1//===- TargetLoweringBase.cpp - Implement the TargetLoweringBase class ----===//
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 implements the TargetLoweringBase class.
10//
11//===----------------------------------------------------------------------===//
12
13#include "llvm/ADT/BitVector.h"
14#include "llvm/ADT/STLExtras.h"
15#include "llvm/ADT/SmallVector.h"
16#include "llvm/ADT/StringExtras.h"
17#include "llvm/ADT/StringRef.h"
18#include "llvm/ADT/Triple.h"
19#include "llvm/ADT/Twine.h"
20#include "llvm/Analysis/Loads.h"
21#include "llvm/Analysis/TargetTransformInfo.h"
22#include "llvm/CodeGen/Analysis.h"
23#include "llvm/CodeGen/ISDOpcodes.h"
24#include "llvm/CodeGen/MachineBasicBlock.h"
25#include "llvm/CodeGen/MachineFrameInfo.h"
26#include "llvm/CodeGen/MachineFunction.h"
27#include "llvm/CodeGen/MachineInstr.h"
28#include "llvm/CodeGen/MachineInstrBuilder.h"
29#include "llvm/CodeGen/MachineMemOperand.h"
30#include "llvm/CodeGen/MachineOperand.h"
31#include "llvm/CodeGen/MachineRegisterInfo.h"
32#include "llvm/CodeGen/RuntimeLibcalls.h"
33#include "llvm/CodeGen/StackMaps.h"
34#include "llvm/CodeGen/TargetLowering.h"
35#include "llvm/CodeGen/TargetOpcodes.h"
36#include "llvm/CodeGen/TargetRegisterInfo.h"
37#include "llvm/CodeGen/ValueTypes.h"
38#include "llvm/IR/Attributes.h"
39#include "llvm/IR/CallingConv.h"
40#include "llvm/IR/DataLayout.h"
41#include "llvm/IR/DerivedTypes.h"
42#include "llvm/IR/Function.h"
43#include "llvm/IR/GlobalValue.h"
44#include "llvm/IR/GlobalVariable.h"
45#include "llvm/IR/IRBuilder.h"
46#include "llvm/IR/Module.h"
47#include "llvm/IR/Type.h"
48#include "llvm/Support/BranchProbability.h"
49#include "llvm/Support/Casting.h"
50#include "llvm/Support/CommandLine.h"
51#include "llvm/Support/Compiler.h"
52#include "llvm/Support/ErrorHandling.h"
53#include "llvm/Support/MachineValueType.h"
54#include "llvm/Support/MathExtras.h"
55#include "llvm/Target/TargetMachine.h"
56#include "llvm/Transforms/Utils/SizeOpts.h"
57#include <algorithm>
58#include <cassert>
59#include <cstddef>
60#include <cstdint>
61#include <cstring>
62#include <iterator>
63#include <string>
64#include <tuple>
65#include <utility>
66
67using namespace llvm;
68
69static cl::opt<bool> JumpIsExpensiveOverride(
70    "jump-is-expensive", cl::init(false),
71    cl::desc("Do not create extra branches to split comparison logic."),
72    cl::Hidden);
73
74static cl::opt<unsigned> MinimumJumpTableEntries
75  ("min-jump-table-entries", cl::init(4), cl::Hidden,
76   cl::desc("Set minimum number of entries to use a jump table."));
77
78static cl::opt<unsigned> MaximumJumpTableSize
79  ("max-jump-table-size", cl::init(UINT_MAX), cl::Hidden,
80   cl::desc("Set maximum size of jump tables."));
81
82/// Minimum jump table density for normal functions.
83static cl::opt<unsigned>
84    JumpTableDensity("jump-table-density", cl::init(10), cl::Hidden,
85                     cl::desc("Minimum density for building a jump table in "
86                              "a normal function"));
87
88/// Minimum jump table density for -Os or -Oz functions.
89static cl::opt<unsigned> OptsizeJumpTableDensity(
90    "optsize-jump-table-density", cl::init(40), cl::Hidden,
91    cl::desc("Minimum density for building a jump table in "
92             "an optsize function"));
93
94// FIXME: This option is only to test if the strict fp operation processed
95// correctly by preventing mutating strict fp operation to normal fp operation
96// during development. When the backend supports strict float operation, this
97// option will be meaningless.
98static cl::opt<bool> DisableStrictNodeMutation("disable-strictnode-mutation",
99       cl::desc("Don't mutate strict-float node to a legalize node"),
100       cl::init(false), cl::Hidden);
101
102static bool darwinHasSinCos(const Triple &TT) {
103  assert(TT.isOSDarwin() && "should be called with darwin triple");
104  // Don't bother with 32 bit x86.
105  if (TT.getArch() == Triple::x86)
106    return false;
107  // Macos < 10.9 has no sincos_stret.
108  if (TT.isMacOSX())
109    return !TT.isMacOSXVersionLT(10, 9) && TT.isArch64Bit();
110  // iOS < 7.0 has no sincos_stret.
111  if (TT.isiOS())
112    return !TT.isOSVersionLT(7, 0);
113  // Any other darwin such as WatchOS/TvOS is new enough.
114  return true;
115}
116
117// Although this default value is arbitrary, it is not random. It is assumed
118// that a condition that evaluates the same way by a higher percentage than this
119// is best represented as control flow. Therefore, the default value N should be
120// set such that the win from N% correct executions is greater than the loss
121// from (100 - N)% mispredicted executions for the majority of intended targets.
122static cl::opt<int> MinPercentageForPredictableBranch(
123    "min-predictable-branch", cl::init(99),
124    cl::desc("Minimum percentage (0-100) that a condition must be either true "
125             "or false to assume that the condition is predictable"),
126    cl::Hidden);
127
128void TargetLoweringBase::InitLibcalls(const Triple &TT) {
129#define HANDLE_LIBCALL(code, name) \
130  setLibcallName(RTLIB::code, name);
131#include "llvm/IR/RuntimeLibcalls.def"
132#undef HANDLE_LIBCALL
133  // Initialize calling conventions to their default.
134  for (int LC = 0; LC < RTLIB::UNKNOWN_LIBCALL; ++LC)
135    setLibcallCallingConv((RTLIB::Libcall)LC, CallingConv::C);
136
137  // For IEEE quad-precision libcall names, PPC uses "kf" instead of "tf".
138  if (TT.getArch() == Triple::ppc || TT.isPPC64()) {
139    setLibcallName(RTLIB::ADD_F128, "__addkf3");
140    setLibcallName(RTLIB::SUB_F128, "__subkf3");
141    setLibcallName(RTLIB::MUL_F128, "__mulkf3");
142    setLibcallName(RTLIB::DIV_F128, "__divkf3");
143    setLibcallName(RTLIB::FPEXT_F32_F128, "__extendsfkf2");
144    setLibcallName(RTLIB::FPEXT_F64_F128, "__extenddfkf2");
145    setLibcallName(RTLIB::FPROUND_F128_F32, "__trunckfsf2");
146    setLibcallName(RTLIB::FPROUND_F128_F64, "__trunckfdf2");
147    setLibcallName(RTLIB::FPTOSINT_F128_I32, "__fixkfsi");
148    setLibcallName(RTLIB::FPTOSINT_F128_I64, "__fixkfdi");
149    setLibcallName(RTLIB::FPTOUINT_F128_I32, "__fixunskfsi");
150    setLibcallName(RTLIB::FPTOUINT_F128_I64, "__fixunskfdi");
151    setLibcallName(RTLIB::SINTTOFP_I32_F128, "__floatsikf");
152    setLibcallName(RTLIB::SINTTOFP_I64_F128, "__floatdikf");
153    setLibcallName(RTLIB::UINTTOFP_I32_F128, "__floatunsikf");
154    setLibcallName(RTLIB::UINTTOFP_I64_F128, "__floatundikf");
155    setLibcallName(RTLIB::OEQ_F128, "__eqkf2");
156    setLibcallName(RTLIB::UNE_F128, "__nekf2");
157    setLibcallName(RTLIB::OGE_F128, "__gekf2");
158    setLibcallName(RTLIB::OLT_F128, "__ltkf2");
159    setLibcallName(RTLIB::OLE_F128, "__lekf2");
160    setLibcallName(RTLIB::OGT_F128, "__gtkf2");
161    setLibcallName(RTLIB::UO_F128, "__unordkf2");
162  }
163
164  // A few names are different on particular architectures or environments.
165  if (TT.isOSDarwin()) {
166    // For f16/f32 conversions, Darwin uses the standard naming scheme, instead
167    // of the gnueabi-style __gnu_*_ieee.
168    // FIXME: What about other targets?
169    setLibcallName(RTLIB::FPEXT_F16_F32, "__extendhfsf2");
170    setLibcallName(RTLIB::FPROUND_F32_F16, "__truncsfhf2");
171
172    // Some darwins have an optimized __bzero/bzero function.
173    switch (TT.getArch()) {
174    case Triple::x86:
175    case Triple::x86_64:
176      if (TT.isMacOSX() && !TT.isMacOSXVersionLT(10, 6))
177        setLibcallName(RTLIB::BZERO, "__bzero");
178      break;
179    case Triple::aarch64:
180    case Triple::aarch64_32:
181      setLibcallName(RTLIB::BZERO, "bzero");
182      break;
183    default:
184      break;
185    }
186
187    if (darwinHasSinCos(TT)) {
188      setLibcallName(RTLIB::SINCOS_STRET_F32, "__sincosf_stret");
189      setLibcallName(RTLIB::SINCOS_STRET_F64, "__sincos_stret");
190      if (TT.isWatchABI()) {
191        setLibcallCallingConv(RTLIB::SINCOS_STRET_F32,
192                              CallingConv::ARM_AAPCS_VFP);
193        setLibcallCallingConv(RTLIB::SINCOS_STRET_F64,
194                              CallingConv::ARM_AAPCS_VFP);
195      }
196    }
197  } else {
198    setLibcallName(RTLIB::FPEXT_F16_F32, "__gnu_h2f_ieee");
199    setLibcallName(RTLIB::FPROUND_F32_F16, "__gnu_f2h_ieee");
200  }
201
202  if (TT.isGNUEnvironment() || TT.isOSFuchsia() ||
203      (TT.isAndroid() && !TT.isAndroidVersionLT(9))) {
204    setLibcallName(RTLIB::SINCOS_F32, "sincosf");
205    setLibcallName(RTLIB::SINCOS_F64, "sincos");
206    setLibcallName(RTLIB::SINCOS_F80, "sincosl");
207    setLibcallName(RTLIB::SINCOS_F128, "sincosl");
208    setLibcallName(RTLIB::SINCOS_PPCF128, "sincosl");
209  }
210
211  if (TT.isPS4CPU()) {
212    setLibcallName(RTLIB::SINCOS_F32, "sincosf");
213    setLibcallName(RTLIB::SINCOS_F64, "sincos");
214  }
215
216  if (TT.isOSOpenBSD()) {
217    setLibcallName(RTLIB::STACKPROTECTOR_CHECK_FAIL, nullptr);
218  }
219}
220
221/// getFPEXT - Return the FPEXT_*_* value for the given types, or
222/// UNKNOWN_LIBCALL if there is none.
223RTLIB::Libcall RTLIB::getFPEXT(EVT OpVT, EVT RetVT) {
224  if (OpVT == MVT::f16) {
225    if (RetVT == MVT::f32)
226      return FPEXT_F16_F32;
227  } else if (OpVT == MVT::f32) {
228    if (RetVT == MVT::f64)
229      return FPEXT_F32_F64;
230    if (RetVT == MVT::f128)
231      return FPEXT_F32_F128;
232    if (RetVT == MVT::ppcf128)
233      return FPEXT_F32_PPCF128;
234  } else if (OpVT == MVT::f64) {
235    if (RetVT == MVT::f128)
236      return FPEXT_F64_F128;
237    else if (RetVT == MVT::ppcf128)
238      return FPEXT_F64_PPCF128;
239  } else if (OpVT == MVT::f80) {
240    if (RetVT == MVT::f128)
241      return FPEXT_F80_F128;
242  }
243
244  return UNKNOWN_LIBCALL;
245}
246
247/// getFPROUND - Return the FPROUND_*_* value for the given types, or
248/// UNKNOWN_LIBCALL if there is none.
249RTLIB::Libcall RTLIB::getFPROUND(EVT OpVT, EVT RetVT) {
250  if (RetVT == MVT::f16) {
251    if (OpVT == MVT::f32)
252      return FPROUND_F32_F16;
253    if (OpVT == MVT::f64)
254      return FPROUND_F64_F16;
255    if (OpVT == MVT::f80)
256      return FPROUND_F80_F16;
257    if (OpVT == MVT::f128)
258      return FPROUND_F128_F16;
259    if (OpVT == MVT::ppcf128)
260      return FPROUND_PPCF128_F16;
261  } else if (RetVT == MVT::f32) {
262    if (OpVT == MVT::f64)
263      return FPROUND_F64_F32;
264    if (OpVT == MVT::f80)
265      return FPROUND_F80_F32;
266    if (OpVT == MVT::f128)
267      return FPROUND_F128_F32;
268    if (OpVT == MVT::ppcf128)
269      return FPROUND_PPCF128_F32;
270  } else if (RetVT == MVT::f64) {
271    if (OpVT == MVT::f80)
272      return FPROUND_F80_F64;
273    if (OpVT == MVT::f128)
274      return FPROUND_F128_F64;
275    if (OpVT == MVT::ppcf128)
276      return FPROUND_PPCF128_F64;
277  } else if (RetVT == MVT::f80) {
278    if (OpVT == MVT::f128)
279      return FPROUND_F128_F80;
280  }
281
282  return UNKNOWN_LIBCALL;
283}
284
285/// getFPTOSINT - Return the FPTOSINT_*_* value for the given types, or
286/// UNKNOWN_LIBCALL if there is none.
287RTLIB::Libcall RTLIB::getFPTOSINT(EVT OpVT, EVT RetVT) {
288  if (OpVT == MVT::f32) {
289    if (RetVT == MVT::i32)
290      return FPTOSINT_F32_I32;
291    if (RetVT == MVT::i64)
292      return FPTOSINT_F32_I64;
293    if (RetVT == MVT::i128)
294      return FPTOSINT_F32_I128;
295  } else if (OpVT == MVT::f64) {
296    if (RetVT == MVT::i32)
297      return FPTOSINT_F64_I32;
298    if (RetVT == MVT::i64)
299      return FPTOSINT_F64_I64;
300    if (RetVT == MVT::i128)
301      return FPTOSINT_F64_I128;
302  } else if (OpVT == MVT::f80) {
303    if (RetVT == MVT::i32)
304      return FPTOSINT_F80_I32;
305    if (RetVT == MVT::i64)
306      return FPTOSINT_F80_I64;
307    if (RetVT == MVT::i128)
308      return FPTOSINT_F80_I128;
309  } else if (OpVT == MVT::f128) {
310    if (RetVT == MVT::i32)
311      return FPTOSINT_F128_I32;
312    if (RetVT == MVT::i64)
313      return FPTOSINT_F128_I64;
314    if (RetVT == MVT::i128)
315      return FPTOSINT_F128_I128;
316  } else if (OpVT == MVT::ppcf128) {
317    if (RetVT == MVT::i32)
318      return FPTOSINT_PPCF128_I32;
319    if (RetVT == MVT::i64)
320      return FPTOSINT_PPCF128_I64;
321    if (RetVT == MVT::i128)
322      return FPTOSINT_PPCF128_I128;
323  }
324  return UNKNOWN_LIBCALL;
325}
326
327/// getFPTOUINT - Return the FPTOUINT_*_* value for the given types, or
328/// UNKNOWN_LIBCALL if there is none.
329RTLIB::Libcall RTLIB::getFPTOUINT(EVT OpVT, EVT RetVT) {
330  if (OpVT == MVT::f32) {
331    if (RetVT == MVT::i32)
332      return FPTOUINT_F32_I32;
333    if (RetVT == MVT::i64)
334      return FPTOUINT_F32_I64;
335    if (RetVT == MVT::i128)
336      return FPTOUINT_F32_I128;
337  } else if (OpVT == MVT::f64) {
338    if (RetVT == MVT::i32)
339      return FPTOUINT_F64_I32;
340    if (RetVT == MVT::i64)
341      return FPTOUINT_F64_I64;
342    if (RetVT == MVT::i128)
343      return FPTOUINT_F64_I128;
344  } else if (OpVT == MVT::f80) {
345    if (RetVT == MVT::i32)
346      return FPTOUINT_F80_I32;
347    if (RetVT == MVT::i64)
348      return FPTOUINT_F80_I64;
349    if (RetVT == MVT::i128)
350      return FPTOUINT_F80_I128;
351  } else if (OpVT == MVT::f128) {
352    if (RetVT == MVT::i32)
353      return FPTOUINT_F128_I32;
354    if (RetVT == MVT::i64)
355      return FPTOUINT_F128_I64;
356    if (RetVT == MVT::i128)
357      return FPTOUINT_F128_I128;
358  } else if (OpVT == MVT::ppcf128) {
359    if (RetVT == MVT::i32)
360      return FPTOUINT_PPCF128_I32;
361    if (RetVT == MVT::i64)
362      return FPTOUINT_PPCF128_I64;
363    if (RetVT == MVT::i128)
364      return FPTOUINT_PPCF128_I128;
365  }
366  return UNKNOWN_LIBCALL;
367}
368
369/// getSINTTOFP - Return the SINTTOFP_*_* value for the given types, or
370/// UNKNOWN_LIBCALL if there is none.
371RTLIB::Libcall RTLIB::getSINTTOFP(EVT OpVT, EVT RetVT) {
372  if (OpVT == MVT::i32) {
373    if (RetVT == MVT::f32)
374      return SINTTOFP_I32_F32;
375    if (RetVT == MVT::f64)
376      return SINTTOFP_I32_F64;
377    if (RetVT == MVT::f80)
378      return SINTTOFP_I32_F80;
379    if (RetVT == MVT::f128)
380      return SINTTOFP_I32_F128;
381    if (RetVT == MVT::ppcf128)
382      return SINTTOFP_I32_PPCF128;
383  } else if (OpVT == MVT::i64) {
384    if (RetVT == MVT::f32)
385      return SINTTOFP_I64_F32;
386    if (RetVT == MVT::f64)
387      return SINTTOFP_I64_F64;
388    if (RetVT == MVT::f80)
389      return SINTTOFP_I64_F80;
390    if (RetVT == MVT::f128)
391      return SINTTOFP_I64_F128;
392    if (RetVT == MVT::ppcf128)
393      return SINTTOFP_I64_PPCF128;
394  } else if (OpVT == MVT::i128) {
395    if (RetVT == MVT::f32)
396      return SINTTOFP_I128_F32;
397    if (RetVT == MVT::f64)
398      return SINTTOFP_I128_F64;
399    if (RetVT == MVT::f80)
400      return SINTTOFP_I128_F80;
401    if (RetVT == MVT::f128)
402      return SINTTOFP_I128_F128;
403    if (RetVT == MVT::ppcf128)
404      return SINTTOFP_I128_PPCF128;
405  }
406  return UNKNOWN_LIBCALL;
407}
408
409/// getUINTTOFP - Return the UINTTOFP_*_* value for the given types, or
410/// UNKNOWN_LIBCALL if there is none.
411RTLIB::Libcall RTLIB::getUINTTOFP(EVT OpVT, EVT RetVT) {
412  if (OpVT == MVT::i32) {
413    if (RetVT == MVT::f32)
414      return UINTTOFP_I32_F32;
415    if (RetVT == MVT::f64)
416      return UINTTOFP_I32_F64;
417    if (RetVT == MVT::f80)
418      return UINTTOFP_I32_F80;
419    if (RetVT == MVT::f128)
420      return UINTTOFP_I32_F128;
421    if (RetVT == MVT::ppcf128)
422      return UINTTOFP_I32_PPCF128;
423  } else if (OpVT == MVT::i64) {
424    if (RetVT == MVT::f32)
425      return UINTTOFP_I64_F32;
426    if (RetVT == MVT::f64)
427      return UINTTOFP_I64_F64;
428    if (RetVT == MVT::f80)
429      return UINTTOFP_I64_F80;
430    if (RetVT == MVT::f128)
431      return UINTTOFP_I64_F128;
432    if (RetVT == MVT::ppcf128)
433      return UINTTOFP_I64_PPCF128;
434  } else if (OpVT == MVT::i128) {
435    if (RetVT == MVT::f32)
436      return UINTTOFP_I128_F32;
437    if (RetVT == MVT::f64)
438      return UINTTOFP_I128_F64;
439    if (RetVT == MVT::f80)
440      return UINTTOFP_I128_F80;
441    if (RetVT == MVT::f128)
442      return UINTTOFP_I128_F128;
443    if (RetVT == MVT::ppcf128)
444      return UINTTOFP_I128_PPCF128;
445  }
446  return UNKNOWN_LIBCALL;
447}
448
449RTLIB::Libcall RTLIB::getSYNC(unsigned Opc, MVT VT) {
450#define OP_TO_LIBCALL(Name, Enum)                                              \
451  case Name:                                                                   \
452    switch (VT.SimpleTy) {                                                     \
453    default:                                                                   \
454      return UNKNOWN_LIBCALL;                                                  \
455    case MVT::i8:                                                              \
456      return Enum##_1;                                                         \
457    case MVT::i16:                                                             \
458      return Enum##_2;                                                         \
459    case MVT::i32:                                                             \
460      return Enum##_4;                                                         \
461    case MVT::i64:                                                             \
462      return Enum##_8;                                                         \
463    case MVT::i128:                                                            \
464      return Enum##_16;                                                        \
465    }
466
467  switch (Opc) {
468    OP_TO_LIBCALL(ISD::ATOMIC_SWAP, SYNC_LOCK_TEST_AND_SET)
469    OP_TO_LIBCALL(ISD::ATOMIC_CMP_SWAP, SYNC_VAL_COMPARE_AND_SWAP)
470    OP_TO_LIBCALL(ISD::ATOMIC_LOAD_ADD, SYNC_FETCH_AND_ADD)
471    OP_TO_LIBCALL(ISD::ATOMIC_LOAD_SUB, SYNC_FETCH_AND_SUB)
472    OP_TO_LIBCALL(ISD::ATOMIC_LOAD_AND, SYNC_FETCH_AND_AND)
473    OP_TO_LIBCALL(ISD::ATOMIC_LOAD_OR, SYNC_FETCH_AND_OR)
474    OP_TO_LIBCALL(ISD::ATOMIC_LOAD_XOR, SYNC_FETCH_AND_XOR)
475    OP_TO_LIBCALL(ISD::ATOMIC_LOAD_NAND, SYNC_FETCH_AND_NAND)
476    OP_TO_LIBCALL(ISD::ATOMIC_LOAD_MAX, SYNC_FETCH_AND_MAX)
477    OP_TO_LIBCALL(ISD::ATOMIC_LOAD_UMAX, SYNC_FETCH_AND_UMAX)
478    OP_TO_LIBCALL(ISD::ATOMIC_LOAD_MIN, SYNC_FETCH_AND_MIN)
479    OP_TO_LIBCALL(ISD::ATOMIC_LOAD_UMIN, SYNC_FETCH_AND_UMIN)
480  }
481
482#undef OP_TO_LIBCALL
483
484  return UNKNOWN_LIBCALL;
485}
486
487RTLIB::Libcall RTLIB::getMEMCPY_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
488  switch (ElementSize) {
489  case 1:
490    return MEMCPY_ELEMENT_UNORDERED_ATOMIC_1;
491  case 2:
492    return MEMCPY_ELEMENT_UNORDERED_ATOMIC_2;
493  case 4:
494    return MEMCPY_ELEMENT_UNORDERED_ATOMIC_4;
495  case 8:
496    return MEMCPY_ELEMENT_UNORDERED_ATOMIC_8;
497  case 16:
498    return MEMCPY_ELEMENT_UNORDERED_ATOMIC_16;
499  default:
500    return UNKNOWN_LIBCALL;
501  }
502}
503
504RTLIB::Libcall RTLIB::getMEMMOVE_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
505  switch (ElementSize) {
506  case 1:
507    return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_1;
508  case 2:
509    return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_2;
510  case 4:
511    return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_4;
512  case 8:
513    return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_8;
514  case 16:
515    return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_16;
516  default:
517    return UNKNOWN_LIBCALL;
518  }
519}
520
521RTLIB::Libcall RTLIB::getMEMSET_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
522  switch (ElementSize) {
523  case 1:
524    return MEMSET_ELEMENT_UNORDERED_ATOMIC_1;
525  case 2:
526    return MEMSET_ELEMENT_UNORDERED_ATOMIC_2;
527  case 4:
528    return MEMSET_ELEMENT_UNORDERED_ATOMIC_4;
529  case 8:
530    return MEMSET_ELEMENT_UNORDERED_ATOMIC_8;
531  case 16:
532    return MEMSET_ELEMENT_UNORDERED_ATOMIC_16;
533  default:
534    return UNKNOWN_LIBCALL;
535  }
536}
537
538/// InitCmpLibcallCCs - Set default comparison libcall CC.
539static void InitCmpLibcallCCs(ISD::CondCode *CCs) {
540  memset(CCs, ISD::SETCC_INVALID, sizeof(ISD::CondCode)*RTLIB::UNKNOWN_LIBCALL);
541  CCs[RTLIB::OEQ_F32] = ISD::SETEQ;
542  CCs[RTLIB::OEQ_F64] = ISD::SETEQ;
543  CCs[RTLIB::OEQ_F128] = ISD::SETEQ;
544  CCs[RTLIB::OEQ_PPCF128] = ISD::SETEQ;
545  CCs[RTLIB::UNE_F32] = ISD::SETNE;
546  CCs[RTLIB::UNE_F64] = ISD::SETNE;
547  CCs[RTLIB::UNE_F128] = ISD::SETNE;
548  CCs[RTLIB::UNE_PPCF128] = ISD::SETNE;
549  CCs[RTLIB::OGE_F32] = ISD::SETGE;
550  CCs[RTLIB::OGE_F64] = ISD::SETGE;
551  CCs[RTLIB::OGE_F128] = ISD::SETGE;
552  CCs[RTLIB::OGE_PPCF128] = ISD::SETGE;
553  CCs[RTLIB::OLT_F32] = ISD::SETLT;
554  CCs[RTLIB::OLT_F64] = ISD::SETLT;
555  CCs[RTLIB::OLT_F128] = ISD::SETLT;
556  CCs[RTLIB::OLT_PPCF128] = ISD::SETLT;
557  CCs[RTLIB::OLE_F32] = ISD::SETLE;
558  CCs[RTLIB::OLE_F64] = ISD::SETLE;
559  CCs[RTLIB::OLE_F128] = ISD::SETLE;
560  CCs[RTLIB::OLE_PPCF128] = ISD::SETLE;
561  CCs[RTLIB::OGT_F32] = ISD::SETGT;
562  CCs[RTLIB::OGT_F64] = ISD::SETGT;
563  CCs[RTLIB::OGT_F128] = ISD::SETGT;
564  CCs[RTLIB::OGT_PPCF128] = ISD::SETGT;
565  CCs[RTLIB::UO_F32] = ISD::SETNE;
566  CCs[RTLIB::UO_F64] = ISD::SETNE;
567  CCs[RTLIB::UO_F128] = ISD::SETNE;
568  CCs[RTLIB::UO_PPCF128] = ISD::SETNE;
569}
570
571/// NOTE: The TargetMachine owns TLOF.
572TargetLoweringBase::TargetLoweringBase(const TargetMachine &tm) : TM(tm) {
573  initActions();
574
575  // Perform these initializations only once.
576  MaxStoresPerMemset = MaxStoresPerMemcpy = MaxStoresPerMemmove =
577      MaxLoadsPerMemcmp = 8;
578  MaxGluedStoresPerMemcpy = 0;
579  MaxStoresPerMemsetOptSize = MaxStoresPerMemcpyOptSize =
580      MaxStoresPerMemmoveOptSize = MaxLoadsPerMemcmpOptSize = 4;
581  HasMultipleConditionRegisters = false;
582  HasExtractBitsInsn = false;
583  JumpIsExpensive = JumpIsExpensiveOverride;
584  PredictableSelectIsExpensive = false;
585  EnableExtLdPromotion = false;
586  StackPointerRegisterToSaveRestore = 0;
587  BooleanContents = UndefinedBooleanContent;
588  BooleanFloatContents = UndefinedBooleanContent;
589  BooleanVectorContents = UndefinedBooleanContent;
590  SchedPreferenceInfo = Sched::ILP;
591  GatherAllAliasesMaxDepth = 18;
592  IsStrictFPEnabled = DisableStrictNodeMutation;
593  // TODO: the default will be switched to 0 in the next commit, along
594  // with the Target-specific changes necessary.
595  MaxAtomicSizeInBitsSupported = 1024;
596
597  MinCmpXchgSizeInBits = 0;
598  SupportsUnalignedAtomics = false;
599
600  std::fill(std::begin(LibcallRoutineNames), std::end(LibcallRoutineNames), nullptr);
601
602  InitLibcalls(TM.getTargetTriple());
603  InitCmpLibcallCCs(CmpLibcallCCs);
604}
605
606void TargetLoweringBase::initActions() {
607  // All operations default to being supported.
608  memset(OpActions, 0, sizeof(OpActions));
609  memset(LoadExtActions, 0, sizeof(LoadExtActions));
610  memset(TruncStoreActions, 0, sizeof(TruncStoreActions));
611  memset(IndexedModeActions, 0, sizeof(IndexedModeActions));
612  memset(CondCodeActions, 0, sizeof(CondCodeActions));
613  std::fill(std::begin(RegClassForVT), std::end(RegClassForVT), nullptr);
614  std::fill(std::begin(TargetDAGCombineArray),
615            std::end(TargetDAGCombineArray), 0);
616
617  for (MVT VT : MVT::fp_valuetypes()) {
618    MVT IntVT = MVT::getIntegerVT(VT.getSizeInBits().getFixedSize());
619    if (IntVT.isValid()) {
620      setOperationAction(ISD::ATOMIC_SWAP, VT, Promote);
621      AddPromotedToType(ISD::ATOMIC_SWAP, VT, IntVT);
622    }
623  }
624
625  // Set default actions for various operations.
626  for (MVT VT : MVT::all_valuetypes()) {
627    // Default all indexed load / store to expand.
628    for (unsigned IM = (unsigned)ISD::PRE_INC;
629         IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) {
630      setIndexedLoadAction(IM, VT, Expand);
631      setIndexedStoreAction(IM, VT, Expand);
632      setIndexedMaskedLoadAction(IM, VT, Expand);
633      setIndexedMaskedStoreAction(IM, VT, Expand);
634    }
635
636    // Most backends expect to see the node which just returns the value loaded.
637    setOperationAction(ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS, VT, Expand);
638
639    // These operations default to expand.
640    setOperationAction(ISD::FGETSIGN, VT, Expand);
641    setOperationAction(ISD::CONCAT_VECTORS, VT, Expand);
642    setOperationAction(ISD::FMINNUM, VT, Expand);
643    setOperationAction(ISD::FMAXNUM, VT, Expand);
644    setOperationAction(ISD::FMINNUM_IEEE, VT, Expand);
645    setOperationAction(ISD::FMAXNUM_IEEE, VT, Expand);
646    setOperationAction(ISD::FMINIMUM, VT, Expand);
647    setOperationAction(ISD::FMAXIMUM, VT, Expand);
648    setOperationAction(ISD::FMAD, VT, Expand);
649    setOperationAction(ISD::SMIN, VT, Expand);
650    setOperationAction(ISD::SMAX, VT, Expand);
651    setOperationAction(ISD::UMIN, VT, Expand);
652    setOperationAction(ISD::UMAX, VT, Expand);
653    setOperationAction(ISD::ABS, VT, Expand);
654    setOperationAction(ISD::FSHL, VT, Expand);
655    setOperationAction(ISD::FSHR, VT, Expand);
656    setOperationAction(ISD::SADDSAT, VT, Expand);
657    setOperationAction(ISD::UADDSAT, VT, Expand);
658    setOperationAction(ISD::SSUBSAT, VT, Expand);
659    setOperationAction(ISD::USUBSAT, VT, Expand);
660    setOperationAction(ISD::SMULFIX, VT, Expand);
661    setOperationAction(ISD::SMULFIXSAT, VT, Expand);
662    setOperationAction(ISD::UMULFIX, VT, Expand);
663    setOperationAction(ISD::UMULFIXSAT, VT, Expand);
664    setOperationAction(ISD::SDIVFIX, VT, Expand);
665    setOperationAction(ISD::SDIVFIXSAT, VT, Expand);
666    setOperationAction(ISD::UDIVFIX, VT, Expand);
667    setOperationAction(ISD::UDIVFIXSAT, VT, Expand);
668
669    // Overflow operations default to expand
670    setOperationAction(ISD::SADDO, VT, Expand);
671    setOperationAction(ISD::SSUBO, VT, Expand);
672    setOperationAction(ISD::UADDO, VT, Expand);
673    setOperationAction(ISD::USUBO, VT, Expand);
674    setOperationAction(ISD::SMULO, VT, Expand);
675    setOperationAction(ISD::UMULO, VT, Expand);
676
677    // ADDCARRY operations default to expand
678    setOperationAction(ISD::ADDCARRY, VT, Expand);
679    setOperationAction(ISD::SUBCARRY, VT, Expand);
680    setOperationAction(ISD::SETCCCARRY, VT, Expand);
681
682    // ADDC/ADDE/SUBC/SUBE default to expand.
683    setOperationAction(ISD::ADDC, VT, Expand);
684    setOperationAction(ISD::ADDE, VT, Expand);
685    setOperationAction(ISD::SUBC, VT, Expand);
686    setOperationAction(ISD::SUBE, VT, Expand);
687
688    // These default to Expand so they will be expanded to CTLZ/CTTZ by default.
689    setOperationAction(ISD::CTLZ_ZERO_UNDEF, VT, Expand);
690    setOperationAction(ISD::CTTZ_ZERO_UNDEF, VT, Expand);
691
692    setOperationAction(ISD::BITREVERSE, VT, Expand);
693
694    // These library functions default to expand.
695    setOperationAction(ISD::FROUND, VT, Expand);
696    setOperationAction(ISD::FROUNDEVEN, VT, Expand);
697    setOperationAction(ISD::FPOWI, VT, Expand);
698
699    // These operations default to expand for vector types.
700    if (VT.isVector()) {
701      setOperationAction(ISD::FCOPYSIGN, VT, Expand);
702      setOperationAction(ISD::SIGN_EXTEND_INREG, VT, Expand);
703      setOperationAction(ISD::ANY_EXTEND_VECTOR_INREG, VT, Expand);
704      setOperationAction(ISD::SIGN_EXTEND_VECTOR_INREG, VT, Expand);
705      setOperationAction(ISD::ZERO_EXTEND_VECTOR_INREG, VT, Expand);
706      setOperationAction(ISD::SPLAT_VECTOR, VT, Expand);
707    }
708
709    // Constrained floating-point operations default to expand.
710#define DAG_INSTRUCTION(NAME, NARG, ROUND_MODE, INTRINSIC, DAGN)               \
711    setOperationAction(ISD::STRICT_##DAGN, VT, Expand);
712#include "llvm/IR/ConstrainedOps.def"
713
714    // For most targets @llvm.get.dynamic.area.offset just returns 0.
715    setOperationAction(ISD::GET_DYNAMIC_AREA_OFFSET, VT, Expand);
716
717    // Vector reduction default to expand.
718    setOperationAction(ISD::VECREDUCE_FADD, VT, Expand);
719    setOperationAction(ISD::VECREDUCE_FMUL, VT, Expand);
720    setOperationAction(ISD::VECREDUCE_ADD, VT, Expand);
721    setOperationAction(ISD::VECREDUCE_MUL, VT, Expand);
722    setOperationAction(ISD::VECREDUCE_AND, VT, Expand);
723    setOperationAction(ISD::VECREDUCE_OR, VT, Expand);
724    setOperationAction(ISD::VECREDUCE_XOR, VT, Expand);
725    setOperationAction(ISD::VECREDUCE_SMAX, VT, Expand);
726    setOperationAction(ISD::VECREDUCE_SMIN, VT, Expand);
727    setOperationAction(ISD::VECREDUCE_UMAX, VT, Expand);
728    setOperationAction(ISD::VECREDUCE_UMIN, VT, Expand);
729    setOperationAction(ISD::VECREDUCE_FMAX, VT, Expand);
730    setOperationAction(ISD::VECREDUCE_FMIN, VT, Expand);
731  }
732
733  // Most targets ignore the @llvm.prefetch intrinsic.
734  setOperationAction(ISD::PREFETCH, MVT::Other, Expand);
735
736  // Most targets also ignore the @llvm.readcyclecounter intrinsic.
737  setOperationAction(ISD::READCYCLECOUNTER, MVT::i64, Expand);
738
739  // ConstantFP nodes default to expand.  Targets can either change this to
740  // Legal, in which case all fp constants are legal, or use isFPImmLegal()
741  // to optimize expansions for certain constants.
742  setOperationAction(ISD::ConstantFP, MVT::f16, Expand);
743  setOperationAction(ISD::ConstantFP, MVT::f32, Expand);
744  setOperationAction(ISD::ConstantFP, MVT::f64, Expand);
745  setOperationAction(ISD::ConstantFP, MVT::f80, Expand);
746  setOperationAction(ISD::ConstantFP, MVT::f128, Expand);
747
748  // These library functions default to expand.
749  for (MVT VT : {MVT::f32, MVT::f64, MVT::f128}) {
750    setOperationAction(ISD::FCBRT,      VT, Expand);
751    setOperationAction(ISD::FLOG ,      VT, Expand);
752    setOperationAction(ISD::FLOG2,      VT, Expand);
753    setOperationAction(ISD::FLOG10,     VT, Expand);
754    setOperationAction(ISD::FEXP ,      VT, Expand);
755    setOperationAction(ISD::FEXP2,      VT, Expand);
756    setOperationAction(ISD::FFLOOR,     VT, Expand);
757    setOperationAction(ISD::FNEARBYINT, VT, Expand);
758    setOperationAction(ISD::FCEIL,      VT, Expand);
759    setOperationAction(ISD::FRINT,      VT, Expand);
760    setOperationAction(ISD::FTRUNC,     VT, Expand);
761    setOperationAction(ISD::FROUND,     VT, Expand);
762    setOperationAction(ISD::FROUNDEVEN, VT, Expand);
763    setOperationAction(ISD::LROUND,     VT, Expand);
764    setOperationAction(ISD::LLROUND,    VT, Expand);
765    setOperationAction(ISD::LRINT,      VT, Expand);
766    setOperationAction(ISD::LLRINT,     VT, Expand);
767  }
768
769  // Default ISD::TRAP to expand (which turns it into abort).
770  setOperationAction(ISD::TRAP, MVT::Other, Expand);
771
772  // On most systems, DEBUGTRAP and TRAP have no difference. The "Expand"
773  // here is to inform DAG Legalizer to replace DEBUGTRAP with TRAP.
774  setOperationAction(ISD::DEBUGTRAP, MVT::Other, Expand);
775}
776
777MVT TargetLoweringBase::getScalarShiftAmountTy(const DataLayout &DL,
778                                               EVT) const {
779  return MVT::getIntegerVT(DL.getPointerSizeInBits(0));
780}
781
782EVT TargetLoweringBase::getShiftAmountTy(EVT LHSTy, const DataLayout &DL,
783                                         bool LegalTypes) const {
784  assert(LHSTy.isInteger() && "Shift amount is not an integer type!");
785  if (LHSTy.isVector())
786    return LHSTy;
787  return LegalTypes ? getScalarShiftAmountTy(DL, LHSTy)
788                    : getPointerTy(DL);
789}
790
791bool TargetLoweringBase::canOpTrap(unsigned Op, EVT VT) const {
792  assert(isTypeLegal(VT));
793  switch (Op) {
794  default:
795    return false;
796  case ISD::SDIV:
797  case ISD::UDIV:
798  case ISD::SREM:
799  case ISD::UREM:
800    return true;
801  }
802}
803
804void TargetLoweringBase::setJumpIsExpensive(bool isExpensive) {
805  // If the command-line option was specified, ignore this request.
806  if (!JumpIsExpensiveOverride.getNumOccurrences())
807    JumpIsExpensive = isExpensive;
808}
809
810TargetLoweringBase::LegalizeKind
811TargetLoweringBase::getTypeConversion(LLVMContext &Context, EVT VT) const {
812  // If this is a simple type, use the ComputeRegisterProp mechanism.
813  if (VT.isSimple()) {
814    MVT SVT = VT.getSimpleVT();
815    assert((unsigned)SVT.SimpleTy < array_lengthof(TransformToType));
816    MVT NVT = TransformToType[SVT.SimpleTy];
817    LegalizeTypeAction LA = ValueTypeActions.getTypeAction(SVT);
818
819    assert((LA == TypeLegal || LA == TypeSoftenFloat ||
820            LA == TypeSoftPromoteHalf ||
821            (NVT.isVector() ||
822             ValueTypeActions.getTypeAction(NVT) != TypePromoteInteger)) &&
823           "Promote may not follow Expand or Promote");
824
825    if (LA == TypeSplitVector)
826      return LegalizeKind(LA,
827                          EVT::getVectorVT(Context, SVT.getVectorElementType(),
828                                           SVT.getVectorElementCount() / 2));
829    if (LA == TypeScalarizeVector)
830      return LegalizeKind(LA, SVT.getVectorElementType());
831    return LegalizeKind(LA, NVT);
832  }
833
834  // Handle Extended Scalar Types.
835  if (!VT.isVector()) {
836    assert(VT.isInteger() && "Float types must be simple");
837    unsigned BitSize = VT.getSizeInBits();
838    // First promote to a power-of-two size, then expand if necessary.
839    if (BitSize < 8 || !isPowerOf2_32(BitSize)) {
840      EVT NVT = VT.getRoundIntegerType(Context);
841      assert(NVT != VT && "Unable to round integer VT");
842      LegalizeKind NextStep = getTypeConversion(Context, NVT);
843      // Avoid multi-step promotion.
844      if (NextStep.first == TypePromoteInteger)
845        return NextStep;
846      // Return rounded integer type.
847      return LegalizeKind(TypePromoteInteger, NVT);
848    }
849
850    return LegalizeKind(TypeExpandInteger,
851                        EVT::getIntegerVT(Context, VT.getSizeInBits() / 2));
852  }
853
854  // Handle vector types.
855  ElementCount NumElts = VT.getVectorElementCount();
856  EVT EltVT = VT.getVectorElementType();
857
858  // Vectors with only one element are always scalarized.
859  if (NumElts == 1)
860    return LegalizeKind(TypeScalarizeVector, EltVT);
861
862  if (VT.getVectorElementCount() == ElementCount(1, true))
863    report_fatal_error("Cannot legalize this vector");
864
865  // Try to widen vector elements until the element type is a power of two and
866  // promote it to a legal type later on, for example:
867  // <3 x i8> -> <4 x i8> -> <4 x i32>
868  if (EltVT.isInteger()) {
869    // Vectors with a number of elements that is not a power of two are always
870    // widened, for example <3 x i8> -> <4 x i8>.
871    if (!VT.isPow2VectorType()) {
872      NumElts = NumElts.NextPowerOf2();
873      EVT NVT = EVT::getVectorVT(Context, EltVT, NumElts);
874      return LegalizeKind(TypeWidenVector, NVT);
875    }
876
877    // Examine the element type.
878    LegalizeKind LK = getTypeConversion(Context, EltVT);
879
880    // If type is to be expanded, split the vector.
881    //  <4 x i140> -> <2 x i140>
882    if (LK.first == TypeExpandInteger)
883      return LegalizeKind(TypeSplitVector,
884                          EVT::getVectorVT(Context, EltVT, NumElts / 2));
885
886    // Promote the integer element types until a legal vector type is found
887    // or until the element integer type is too big. If a legal type was not
888    // found, fallback to the usual mechanism of widening/splitting the
889    // vector.
890    EVT OldEltVT = EltVT;
891    while (true) {
892      // Increase the bitwidth of the element to the next pow-of-two
893      // (which is greater than 8 bits).
894      EltVT = EVT::getIntegerVT(Context, 1 + EltVT.getSizeInBits())
895                  .getRoundIntegerType(Context);
896
897      // Stop trying when getting a non-simple element type.
898      // Note that vector elements may be greater than legal vector element
899      // types. Example: X86 XMM registers hold 64bit element on 32bit
900      // systems.
901      if (!EltVT.isSimple())
902        break;
903
904      // Build a new vector type and check if it is legal.
905      MVT NVT = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
906      // Found a legal promoted vector type.
907      if (NVT != MVT() && ValueTypeActions.getTypeAction(NVT) == TypeLegal)
908        return LegalizeKind(TypePromoteInteger,
909                            EVT::getVectorVT(Context, EltVT, NumElts));
910    }
911
912    // Reset the type to the unexpanded type if we did not find a legal vector
913    // type with a promoted vector element type.
914    EltVT = OldEltVT;
915  }
916
917  // Try to widen the vector until a legal type is found.
918  // If there is no wider legal type, split the vector.
919  while (true) {
920    // Round up to the next power of 2.
921    NumElts = NumElts.NextPowerOf2();
922
923    // If there is no simple vector type with this many elements then there
924    // cannot be a larger legal vector type.  Note that this assumes that
925    // there are no skipped intermediate vector types in the simple types.
926    if (!EltVT.isSimple())
927      break;
928    MVT LargerVector = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
929    if (LargerVector == MVT())
930      break;
931
932    // If this type is legal then widen the vector.
933    if (ValueTypeActions.getTypeAction(LargerVector) == TypeLegal)
934      return LegalizeKind(TypeWidenVector, LargerVector);
935  }
936
937  // Widen odd vectors to next power of two.
938  if (!VT.isPow2VectorType()) {
939    EVT NVT = VT.getPow2VectorType(Context);
940    return LegalizeKind(TypeWidenVector, NVT);
941  }
942
943  // Vectors with illegal element types are expanded.
944  EVT NVT = EVT::getVectorVT(Context, EltVT, VT.getVectorElementCount() / 2);
945  return LegalizeKind(TypeSplitVector, NVT);
946}
947
948static unsigned getVectorTypeBreakdownMVT(MVT VT, MVT &IntermediateVT,
949                                          unsigned &NumIntermediates,
950                                          MVT &RegisterVT,
951                                          TargetLoweringBase *TLI) {
952  // Figure out the right, legal destination reg to copy into.
953  ElementCount EC = VT.getVectorElementCount();
954  MVT EltTy = VT.getVectorElementType();
955
956  unsigned NumVectorRegs = 1;
957
958  // Scalable vectors cannot be scalarized, so splitting or widening is
959  // required.
960  if (VT.isScalableVector() && !isPowerOf2_32(EC.Min))
961    llvm_unreachable(
962        "Splitting or widening of non-power-of-2 MVTs is not implemented.");
963
964  // FIXME: We don't support non-power-of-2-sized vectors for now.
965  // Ideally we could break down into LHS/RHS like LegalizeDAG does.
966  if (!isPowerOf2_32(EC.Min)) {
967    // Split EC to unit size (scalable property is preserved).
968    NumVectorRegs = EC.Min;
969    EC = EC / NumVectorRegs;
970  }
971
972  // Divide the input until we get to a supported size. This will
973  // always end up with an EC that represent a scalar or a scalable
974  // scalar.
975  while (EC.Min > 1 && !TLI->isTypeLegal(MVT::getVectorVT(EltTy, EC))) {
976    EC.Min >>= 1;
977    NumVectorRegs <<= 1;
978  }
979
980  NumIntermediates = NumVectorRegs;
981
982  MVT NewVT = MVT::getVectorVT(EltTy, EC);
983  if (!TLI->isTypeLegal(NewVT))
984    NewVT = EltTy;
985  IntermediateVT = NewVT;
986
987  unsigned LaneSizeInBits = NewVT.getScalarSizeInBits().getFixedSize();
988
989  // Convert sizes such as i33 to i64.
990  if (!isPowerOf2_32(LaneSizeInBits))
991    LaneSizeInBits = NextPowerOf2(LaneSizeInBits);
992
993  MVT DestVT = TLI->getRegisterType(NewVT);
994  RegisterVT = DestVT;
995  if (EVT(DestVT).bitsLT(NewVT))    // Value is expanded, e.g. i64 -> i16.
996    return NumVectorRegs *
997           (LaneSizeInBits / DestVT.getScalarSizeInBits().getFixedSize());
998
999  // Otherwise, promotion or legal types use the same number of registers as
1000  // the vector decimated to the appropriate level.
1001  return NumVectorRegs;
1002}
1003
1004/// isLegalRC - Return true if the value types that can be represented by the
1005/// specified register class are all legal.
1006bool TargetLoweringBase::isLegalRC(const TargetRegisterInfo &TRI,
1007                                   const TargetRegisterClass &RC) const {
1008  for (auto I = TRI.legalclasstypes_begin(RC); *I != MVT::Other; ++I)
1009    if (isTypeLegal(*I))
1010      return true;
1011  return false;
1012}
1013
1014/// Replace/modify any TargetFrameIndex operands with a targte-dependent
1015/// sequence of memory operands that is recognized by PrologEpilogInserter.
1016MachineBasicBlock *
1017TargetLoweringBase::emitPatchPoint(MachineInstr &InitialMI,
1018                                   MachineBasicBlock *MBB) const {
1019  MachineInstr *MI = &InitialMI;
1020  MachineFunction &MF = *MI->getMF();
1021  MachineFrameInfo &MFI = MF.getFrameInfo();
1022
1023  // We're handling multiple types of operands here:
1024  // PATCHPOINT MetaArgs - live-in, read only, direct
1025  // STATEPOINT Deopt Spill - live-through, read only, indirect
1026  // STATEPOINT Deopt Alloca - live-through, read only, direct
1027  // (We're currently conservative and mark the deopt slots read/write in
1028  // practice.)
1029  // STATEPOINT GC Spill - live-through, read/write, indirect
1030  // STATEPOINT GC Alloca - live-through, read/write, direct
1031  // The live-in vs live-through is handled already (the live through ones are
1032  // all stack slots), but we need to handle the different type of stackmap
1033  // operands and memory effects here.
1034
1035  if (!llvm::any_of(MI->operands(),
1036                    [](MachineOperand &Operand) { return Operand.isFI(); }))
1037    return MBB;
1038
1039  MachineInstrBuilder MIB = BuildMI(MF, MI->getDebugLoc(), MI->getDesc());
1040
1041  // Inherit previous memory operands.
1042  MIB.cloneMemRefs(*MI);
1043
1044  for (auto &MO : MI->operands()) {
1045    if (!MO.isFI()) {
1046      MIB.add(MO);
1047      continue;
1048    }
1049
1050    // foldMemoryOperand builds a new MI after replacing a single FI operand
1051    // with the canonical set of five x86 addressing-mode operands.
1052    int FI = MO.getIndex();
1053
1054    // Add frame index operands recognized by stackmaps.cpp
1055    if (MFI.isStatepointSpillSlotObjectIndex(FI)) {
1056      // indirect-mem-ref tag, size, #FI, offset.
1057      // Used for spills inserted by StatepointLowering.  This codepath is not
1058      // used for patchpoints/stackmaps at all, for these spilling is done via
1059      // foldMemoryOperand callback only.
1060      assert(MI->getOpcode() == TargetOpcode::STATEPOINT && "sanity");
1061      MIB.addImm(StackMaps::IndirectMemRefOp);
1062      MIB.addImm(MFI.getObjectSize(FI));
1063      MIB.add(MO);
1064      MIB.addImm(0);
1065    } else {
1066      // direct-mem-ref tag, #FI, offset.
1067      // Used by patchpoint, and direct alloca arguments to statepoints
1068      MIB.addImm(StackMaps::DirectMemRefOp);
1069      MIB.add(MO);
1070      MIB.addImm(0);
1071    }
1072
1073    assert(MIB->mayLoad() && "Folded a stackmap use to a non-load!");
1074
1075    // Add a new memory operand for this FI.
1076    assert(MFI.getObjectOffset(FI) != -1);
1077
1078    // Note: STATEPOINT MMOs are added during SelectionDAG.  STACKMAP, and
1079    // PATCHPOINT should be updated to do the same. (TODO)
1080    if (MI->getOpcode() != TargetOpcode::STATEPOINT) {
1081      auto Flags = MachineMemOperand::MOLoad;
1082      MachineMemOperand *MMO = MF.getMachineMemOperand(
1083          MachinePointerInfo::getFixedStack(MF, FI), Flags,
1084          MF.getDataLayout().getPointerSize(), MFI.getObjectAlign(FI));
1085      MIB->addMemOperand(MF, MMO);
1086    }
1087  }
1088  MBB->insert(MachineBasicBlock::iterator(MI), MIB);
1089  MI->eraseFromParent();
1090  return MBB;
1091}
1092
1093MachineBasicBlock *
1094TargetLoweringBase::emitXRayCustomEvent(MachineInstr &MI,
1095                                        MachineBasicBlock *MBB) const {
1096  assert(MI.getOpcode() == TargetOpcode::PATCHABLE_EVENT_CALL &&
1097         "Called emitXRayCustomEvent on the wrong MI!");
1098  auto &MF = *MI.getMF();
1099  auto MIB = BuildMI(MF, MI.getDebugLoc(), MI.getDesc());
1100  for (unsigned OpIdx = 0; OpIdx != MI.getNumOperands(); ++OpIdx)
1101    MIB.add(MI.getOperand(OpIdx));
1102
1103  MBB->insert(MachineBasicBlock::iterator(MI), MIB);
1104  MI.eraseFromParent();
1105  return MBB;
1106}
1107
1108MachineBasicBlock *
1109TargetLoweringBase::emitXRayTypedEvent(MachineInstr &MI,
1110                                       MachineBasicBlock *MBB) const {
1111  assert(MI.getOpcode() == TargetOpcode::PATCHABLE_TYPED_EVENT_CALL &&
1112         "Called emitXRayTypedEvent on the wrong MI!");
1113  auto &MF = *MI.getMF();
1114  auto MIB = BuildMI(MF, MI.getDebugLoc(), MI.getDesc());
1115  for (unsigned OpIdx = 0; OpIdx != MI.getNumOperands(); ++OpIdx)
1116    MIB.add(MI.getOperand(OpIdx));
1117
1118  MBB->insert(MachineBasicBlock::iterator(MI), MIB);
1119  MI.eraseFromParent();
1120  return MBB;
1121}
1122
1123/// findRepresentativeClass - Return the largest legal super-reg register class
1124/// of the register class for the specified type and its associated "cost".
1125// This function is in TargetLowering because it uses RegClassForVT which would
1126// need to be moved to TargetRegisterInfo and would necessitate moving
1127// isTypeLegal over as well - a massive change that would just require
1128// TargetLowering having a TargetRegisterInfo class member that it would use.
1129std::pair<const TargetRegisterClass *, uint8_t>
1130TargetLoweringBase::findRepresentativeClass(const TargetRegisterInfo *TRI,
1131                                            MVT VT) const {
1132  const TargetRegisterClass *RC = RegClassForVT[VT.SimpleTy];
1133  if (!RC)
1134    return std::make_pair(RC, 0);
1135
1136  // Compute the set of all super-register classes.
1137  BitVector SuperRegRC(TRI->getNumRegClasses());
1138  for (SuperRegClassIterator RCI(RC, TRI); RCI.isValid(); ++RCI)
1139    SuperRegRC.setBitsInMask(RCI.getMask());
1140
1141  // Find the first legal register class with the largest spill size.
1142  const TargetRegisterClass *BestRC = RC;
1143  for (unsigned i : SuperRegRC.set_bits()) {
1144    const TargetRegisterClass *SuperRC = TRI->getRegClass(i);
1145    // We want the largest possible spill size.
1146    if (TRI->getSpillSize(*SuperRC) <= TRI->getSpillSize(*BestRC))
1147      continue;
1148    if (!isLegalRC(*TRI, *SuperRC))
1149      continue;
1150    BestRC = SuperRC;
1151  }
1152  return std::make_pair(BestRC, 1);
1153}
1154
1155/// computeRegisterProperties - Once all of the register classes are added,
1156/// this allows us to compute derived properties we expose.
1157void TargetLoweringBase::computeRegisterProperties(
1158    const TargetRegisterInfo *TRI) {
1159  static_assert(MVT::LAST_VALUETYPE <= MVT::MAX_ALLOWED_VALUETYPE,
1160                "Too many value types for ValueTypeActions to hold!");
1161
1162  // Everything defaults to needing one register.
1163  for (unsigned i = 0; i != MVT::LAST_VALUETYPE; ++i) {
1164    NumRegistersForVT[i] = 1;
1165    RegisterTypeForVT[i] = TransformToType[i] = (MVT::SimpleValueType)i;
1166  }
1167  // ...except isVoid, which doesn't need any registers.
1168  NumRegistersForVT[MVT::isVoid] = 0;
1169
1170  // Find the largest integer register class.
1171  unsigned LargestIntReg = MVT::LAST_INTEGER_VALUETYPE;
1172  for (; RegClassForVT[LargestIntReg] == nullptr; --LargestIntReg)
1173    assert(LargestIntReg != MVT::i1 && "No integer registers defined!");
1174
1175  // Every integer value type larger than this largest register takes twice as
1176  // many registers to represent as the previous ValueType.
1177  for (unsigned ExpandedReg = LargestIntReg + 1;
1178       ExpandedReg <= MVT::LAST_INTEGER_VALUETYPE; ++ExpandedReg) {
1179    NumRegistersForVT[ExpandedReg] = 2*NumRegistersForVT[ExpandedReg-1];
1180    RegisterTypeForVT[ExpandedReg] = (MVT::SimpleValueType)LargestIntReg;
1181    TransformToType[ExpandedReg] = (MVT::SimpleValueType)(ExpandedReg - 1);
1182    ValueTypeActions.setTypeAction((MVT::SimpleValueType)ExpandedReg,
1183                                   TypeExpandInteger);
1184  }
1185
1186  // Inspect all of the ValueType's smaller than the largest integer
1187  // register to see which ones need promotion.
1188  unsigned LegalIntReg = LargestIntReg;
1189  for (unsigned IntReg = LargestIntReg - 1;
1190       IntReg >= (unsigned)MVT::i1; --IntReg) {
1191    MVT IVT = (MVT::SimpleValueType)IntReg;
1192    if (isTypeLegal(IVT)) {
1193      LegalIntReg = IntReg;
1194    } else {
1195      RegisterTypeForVT[IntReg] = TransformToType[IntReg] =
1196        (MVT::SimpleValueType)LegalIntReg;
1197      ValueTypeActions.setTypeAction(IVT, TypePromoteInteger);
1198    }
1199  }
1200
1201  // ppcf128 type is really two f64's.
1202  if (!isTypeLegal(MVT::ppcf128)) {
1203    if (isTypeLegal(MVT::f64)) {
1204      NumRegistersForVT[MVT::ppcf128] = 2*NumRegistersForVT[MVT::f64];
1205      RegisterTypeForVT[MVT::ppcf128] = MVT::f64;
1206      TransformToType[MVT::ppcf128] = MVT::f64;
1207      ValueTypeActions.setTypeAction(MVT::ppcf128, TypeExpandFloat);
1208    } else {
1209      NumRegistersForVT[MVT::ppcf128] = NumRegistersForVT[MVT::i128];
1210      RegisterTypeForVT[MVT::ppcf128] = RegisterTypeForVT[MVT::i128];
1211      TransformToType[MVT::ppcf128] = MVT::i128;
1212      ValueTypeActions.setTypeAction(MVT::ppcf128, TypeSoftenFloat);
1213    }
1214  }
1215
1216  // Decide how to handle f128. If the target does not have native f128 support,
1217  // expand it to i128 and we will be generating soft float library calls.
1218  if (!isTypeLegal(MVT::f128)) {
1219    NumRegistersForVT[MVT::f128] = NumRegistersForVT[MVT::i128];
1220    RegisterTypeForVT[MVT::f128] = RegisterTypeForVT[MVT::i128];
1221    TransformToType[MVT::f128] = MVT::i128;
1222    ValueTypeActions.setTypeAction(MVT::f128, TypeSoftenFloat);
1223  }
1224
1225  // Decide how to handle f64. If the target does not have native f64 support,
1226  // expand it to i64 and we will be generating soft float library calls.
1227  if (!isTypeLegal(MVT::f64)) {
1228    NumRegistersForVT[MVT::f64] = NumRegistersForVT[MVT::i64];
1229    RegisterTypeForVT[MVT::f64] = RegisterTypeForVT[MVT::i64];
1230    TransformToType[MVT::f64] = MVT::i64;
1231    ValueTypeActions.setTypeAction(MVT::f64, TypeSoftenFloat);
1232  }
1233
1234  // Decide how to handle f32. If the target does not have native f32 support,
1235  // expand it to i32 and we will be generating soft float library calls.
1236  if (!isTypeLegal(MVT::f32)) {
1237    NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::i32];
1238    RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::i32];
1239    TransformToType[MVT::f32] = MVT::i32;
1240    ValueTypeActions.setTypeAction(MVT::f32, TypeSoftenFloat);
1241  }
1242
1243  // Decide how to handle f16. If the target does not have native f16 support,
1244  // promote it to f32, because there are no f16 library calls (except for
1245  // conversions).
1246  if (!isTypeLegal(MVT::f16)) {
1247    // Allow targets to control how we legalize half.
1248    if (softPromoteHalfType()) {
1249      NumRegistersForVT[MVT::f16] = NumRegistersForVT[MVT::i16];
1250      RegisterTypeForVT[MVT::f16] = RegisterTypeForVT[MVT::i16];
1251      TransformToType[MVT::f16] = MVT::f32;
1252      ValueTypeActions.setTypeAction(MVT::f16, TypeSoftPromoteHalf);
1253    } else {
1254      NumRegistersForVT[MVT::f16] = NumRegistersForVT[MVT::f32];
1255      RegisterTypeForVT[MVT::f16] = RegisterTypeForVT[MVT::f32];
1256      TransformToType[MVT::f16] = MVT::f32;
1257      ValueTypeActions.setTypeAction(MVT::f16, TypePromoteFloat);
1258    }
1259  }
1260
1261  // Loop over all of the vector value types to see which need transformations.
1262  for (unsigned i = MVT::FIRST_VECTOR_VALUETYPE;
1263       i <= (unsigned)MVT::LAST_VECTOR_VALUETYPE; ++i) {
1264    MVT VT = (MVT::SimpleValueType) i;
1265    if (isTypeLegal(VT))
1266      continue;
1267
1268    MVT EltVT = VT.getVectorElementType();
1269    ElementCount EC = VT.getVectorElementCount();
1270    bool IsLegalWiderType = false;
1271    bool IsScalable = VT.isScalableVector();
1272    LegalizeTypeAction PreferredAction = getPreferredVectorAction(VT);
1273    switch (PreferredAction) {
1274    case TypePromoteInteger: {
1275      MVT::SimpleValueType EndVT = IsScalable ?
1276                                   MVT::LAST_INTEGER_SCALABLE_VECTOR_VALUETYPE :
1277                                   MVT::LAST_INTEGER_FIXEDLEN_VECTOR_VALUETYPE;
1278      // Try to promote the elements of integer vectors. If no legal
1279      // promotion was found, fall through to the widen-vector method.
1280      for (unsigned nVT = i + 1;
1281           (MVT::SimpleValueType)nVT <= EndVT; ++nVT) {
1282        MVT SVT = (MVT::SimpleValueType) nVT;
1283        // Promote vectors of integers to vectors with the same number
1284        // of elements, with a wider element type.
1285        if (SVT.getScalarSizeInBits() > EltVT.getSizeInBits() &&
1286            SVT.getVectorElementCount() == EC && isTypeLegal(SVT)) {
1287          TransformToType[i] = SVT;
1288          RegisterTypeForVT[i] = SVT;
1289          NumRegistersForVT[i] = 1;
1290          ValueTypeActions.setTypeAction(VT, TypePromoteInteger);
1291          IsLegalWiderType = true;
1292          break;
1293        }
1294      }
1295      if (IsLegalWiderType)
1296        break;
1297      LLVM_FALLTHROUGH;
1298    }
1299
1300    case TypeWidenVector:
1301      if (isPowerOf2_32(EC.Min)) {
1302        // Try to widen the vector.
1303        for (unsigned nVT = i + 1; nVT <= MVT::LAST_VECTOR_VALUETYPE; ++nVT) {
1304          MVT SVT = (MVT::SimpleValueType) nVT;
1305          if (SVT.getVectorElementType() == EltVT &&
1306              SVT.isScalableVector() == IsScalable &&
1307              SVT.getVectorElementCount().Min > EC.Min && isTypeLegal(SVT)) {
1308            TransformToType[i] = SVT;
1309            RegisterTypeForVT[i] = SVT;
1310            NumRegistersForVT[i] = 1;
1311            ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1312            IsLegalWiderType = true;
1313            break;
1314          }
1315        }
1316        if (IsLegalWiderType)
1317          break;
1318      } else {
1319        // Only widen to the next power of 2 to keep consistency with EVT.
1320        MVT NVT = VT.getPow2VectorType();
1321        if (isTypeLegal(NVT)) {
1322          TransformToType[i] = NVT;
1323          ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1324          RegisterTypeForVT[i] = NVT;
1325          NumRegistersForVT[i] = 1;
1326          break;
1327        }
1328      }
1329      LLVM_FALLTHROUGH;
1330
1331    case TypeSplitVector:
1332    case TypeScalarizeVector: {
1333      MVT IntermediateVT;
1334      MVT RegisterVT;
1335      unsigned NumIntermediates;
1336      unsigned NumRegisters = getVectorTypeBreakdownMVT(VT, IntermediateVT,
1337          NumIntermediates, RegisterVT, this);
1338      NumRegistersForVT[i] = NumRegisters;
1339      assert(NumRegistersForVT[i] == NumRegisters &&
1340             "NumRegistersForVT size cannot represent NumRegisters!");
1341      RegisterTypeForVT[i] = RegisterVT;
1342
1343      MVT NVT = VT.getPow2VectorType();
1344      if (NVT == VT) {
1345        // Type is already a power of 2.  The default action is to split.
1346        TransformToType[i] = MVT::Other;
1347        if (PreferredAction == TypeScalarizeVector)
1348          ValueTypeActions.setTypeAction(VT, TypeScalarizeVector);
1349        else if (PreferredAction == TypeSplitVector)
1350          ValueTypeActions.setTypeAction(VT, TypeSplitVector);
1351        else if (EC.Min > 1)
1352          ValueTypeActions.setTypeAction(VT, TypeSplitVector);
1353        else
1354          ValueTypeActions.setTypeAction(VT, EC.Scalable
1355                                                 ? TypeScalarizeScalableVector
1356                                                 : TypeScalarizeVector);
1357      } else {
1358        TransformToType[i] = NVT;
1359        ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1360      }
1361      break;
1362    }
1363    default:
1364      llvm_unreachable("Unknown vector legalization action!");
1365    }
1366  }
1367
1368  // Determine the 'representative' register class for each value type.
1369  // An representative register class is the largest (meaning one which is
1370  // not a sub-register class / subreg register class) legal register class for
1371  // a group of value types. For example, on i386, i8, i16, and i32
1372  // representative would be GR32; while on x86_64 it's GR64.
1373  for (unsigned i = 0; i != MVT::LAST_VALUETYPE; ++i) {
1374    const TargetRegisterClass* RRC;
1375    uint8_t Cost;
1376    std::tie(RRC, Cost) = findRepresentativeClass(TRI, (MVT::SimpleValueType)i);
1377    RepRegClassForVT[i] = RRC;
1378    RepRegClassCostForVT[i] = Cost;
1379  }
1380}
1381
1382EVT TargetLoweringBase::getSetCCResultType(const DataLayout &DL, LLVMContext &,
1383                                           EVT VT) const {
1384  assert(!VT.isVector() && "No default SetCC type for vectors!");
1385  return getPointerTy(DL).SimpleTy;
1386}
1387
1388MVT::SimpleValueType TargetLoweringBase::getCmpLibcallReturnType() const {
1389  return MVT::i32; // return the default value
1390}
1391
1392/// getVectorTypeBreakdown - Vector types are broken down into some number of
1393/// legal first class types.  For example, MVT::v8f32 maps to 2 MVT::v4f32
1394/// with Altivec or SSE1, or 8 promoted MVT::f64 values with the X86 FP stack.
1395/// Similarly, MVT::v2i64 turns into 4 MVT::i32 values with both PPC and X86.
1396///
1397/// This method returns the number of registers needed, and the VT for each
1398/// register.  It also returns the VT and quantity of the intermediate values
1399/// before they are promoted/expanded.
1400unsigned TargetLoweringBase::getVectorTypeBreakdown(LLVMContext &Context, EVT VT,
1401                                                EVT &IntermediateVT,
1402                                                unsigned &NumIntermediates,
1403                                                MVT &RegisterVT) const {
1404  ElementCount EltCnt = VT.getVectorElementCount();
1405
1406  // If there is a wider vector type with the same element type as this one,
1407  // or a promoted vector type that has the same number of elements which
1408  // are wider, then we should convert to that legal vector type.
1409  // This handles things like <2 x float> -> <4 x float> and
1410  // <4 x i1> -> <4 x i32>.
1411  LegalizeTypeAction TA = getTypeAction(Context, VT);
1412  if (EltCnt.Min != 1 && (TA == TypeWidenVector || TA == TypePromoteInteger)) {
1413    EVT RegisterEVT = getTypeToTransformTo(Context, VT);
1414    if (isTypeLegal(RegisterEVT)) {
1415      IntermediateVT = RegisterEVT;
1416      RegisterVT = RegisterEVT.getSimpleVT();
1417      NumIntermediates = 1;
1418      return 1;
1419    }
1420  }
1421
1422  // Figure out the right, legal destination reg to copy into.
1423  EVT EltTy = VT.getVectorElementType();
1424
1425  unsigned NumVectorRegs = 1;
1426
1427  // Scalable vectors cannot be scalarized, so handle the legalisation of the
1428  // types like done elsewhere in SelectionDAG.
1429  if (VT.isScalableVector() && !isPowerOf2_32(EltCnt.Min)) {
1430    LegalizeKind LK;
1431    EVT PartVT = VT;
1432    do {
1433      // Iterate until we've found a legal (part) type to hold VT.
1434      LK = getTypeConversion(Context, PartVT);
1435      PartVT = LK.second;
1436    } while (LK.first != TypeLegal);
1437
1438    NumIntermediates =
1439        VT.getVectorElementCount().Min / PartVT.getVectorElementCount().Min;
1440
1441    // FIXME: This code needs to be extended to handle more complex vector
1442    // breakdowns, like nxv7i64 -> nxv8i64 -> 4 x nxv2i64. Currently the only
1443    // supported cases are vectors that are broken down into equal parts
1444    // such as nxv6i64 -> 3 x nxv2i64.
1445    assert(NumIntermediates * PartVT.getVectorElementCount().Min ==
1446               VT.getVectorElementCount().Min &&
1447           "Expected an integer multiple of PartVT");
1448    IntermediateVT = PartVT;
1449    RegisterVT = getRegisterType(Context, IntermediateVT);
1450    return NumIntermediates;
1451  }
1452
1453  // FIXME: We don't support non-power-of-2-sized vectors for now.  Ideally
1454  // we could break down into LHS/RHS like LegalizeDAG does.
1455  if (!isPowerOf2_32(EltCnt.Min)) {
1456    NumVectorRegs = EltCnt.Min;
1457    EltCnt.Min = 1;
1458  }
1459
1460  // Divide the input until we get to a supported size.  This will always
1461  // end with a scalar if the target doesn't support vectors.
1462  while (EltCnt.Min > 1 &&
1463         !isTypeLegal(EVT::getVectorVT(Context, EltTy, EltCnt))) {
1464    EltCnt.Min >>= 1;
1465    NumVectorRegs <<= 1;
1466  }
1467
1468  NumIntermediates = NumVectorRegs;
1469
1470  EVT NewVT = EVT::getVectorVT(Context, EltTy, EltCnt);
1471  if (!isTypeLegal(NewVT))
1472    NewVT = EltTy;
1473  IntermediateVT = NewVT;
1474
1475  MVT DestVT = getRegisterType(Context, NewVT);
1476  RegisterVT = DestVT;
1477
1478  if (EVT(DestVT).bitsLT(NewVT)) {  // Value is expanded, e.g. i64 -> i16.
1479    TypeSize NewVTSize = NewVT.getSizeInBits();
1480    // Convert sizes such as i33 to i64.
1481    if (!isPowerOf2_32(NewVTSize.getKnownMinSize()))
1482      NewVTSize = NewVTSize.NextPowerOf2();
1483    return NumVectorRegs*(NewVTSize/DestVT.getSizeInBits());
1484  }
1485
1486  // Otherwise, promotion or legal types use the same number of registers as
1487  // the vector decimated to the appropriate level.
1488  return NumVectorRegs;
1489}
1490
1491bool TargetLoweringBase::isSuitableForJumpTable(const SwitchInst *SI,
1492                                                uint64_t NumCases,
1493                                                uint64_t Range,
1494                                                ProfileSummaryInfo *PSI,
1495                                                BlockFrequencyInfo *BFI) const {
1496  // FIXME: This function check the maximum table size and density, but the
1497  // minimum size is not checked. It would be nice if the minimum size is
1498  // also combined within this function. Currently, the minimum size check is
1499  // performed in findJumpTable() in SelectionDAGBuiler and
1500  // getEstimatedNumberOfCaseClusters() in BasicTTIImpl.
1501  const bool OptForSize =
1502      SI->getParent()->getParent()->hasOptSize() ||
1503      llvm::shouldOptimizeForSize(SI->getParent(), PSI, BFI);
1504  const unsigned MinDensity = getMinimumJumpTableDensity(OptForSize);
1505  const unsigned MaxJumpTableSize = getMaximumJumpTableSize();
1506
1507  // Check whether the number of cases is small enough and
1508  // the range is dense enough for a jump table.
1509  return (OptForSize || Range <= MaxJumpTableSize) &&
1510         (NumCases * 100 >= Range * MinDensity);
1511}
1512
1513/// Get the EVTs and ArgFlags collections that represent the legalized return
1514/// type of the given function.  This does not require a DAG or a return value,
1515/// and is suitable for use before any DAGs for the function are constructed.
1516/// TODO: Move this out of TargetLowering.cpp.
1517void llvm::GetReturnInfo(CallingConv::ID CC, Type *ReturnType,
1518                         AttributeList attr,
1519                         SmallVectorImpl<ISD::OutputArg> &Outs,
1520                         const TargetLowering &TLI, const DataLayout &DL) {
1521  SmallVector<EVT, 4> ValueVTs;
1522  ComputeValueVTs(TLI, DL, ReturnType, ValueVTs);
1523  unsigned NumValues = ValueVTs.size();
1524  if (NumValues == 0) return;
1525
1526  for (unsigned j = 0, f = NumValues; j != f; ++j) {
1527    EVT VT = ValueVTs[j];
1528    ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
1529
1530    if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::SExt))
1531      ExtendKind = ISD::SIGN_EXTEND;
1532    else if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::ZExt))
1533      ExtendKind = ISD::ZERO_EXTEND;
1534
1535    // FIXME: C calling convention requires the return type to be promoted to
1536    // at least 32-bit. But this is not necessary for non-C calling
1537    // conventions. The frontend should mark functions whose return values
1538    // require promoting with signext or zeroext attributes.
1539    if (ExtendKind != ISD::ANY_EXTEND && VT.isInteger()) {
1540      MVT MinVT = TLI.getRegisterType(ReturnType->getContext(), MVT::i32);
1541      if (VT.bitsLT(MinVT))
1542        VT = MinVT;
1543    }
1544
1545    unsigned NumParts =
1546        TLI.getNumRegistersForCallingConv(ReturnType->getContext(), CC, VT);
1547    MVT PartVT =
1548        TLI.getRegisterTypeForCallingConv(ReturnType->getContext(), CC, VT);
1549
1550    // 'inreg' on function refers to return value
1551    ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy();
1552    if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::InReg))
1553      Flags.setInReg();
1554
1555    // Propagate extension type if any
1556    if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::SExt))
1557      Flags.setSExt();
1558    else if (attr.hasAttribute(AttributeList::ReturnIndex, Attribute::ZExt))
1559      Flags.setZExt();
1560
1561    for (unsigned i = 0; i < NumParts; ++i)
1562      Outs.push_back(ISD::OutputArg(Flags, PartVT, VT, /*isfixed=*/true, 0, 0));
1563  }
1564}
1565
1566/// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
1567/// function arguments in the caller parameter area.  This is the actual
1568/// alignment, not its logarithm.
1569unsigned TargetLoweringBase::getByValTypeAlignment(Type *Ty,
1570                                                   const DataLayout &DL) const {
1571  return DL.getABITypeAlign(Ty).value();
1572}
1573
1574bool TargetLoweringBase::allowsMemoryAccessForAlignment(
1575    LLVMContext &Context, const DataLayout &DL, EVT VT, unsigned AddrSpace,
1576    Align Alignment, MachineMemOperand::Flags Flags, bool *Fast) const {
1577  // Check if the specified alignment is sufficient based on the data layout.
1578  // TODO: While using the data layout works in practice, a better solution
1579  // would be to implement this check directly (make this a virtual function).
1580  // For example, the ABI alignment may change based on software platform while
1581  // this function should only be affected by hardware implementation.
1582  Type *Ty = VT.getTypeForEVT(Context);
1583  if (Alignment >= DL.getABITypeAlign(Ty)) {
1584    // Assume that an access that meets the ABI-specified alignment is fast.
1585    if (Fast != nullptr)
1586      *Fast = true;
1587    return true;
1588  }
1589
1590  // This is a misaligned access.
1591  return allowsMisalignedMemoryAccesses(VT, AddrSpace, Alignment.value(), Flags,
1592                                        Fast);
1593}
1594
1595bool TargetLoweringBase::allowsMemoryAccessForAlignment(
1596    LLVMContext &Context, const DataLayout &DL, EVT VT,
1597    const MachineMemOperand &MMO, bool *Fast) const {
1598  return allowsMemoryAccessForAlignment(Context, DL, VT, MMO.getAddrSpace(),
1599                                        MMO.getAlign(), MMO.getFlags(), Fast);
1600}
1601
1602bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1603                                            const DataLayout &DL, EVT VT,
1604                                            unsigned AddrSpace, Align Alignment,
1605                                            MachineMemOperand::Flags Flags,
1606                                            bool *Fast) const {
1607  return allowsMemoryAccessForAlignment(Context, DL, VT, AddrSpace, Alignment,
1608                                        Flags, Fast);
1609}
1610
1611bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1612                                            const DataLayout &DL, EVT VT,
1613                                            const MachineMemOperand &MMO,
1614                                            bool *Fast) const {
1615  return allowsMemoryAccess(Context, DL, VT, MMO.getAddrSpace(), MMO.getAlign(),
1616                            MMO.getFlags(), Fast);
1617}
1618
1619BranchProbability TargetLoweringBase::getPredictableBranchThreshold() const {
1620  return BranchProbability(MinPercentageForPredictableBranch, 100);
1621}
1622
1623//===----------------------------------------------------------------------===//
1624//  TargetTransformInfo Helpers
1625//===----------------------------------------------------------------------===//
1626
1627int TargetLoweringBase::InstructionOpcodeToISD(unsigned Opcode) const {
1628  enum InstructionOpcodes {
1629#define HANDLE_INST(NUM, OPCODE, CLASS) OPCODE = NUM,
1630#define LAST_OTHER_INST(NUM) InstructionOpcodesCount = NUM
1631#include "llvm/IR/Instruction.def"
1632  };
1633  switch (static_cast<InstructionOpcodes>(Opcode)) {
1634  case Ret:            return 0;
1635  case Br:             return 0;
1636  case Switch:         return 0;
1637  case IndirectBr:     return 0;
1638  case Invoke:         return 0;
1639  case CallBr:         return 0;
1640  case Resume:         return 0;
1641  case Unreachable:    return 0;
1642  case CleanupRet:     return 0;
1643  case CatchRet:       return 0;
1644  case CatchPad:       return 0;
1645  case CatchSwitch:    return 0;
1646  case CleanupPad:     return 0;
1647  case FNeg:           return ISD::FNEG;
1648  case Add:            return ISD::ADD;
1649  case FAdd:           return ISD::FADD;
1650  case Sub:            return ISD::SUB;
1651  case FSub:           return ISD::FSUB;
1652  case Mul:            return ISD::MUL;
1653  case FMul:           return ISD::FMUL;
1654  case UDiv:           return ISD::UDIV;
1655  case SDiv:           return ISD::SDIV;
1656  case FDiv:           return ISD::FDIV;
1657  case URem:           return ISD::UREM;
1658  case SRem:           return ISD::SREM;
1659  case FRem:           return ISD::FREM;
1660  case Shl:            return ISD::SHL;
1661  case LShr:           return ISD::SRL;
1662  case AShr:           return ISD::SRA;
1663  case And:            return ISD::AND;
1664  case Or:             return ISD::OR;
1665  case Xor:            return ISD::XOR;
1666  case Alloca:         return 0;
1667  case Load:           return ISD::LOAD;
1668  case Store:          return ISD::STORE;
1669  case GetElementPtr:  return 0;
1670  case Fence:          return 0;
1671  case AtomicCmpXchg:  return 0;
1672  case AtomicRMW:      return 0;
1673  case Trunc:          return ISD::TRUNCATE;
1674  case ZExt:           return ISD::ZERO_EXTEND;
1675  case SExt:           return ISD::SIGN_EXTEND;
1676  case FPToUI:         return ISD::FP_TO_UINT;
1677  case FPToSI:         return ISD::FP_TO_SINT;
1678  case UIToFP:         return ISD::UINT_TO_FP;
1679  case SIToFP:         return ISD::SINT_TO_FP;
1680  case FPTrunc:        return ISD::FP_ROUND;
1681  case FPExt:          return ISD::FP_EXTEND;
1682  case PtrToInt:       return ISD::BITCAST;
1683  case IntToPtr:       return ISD::BITCAST;
1684  case BitCast:        return ISD::BITCAST;
1685  case AddrSpaceCast:  return ISD::ADDRSPACECAST;
1686  case ICmp:           return ISD::SETCC;
1687  case FCmp:           return ISD::SETCC;
1688  case PHI:            return 0;
1689  case Call:           return 0;
1690  case Select:         return ISD::SELECT;
1691  case UserOp1:        return 0;
1692  case UserOp2:        return 0;
1693  case VAArg:          return 0;
1694  case ExtractElement: return ISD::EXTRACT_VECTOR_ELT;
1695  case InsertElement:  return ISD::INSERT_VECTOR_ELT;
1696  case ShuffleVector:  return ISD::VECTOR_SHUFFLE;
1697  case ExtractValue:   return ISD::MERGE_VALUES;
1698  case InsertValue:    return ISD::MERGE_VALUES;
1699  case LandingPad:     return 0;
1700  case Freeze:         return ISD::FREEZE;
1701  }
1702
1703  llvm_unreachable("Unknown instruction type encountered!");
1704}
1705
1706std::pair<int, MVT>
1707TargetLoweringBase::getTypeLegalizationCost(const DataLayout &DL,
1708                                            Type *Ty) const {
1709  LLVMContext &C = Ty->getContext();
1710  EVT MTy = getValueType(DL, Ty);
1711
1712  int Cost = 1;
1713  // We keep legalizing the type until we find a legal kind. We assume that
1714  // the only operation that costs anything is the split. After splitting
1715  // we need to handle two types.
1716  while (true) {
1717    LegalizeKind LK = getTypeConversion(C, MTy);
1718
1719    if (LK.first == TypeLegal)
1720      return std::make_pair(Cost, MTy.getSimpleVT());
1721
1722    if (LK.first == TypeSplitVector || LK.first == TypeExpandInteger)
1723      Cost *= 2;
1724
1725    // Do not loop with f128 type.
1726    if (MTy == LK.second)
1727      return std::make_pair(Cost, MTy.getSimpleVT());
1728
1729    // Keep legalizing the type.
1730    MTy = LK.second;
1731  }
1732}
1733
1734Value *TargetLoweringBase::getDefaultSafeStackPointerLocation(IRBuilder<> &IRB,
1735                                                              bool UseTLS) const {
1736  // compiler-rt provides a variable with a magic name.  Targets that do not
1737  // link with compiler-rt may also provide such a variable.
1738  Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1739  const char *UnsafeStackPtrVar = "__safestack_unsafe_stack_ptr";
1740  auto UnsafeStackPtr =
1741      dyn_cast_or_null<GlobalVariable>(M->getNamedValue(UnsafeStackPtrVar));
1742
1743  Type *StackPtrTy = Type::getInt8PtrTy(M->getContext());
1744
1745  if (!UnsafeStackPtr) {
1746    auto TLSModel = UseTLS ?
1747        GlobalValue::InitialExecTLSModel :
1748        GlobalValue::NotThreadLocal;
1749    // The global variable is not defined yet, define it ourselves.
1750    // We use the initial-exec TLS model because we do not support the
1751    // variable living anywhere other than in the main executable.
1752    UnsafeStackPtr = new GlobalVariable(
1753        *M, StackPtrTy, false, GlobalValue::ExternalLinkage, nullptr,
1754        UnsafeStackPtrVar, nullptr, TLSModel);
1755  } else {
1756    // The variable exists, check its type and attributes.
1757    if (UnsafeStackPtr->getValueType() != StackPtrTy)
1758      report_fatal_error(Twine(UnsafeStackPtrVar) + " must have void* type");
1759    if (UseTLS != UnsafeStackPtr->isThreadLocal())
1760      report_fatal_error(Twine(UnsafeStackPtrVar) + " must " +
1761                         (UseTLS ? "" : "not ") + "be thread-local");
1762  }
1763  return UnsafeStackPtr;
1764}
1765
1766Value *TargetLoweringBase::getSafeStackPointerLocation(IRBuilder<> &IRB) const {
1767  if (!TM.getTargetTriple().isAndroid())
1768    return getDefaultSafeStackPointerLocation(IRB, true);
1769
1770  // Android provides a libc function to retrieve the address of the current
1771  // thread's unsafe stack pointer.
1772  Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1773  Type *StackPtrTy = Type::getInt8PtrTy(M->getContext());
1774  FunctionCallee Fn = M->getOrInsertFunction("__safestack_pointer_address",
1775                                             StackPtrTy->getPointerTo(0));
1776  return IRB.CreateCall(Fn);
1777}
1778
1779//===----------------------------------------------------------------------===//
1780//  Loop Strength Reduction hooks
1781//===----------------------------------------------------------------------===//
1782
1783/// isLegalAddressingMode - Return true if the addressing mode represented
1784/// by AM is legal for this target, for a load/store of the specified type.
1785bool TargetLoweringBase::isLegalAddressingMode(const DataLayout &DL,
1786                                               const AddrMode &AM, Type *Ty,
1787                                               unsigned AS, Instruction *I) const {
1788  // The default implementation of this implements a conservative RISCy, r+r and
1789  // r+i addr mode.
1790
1791  // Allows a sign-extended 16-bit immediate field.
1792  if (AM.BaseOffs <= -(1LL << 16) || AM.BaseOffs >= (1LL << 16)-1)
1793    return false;
1794
1795  // No global is ever allowed as a base.
1796  if (AM.BaseGV)
1797    return false;
1798
1799  // Only support r+r,
1800  switch (AM.Scale) {
1801  case 0:  // "r+i" or just "i", depending on HasBaseReg.
1802    break;
1803  case 1:
1804    if (AM.HasBaseReg && AM.BaseOffs)  // "r+r+i" is not allowed.
1805      return false;
1806    // Otherwise we have r+r or r+i.
1807    break;
1808  case 2:
1809    if (AM.HasBaseReg || AM.BaseOffs)  // 2*r+r  or  2*r+i is not allowed.
1810      return false;
1811    // Allow 2*r as r+r.
1812    break;
1813  default: // Don't allow n * r
1814    return false;
1815  }
1816
1817  return true;
1818}
1819
1820//===----------------------------------------------------------------------===//
1821//  Stack Protector
1822//===----------------------------------------------------------------------===//
1823
1824// For OpenBSD return its special guard variable. Otherwise return nullptr,
1825// so that SelectionDAG handle SSP.
1826Value *TargetLoweringBase::getIRStackGuard(IRBuilder<> &IRB) const {
1827  if (getTargetMachine().getTargetTriple().isOSOpenBSD()) {
1828    Module &M = *IRB.GetInsertBlock()->getParent()->getParent();
1829    PointerType *PtrTy = Type::getInt8PtrTy(M.getContext());
1830    Constant *C = M.getOrInsertGlobal("__guard_local", PtrTy);
1831    if (GlobalVariable *G = dyn_cast_or_null<GlobalVariable>(C))
1832      G->setVisibility(GlobalValue::HiddenVisibility);
1833    return C;
1834  }
1835  return nullptr;
1836}
1837
1838// Currently only support "standard" __stack_chk_guard.
1839// TODO: add LOAD_STACK_GUARD support.
1840void TargetLoweringBase::insertSSPDeclarations(Module &M) const {
1841  if (!M.getNamedValue("__stack_chk_guard"))
1842    new GlobalVariable(M, Type::getInt8PtrTy(M.getContext()), false,
1843                       GlobalVariable::ExternalLinkage,
1844                       nullptr, "__stack_chk_guard");
1845}
1846
1847// Currently only support "standard" __stack_chk_guard.
1848// TODO: add LOAD_STACK_GUARD support.
1849Value *TargetLoweringBase::getSDagStackGuard(const Module &M) const {
1850  return M.getNamedValue("__stack_chk_guard");
1851}
1852
1853Function *TargetLoweringBase::getSSPStackGuardCheck(const Module &M) const {
1854  return nullptr;
1855}
1856
1857unsigned TargetLoweringBase::getMinimumJumpTableEntries() const {
1858  return MinimumJumpTableEntries;
1859}
1860
1861void TargetLoweringBase::setMinimumJumpTableEntries(unsigned Val) {
1862  MinimumJumpTableEntries = Val;
1863}
1864
1865unsigned TargetLoweringBase::getMinimumJumpTableDensity(bool OptForSize) const {
1866  return OptForSize ? OptsizeJumpTableDensity : JumpTableDensity;
1867}
1868
1869unsigned TargetLoweringBase::getMaximumJumpTableSize() const {
1870  return MaximumJumpTableSize;
1871}
1872
1873void TargetLoweringBase::setMaximumJumpTableSize(unsigned Val) {
1874  MaximumJumpTableSize = Val;
1875}
1876
1877bool TargetLoweringBase::isJumpTableRelative() const {
1878  return getTargetMachine().isPositionIndependent();
1879}
1880
1881//===----------------------------------------------------------------------===//
1882//  Reciprocal Estimates
1883//===----------------------------------------------------------------------===//
1884
1885/// Get the reciprocal estimate attribute string for a function that will
1886/// override the target defaults.
1887static StringRef getRecipEstimateForFunc(MachineFunction &MF) {
1888  const Function &F = MF.getFunction();
1889  return F.getFnAttribute("reciprocal-estimates").getValueAsString();
1890}
1891
1892/// Construct a string for the given reciprocal operation of the given type.
1893/// This string should match the corresponding option to the front-end's
1894/// "-mrecip" flag assuming those strings have been passed through in an
1895/// attribute string. For example, "vec-divf" for a division of a vXf32.
1896static std::string getReciprocalOpName(bool IsSqrt, EVT VT) {
1897  std::string Name = VT.isVector() ? "vec-" : "";
1898
1899  Name += IsSqrt ? "sqrt" : "div";
1900
1901  // TODO: Handle "half" or other float types?
1902  if (VT.getScalarType() == MVT::f64) {
1903    Name += "d";
1904  } else {
1905    assert(VT.getScalarType() == MVT::f32 &&
1906           "Unexpected FP type for reciprocal estimate");
1907    Name += "f";
1908  }
1909
1910  return Name;
1911}
1912
1913/// Return the character position and value (a single numeric character) of a
1914/// customized refinement operation in the input string if it exists. Return
1915/// false if there is no customized refinement step count.
1916static bool parseRefinementStep(StringRef In, size_t &Position,
1917                                uint8_t &Value) {
1918  const char RefStepToken = ':';
1919  Position = In.find(RefStepToken);
1920  if (Position == StringRef::npos)
1921    return false;
1922
1923  StringRef RefStepString = In.substr(Position + 1);
1924  // Allow exactly one numeric character for the additional refinement
1925  // step parameter.
1926  if (RefStepString.size() == 1) {
1927    char RefStepChar = RefStepString[0];
1928    if (RefStepChar >= '0' && RefStepChar <= '9') {
1929      Value = RefStepChar - '0';
1930      return true;
1931    }
1932  }
1933  report_fatal_error("Invalid refinement step for -recip.");
1934}
1935
1936/// For the input attribute string, return one of the ReciprocalEstimate enum
1937/// status values (enabled, disabled, or not specified) for this operation on
1938/// the specified data type.
1939static int getOpEnabled(bool IsSqrt, EVT VT, StringRef Override) {
1940  if (Override.empty())
1941    return TargetLoweringBase::ReciprocalEstimate::Unspecified;
1942
1943  SmallVector<StringRef, 4> OverrideVector;
1944  Override.split(OverrideVector, ',');
1945  unsigned NumArgs = OverrideVector.size();
1946
1947  // Check if "all", "none", or "default" was specified.
1948  if (NumArgs == 1) {
1949    // Look for an optional setting of the number of refinement steps needed
1950    // for this type of reciprocal operation.
1951    size_t RefPos;
1952    uint8_t RefSteps;
1953    if (parseRefinementStep(Override, RefPos, RefSteps)) {
1954      // Split the string for further processing.
1955      Override = Override.substr(0, RefPos);
1956    }
1957
1958    // All reciprocal types are enabled.
1959    if (Override == "all")
1960      return TargetLoweringBase::ReciprocalEstimate::Enabled;
1961
1962    // All reciprocal types are disabled.
1963    if (Override == "none")
1964      return TargetLoweringBase::ReciprocalEstimate::Disabled;
1965
1966    // Target defaults for enablement are used.
1967    if (Override == "default")
1968      return TargetLoweringBase::ReciprocalEstimate::Unspecified;
1969  }
1970
1971  // The attribute string may omit the size suffix ('f'/'d').
1972  std::string VTName = getReciprocalOpName(IsSqrt, VT);
1973  std::string VTNameNoSize = VTName;
1974  VTNameNoSize.pop_back();
1975  static const char DisabledPrefix = '!';
1976
1977  for (StringRef RecipType : OverrideVector) {
1978    size_t RefPos;
1979    uint8_t RefSteps;
1980    if (parseRefinementStep(RecipType, RefPos, RefSteps))
1981      RecipType = RecipType.substr(0, RefPos);
1982
1983    // Ignore the disablement token for string matching.
1984    bool IsDisabled = RecipType[0] == DisabledPrefix;
1985    if (IsDisabled)
1986      RecipType = RecipType.substr(1);
1987
1988    if (RecipType.equals(VTName) || RecipType.equals(VTNameNoSize))
1989      return IsDisabled ? TargetLoweringBase::ReciprocalEstimate::Disabled
1990                        : TargetLoweringBase::ReciprocalEstimate::Enabled;
1991  }
1992
1993  return TargetLoweringBase::ReciprocalEstimate::Unspecified;
1994}
1995
1996/// For the input attribute string, return the customized refinement step count
1997/// for this operation on the specified data type. If the step count does not
1998/// exist, return the ReciprocalEstimate enum value for unspecified.
1999static int getOpRefinementSteps(bool IsSqrt, EVT VT, StringRef Override) {
2000  if (Override.empty())
2001    return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2002
2003  SmallVector<StringRef, 4> OverrideVector;
2004  Override.split(OverrideVector, ',');
2005  unsigned NumArgs = OverrideVector.size();
2006
2007  // Check if "all", "default", or "none" was specified.
2008  if (NumArgs == 1) {
2009    // Look for an optional setting of the number of refinement steps needed
2010    // for this type of reciprocal operation.
2011    size_t RefPos;
2012    uint8_t RefSteps;
2013    if (!parseRefinementStep(Override, RefPos, RefSteps))
2014      return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2015
2016    // Split the string for further processing.
2017    Override = Override.substr(0, RefPos);
2018    assert(Override != "none" &&
2019           "Disabled reciprocals, but specifed refinement steps?");
2020
2021    // If this is a general override, return the specified number of steps.
2022    if (Override == "all" || Override == "default")
2023      return RefSteps;
2024  }
2025
2026  // The attribute string may omit the size suffix ('f'/'d').
2027  std::string VTName = getReciprocalOpName(IsSqrt, VT);
2028  std::string VTNameNoSize = VTName;
2029  VTNameNoSize.pop_back();
2030
2031  for (StringRef RecipType : OverrideVector) {
2032    size_t RefPos;
2033    uint8_t RefSteps;
2034    if (!parseRefinementStep(RecipType, RefPos, RefSteps))
2035      continue;
2036
2037    RecipType = RecipType.substr(0, RefPos);
2038    if (RecipType.equals(VTName) || RecipType.equals(VTNameNoSize))
2039      return RefSteps;
2040  }
2041
2042  return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2043}
2044
2045int TargetLoweringBase::getRecipEstimateSqrtEnabled(EVT VT,
2046                                                    MachineFunction &MF) const {
2047  return getOpEnabled(true, VT, getRecipEstimateForFunc(MF));
2048}
2049
2050int TargetLoweringBase::getRecipEstimateDivEnabled(EVT VT,
2051                                                   MachineFunction &MF) const {
2052  return getOpEnabled(false, VT, getRecipEstimateForFunc(MF));
2053}
2054
2055int TargetLoweringBase::getSqrtRefinementSteps(EVT VT,
2056                                               MachineFunction &MF) const {
2057  return getOpRefinementSteps(true, VT, getRecipEstimateForFunc(MF));
2058}
2059
2060int TargetLoweringBase::getDivRefinementSteps(EVT VT,
2061                                              MachineFunction &MF) const {
2062  return getOpRefinementSteps(false, VT, getRecipEstimateForFunc(MF));
2063}
2064
2065void TargetLoweringBase::finalizeLowering(MachineFunction &MF) const {
2066  MF.getRegInfo().freezeReservedRegs(MF);
2067}
2068
2069MachineMemOperand::Flags
2070TargetLoweringBase::getLoadMemOperandFlags(const LoadInst &LI,
2071                                           const DataLayout &DL) const {
2072  MachineMemOperand::Flags Flags = MachineMemOperand::MOLoad;
2073  if (LI.isVolatile())
2074    Flags |= MachineMemOperand::MOVolatile;
2075
2076  if (LI.hasMetadata(LLVMContext::MD_nontemporal))
2077    Flags |= MachineMemOperand::MONonTemporal;
2078
2079  if (LI.hasMetadata(LLVMContext::MD_invariant_load))
2080    Flags |= MachineMemOperand::MOInvariant;
2081
2082  if (isDereferenceablePointer(LI.getPointerOperand(), LI.getType(), DL))
2083    Flags |= MachineMemOperand::MODereferenceable;
2084
2085  Flags |= getTargetMMOFlags(LI);
2086  return Flags;
2087}
2088
2089MachineMemOperand::Flags
2090TargetLoweringBase::getStoreMemOperandFlags(const StoreInst &SI,
2091                                            const DataLayout &DL) const {
2092  MachineMemOperand::Flags Flags = MachineMemOperand::MOStore;
2093
2094  if (SI.isVolatile())
2095    Flags |= MachineMemOperand::MOVolatile;
2096
2097  if (SI.hasMetadata(LLVMContext::MD_nontemporal))
2098    Flags |= MachineMemOperand::MONonTemporal;
2099
2100  // FIXME: Not preserving dereferenceable
2101  Flags |= getTargetMMOFlags(SI);
2102  return Flags;
2103}
2104
2105MachineMemOperand::Flags
2106TargetLoweringBase::getAtomicMemOperandFlags(const Instruction &AI,
2107                                             const DataLayout &DL) const {
2108  auto Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOStore;
2109
2110  if (const AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(&AI)) {
2111    if (RMW->isVolatile())
2112      Flags |= MachineMemOperand::MOVolatile;
2113  } else if (const AtomicCmpXchgInst *CmpX = dyn_cast<AtomicCmpXchgInst>(&AI)) {
2114    if (CmpX->isVolatile())
2115      Flags |= MachineMemOperand::MOVolatile;
2116  } else
2117    llvm_unreachable("not an atomic instruction");
2118
2119  // FIXME: Not preserving dereferenceable
2120  Flags |= getTargetMMOFlags(AI);
2121  return Flags;
2122}
2123
2124//===----------------------------------------------------------------------===//
2125//  GlobalISel Hooks
2126//===----------------------------------------------------------------------===//
2127
2128bool TargetLoweringBase::shouldLocalize(const MachineInstr &MI,
2129                                        const TargetTransformInfo *TTI) const {
2130  auto &MF = *MI.getMF();
2131  auto &MRI = MF.getRegInfo();
2132  // Assuming a spill and reload of a value has a cost of 1 instruction each,
2133  // this helper function computes the maximum number of uses we should consider
2134  // for remat. E.g. on arm64 global addresses take 2 insts to materialize. We
2135  // break even in terms of code size when the original MI has 2 users vs
2136  // choosing to potentially spill. Any more than 2 users we we have a net code
2137  // size increase. This doesn't take into account register pressure though.
2138  auto maxUses = [](unsigned RematCost) {
2139    // A cost of 1 means remats are basically free.
2140    if (RematCost == 1)
2141      return UINT_MAX;
2142    if (RematCost == 2)
2143      return 2U;
2144
2145    // Remat is too expensive, only sink if there's one user.
2146    if (RematCost > 2)
2147      return 1U;
2148    llvm_unreachable("Unexpected remat cost");
2149  };
2150
2151  // Helper to walk through uses and terminate if we've reached a limit. Saves
2152  // us spending time traversing uses if all we want to know is if it's >= min.
2153  auto isUsesAtMost = [&](unsigned Reg, unsigned MaxUses) {
2154    unsigned NumUses = 0;
2155    auto UI = MRI.use_instr_nodbg_begin(Reg), UE = MRI.use_instr_nodbg_end();
2156    for (; UI != UE && NumUses < MaxUses; ++UI) {
2157      NumUses++;
2158    }
2159    // If we haven't reached the end yet then there are more than MaxUses users.
2160    return UI == UE;
2161  };
2162
2163  switch (MI.getOpcode()) {
2164  default:
2165    return false;
2166  // Constants-like instructions should be close to their users.
2167  // We don't want long live-ranges for them.
2168  case TargetOpcode::G_CONSTANT:
2169  case TargetOpcode::G_FCONSTANT:
2170  case TargetOpcode::G_FRAME_INDEX:
2171  case TargetOpcode::G_INTTOPTR:
2172    return true;
2173  case TargetOpcode::G_GLOBAL_VALUE: {
2174    unsigned RematCost = TTI->getGISelRematGlobalCost();
2175    Register Reg = MI.getOperand(0).getReg();
2176    unsigned MaxUses = maxUses(RematCost);
2177    if (MaxUses == UINT_MAX)
2178      return true; // Remats are "free" so always localize.
2179    bool B = isUsesAtMost(Reg, MaxUses);
2180    return B;
2181  }
2182  }
2183}
2184