {
433      Out.back() += 1;
434    } else {
435      Out.push_back(1);
436      CurrentArgIndex = Arg.OrigArgIndex;
437    }
438  }
439}
440
441static void AnalyzeVarArgs(CCState &State,
442                           const SmallVectorImpl<ISD::OutputArg> &Outs) {
443  State.AnalyzeCallOperands(Outs, CC_MSP430_AssignStack);
444}
445
446static void AnalyzeVarArgs(CCState &State,
447                           const SmallVectorImpl<ISD::InputArg> &Ins) {
448  State.AnalyzeFormalArguments(Ins, CC_MSP430_AssignStack);
449}
450
451/// Analyze incoming and outgoing function arguments. We need custom C++ code
452/// to handle special constraints in the ABI like reversing the order of the
453/// pieces of splitted arguments. In addition, all pieces of a certain argument
454/// have to be passed either using registers or the stack but never mixing both.
455template<typename ArgT>
456static void AnalyzeArguments(CCState &State,
457                             SmallVectorImpl<CCValAssign> &ArgLocs,
458                             const SmallVectorImpl<ArgT> &Args) {
459  static const MCPhysReg CRegList[] = {
460    MSP430::R12, MSP430::R13, MSP430::R14, MSP430::R15
461  };
462  static const unsigned CNbRegs = std::size(CRegList);
463  static const MCPhysReg BuiltinRegList[] = {
464    MSP430::R8, MSP430::R9, MSP430::R10, MSP430::R11,
465    MSP430::R12, MSP430::R13, MSP430::R14, MSP430::R15
466  };
467  static const unsigned BuiltinNbRegs = std::size(BuiltinRegList);
468
469  ArrayRef<MCPhysReg> RegList;
470  unsigned NbRegs;
471
472  bool Builtin = (State.getCallingConv() == CallingConv::MSP430_BUILTIN);
473  if (Builtin) {
474    RegList = BuiltinRegList;
475    NbRegs = BuiltinNbRegs;
476  } else {
477    RegList = CRegList;
478    NbRegs = CNbRegs;
479  }
480
481  if (State.isVarArg()) {
482    AnalyzeVarArgs(State, Args);
483    return;
484  }
485
486  SmallVector<unsigned, 4> ArgsParts;
487  ParseFunctionArgs(Args, ArgsParts);
488
489  if (Builtin) {
490    assert(ArgsParts.size() == 2 &&
491        "Builtin calling convention requires two arguments");
492  }
493
494  unsigned RegsLeft = NbRegs;
495  bool UsedStack = false;
496  unsigned ValNo = 0;
497
498  for (unsigned i = 0, e = ArgsParts.size(); i != e; i++) {
499    MVT ArgVT = Args[ValNo].VT;
500    ISD::ArgFlagsTy ArgFlags = Args[ValNo].Flags;
501    MVT LocVT = ArgVT;
502    CCValAssign::LocInfo LocInfo = CCValAssign::Full;
503
504    // Promote i8 to i16
505    if (LocVT == MVT::i8) {
506      LocVT = MVT::i16;
507      if (ArgFlags.isSExt())
508          LocInfo = CCValAssign::SExt;
509      else if (ArgFlags.isZExt())
510          LocInfo = CCValAssign::ZExt;
511      else
512          LocInfo = CCValAssign::AExt;
513    }
514
515    // Handle byval arguments
516    if (ArgFlags.isByVal()) {
517      State.HandleByVal(ValNo++, ArgVT, LocVT, LocInfo, 2, Align(2), ArgFlags);
518      continue;
519    }
520
521    unsigned Parts = ArgsParts[i];
522
523    if (Builtin) {
524      assert(Parts == 4 &&
525          "Builtin calling convention requires 64-bit arguments");
526    }
527
528    if (!UsedStack && Parts == 2 && RegsLeft == 1) {
529      // Special case for 32-bit register split, see EABI section 3.3.3
530      unsigned Reg = State.AllocateReg(RegList);
531      State.addLoc(CCValAssign::getReg(ValNo++, ArgVT, Reg, LocVT, LocInfo));
532      RegsLeft -= 1;
533
534      UsedStack = true;
535      CC_MSP430_AssignStack(ValNo++, ArgVT, LocVT, LocInfo, ArgFlags, State);
536    } else if (Parts <= RegsLeft) {
537      for (unsigned j = 0; j < Parts; j++) {
538        unsigned Reg = State.AllocateReg(RegList);
539        State.addLoc(CCValAssign::getReg(ValNo++, ArgVT, Reg, LocVT, LocInfo));
540        RegsLeft--;
541      }
542    } else {
543      UsedStack = true;
544      for (unsigned j = 0; j < Parts; j++)
545        CC_MSP430_AssignStack(ValNo++, ArgVT, LocVT, LocInfo, ArgFlags, State);
546    }
547  }
548}
549
550static void AnalyzeRetResult(CCState &State,
551                             const SmallVectorImpl<ISD::InputArg> &Ins) {
552  State.AnalyzeCallResult(Ins, RetCC_MSP430);
553}
554
555static void AnalyzeRetResult(CCState &State,
556                             const SmallVectorImpl<ISD::OutputArg> &Outs) {
557  State.AnalyzeReturn(Outs, RetCC_MSP430);
558}
559
560template<typename ArgT>
561static void AnalyzeReturnValues(CCState &State,
562                                SmallVectorImpl<CCValAssign> &RVLocs,
563                                const SmallVectorImpl<ArgT> &Args) {
564  AnalyzeRetResult(State, Args);
565}
566
567SDValue MSP430TargetLowering::LowerFormalArguments(
568    SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
569    const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &dl,
570    SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const {
571
572  switch (CallConv) {
573  default:
574    report_fatal_error("Unsupported calling convention");
575  case CallingConv::C:
576  case CallingConv::Fast:
577    return LowerCCCArguments(Chain, CallConv, isVarArg, Ins, dl, DAG, InVals);
578  case CallingConv::MSP430_INTR:
579    if (Ins.empty())
580      return Chain;
581    report_fatal_error("ISRs cannot have arguments");
582  }
583}
584
585SDValue
586MSP430TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
587                                SmallVectorImpl<SDValue> &InVals) const {
588  SelectionDAG &DAG                     = CLI.DAG;
589  SDLoc &dl                             = CLI.DL;
590  SmallVectorImpl<ISD::OutputArg> &Outs = CLI.Outs;
591  SmallVectorImpl<SDValue> &OutVals     = CLI.OutVals;
592  SmallVectorImpl<ISD::InputArg> &Ins   = CLI.Ins;
593  SDValue Chain                         = CLI.Chain;
594  SDValue Callee                        = CLI.Callee;
595  bool &isTailCall                      = CLI.IsTailCall;
596  CallingConv::ID CallConv              = CLI.CallConv;
597  bool isVarArg                         = CLI.IsVarArg;
598
599  // MSP430 target does not yet support tail call optimization.
600  isTailCall = false;
601
602  switch (CallConv) {
603  default:
604    report_fatal_error("Unsupported calling convention");
605  case CallingConv::MSP430_BUILTIN:
606  case CallingConv::Fast:
607  case CallingConv::C:
608    return LowerCCCCallTo(Chain, Callee, CallConv, isVarArg, isTailCall,
609                          Outs, OutVals, Ins, dl, DAG, InVals);
610  case CallingConv::MSP430_INTR:
611    report_fatal_error("ISRs cannot be called directly");
612  }
613}
614
615/// LowerCCCArguments - transform physical registers into virtual registers and
616/// generate load operations for arguments places on the stack.
617// FIXME: struct return stuff
618SDValue MSP430TargetLowering::LowerCCCArguments(
619    SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
620    const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &dl,
621    SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const {
622  MachineFunction &MF = DAG.getMachineFunction();
623  MachineFrameInfo &MFI = MF.getFrameInfo();
624  MachineRegisterInfo &RegInfo = MF.getRegInfo();
625  MSP430MachineFunctionInfo *FuncInfo = MF.getInfo<MSP430MachineFunctionInfo>();
626
627  // Assign locations to all of the incoming arguments.
628  SmallVector<CCValAssign, 16> ArgLocs;
629  CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), ArgLocs,
630                 *DAG.getContext());
631  AnalyzeArguments(CCInfo, ArgLocs, Ins);
632
633  // Create frame index for the start of the first vararg value
634  if (isVarArg) {
635    unsigned Offset = CCInfo.getStackSize();
636    FuncInfo->setVarArgsFrameIndex(MFI.CreateFixedObject(1, Offset, true));
637  }
638
639  for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
640    CCValAssign &VA = ArgLocs[i];
641    if (VA.isRegLoc()) {
642      // Arguments passed in registers
643      EVT RegVT = VA.getLocVT();
644      switch (RegVT.getSimpleVT().SimpleTy) {
645      default:
646        {
647#ifndef NDEBUG
648          errs() << "LowerFormalArguments Unhandled argument type: "
649                 << RegVT << "\n";
650#endif
651          llvm_unreachable(nullptr);
652        }
653      case MVT::i16:
654        Register VReg = RegInfo.createVirtualRegister(&MSP430::GR16RegClass);
655        RegInfo.addLiveIn(VA.getLocReg(), VReg);
656        SDValue ArgValue = DAG.getCopyFromReg(Chain, dl, VReg, RegVT);
657
658        // If this is an 8-bit value, it is really passed promoted to 16
659        // bits. Insert an assert[sz]ext to capture this, then truncate to the
660        // right size.
661        if (VA.getLocInfo() == CCValAssign::SExt)
662          ArgValue = DAG.getNode(ISD::AssertSext, dl, RegVT, ArgValue,
663                                 DAG.getValueType(VA.getValVT()));
664        else if (VA.getLocInfo() == CCValAssign::ZExt)
665          ArgValue = DAG.getNode(ISD::AssertZext, dl, RegVT, ArgValue,
666                                 DAG.getValueType(VA.getValVT()));
667
668        if (VA.getLocInfo() != CCValAssign::Full)
669          ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue);
670
671        InVals.push_back(ArgValue);
672      }
673    } else {
674      // Only arguments passed on the stack should make it here.
675      assert(VA.isMemLoc());
676
677      SDValue InVal;
678      ISD::ArgFlagsTy Flags = Ins[i].Flags;
679
680      if (Flags.isByVal()) {
681        MVT PtrVT = VA.getLocVT();
682        int FI = MFI.CreateFixedObject(Flags.getByValSize(),
683                                       VA.getLocMemOffset(), true);
684        InVal = DAG.getFrameIndex(FI, PtrVT);
685      } else {
686        // Load the argument to a virtual register
687        unsigned ObjSize = VA.getLocVT().getSizeInBits()/8;
688        if (ObjSize > 2) {
689            errs() << "LowerFormalArguments Unhandled argument type: "
690                << VA.getLocVT() << "\n";
691        }
692        // Create the frame index object for this incoming parameter...
693        int FI = MFI.CreateFixedObject(ObjSize, VA.getLocMemOffset(), true);
694
695        // Create the SelectionDAG nodes corresponding to a load
696        //from this parameter
697        SDValue FIN = DAG.getFrameIndex(FI, MVT::i16);
698        InVal = DAG.getLoad(
699            VA.getLocVT(), dl, Chain, FIN,
700            MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI));
701      }
702
703      InVals.push_back(InVal);
704    }
705  }
706
707  for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
708    if (Ins[i].Flags.isSRet()) {
709      Register Reg = FuncInfo->getSRetReturnReg();
710      if (!Reg) {
711        Reg = MF.getRegInfo().createVirtualRegister(
712            getRegClassFor(MVT::i16));
713        FuncInfo->setSRetReturnReg(Reg);
714      }
715      SDValue Copy = DAG.getCopyToReg(DAG.getEntryNode(), dl, Reg, InVals[i]);
716      Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Copy, Chain);
717    }
718  }
719
720  return Chain;
721}
722
723bool
724MSP430TargetLowering::CanLowerReturn(CallingConv::ID CallConv,
725                                     MachineFunction &MF,
726                                     bool IsVarArg,
727                                     const SmallVectorImpl<ISD::OutputArg> &Outs,
728                                     LLVMContext &Context) const {
729  SmallVector<CCValAssign, 16> RVLocs;
730  CCState CCInfo(CallConv, IsVarArg, MF, RVLocs, Context);
731  return CCInfo.CheckReturn(Outs, RetCC_MSP430);
732}
733
734SDValue
735MSP430TargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
736                                  bool isVarArg,
737                                  const SmallVectorImpl<ISD::OutputArg> &Outs,
738                                  const SmallVectorImpl<SDValue> &OutVals,
739                                  const SDLoc &dl, SelectionDAG &DAG) const {
740
741  MachineFunction &MF = DAG.getMachineFunction();
742
743  // CCValAssign - represent the assignment of the return value to a location
744  SmallVector<CCValAssign, 16> RVLocs;
745
746  // ISRs cannot return any value.
747  if (CallConv == CallingConv::MSP430_INTR && !Outs.empty())
748    report_fatal_error("ISRs cannot return any value");
749
750  // CCState - Info about the registers and stack slot.
751  CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), RVLocs,
752                 *DAG.getContext());
753
754  // Analize return values.
755  AnalyzeReturnValues(CCInfo, RVLocs, Outs);
756
757  SDValue Glue;
758  SmallVector<SDValue, 4> RetOps(1, Chain);
759
760  // Copy the result values into the output registers.
761  for (unsigned i = 0; i != RVLocs.size(); ++i) {
762    CCValAssign &VA = RVLocs[i];
763    assert(VA.isRegLoc() && "Can only return in registers!");
764
765    Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(),
766                             OutVals[i], Glue);
767
768    // Guarantee that all emitted copies are stuck together,
769    // avoiding something bad.
770    Glue = Chain.getValue(1);
771    RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
772  }
773
774  if (MF.getFunction().hasStructRetAttr()) {
775    MSP430MachineFunctionInfo *FuncInfo = MF.getInfo<MSP430MachineFunctionInfo>();
776    Register Reg = FuncInfo->getSRetReturnReg();
777
778    if (!Reg)
779      llvm_unreachable("sret virtual register not created in entry block");
780
781    MVT PtrVT = getFrameIndexTy(DAG.getDataLayout());
782    SDValue Val =
783      DAG.getCopyFromReg(Chain, dl, Reg, PtrVT);
784    unsigned R12 = MSP430::R12;
785
786    Chain = DAG.getCopyToReg(Chain, dl, R12, Val, Glue);
787    Glue = Chain.getValue(1);
788    RetOps.push_back(DAG.getRegister(R12, PtrVT));
789  }
790
791  unsigned Opc = (CallConv == CallingConv::MSP430_INTR ?
792                  MSP430ISD::RETI_GLUE : MSP430ISD::RET_GLUE);
793
794  RetOps[0] = Chain;  // Update chain.
795
796  // Add the glue if we have it.
797  if (Glue.getNode())
798    RetOps.push_back(Glue);
799
800  return DAG.getNode(Opc, dl, MVT::Other, RetOps);
801}
802
803/// LowerCCCCallTo - functions arguments are copied from virtual regs to
804/// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
805SDValue MSP430TargetLowering::LowerCCCCallTo(
806    SDValue Chain, SDValue Callee, CallingConv::ID CallConv, bool isVarArg,
807    bool isTailCall, const SmallVectorImpl<ISD::OutputArg> &Outs,
808    const SmallVectorImpl<SDValue> &OutVals,
809    const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &dl,
810    SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const {
811  // Analyze operands of the call, assigning locations to each operand.
812  SmallVector<CCValAssign, 16> ArgLocs;
813  CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), ArgLocs,
814                 *DAG.getContext());
815  AnalyzeArguments(CCInfo, ArgLocs, Outs);
816
817  // Get a count of how many bytes are to be pushed on the stack.
818  unsigned NumBytes = CCInfo.getStackSize();
819  MVT PtrVT = getFrameIndexTy(DAG.getDataLayout());
820
821  Chain = DAG.getCALLSEQ_START(Chain, NumBytes, 0, dl);
822
823  SmallVector<std::pair<unsigned, SDValue>, 4> RegsToPass;
824  SmallVector<SDValue, 12> MemOpChains;
825  SDValue StackPtr;
826
827  // Walk the register/memloc assignments, inserting copies/loads.
828  for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
829    CCValAssign &VA = ArgLocs[i];
830
831    SDValue Arg = OutVals[i];
832
833    // Promote the value if needed.
834    switch (VA.getLocInfo()) {
835      default: llvm_unreachable("Unknown loc info!");
836      case CCValAssign::Full: break;
837      case CCValAssign::SExt:
838        Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, VA.getLocVT(), Arg);
839        break;
840      case CCValAssign::ZExt:
841        Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, VA.getLocVT(), Arg);
842        break;
843      case CCValAssign::AExt:
844        Arg = DAG.getNode(ISD::ANY_EXTEND, dl, VA.getLocVT(), Arg);
845        break;
846    }
847
848    // Arguments that can be passed on register must be kept at RegsToPass
849    // vector
850    if (VA.isRegLoc()) {
851      RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
852    } else {
853      assert(VA.isMemLoc());
854
855      if (!StackPtr.getNode())
856        StackPtr = DAG.getCopyFromReg(Chain, dl, MSP430::SP, PtrVT);
857
858      SDValue PtrOff =
859          DAG.getNode(ISD::ADD, dl, PtrVT, StackPtr,
860                      DAG.getIntPtrConstant(VA.getLocMemOffset(), dl));
861
862      SDValue MemOp;
863      ISD::ArgFlagsTy Flags = Outs[i].Flags;
864
865      if (Flags.isByVal()) {
866        SDValue SizeNode = DAG.getConstant(Flags.getByValSize(), dl, MVT::i16);
867        MemOp = DAG.getMemcpy(
868            Chain, dl, PtrOff, Arg, SizeNode, Flags.getNonZeroByValAlign(),
869            /*isVolatile*/ false,
870            /*AlwaysInline=*/true,
871            /*isTailCall=*/false, MachinePointerInfo(), MachinePointerInfo());
872      } else {
873        MemOp = DAG.getStore(Chain, dl, Arg, PtrOff, MachinePointerInfo());
874      }
875
876      MemOpChains.push_back(MemOp);
877    }
878  }
879
880  // Transform all store nodes into one single node because all store nodes are
881  // independent of each other.
882  if (!MemOpChains.empty())
883    Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, MemOpChains);
884
885  // Build a sequence of copy-to-reg nodes chained together with token chain and
886  // flag operands which copy the outgoing args into registers.  The InGlue in
887  // necessary since all emitted instructions must be stuck together.
888  SDValue InGlue;
889  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
890    Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
891                             RegsToPass[i].second, InGlue);
892    InGlue = Chain.getValue(1);
893  }
894
895  // If the callee is a GlobalAddress node (quite common, every direct call is)
896  // turn it into a TargetGlobalAddress node so that legalize doesn't hack it.
897  // Likewise ExternalSymbol -> TargetExternalSymbol.
898  if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
899    Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, MVT::i16);
900  else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(Callee))
901    Callee = DAG.getTargetExternalSymbol(E->getSymbol(), MVT::i16);
902
903  // Returns a chain & a flag for retval copy to use.
904  SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
905  SmallVector<SDValue, 8> Ops;
906  Ops.push_back(Chain);
907  Ops.push_back(Callee);
908
909  // Add argument registers to the end of the list so that they are
910  // known live into the call.
911  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
912    Ops.push_back(DAG.getRegister(RegsToPass[i].first,
913                                  RegsToPass[i].second.getValueType()));
914
915  if (InGlue.getNode())
916    Ops.push_back(InGlue);
917
918  Chain = DAG.getNode(MSP430ISD::CALL, dl, NodeTys, Ops);
919  InGlue = Chain.getValue(1);
920
921  // Create the CALLSEQ_END node.
922  Chain = DAG.getCALLSEQ_END(Chain, NumBytes, 0, InGlue, dl);
923  InGlue = Chain.getValue(1);
924
925  // Handle result values, copying them out of physregs into vregs that we
926  // return.
927  return LowerCallResult(Chain, InGlue, CallConv, isVarArg, Ins, dl,
928                         DAG, InVals);
929}
930
931/// LowerCallResult - Lower the result values of a call into the
932/// appropriate copies out of appropriate physical registers.
933///
934SDValue MSP430TargetLowering::LowerCallResult(
935    SDValue Chain, SDValue InGlue, CallingConv::ID CallConv, bool isVarArg,
936    const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &dl,
937    SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const {
938
939  // Assign locations to each value returned by this call.
940  SmallVector<CCValAssign, 16> RVLocs;
941  CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(), RVLocs,
942                 *DAG.getContext());
943
944  AnalyzeReturnValues(CCInfo, RVLocs, Ins);
945
946  // Copy all of the result registers out of their specified physreg.
947  for (unsigned i = 0; i != RVLocs.size(); ++i) {
948    Chain = DAG.getCopyFromReg(Chain, dl, RVLocs[i].getLocReg(),
949                               RVLocs[i].getValVT(), InGlue).getValue(1);
950    InGlue = Chain.getValue(2);
951    InVals.push_back(Chain.getValue(0));
952  }
953
954  return Chain;
955}
956
957SDValue MSP430TargetLowering::LowerShifts(SDValue Op,
958                                          SelectionDAG &DAG) const {
959  unsigned Opc = Op.getOpcode();
960  SDNode* N = Op.getNode();
961  EVT VT = Op.getValueType();
962  SDLoc dl(N);
963
964  // Expand non-constant shifts to loops:
965  if (!isa<ConstantSDNode>(N->getOperand(1)))
966    return Op;
967
968  uint64_t ShiftAmount = N->getConstantOperandVal(1);
969
970  // Expand the stuff into sequence of shifts.
971  SDValue Victim = N->getOperand(0);
972
973  if (ShiftAmount >= 8) {
974    assert(VT == MVT::i16 && "Can not shift i8 by 8 and more");
975    switch(Opc) {
976    default:
977      llvm_unreachable("Unknown shift");
978    case ISD::SHL:
979      // foo << (8 + N) => swpb(zext(foo)) << N
980      Victim = DAG.getZeroExtendInReg(Victim, dl, MVT::i8);
981      Victim = DAG.getNode(ISD::BSWAP, dl, VT, Victim);
982      break;
983    case ISD::SRA:
984    case ISD::SRL:
985      // foo >> (8 + N) => sxt(swpb(foo)) >> N
986      Victim = DAG.getNode(ISD::BSWAP, dl, VT, Victim);
987      Victim = (Opc == ISD::SRA)
988                   ? DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, VT, Victim,
989                                 DAG.getValueType(MVT::i8))
990                   : DAG.getZeroExtendInReg(Victim, dl, MVT::i8);
991      break;
992    }
993    ShiftAmount -= 8;
994  }
995
996  if (Opc == ISD::SRL && ShiftAmount) {
997    // Emit a special goodness here:
998    // srl A, 1 => clrc; rrc A
999    Victim = DAG.getNode(MSP430ISD::RRCL, dl, VT, Victim);
1000    ShiftAmount -= 1;
1001  }
1002
1003  while (ShiftAmount--)
1004    Victim = DAG.getNode((Opc == ISD::SHL ? MSP430ISD::RLA : MSP430ISD::RRA),
1005                         dl, VT, Victim);
1006
1007  return Victim;
1008}
1009
1010SDValue MSP430TargetLowering::LowerGlobalAddress(SDValue Op,
1011                                                 SelectionDAG &DAG) const {
1012  const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
1013  int64_t Offset = cast<GlobalAddressSDNode>(Op)->getOffset();
1014  EVT PtrVT = Op.getValueType();
1015
1016  // Create the TargetGlobalAddress node, folding in the constant offset.
1017  SDValue Result = DAG.getTargetGlobalAddress(GV, SDLoc(Op), PtrVT, Offset);
1018  return DAG.getNode(MSP430ISD::Wrapper, SDLoc(Op), PtrVT, Result);
1019}
1020
1021SDValue MSP430TargetLowering::LowerExternalSymbol(SDValue Op,
1022                                                  SelectionDAG &DAG) const {
1023  SDLoc dl(Op);
1024  const char *Sym = cast<ExternalSymbolSDNode>(Op)->getSymbol();
1025  EVT PtrVT = Op.getValueType();
1026  SDValue Result = DAG.getTargetExternalSymbol(Sym, PtrVT);
1027
1028  return DAG.getNode(MSP430ISD::Wrapper, dl, PtrVT, Result);
1029}
1030
1031SDValue MSP430TargetLowering::LowerBlockAddress(SDValue Op,
1032                                                SelectionDAG &DAG) const {
1033  SDLoc dl(Op);
1034  const BlockAddress *BA = cast<BlockAddressSDNode>(Op)->getBlockAddress();
1035  EVT PtrVT = Op.getValueType();
1036  SDValue Result = DAG.getTargetBlockAddress(BA, PtrVT);
1037
1038  return DAG.getNode(MSP430ISD::Wrapper, dl, PtrVT, Result);
1039}
1040
1041static SDValue EmitCMP(SDValue &LHS, SDValue &RHS, SDValue &TargetCC,
1042                       ISD::CondCode CC, const SDLoc &dl, SelectionDAG &DAG) {
1043  // FIXME: Handle bittests someday
1044  assert(!LHS.getValueType().isFloatingPoint() && "We don't handle FP yet");
1045
1046  // FIXME: Handle jump negative someday
1047  MSP430CC::CondCodes TCC = MSP430CC::COND_INVALID;
1048  switch (CC) {
1049  default: llvm_unreachable("Invalid integer condition!");
1050  case ISD::SETEQ:
1051    TCC = MSP430CC::COND_E;     // aka COND_Z
1052    // Minor optimization: if LHS is a constant, swap operands, then the
1053    // constant can be folded into comparison.
1054    if (LHS.getOpcode() == ISD::Constant)
1055      std::swap(LHS, RHS);
1056    break;
1057  case ISD::SETNE:
1058    TCC = MSP430CC::COND_NE;    // aka COND_NZ
1059    // Minor optimization: if LHS is a constant, swap operands, then the
1060    // constant can be folded into comparison.
1061    if (LHS.getOpcode() == ISD::Constant)
1062      std::swap(LHS, RHS);
1063    break;
1064  case ISD::SETULE:
1065    std::swap(LHS, RHS);
1066    [[fallthrough]];
1067  case ISD::SETUGE:
1068    // Turn lhs u>= rhs with lhs constant into rhs u< lhs+1, this allows us to
1069    // fold constant into instruction.
1070    if (const ConstantSDNode * C = dyn_cast<ConstantSDNode>(LHS)) {
1071      LHS = RHS;
1072      RHS = DAG.getConstant(C->getSExtValue() + 1, dl, C->getValueType(0));
1073      TCC = MSP430CC::COND_LO;
1074      break;
1075    }
1076    TCC = MSP430CC::COND_HS;    // aka COND_C
1077    break;
1078  case ISD::SETUGT:
1079    std::swap(LHS, RHS);
1080    [[fallthrough]];
1081  case ISD::SETULT:
1082    // Turn lhs u< rhs with lhs constant into rhs u>= lhs+1, this allows us to
1083    // fold constant into instruction.
1084    if (const ConstantSDNode * C = dyn_cast<ConstantSDNode>(LHS)) {
1085      LHS = RHS;
1086      RHS = DAG.getConstant(C->getSExtValue() + 1, dl, C->getValueType(0));
1087      TCC = MSP430CC::COND_HS;
1088      break;
1089    }
1090    TCC = MSP430CC::COND_LO;    // aka COND_NC
1091    break;
1092  case ISD::SETLE:
1093    std::swap(LHS, RHS);
1094    [[fallthrough]];
1095  case ISD::SETGE:
1096    // Turn lhs >= rhs with lhs constant into rhs < lhs+1, this allows us to
1097    // fold constant into instruction.
1098    if (const ConstantSDNode * C = dyn_cast<ConstantSDNode>(LHS)) {
1099      LHS = RHS;
1100      RHS = DAG.getConstant(C->getSExtValue() + 1, dl, C->getValueType(0));
1101      TCC = MSP430CC::COND_L;
1102      break;
1103    }
1104    TCC = MSP430CC::COND_GE;
1105    break;
1106  case ISD::SETGT:
1107    std::swap(LHS, RHS);
1108    [[fallthrough]];
1109  case ISD::SETLT:
1110    // Turn lhs < rhs with lhs constant into rhs >= lhs+1, this allows us to
1111    // fold constant into instruction.
1112    if (const ConstantSDNode * C = dyn_cast<ConstantSDNode>(LHS)) {
1113      LHS = RHS;
1114      RHS = DAG.getConstant(C->getSExtValue() + 1, dl, C->getValueType(0));
1115      TCC = MSP430CC::COND_GE;
1116      break;
1117    }
1118    TCC = MSP430CC::COND_L;
1119    break;
1120  }
1121
1122  TargetCC = DAG.getConstant(TCC, dl, MVT::i8);
1123  return DAG.getNode(MSP430ISD::CMP, dl, MVT::Glue, LHS, RHS);
1124}
1125
1126
1127SDValue MSP430TargetLowering::LowerBR_CC(SDValue Op, SelectionDAG &DAG) const {
1128  SDValue Chain = Op.getOperand(0);
1129  ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(1))->get();
1130  SDValue LHS   = Op.getOperand(2);
1131  SDValue RHS   = Op.getOperand(3);
1132  SDValue Dest  = Op.getOperand(4);
1133  SDLoc dl  (Op);
1134
1135  SDValue TargetCC;
1136  SDValue Flag = EmitCMP(LHS, RHS, TargetCC, CC, dl, DAG);
1137
1138  return DAG.getNode(MSP430ISD::BR_CC, dl, Op.getValueType(),
1139                     Chain, Dest, TargetCC, Flag);
1140}
1141
1142SDValue MSP430TargetLowering::LowerSETCC(SDValue Op, SelectionDAG &DAG) const {
1143  SDValue LHS   = Op.getOperand(0);
1144  SDValue RHS   = Op.getOperand(1);
1145  SDLoc dl  (Op);
1146
1147  // If we are doing an AND and testing against zero, then the CMP
1148  // will not be generated.  The AND (or BIT) will generate the condition codes,
1149  // but they are different from CMP.
1150  // FIXME: since we're doing a post-processing, use a pseudoinstr here, so
1151  // lowering & isel wouldn't diverge.
1152  bool andCC = isNullConstant(RHS) && LHS.hasOneUse() &&
1153               (LHS.getOpcode() == ISD::AND ||
1154                (LHS.getOpcode() == ISD::TRUNCATE &&
1155                 LHS.getOperand(0).getOpcode() == ISD::AND));
1156  ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
1157  SDValue TargetCC;
1158  SDValue Flag = EmitCMP(LHS, RHS, TargetCC, CC, dl, DAG);
1159
1160  // Get the condition codes directly from the status register, if its easy.
1161  // Otherwise a branch will be generated.  Note that the AND and BIT
1162  // instructions generate different flags than CMP, the carry bit can be used
1163  // for NE/EQ.
1164  bool Invert = false;
1165  bool Shift = false;
1166  bool Convert = true;
1167  switch (TargetCC->getAsZExtVal()) {
1168  default:
1169    Convert = false;
1170    break;
1171   case MSP430CC::COND_HS:
1172     // Res = SR & 1, no processing is required
1173     break;
1174   case MSP430CC::COND_LO:
1175     // Res = ~(SR & 1)
1176     Invert = true;
1177     break;
1178   case MSP430CC::COND_NE:
1179     if (andCC) {
1180       // C = ~Z, thus Res = SR & 1, no processing is required
1181     } else {
1182       // Res = ~((SR >> 1) & 1)
1183       Shift = true;
1184       Invert = true;
1185     }
1186     break;
1187   case MSP430CC::COND_E:
1188     Shift = true;
1189     // C = ~Z for AND instruction, thus we can put Res = ~(SR & 1), however,
1190     // Res = (SR >> 1) & 1 is 1 word shorter.
1191     break;
1192   }
1193  EVT VT = Op.getValueType();
1194  SDValue One  = DAG.getConstant(1, dl, VT);
1195  if (Convert) {
1196    SDValue SR = DAG.getCopyFromReg(DAG.getEntryNode(), dl, MSP430::SR,
1197                                    MVT::i16, Flag);
1198    if (Shift)
1199      // FIXME: somewhere this is turned into a SRL, lower it MSP specific?
1200      SR = DAG.getNode(ISD::SRA, dl, MVT::i16, SR, One);
1201    SR = DAG.getNode(ISD::AND, dl, MVT::i16, SR, One);
1202    if (Invert)
1203      SR = DAG.getNode(ISD::XOR, dl, MVT::i16, SR, One);
1204    return SR;
1205  } else {
1206    SDValue Zero = DAG.getConstant(0, dl, VT);
1207    SDValue Ops[] = {One, Zero, TargetCC, Flag};
1208    return DAG.getNode(MSP430ISD::SELECT_CC, dl, Op.getValueType(), Ops);
1209  }
1210}
1211
1212SDValue MSP430TargetLowering::LowerSELECT_CC(SDValue Op,
1213                                             SelectionDAG &DAG) const {
1214  SDValue LHS    = Op.getOperand(0);
1215  SDValue RHS    = Op.getOperand(1);
1216  SDValue TrueV  = Op.getOperand(2);
1217  SDValue FalseV = Op.getOperand(3);
1218  ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(4))->get();
1219  SDLoc dl   (Op);
1220
1221  SDValue TargetCC;
1222  SDValue Flag = EmitCMP(LHS, RHS, TargetCC, CC, dl, DAG);
1223
1224  SDValue Ops[] = {TrueV, FalseV, TargetCC, Flag};
1225
1226  return DAG.getNode(MSP430ISD::SELECT_CC, dl, Op.getValueType(), Ops);
1227}
1228
1229SDValue MSP430TargetLowering::LowerSIGN_EXTEND(SDValue Op,
1230                                               SelectionDAG &DAG) const {
1231  SDValue Val = Op.getOperand(0);
1232  EVT VT      = Op.getValueType();
1233  SDLoc dl(Op);
1234
1235  assert(VT == MVT::i16 && "Only support i16 for now!");
1236
1237  return DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, VT,
1238                     DAG.getNode(ISD::ANY_EXTEND, dl, VT, Val),
1239                     DAG.getValueType(Val.getValueType()));
1240}
1241
1242SDValue
1243MSP430TargetLowering::getReturnAddressFrameIndex(SelectionDAG &DAG) const {
1244  MachineFunction &MF = DAG.getMachineFunction();
1245  MSP430MachineFunctionInfo *FuncInfo = MF.getInfo<MSP430MachineFunctionInfo>();
1246  int ReturnAddrIndex = FuncInfo->getRAIndex();
1247  MVT PtrVT = getFrameIndexTy(MF.getDataLayout());
1248
1249  if (ReturnAddrIndex == 0) {
1250    // Set up a frame object for the return address.
1251    uint64_t SlotSize = PtrVT.getStoreSize();
1252    ReturnAddrIndex = MF.getFrameInfo().CreateFixedObject(SlotSize, -SlotSize,
1253                                                           true);
1254    FuncInfo->setRAIndex(ReturnAddrIndex);
1255  }
1256
1257  return DAG.getFrameIndex(ReturnAddrIndex, PtrVT);
1258}
1259
1260SDValue MSP430TargetLowering::LowerRETURNADDR(SDValue Op,
1261                                              SelectionDAG &DAG) const {
1262  MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
1263  MFI.setReturnAddressIsTaken(true);
1264
1265  if (verifyReturnAddressArgumentIsConstant(Op, DAG))
1266    return SDValue();
1267
1268  unsigned Depth = Op.getConstantOperandVal(0);
1269  SDLoc dl(Op);
1270  EVT PtrVT = Op.getValueType();
1271
1272  if (Depth > 0) {
1273    SDValue FrameAddr = LowerFRAMEADDR(Op, DAG);
1274    SDValue Offset =
1275      DAG.getConstant(PtrVT.getStoreSize(), dl, MVT::i16);
1276    return DAG.getLoad(PtrVT, dl, DAG.getEntryNode(),
1277                       DAG.getNode(ISD::ADD, dl, PtrVT, FrameAddr, Offset),
1278                       MachinePointerInfo());
1279  }
1280
1281  // Just load the return address.
1282  SDValue RetAddrFI = getReturnAddressFrameIndex(DAG);
1283  return DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), RetAddrFI,
1284                     MachinePointerInfo());
1285}
1286
1287SDValue MSP430TargetLowering::LowerFRAMEADDR(SDValue Op,
1288                                             SelectionDAG &DAG) const {
1289  MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
1290  MFI.setFrameAddressIsTaken(true);
1291
1292  EVT VT = Op.getValueType();
1293  SDLoc dl(Op);  // FIXME probably not meaningful
1294  unsigned Depth = Op.getConstantOperandVal(0);
1295  SDValue FrameAddr = DAG.getCopyFromReg(DAG.getEntryNode(), dl,
1296                                         MSP430::R4, VT);
1297  while (Depth--)
1298    FrameAddr = DAG.getLoad(VT, dl, DAG.getEntryNode(), FrameAddr,
1299                            MachinePointerInfo());
1300  return FrameAddr;
1301}
1302
1303SDValue MSP430TargetLowering::LowerVASTART(SDValue Op,
1304                                           SelectionDAG &DAG) const {
1305  MachineFunction &MF = DAG.getMachineFunction();
1306  MSP430MachineFunctionInfo *FuncInfo = MF.getInfo<MSP430MachineFunctionInfo>();
1307
1308  SDValue Ptr = Op.getOperand(1);
1309  EVT PtrVT = Ptr.getValueType();
1310
1311  // Frame index of first vararg argument
1312  SDValue FrameIndex =
1313      DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(), PtrVT);
1314  const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
1315
1316  // Create a store of the frame index to the location operand
1317  return DAG.getStore(Op.getOperand(0), SDLoc(Op), FrameIndex, Ptr,
1318                      MachinePointerInfo(SV));
1319}
1320
1321SDValue MSP430TargetLowering::LowerJumpTable(SDValue Op,
1322                                             SelectionDAG &DAG) const {
1323    JumpTableSDNode *JT = cast<JumpTableSDNode>(Op);
1324    EVT PtrVT = Op.getValueType();
1325    SDValue Result = DAG.getTargetJumpTable(JT->getIndex(), PtrVT);
1326    return DAG.getNode(MSP430ISD::Wrapper, SDLoc(JT), PtrVT, Result);
1327}
1328
1329/// getPostIndexedAddressParts - returns true by value, base pointer and
1330/// offset pointer and addressing mode by reference if this node can be
1331/// combined with a load / store to form a post-indexed load / store.
1332bool MSP430TargetLowering::getPostIndexedAddressParts(SDNode *N, SDNode *Op,
1333                                                      SDValue &Base,
1334                                                      SDValue &Offset,
1335                                                      ISD::MemIndexedMode &AM,
1336                                                      SelectionDAG &DAG) const {
1337
1338  LoadSDNode *LD = cast<LoadSDNode>(N);
1339  if (LD->getExtensionType() != ISD::NON_EXTLOAD)
1340    return false;
1341
1342  EVT VT = LD->getMemoryVT();
1343  if (VT != MVT::i8 && VT != MVT::i16)
1344    return false;
1345
1346  if (Op->getOpcode() != ISD::ADD)
1347    return false;
1348
1349  if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Op->getOperand(1))) {
1350    uint64_t RHSC = RHS->getZExtValue();
1351    if ((VT == MVT::i16 && RHSC != 2) ||
1352        (VT == MVT::i8 && RHSC != 1))
1353      return false;
1354
1355    Base = Op->getOperand(0);
1356    Offset = DAG.getConstant(RHSC, SDLoc(N), VT);
1357    AM = ISD::POST_INC;
1358    return true;
1359  }
1360
1361  return false;
1362}
1363
1364
1365const char *MSP430TargetLowering::getTargetNodeName(unsigned Opcode) const {
1366  switch ((MSP430ISD::NodeType)Opcode) {
1367  case MSP430ISD::FIRST_NUMBER:       break;
1368  case MSP430ISD::RET_GLUE:           return "MSP430ISD::RET_GLUE";
1369  case MSP430ISD::RETI_GLUE:          return "MSP430ISD::RETI_GLUE";
1370  case MSP430ISD::RRA:                return "MSP430ISD::RRA";
1371  case MSP430ISD::RLA:                return "MSP430ISD::RLA";
1372  case MSP430ISD::RRC:                return "MSP430ISD::RRC";
1373  case MSP430ISD::RRCL:               return "MSP430ISD::RRCL";
1374  case MSP430ISD::CALL:               return "MSP430ISD::CALL";
1375  case MSP430ISD::Wrapper:            return "MSP430ISD::Wrapper";
1376  case MSP430ISD::BR_CC:              return "MSP430ISD::BR_CC";
1377  case MSP430ISD::CMP:                return "MSP430ISD::CMP";
1378  case MSP430ISD::SETCC:              return "MSP430ISD::SETCC";
1379  case MSP430ISD::SELECT_CC:          return "MSP430ISD::SELECT_CC";
1380  case MSP430ISD::DADD:               return "MSP430ISD::DADD";
1381  }
1382  return nullptr;
1383}
1384
1385bool MSP430TargetLowering::isTruncateFree(Type *Ty1,
1386                                          Type *Ty2) const {
1387  if (!Ty1->isIntegerTy() || !Ty2->isIntegerTy())
1388    return false;
1389
1390  return (Ty1->getPrimitiveSizeInBits().getFixedValue() >
1391          Ty2->getPrimitiveSizeInBits().getFixedValue());
1392}
1393
1394bool MSP430TargetLowering::isTruncateFree(EVT VT1, EVT VT2) const {
1395  if (!VT1.isInteger() || !VT2.isInteger())
1396    return false;
1397
1398  return (VT1.getFixedSizeInBits() > VT2.getFixedSizeInBits());
1399}
1400
1401bool MSP430TargetLowering::isZExtFree(Type *Ty1, Type *Ty2) const {
1402  // MSP430 implicitly zero-extends 8-bit results in 16-bit registers.
1403  return false && Ty1->isIntegerTy(8) && Ty2->isIntegerTy(16);
1404}
1405
1406bool MSP430TargetLowering::isZExtFree(EVT VT1, EVT VT2) const {
1407  // MSP430 implicitly zero-extends 8-bit results in 16-bit registers.
1408  return false && VT1 == MVT::i8 && VT2 == MVT::i16;
1409}
1410
1411//===----------------------------------------------------------------------===//
1412//  Other Lowering Code
1413//===----------------------------------------------------------------------===//
1414
1415MachineBasicBlock *
1416MSP430TargetLowering::EmitShiftInstr(MachineInstr &MI,
1417                                     MachineBasicBlock *BB) const {
1418  MachineFunction *F = BB->getParent();
1419  MachineRegisterInfo &RI = F->getRegInfo();
1420  DebugLoc dl = MI.getDebugLoc();
1421  const TargetInstrInfo &TII = *F->getSubtarget().getInstrInfo();
1422
1423  unsigned Opc;
1424  bool ClearCarry = false;
1425  const TargetRegisterClass * RC;
1426  switch (MI.getOpcode()) {
1427  default: llvm_unreachable("Invalid shift opcode!");
1428  case MSP430::Shl8:
1429    Opc = MSP430::ADD8rr;
1430    RC = &MSP430::GR8RegClass;
1431    break;
1432  case MSP430::Shl16:
1433    Opc = MSP430::ADD16rr;
1434    RC = &MSP430::GR16RegClass;
1435    break;
1436  case MSP430::Sra8:
1437    Opc = MSP430::RRA8r;
1438    RC = &MSP430::GR8RegClass;
1439    break;
1440  case MSP430::Sra16:
1441    Opc = MSP430::RRA16r;
1442    RC = &MSP430::GR16RegClass;
1443    break;
1444  case MSP430::Srl8:
1445    ClearCarry = true;
1446    Opc = MSP430::RRC8r;
1447    RC = &MSP430::GR8RegClass;
1448    break;
1449  case MSP430::Srl16:
1450    ClearCarry = true;
1451    Opc = MSP430::RRC16r;
1452    RC = &MSP430::GR16RegClass;
1453    break;
1454  case MSP430::Rrcl8:
1455  case MSP430::Rrcl16: {
1456    BuildMI(*BB, MI, dl, TII.get(MSP430::BIC16rc), MSP430::SR)
1457      .addReg(MSP430::SR).addImm(1);
1458    Register SrcReg = MI.getOperand(1).getReg();
1459    Register DstReg = MI.getOperand(0).getReg();
1460    unsigned RrcOpc = MI.getOpcode() == MSP430::Rrcl16
1461                    ? MSP430::RRC16r : MSP430::RRC8r;
1462    BuildMI(*BB, MI, dl, TII.get(RrcOpc), DstReg)
1463      .addReg(SrcReg);
1464    MI.eraseFromParent(); // The pseudo instruction is gone now.
1465    return BB;
1466  }
1467  }
1468
1469  const BasicBlock *LLVM_BB = BB->getBasicBlock();
1470  MachineFunction::iterator I = ++BB->getIterator();
1471
1472  // Create loop block
1473  MachineBasicBlock *LoopBB = F->CreateMachineBasicBlock(LLVM_BB);
1474  MachineBasicBlock *RemBB  = F->CreateMachineBasicBlock(LLVM_BB);
1475
1476  F->insert(I, LoopBB);
1477  F->insert(I, RemBB);
1478
1479  // Update machine-CFG edges by transferring all successors of the current
1480  // block to the block containing instructions after shift.
1481  RemBB->splice(RemBB->begin(), BB, std::next(MachineBasicBlock::iterator(MI)),
1482                BB->end());
1483  RemBB->transferSuccessorsAndUpdatePHIs(BB);
1484
1485  // Add edges BB => LoopBB => RemBB, BB => RemBB, LoopBB => LoopBB
1486  BB->addSuccessor(LoopBB);
1487  BB->addSuccessor(RemBB);
1488  LoopBB->addSuccessor(RemBB);
1489  LoopBB->addSuccessor(LoopBB);
1490
1491  Register ShiftAmtReg = RI.createVirtualRegister(&MSP430::GR8RegClass);
1492  Register ShiftAmtReg2 = RI.createVirtualRegister(&MSP430::GR8RegClass);
1493  Register ShiftReg = RI.createVirtualRegister(RC);
1494  Register ShiftReg2 = RI.createVirtualRegister(RC);
1495  Register ShiftAmtSrcReg = MI.getOperand(2).getReg();
1496  Register SrcReg = MI.getOperand(1).getReg();
1497  Register DstReg = MI.getOperand(0).getReg();
1498
1499  // BB:
1500  // cmp 0, N
1501  // je RemBB
1502  BuildMI(BB, dl, TII.get(MSP430::CMP8ri))
1503    .addReg(ShiftAmtSrcReg).addImm(0);
1504  BuildMI(BB, dl, TII.get(MSP430::JCC))
1505    .addMBB(RemBB)
1506    .addImm(MSP430CC::COND_E);
1507
1508  // LoopBB:
1509  // ShiftReg = phi [%SrcReg, BB], [%ShiftReg2, LoopBB]
1510  // ShiftAmt = phi [%N, BB],      [%ShiftAmt2, LoopBB]
1511  // ShiftReg2 = shift ShiftReg
1512  // ShiftAmt2 = ShiftAmt - 1;
1513  BuildMI(LoopBB, dl, TII.get(MSP430::PHI), ShiftReg)
1514    .addReg(SrcReg).addMBB(BB)
1515    .addReg(ShiftReg2).addMBB(LoopBB);
1516  BuildMI(LoopBB, dl, TII.get(MSP430::PHI), ShiftAmtReg)
1517    .addReg(ShiftAmtSrcReg).addMBB(BB)
1518    .addReg(ShiftAmtReg2).addMBB(LoopBB);
1519  if (ClearCarry)
1520    BuildMI(LoopBB, dl, TII.get(MSP430::BIC16rc), MSP430::SR)
1521      .addReg(MSP430::SR).addImm(1);
1522  if (Opc == MSP430::ADD8rr || Opc == MSP430::ADD16rr)
1523    BuildMI(LoopBB, dl, TII.get(Opc), ShiftReg2)
1524      .addReg(ShiftReg)
1525      .addReg(ShiftReg);
1526  else
1527    BuildMI(LoopBB, dl, TII.get(Opc), ShiftReg2)
1528      .addReg(ShiftReg);
1529  BuildMI(LoopBB, dl, TII.get(MSP430::SUB8ri), ShiftAmtReg2)
1530    .addReg(ShiftAmtReg).addImm(1);
1531  BuildMI(LoopBB, dl, TII.get(MSP430::JCC))
1532    .addMBB(LoopBB)
1533    .addImm(MSP430CC::COND_NE);
1534
1535  // RemBB:
1536  // DestReg = phi [%SrcReg, BB], [%ShiftReg, LoopBB]
1537  BuildMI(*RemBB, RemBB->begin(), dl, TII.get(MSP430::PHI), DstReg)
1538    .addReg(SrcReg).addMBB(BB)
1539    .addReg(ShiftReg2).addMBB(LoopBB);
1540
1541  MI.eraseFromParent(); // The pseudo instruction is gone now.
1542  return RemBB;
1543}
1544
1545MachineBasicBlock *
1546MSP430TargetLowering::EmitInstrWithCustomInserter(MachineInstr &MI,
1547                                                  MachineBasicBlock *BB) const {
1548  unsigned Opc = MI.getOpcode();
1549
1550  if (Opc == MSP430::Shl8  || Opc == MSP430::Shl16 ||
1551      Opc == MSP430::Sra8  || Opc == MSP430::Sra16 ||
1552      Opc == MSP430::Srl8  || Opc == MSP430::Srl16 ||
1553      Opc == MSP430::Rrcl8 || Opc == MSP430::Rrcl16)
1554    return EmitShiftInstr(MI, BB);
1555
1556  const TargetInstrInfo &TII = *BB->getParent()->getSubtarget().getInstrInfo();
1557  DebugLoc dl = MI.getDebugLoc();
1558
1559  assert((Opc == MSP430::Select16 || Opc == MSP430::Select8) &&
1560         "Unexpected instr type to insert");
1561
1562  // To "insert" a SELECT instruction, we actually have to insert the diamond
1563  // control-flow pattern.  The incoming instruction knows the destination vreg
1564  // to set, the condition code register to branch on, the true/false values to
1565  // select between, and a branch opcode to use.
1566  const BasicBlock *LLVM_BB = BB->getBasicBlock();
1567  MachineFunction::iterator I = ++BB->getIterator();
1568
1569  //  thisMBB:
1570  //  ...
1571  //   TrueVal = ...
1572  //   cmpTY ccX, r1, r2
1573  //   jCC copy1MBB
1574  //   fallthrough --> copy0MBB
1575  MachineBasicBlock *thisMBB = BB;
1576  MachineFunction *F = BB->getParent();
1577  MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
1578  MachineBasicBlock *copy1MBB = F->CreateMachineBasicBlock(LLVM_BB);
1579  F->insert(I, copy0MBB);
1580  F->insert(I, copy1MBB);
1581  // Update machine-CFG edges by transferring all successors of the current
1582  // block to the new block which will contain the Phi node for the select.
1583  copy1MBB->splice(copy1MBB->begin(), BB,
1584                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1585  copy1MBB->transferSuccessorsAndUpdatePHIs(BB);
1586  // Next, add the true and fallthrough blocks as its successors.
1587  BB->addSuccessor(copy0MBB);
1588  BB->addSuccessor(copy1MBB);
1589
1590  BuildMI(BB, dl, TII.get(MSP430::JCC))
1591      .addMBB(copy1MBB)
1592      .addImm(MI.getOperand(3).getImm());
1593
1594  //  copy0MBB:
1595  //   %FalseValue = ...
1596  //   # fallthrough to copy1MBB
1597  BB = copy0MBB;
1598
1599  // Update machine-CFG edges
1600  BB->addSuccessor(copy1MBB);
1601
1602  //  copy1MBB:
1603  //   %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ]
1604  //  ...
1605  BB = copy1MBB;
1606  BuildMI(*BB, BB->begin(), dl, TII.get(MSP430::PHI), MI.getOperand(0).getReg())
1607      .addReg(MI.getOperand(2).getReg())
1608      .addMBB(copy0MBB)
1609      .addReg(MI.getOperand(1).getReg())
1610      .addMBB(thisMBB);
1611
1612  MI.eraseFromParent(); // The pseudo instruction is gone now.
1613  return BB;
1614}
1615