xref: /llvm-project/llvm/lib/CodeGen/TargetLoweringBase.cpp (revision 8300f30a9234ee46b2b941e8b07cb7d104c846cb)
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/Twine.h"
19 #include "llvm/Analysis/Loads.h"
20 #include "llvm/Analysis/TargetTransformInfo.h"
21 #include "llvm/CodeGen/Analysis.h"
22 #include "llvm/CodeGen/ISDOpcodes.h"
23 #include "llvm/CodeGen/MachineBasicBlock.h"
24 #include "llvm/CodeGen/MachineFrameInfo.h"
25 #include "llvm/CodeGen/MachineFunction.h"
26 #include "llvm/CodeGen/MachineInstr.h"
27 #include "llvm/CodeGen/MachineInstrBuilder.h"
28 #include "llvm/CodeGen/MachineMemOperand.h"
29 #include "llvm/CodeGen/MachineOperand.h"
30 #include "llvm/CodeGen/MachineRegisterInfo.h"
31 #include "llvm/CodeGen/RuntimeLibcalls.h"
32 #include "llvm/CodeGen/StackMaps.h"
33 #include "llvm/CodeGen/TargetLowering.h"
34 #include "llvm/CodeGen/TargetOpcodes.h"
35 #include "llvm/CodeGen/TargetRegisterInfo.h"
36 #include "llvm/CodeGen/ValueTypes.h"
37 #include "llvm/CodeGenTypes/MachineValueType.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/Casting.h"
49 #include "llvm/Support/CommandLine.h"
50 #include "llvm/Support/Compiler.h"
51 #include "llvm/Support/ErrorHandling.h"
52 #include "llvm/Support/MathExtras.h"
53 #include "llvm/Target/TargetMachine.h"
54 #include "llvm/Target/TargetOptions.h"
55 #include "llvm/TargetParser/Triple.h"
56 #include "llvm/Transforms/Utils/SizeOpts.h"
57 #include <algorithm>
58 #include <cassert>
59 #include <cstdint>
60 #include <cstring>
61 #include <iterator>
62 #include <string>
63 #include <tuple>
64 #include <utility>
65 
66 using namespace llvm;
67 
68 static cl::opt<bool> JumpIsExpensiveOverride(
69     "jump-is-expensive", cl::init(false),
70     cl::desc("Do not create extra branches to split comparison logic."),
71     cl::Hidden);
72 
73 static cl::opt<unsigned> MinimumJumpTableEntries
74   ("min-jump-table-entries", cl::init(4), cl::Hidden,
75    cl::desc("Set minimum number of entries to use a jump table."));
76 
77 static cl::opt<unsigned> MaximumJumpTableSize
78   ("max-jump-table-size", cl::init(UINT_MAX), cl::Hidden,
79    cl::desc("Set maximum size of jump tables."));
80 
81 /// Minimum jump table density for normal functions.
82 static cl::opt<unsigned>
83     JumpTableDensity("jump-table-density", cl::init(10), cl::Hidden,
84                      cl::desc("Minimum density for building a jump table in "
85                               "a normal function"));
86 
87 /// Minimum jump table density for -Os or -Oz functions.
88 static cl::opt<unsigned> OptsizeJumpTableDensity(
89     "optsize-jump-table-density", cl::init(40), cl::Hidden,
90     cl::desc("Minimum density for building a jump table in "
91              "an optsize function"));
92 
93 // FIXME: This option is only to test if the strict fp operation processed
94 // correctly by preventing mutating strict fp operation to normal fp operation
95 // during development. When the backend supports strict float operation, this
96 // option will be meaningless.
97 static cl::opt<bool> DisableStrictNodeMutation("disable-strictnode-mutation",
98        cl::desc("Don't mutate strict-float node to a legalize node"),
99        cl::init(false), cl::Hidden);
100 
101 static bool darwinHasSinCos(const Triple &TT) {
102   assert(TT.isOSDarwin() && "should be called with darwin triple");
103   // Don't bother with 32 bit x86.
104   if (TT.getArch() == Triple::x86)
105     return false;
106   // Macos < 10.9 has no sincos_stret.
107   if (TT.isMacOSX())
108     return !TT.isMacOSXVersionLT(10, 9) && TT.isArch64Bit();
109   // iOS < 7.0 has no sincos_stret.
110   if (TT.isiOS())
111     return !TT.isOSVersionLT(7, 0);
112   // Any other darwin such as WatchOS/TvOS is new enough.
113   return true;
114 }
115 
116 void TargetLoweringBase::InitLibcalls(const Triple &TT) {
117 #define HANDLE_LIBCALL(code, name) \
118   setLibcallName(RTLIB::code, name);
119 #include "llvm/IR/RuntimeLibcalls.def"
120 #undef HANDLE_LIBCALL
121   // Initialize calling conventions to their default.
122   for (int LC = 0; LC < RTLIB::UNKNOWN_LIBCALL; ++LC)
123     setLibcallCallingConv((RTLIB::Libcall)LC, CallingConv::C);
124 
125   // Use the f128 variants of math functions on x86_64
126   if (TT.getArch() == Triple::ArchType::x86_64 && TT.isGNUEnvironment()) {
127     setLibcallName(RTLIB::REM_F128, "fmodf128");
128     setLibcallName(RTLIB::FMA_F128, "fmaf128");
129     setLibcallName(RTLIB::SQRT_F128, "sqrtf128");
130     setLibcallName(RTLIB::CBRT_F128, "cbrtf128");
131     setLibcallName(RTLIB::LOG_F128, "logf128");
132     setLibcallName(RTLIB::LOG_FINITE_F128, "__logf128_finite");
133     setLibcallName(RTLIB::LOG2_F128, "log2f128");
134     setLibcallName(RTLIB::LOG2_FINITE_F128, "__log2f128_finite");
135     setLibcallName(RTLIB::LOG10_F128, "log10f128");
136     setLibcallName(RTLIB::LOG10_FINITE_F128, "__log10f128_finite");
137     setLibcallName(RTLIB::EXP_F128, "expf128");
138     setLibcallName(RTLIB::EXP_FINITE_F128, "__expf128_finite");
139     setLibcallName(RTLIB::EXP2_F128, "exp2f128");
140     setLibcallName(RTLIB::EXP2_FINITE_F128, "__exp2f128_finite");
141     setLibcallName(RTLIB::EXP10_F128, "exp10f128");
142     setLibcallName(RTLIB::SIN_F128, "sinf128");
143     setLibcallName(RTLIB::COS_F128, "cosf128");
144     setLibcallName(RTLIB::SINCOS_F128, "sincosf128");
145     setLibcallName(RTLIB::POW_F128, "powf128");
146     setLibcallName(RTLIB::POW_FINITE_F128, "__powf128_finite");
147     setLibcallName(RTLIB::CEIL_F128, "ceilf128");
148     setLibcallName(RTLIB::TRUNC_F128, "truncf128");
149     setLibcallName(RTLIB::RINT_F128, "rintf128");
150     setLibcallName(RTLIB::NEARBYINT_F128, "nearbyintf128");
151     setLibcallName(RTLIB::ROUND_F128, "roundf128");
152     setLibcallName(RTLIB::ROUNDEVEN_F128, "roundevenf128");
153     setLibcallName(RTLIB::FLOOR_F128, "floorf128");
154     setLibcallName(RTLIB::COPYSIGN_F128, "copysignf128");
155     setLibcallName(RTLIB::FMIN_F128, "fminf128");
156     setLibcallName(RTLIB::FMAX_F128, "fmaxf128");
157     setLibcallName(RTLIB::LROUND_F128, "lroundf128");
158     setLibcallName(RTLIB::LLROUND_F128, "llroundf128");
159     setLibcallName(RTLIB::LRINT_F128, "lrintf128");
160     setLibcallName(RTLIB::LLRINT_F128, "llrintf128");
161     setLibcallName(RTLIB::LDEXP_F128, "ldexpf128");
162     setLibcallName(RTLIB::FREXP_F128, "frexpf128");
163   }
164 
165   // For IEEE quad-precision libcall names, PPC uses "kf" instead of "tf".
166   if (TT.isPPC()) {
167     setLibcallName(RTLIB::ADD_F128, "__addkf3");
168     setLibcallName(RTLIB::SUB_F128, "__subkf3");
169     setLibcallName(RTLIB::MUL_F128, "__mulkf3");
170     setLibcallName(RTLIB::DIV_F128, "__divkf3");
171     setLibcallName(RTLIB::POWI_F128, "__powikf2");
172     setLibcallName(RTLIB::FPEXT_F32_F128, "__extendsfkf2");
173     setLibcallName(RTLIB::FPEXT_F64_F128, "__extenddfkf2");
174     setLibcallName(RTLIB::FPROUND_F128_F32, "__trunckfsf2");
175     setLibcallName(RTLIB::FPROUND_F128_F64, "__trunckfdf2");
176     setLibcallName(RTLIB::FPTOSINT_F128_I32, "__fixkfsi");
177     setLibcallName(RTLIB::FPTOSINT_F128_I64, "__fixkfdi");
178     setLibcallName(RTLIB::FPTOSINT_F128_I128, "__fixkfti");
179     setLibcallName(RTLIB::FPTOUINT_F128_I32, "__fixunskfsi");
180     setLibcallName(RTLIB::FPTOUINT_F128_I64, "__fixunskfdi");
181     setLibcallName(RTLIB::FPTOUINT_F128_I128, "__fixunskfti");
182     setLibcallName(RTLIB::SINTTOFP_I32_F128, "__floatsikf");
183     setLibcallName(RTLIB::SINTTOFP_I64_F128, "__floatdikf");
184     setLibcallName(RTLIB::SINTTOFP_I128_F128, "__floattikf");
185     setLibcallName(RTLIB::UINTTOFP_I32_F128, "__floatunsikf");
186     setLibcallName(RTLIB::UINTTOFP_I64_F128, "__floatundikf");
187     setLibcallName(RTLIB::UINTTOFP_I128_F128, "__floatuntikf");
188     setLibcallName(RTLIB::OEQ_F128, "__eqkf2");
189     setLibcallName(RTLIB::UNE_F128, "__nekf2");
190     setLibcallName(RTLIB::OGE_F128, "__gekf2");
191     setLibcallName(RTLIB::OLT_F128, "__ltkf2");
192     setLibcallName(RTLIB::OLE_F128, "__lekf2");
193     setLibcallName(RTLIB::OGT_F128, "__gtkf2");
194     setLibcallName(RTLIB::UO_F128, "__unordkf2");
195   }
196 
197   // A few names are different on particular architectures or environments.
198   if (TT.isOSDarwin()) {
199     // For f16/f32 conversions, Darwin uses the standard naming scheme, instead
200     // of the gnueabi-style __gnu_*_ieee.
201     // FIXME: What about other targets?
202     setLibcallName(RTLIB::FPEXT_F16_F32, "__extendhfsf2");
203     setLibcallName(RTLIB::FPROUND_F32_F16, "__truncsfhf2");
204 
205     // Some darwins have an optimized __bzero/bzero function.
206     switch (TT.getArch()) {
207     case Triple::x86:
208     case Triple::x86_64:
209       if (TT.isMacOSX() && !TT.isMacOSXVersionLT(10, 6))
210         setLibcallName(RTLIB::BZERO, "__bzero");
211       break;
212     case Triple::aarch64:
213     case Triple::aarch64_32:
214       setLibcallName(RTLIB::BZERO, "bzero");
215       break;
216     default:
217       break;
218     }
219 
220     if (darwinHasSinCos(TT)) {
221       setLibcallName(RTLIB::SINCOS_STRET_F32, "__sincosf_stret");
222       setLibcallName(RTLIB::SINCOS_STRET_F64, "__sincos_stret");
223       if (TT.isWatchABI()) {
224         setLibcallCallingConv(RTLIB::SINCOS_STRET_F32,
225                               CallingConv::ARM_AAPCS_VFP);
226         setLibcallCallingConv(RTLIB::SINCOS_STRET_F64,
227                               CallingConv::ARM_AAPCS_VFP);
228       }
229     }
230   } else {
231     setLibcallName(RTLIB::FPEXT_F16_F32, "__gnu_h2f_ieee");
232     setLibcallName(RTLIB::FPROUND_F32_F16, "__gnu_f2h_ieee");
233   }
234 
235   if (TT.isGNUEnvironment() || TT.isOSFuchsia() ||
236       (TT.isAndroid() && !TT.isAndroidVersionLT(9))) {
237     setLibcallName(RTLIB::SINCOS_F32, "sincosf");
238     setLibcallName(RTLIB::SINCOS_F64, "sincos");
239     setLibcallName(RTLIB::SINCOS_F80, "sincosl");
240     setLibcallName(RTLIB::SINCOS_F128, "sincosl");
241     setLibcallName(RTLIB::SINCOS_PPCF128, "sincosl");
242   }
243 
244   if (TT.isPS()) {
245     setLibcallName(RTLIB::SINCOS_F32, "sincosf");
246     setLibcallName(RTLIB::SINCOS_F64, "sincos");
247   }
248 
249   if (TT.isOSOpenBSD()) {
250     setLibcallName(RTLIB::STACKPROTECTOR_CHECK_FAIL, nullptr);
251   }
252 
253   if (TT.isOSWindows() && !TT.isOSCygMing()) {
254     setLibcallName(RTLIB::LDEXP_F32, nullptr);
255     setLibcallName(RTLIB::LDEXP_F80, nullptr);
256     setLibcallName(RTLIB::LDEXP_F128, nullptr);
257     setLibcallName(RTLIB::LDEXP_PPCF128, nullptr);
258 
259     setLibcallName(RTLIB::FREXP_F32, nullptr);
260     setLibcallName(RTLIB::FREXP_F80, nullptr);
261     setLibcallName(RTLIB::FREXP_F128, nullptr);
262     setLibcallName(RTLIB::FREXP_PPCF128, nullptr);
263   }
264 }
265 
266 /// GetFPLibCall - Helper to return the right libcall for the given floating
267 /// point type, or UNKNOWN_LIBCALL if there is none.
268 RTLIB::Libcall RTLIB::getFPLibCall(EVT VT,
269                                    RTLIB::Libcall Call_F32,
270                                    RTLIB::Libcall Call_F64,
271                                    RTLIB::Libcall Call_F80,
272                                    RTLIB::Libcall Call_F128,
273                                    RTLIB::Libcall Call_PPCF128) {
274   return
275     VT == MVT::f32 ? Call_F32 :
276     VT == MVT::f64 ? Call_F64 :
277     VT == MVT::f80 ? Call_F80 :
278     VT == MVT::f128 ? Call_F128 :
279     VT == MVT::ppcf128 ? Call_PPCF128 :
280     RTLIB::UNKNOWN_LIBCALL;
281 }
282 
283 /// getFPEXT - Return the FPEXT_*_* value for the given types, or
284 /// UNKNOWN_LIBCALL if there is none.
285 RTLIB::Libcall RTLIB::getFPEXT(EVT OpVT, EVT RetVT) {
286   if (OpVT == MVT::f16) {
287     if (RetVT == MVT::f32)
288       return FPEXT_F16_F32;
289     if (RetVT == MVT::f64)
290       return FPEXT_F16_F64;
291     if (RetVT == MVT::f80)
292       return FPEXT_F16_F80;
293     if (RetVT == MVT::f128)
294       return FPEXT_F16_F128;
295   } else if (OpVT == MVT::f32) {
296     if (RetVT == MVT::f64)
297       return FPEXT_F32_F64;
298     if (RetVT == MVT::f128)
299       return FPEXT_F32_F128;
300     if (RetVT == MVT::ppcf128)
301       return FPEXT_F32_PPCF128;
302   } else if (OpVT == MVT::f64) {
303     if (RetVT == MVT::f128)
304       return FPEXT_F64_F128;
305     else if (RetVT == MVT::ppcf128)
306       return FPEXT_F64_PPCF128;
307   } else if (OpVT == MVT::f80) {
308     if (RetVT == MVT::f128)
309       return FPEXT_F80_F128;
310   } else if (OpVT == MVT::bf16) {
311     if (RetVT == MVT::f32)
312       return FPEXT_BF16_F32;
313   }
314 
315   return UNKNOWN_LIBCALL;
316 }
317 
318 /// getFPROUND - Return the FPROUND_*_* value for the given types, or
319 /// UNKNOWN_LIBCALL if there is none.
320 RTLIB::Libcall RTLIB::getFPROUND(EVT OpVT, EVT RetVT) {
321   if (RetVT == MVT::f16) {
322     if (OpVT == MVT::f32)
323       return FPROUND_F32_F16;
324     if (OpVT == MVT::f64)
325       return FPROUND_F64_F16;
326     if (OpVT == MVT::f80)
327       return FPROUND_F80_F16;
328     if (OpVT == MVT::f128)
329       return FPROUND_F128_F16;
330     if (OpVT == MVT::ppcf128)
331       return FPROUND_PPCF128_F16;
332   } else if (RetVT == MVT::bf16) {
333     if (OpVT == MVT::f32)
334       return FPROUND_F32_BF16;
335     if (OpVT == MVT::f64)
336       return FPROUND_F64_BF16;
337   } else if (RetVT == MVT::f32) {
338     if (OpVT == MVT::f64)
339       return FPROUND_F64_F32;
340     if (OpVT == MVT::f80)
341       return FPROUND_F80_F32;
342     if (OpVT == MVT::f128)
343       return FPROUND_F128_F32;
344     if (OpVT == MVT::ppcf128)
345       return FPROUND_PPCF128_F32;
346   } else if (RetVT == MVT::f64) {
347     if (OpVT == MVT::f80)
348       return FPROUND_F80_F64;
349     if (OpVT == MVT::f128)
350       return FPROUND_F128_F64;
351     if (OpVT == MVT::ppcf128)
352       return FPROUND_PPCF128_F64;
353   } else if (RetVT == MVT::f80) {
354     if (OpVT == MVT::f128)
355       return FPROUND_F128_F80;
356   }
357 
358   return UNKNOWN_LIBCALL;
359 }
360 
361 /// getFPTOSINT - Return the FPTOSINT_*_* value for the given types, or
362 /// UNKNOWN_LIBCALL if there is none.
363 RTLIB::Libcall RTLIB::getFPTOSINT(EVT OpVT, EVT RetVT) {
364   if (OpVT == MVT::f16) {
365     if (RetVT == MVT::i32)
366       return FPTOSINT_F16_I32;
367     if (RetVT == MVT::i64)
368       return FPTOSINT_F16_I64;
369     if (RetVT == MVT::i128)
370       return FPTOSINT_F16_I128;
371   } else if (OpVT == MVT::f32) {
372     if (RetVT == MVT::i32)
373       return FPTOSINT_F32_I32;
374     if (RetVT == MVT::i64)
375       return FPTOSINT_F32_I64;
376     if (RetVT == MVT::i128)
377       return FPTOSINT_F32_I128;
378   } else if (OpVT == MVT::f64) {
379     if (RetVT == MVT::i32)
380       return FPTOSINT_F64_I32;
381     if (RetVT == MVT::i64)
382       return FPTOSINT_F64_I64;
383     if (RetVT == MVT::i128)
384       return FPTOSINT_F64_I128;
385   } else if (OpVT == MVT::f80) {
386     if (RetVT == MVT::i32)
387       return FPTOSINT_F80_I32;
388     if (RetVT == MVT::i64)
389       return FPTOSINT_F80_I64;
390     if (RetVT == MVT::i128)
391       return FPTOSINT_F80_I128;
392   } else if (OpVT == MVT::f128) {
393     if (RetVT == MVT::i32)
394       return FPTOSINT_F128_I32;
395     if (RetVT == MVT::i64)
396       return FPTOSINT_F128_I64;
397     if (RetVT == MVT::i128)
398       return FPTOSINT_F128_I128;
399   } else if (OpVT == MVT::ppcf128) {
400     if (RetVT == MVT::i32)
401       return FPTOSINT_PPCF128_I32;
402     if (RetVT == MVT::i64)
403       return FPTOSINT_PPCF128_I64;
404     if (RetVT == MVT::i128)
405       return FPTOSINT_PPCF128_I128;
406   }
407   return UNKNOWN_LIBCALL;
408 }
409 
410 /// getFPTOUINT - Return the FPTOUINT_*_* value for the given types, or
411 /// UNKNOWN_LIBCALL if there is none.
412 RTLIB::Libcall RTLIB::getFPTOUINT(EVT OpVT, EVT RetVT) {
413   if (OpVT == MVT::f16) {
414     if (RetVT == MVT::i32)
415       return FPTOUINT_F16_I32;
416     if (RetVT == MVT::i64)
417       return FPTOUINT_F16_I64;
418     if (RetVT == MVT::i128)
419       return FPTOUINT_F16_I128;
420   } else if (OpVT == MVT::f32) {
421     if (RetVT == MVT::i32)
422       return FPTOUINT_F32_I32;
423     if (RetVT == MVT::i64)
424       return FPTOUINT_F32_I64;
425     if (RetVT == MVT::i128)
426       return FPTOUINT_F32_I128;
427   } else if (OpVT == MVT::f64) {
428     if (RetVT == MVT::i32)
429       return FPTOUINT_F64_I32;
430     if (RetVT == MVT::i64)
431       return FPTOUINT_F64_I64;
432     if (RetVT == MVT::i128)
433       return FPTOUINT_F64_I128;
434   } else if (OpVT == MVT::f80) {
435     if (RetVT == MVT::i32)
436       return FPTOUINT_F80_I32;
437     if (RetVT == MVT::i64)
438       return FPTOUINT_F80_I64;
439     if (RetVT == MVT::i128)
440       return FPTOUINT_F80_I128;
441   } else if (OpVT == MVT::f128) {
442     if (RetVT == MVT::i32)
443       return FPTOUINT_F128_I32;
444     if (RetVT == MVT::i64)
445       return FPTOUINT_F128_I64;
446     if (RetVT == MVT::i128)
447       return FPTOUINT_F128_I128;
448   } else if (OpVT == MVT::ppcf128) {
449     if (RetVT == MVT::i32)
450       return FPTOUINT_PPCF128_I32;
451     if (RetVT == MVT::i64)
452       return FPTOUINT_PPCF128_I64;
453     if (RetVT == MVT::i128)
454       return FPTOUINT_PPCF128_I128;
455   }
456   return UNKNOWN_LIBCALL;
457 }
458 
459 /// getSINTTOFP - Return the SINTTOFP_*_* value for the given types, or
460 /// UNKNOWN_LIBCALL if there is none.
461 RTLIB::Libcall RTLIB::getSINTTOFP(EVT OpVT, EVT RetVT) {
462   if (OpVT == MVT::i32) {
463     if (RetVT == MVT::f16)
464       return SINTTOFP_I32_F16;
465     if (RetVT == MVT::f32)
466       return SINTTOFP_I32_F32;
467     if (RetVT == MVT::f64)
468       return SINTTOFP_I32_F64;
469     if (RetVT == MVT::f80)
470       return SINTTOFP_I32_F80;
471     if (RetVT == MVT::f128)
472       return SINTTOFP_I32_F128;
473     if (RetVT == MVT::ppcf128)
474       return SINTTOFP_I32_PPCF128;
475   } else if (OpVT == MVT::i64) {
476     if (RetVT == MVT::f16)
477       return SINTTOFP_I64_F16;
478     if (RetVT == MVT::f32)
479       return SINTTOFP_I64_F32;
480     if (RetVT == MVT::f64)
481       return SINTTOFP_I64_F64;
482     if (RetVT == MVT::f80)
483       return SINTTOFP_I64_F80;
484     if (RetVT == MVT::f128)
485       return SINTTOFP_I64_F128;
486     if (RetVT == MVT::ppcf128)
487       return SINTTOFP_I64_PPCF128;
488   } else if (OpVT == MVT::i128) {
489     if (RetVT == MVT::f16)
490       return SINTTOFP_I128_F16;
491     if (RetVT == MVT::f32)
492       return SINTTOFP_I128_F32;
493     if (RetVT == MVT::f64)
494       return SINTTOFP_I128_F64;
495     if (RetVT == MVT::f80)
496       return SINTTOFP_I128_F80;
497     if (RetVT == MVT::f128)
498       return SINTTOFP_I128_F128;
499     if (RetVT == MVT::ppcf128)
500       return SINTTOFP_I128_PPCF128;
501   }
502   return UNKNOWN_LIBCALL;
503 }
504 
505 /// getUINTTOFP - Return the UINTTOFP_*_* value for the given types, or
506 /// UNKNOWN_LIBCALL if there is none.
507 RTLIB::Libcall RTLIB::getUINTTOFP(EVT OpVT, EVT RetVT) {
508   if (OpVT == MVT::i32) {
509     if (RetVT == MVT::f16)
510       return UINTTOFP_I32_F16;
511     if (RetVT == MVT::f32)
512       return UINTTOFP_I32_F32;
513     if (RetVT == MVT::f64)
514       return UINTTOFP_I32_F64;
515     if (RetVT == MVT::f80)
516       return UINTTOFP_I32_F80;
517     if (RetVT == MVT::f128)
518       return UINTTOFP_I32_F128;
519     if (RetVT == MVT::ppcf128)
520       return UINTTOFP_I32_PPCF128;
521   } else if (OpVT == MVT::i64) {
522     if (RetVT == MVT::f16)
523       return UINTTOFP_I64_F16;
524     if (RetVT == MVT::f32)
525       return UINTTOFP_I64_F32;
526     if (RetVT == MVT::f64)
527       return UINTTOFP_I64_F64;
528     if (RetVT == MVT::f80)
529       return UINTTOFP_I64_F80;
530     if (RetVT == MVT::f128)
531       return UINTTOFP_I64_F128;
532     if (RetVT == MVT::ppcf128)
533       return UINTTOFP_I64_PPCF128;
534   } else if (OpVT == MVT::i128) {
535     if (RetVT == MVT::f16)
536       return UINTTOFP_I128_F16;
537     if (RetVT == MVT::f32)
538       return UINTTOFP_I128_F32;
539     if (RetVT == MVT::f64)
540       return UINTTOFP_I128_F64;
541     if (RetVT == MVT::f80)
542       return UINTTOFP_I128_F80;
543     if (RetVT == MVT::f128)
544       return UINTTOFP_I128_F128;
545     if (RetVT == MVT::ppcf128)
546       return UINTTOFP_I128_PPCF128;
547   }
548   return UNKNOWN_LIBCALL;
549 }
550 
551 RTLIB::Libcall RTLIB::getPOWI(EVT RetVT) {
552   return getFPLibCall(RetVT, POWI_F32, POWI_F64, POWI_F80, POWI_F128,
553                       POWI_PPCF128);
554 }
555 
556 RTLIB::Libcall RTLIB::getLDEXP(EVT RetVT) {
557   return getFPLibCall(RetVT, LDEXP_F32, LDEXP_F64, LDEXP_F80, LDEXP_F128,
558                       LDEXP_PPCF128);
559 }
560 
561 RTLIB::Libcall RTLIB::getFREXP(EVT RetVT) {
562   return getFPLibCall(RetVT, FREXP_F32, FREXP_F64, FREXP_F80, FREXP_F128,
563                       FREXP_PPCF128);
564 }
565 
566 RTLIB::Libcall RTLIB::getOutlineAtomicHelper(const Libcall (&LC)[5][4],
567                                              AtomicOrdering Order,
568                                              uint64_t MemSize) {
569   unsigned ModeN, ModelN;
570   switch (MemSize) {
571   case 1:
572     ModeN = 0;
573     break;
574   case 2:
575     ModeN = 1;
576     break;
577   case 4:
578     ModeN = 2;
579     break;
580   case 8:
581     ModeN = 3;
582     break;
583   case 16:
584     ModeN = 4;
585     break;
586   default:
587     return RTLIB::UNKNOWN_LIBCALL;
588   }
589 
590   switch (Order) {
591   case AtomicOrdering::Monotonic:
592     ModelN = 0;
593     break;
594   case AtomicOrdering::Acquire:
595     ModelN = 1;
596     break;
597   case AtomicOrdering::Release:
598     ModelN = 2;
599     break;
600   case AtomicOrdering::AcquireRelease:
601   case AtomicOrdering::SequentiallyConsistent:
602     ModelN = 3;
603     break;
604   default:
605     return UNKNOWN_LIBCALL;
606   }
607 
608   return LC[ModeN][ModelN];
609 }
610 
611 RTLIB::Libcall RTLIB::getOUTLINE_ATOMIC(unsigned Opc, AtomicOrdering Order,
612                                         MVT VT) {
613   if (!VT.isScalarInteger())
614     return UNKNOWN_LIBCALL;
615   uint64_t MemSize = VT.getScalarSizeInBits() / 8;
616 
617 #define LCALLS(A, B)                                                           \
618   { A##B##_RELAX, A##B##_ACQ, A##B##_REL, A##B##_ACQ_REL }
619 #define LCALL5(A)                                                              \
620   LCALLS(A, 1), LCALLS(A, 2), LCALLS(A, 4), LCALLS(A, 8), LCALLS(A, 16)
621   switch (Opc) {
622   case ISD::ATOMIC_CMP_SWAP: {
623     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_CAS)};
624     return getOutlineAtomicHelper(LC, Order, MemSize);
625   }
626   case ISD::ATOMIC_SWAP: {
627     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_SWP)};
628     return getOutlineAtomicHelper(LC, Order, MemSize);
629   }
630   case ISD::ATOMIC_LOAD_ADD: {
631     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDADD)};
632     return getOutlineAtomicHelper(LC, Order, MemSize);
633   }
634   case ISD::ATOMIC_LOAD_OR: {
635     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDSET)};
636     return getOutlineAtomicHelper(LC, Order, MemSize);
637   }
638   case ISD::ATOMIC_LOAD_CLR: {
639     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDCLR)};
640     return getOutlineAtomicHelper(LC, Order, MemSize);
641   }
642   case ISD::ATOMIC_LOAD_XOR: {
643     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDEOR)};
644     return getOutlineAtomicHelper(LC, Order, MemSize);
645   }
646   default:
647     return UNKNOWN_LIBCALL;
648   }
649 #undef LCALLS
650 #undef LCALL5
651 }
652 
653 RTLIB::Libcall RTLIB::getSYNC(unsigned Opc, MVT VT) {
654 #define OP_TO_LIBCALL(Name, Enum)                                              \
655   case Name:                                                                   \
656     switch (VT.SimpleTy) {                                                     \
657     default:                                                                   \
658       return UNKNOWN_LIBCALL;                                                  \
659     case MVT::i8:                                                              \
660       return Enum##_1;                                                         \
661     case MVT::i16:                                                             \
662       return Enum##_2;                                                         \
663     case MVT::i32:                                                             \
664       return Enum##_4;                                                         \
665     case MVT::i64:                                                             \
666       return Enum##_8;                                                         \
667     case MVT::i128:                                                            \
668       return Enum##_16;                                                        \
669     }
670 
671   switch (Opc) {
672     OP_TO_LIBCALL(ISD::ATOMIC_SWAP, SYNC_LOCK_TEST_AND_SET)
673     OP_TO_LIBCALL(ISD::ATOMIC_CMP_SWAP, SYNC_VAL_COMPARE_AND_SWAP)
674     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_ADD, SYNC_FETCH_AND_ADD)
675     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_SUB, SYNC_FETCH_AND_SUB)
676     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_AND, SYNC_FETCH_AND_AND)
677     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_OR, SYNC_FETCH_AND_OR)
678     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_XOR, SYNC_FETCH_AND_XOR)
679     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_NAND, SYNC_FETCH_AND_NAND)
680     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_MAX, SYNC_FETCH_AND_MAX)
681     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_UMAX, SYNC_FETCH_AND_UMAX)
682     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_MIN, SYNC_FETCH_AND_MIN)
683     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_UMIN, SYNC_FETCH_AND_UMIN)
684   }
685 
686 #undef OP_TO_LIBCALL
687 
688   return UNKNOWN_LIBCALL;
689 }
690 
691 RTLIB::Libcall RTLIB::getMEMCPY_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
692   switch (ElementSize) {
693   case 1:
694     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_1;
695   case 2:
696     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_2;
697   case 4:
698     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_4;
699   case 8:
700     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_8;
701   case 16:
702     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_16;
703   default:
704     return UNKNOWN_LIBCALL;
705   }
706 }
707 
708 RTLIB::Libcall RTLIB::getMEMMOVE_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
709   switch (ElementSize) {
710   case 1:
711     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_1;
712   case 2:
713     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_2;
714   case 4:
715     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_4;
716   case 8:
717     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_8;
718   case 16:
719     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_16;
720   default:
721     return UNKNOWN_LIBCALL;
722   }
723 }
724 
725 RTLIB::Libcall RTLIB::getMEMSET_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
726   switch (ElementSize) {
727   case 1:
728     return MEMSET_ELEMENT_UNORDERED_ATOMIC_1;
729   case 2:
730     return MEMSET_ELEMENT_UNORDERED_ATOMIC_2;
731   case 4:
732     return MEMSET_ELEMENT_UNORDERED_ATOMIC_4;
733   case 8:
734     return MEMSET_ELEMENT_UNORDERED_ATOMIC_8;
735   case 16:
736     return MEMSET_ELEMENT_UNORDERED_ATOMIC_16;
737   default:
738     return UNKNOWN_LIBCALL;
739   }
740 }
741 
742 /// InitCmpLibcallCCs - Set default comparison libcall CC.
743 static void InitCmpLibcallCCs(ISD::CondCode *CCs) {
744   std::fill(CCs, CCs + RTLIB::UNKNOWN_LIBCALL, ISD::SETCC_INVALID);
745   CCs[RTLIB::OEQ_F32] = ISD::SETEQ;
746   CCs[RTLIB::OEQ_F64] = ISD::SETEQ;
747   CCs[RTLIB::OEQ_F128] = ISD::SETEQ;
748   CCs[RTLIB::OEQ_PPCF128] = ISD::SETEQ;
749   CCs[RTLIB::UNE_F32] = ISD::SETNE;
750   CCs[RTLIB::UNE_F64] = ISD::SETNE;
751   CCs[RTLIB::UNE_F128] = ISD::SETNE;
752   CCs[RTLIB::UNE_PPCF128] = ISD::SETNE;
753   CCs[RTLIB::OGE_F32] = ISD::SETGE;
754   CCs[RTLIB::OGE_F64] = ISD::SETGE;
755   CCs[RTLIB::OGE_F128] = ISD::SETGE;
756   CCs[RTLIB::OGE_PPCF128] = ISD::SETGE;
757   CCs[RTLIB::OLT_F32] = ISD::SETLT;
758   CCs[RTLIB::OLT_F64] = ISD::SETLT;
759   CCs[RTLIB::OLT_F128] = ISD::SETLT;
760   CCs[RTLIB::OLT_PPCF128] = ISD::SETLT;
761   CCs[RTLIB::OLE_F32] = ISD::SETLE;
762   CCs[RTLIB::OLE_F64] = ISD::SETLE;
763   CCs[RTLIB::OLE_F128] = ISD::SETLE;
764   CCs[RTLIB::OLE_PPCF128] = ISD::SETLE;
765   CCs[RTLIB::OGT_F32] = ISD::SETGT;
766   CCs[RTLIB::OGT_F64] = ISD::SETGT;
767   CCs[RTLIB::OGT_F128] = ISD::SETGT;
768   CCs[RTLIB::OGT_PPCF128] = ISD::SETGT;
769   CCs[RTLIB::UO_F32] = ISD::SETNE;
770   CCs[RTLIB::UO_F64] = ISD::SETNE;
771   CCs[RTLIB::UO_F128] = ISD::SETNE;
772   CCs[RTLIB::UO_PPCF128] = ISD::SETNE;
773 }
774 
775 /// NOTE: The TargetMachine owns TLOF.
776 TargetLoweringBase::TargetLoweringBase(const TargetMachine &tm) : TM(tm) {
777   initActions();
778 
779   // Perform these initializations only once.
780   MaxStoresPerMemset = MaxStoresPerMemcpy = MaxStoresPerMemmove =
781       MaxLoadsPerMemcmp = 8;
782   MaxGluedStoresPerMemcpy = 0;
783   MaxStoresPerMemsetOptSize = MaxStoresPerMemcpyOptSize =
784       MaxStoresPerMemmoveOptSize = MaxLoadsPerMemcmpOptSize = 4;
785   HasMultipleConditionRegisters = false;
786   HasExtractBitsInsn = false;
787   JumpIsExpensive = JumpIsExpensiveOverride;
788   PredictableSelectIsExpensive = false;
789   EnableExtLdPromotion = false;
790   StackPointerRegisterToSaveRestore = 0;
791   BooleanContents = UndefinedBooleanContent;
792   BooleanFloatContents = UndefinedBooleanContent;
793   BooleanVectorContents = UndefinedBooleanContent;
794   SchedPreferenceInfo = Sched::ILP;
795   GatherAllAliasesMaxDepth = 18;
796   IsStrictFPEnabled = DisableStrictNodeMutation;
797   MaxBytesForAlignment = 0;
798   MaxAtomicSizeInBitsSupported = 0;
799 
800   // Assume that even with libcalls, no target supports wider than 128 bit
801   // division.
802   MaxDivRemBitWidthSupported = 128;
803 
804   MaxLargeFPConvertBitWidthSupported = llvm::IntegerType::MAX_INT_BITS;
805 
806   MinCmpXchgSizeInBits = 0;
807   SupportsUnalignedAtomics = false;
808 
809   std::fill(std::begin(LibcallRoutineNames), std::end(LibcallRoutineNames), nullptr);
810 
811   InitLibcalls(TM.getTargetTriple());
812   InitCmpLibcallCCs(CmpLibcallCCs);
813 }
814 
815 void TargetLoweringBase::initActions() {
816   // All operations default to being supported.
817   memset(OpActions, 0, sizeof(OpActions));
818   memset(LoadExtActions, 0, sizeof(LoadExtActions));
819   memset(TruncStoreActions, 0, sizeof(TruncStoreActions));
820   memset(IndexedModeActions, 0, sizeof(IndexedModeActions));
821   memset(CondCodeActions, 0, sizeof(CondCodeActions));
822   std::fill(std::begin(RegClassForVT), std::end(RegClassForVT), nullptr);
823   std::fill(std::begin(TargetDAGCombineArray),
824             std::end(TargetDAGCombineArray), 0);
825 
826   // We're somewhat special casing MVT::i2 and MVT::i4. Ideally we want to
827   // remove this and targets should individually set these types if not legal.
828   for (ISD::NodeType NT : enum_seq(ISD::DELETED_NODE, ISD::BUILTIN_OP_END,
829                                    force_iteration_on_noniterable_enum)) {
830     for (MVT VT : {MVT::i2, MVT::i4})
831       OpActions[(unsigned)VT.SimpleTy][NT] = Expand;
832   }
833   for (MVT AVT : MVT::all_valuetypes()) {
834     for (MVT VT : {MVT::i2, MVT::i4, MVT::v128i2, MVT::v64i4}) {
835       setTruncStoreAction(AVT, VT, Expand);
836       setLoadExtAction(ISD::EXTLOAD, AVT, VT, Expand);
837       setLoadExtAction(ISD::ZEXTLOAD, AVT, VT, Expand);
838     }
839   }
840   for (unsigned IM = (unsigned)ISD::PRE_INC;
841        IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) {
842     for (MVT VT : {MVT::i2, MVT::i4}) {
843       setIndexedLoadAction(IM, VT, Expand);
844       setIndexedStoreAction(IM, VT, Expand);
845       setIndexedMaskedLoadAction(IM, VT, Expand);
846       setIndexedMaskedStoreAction(IM, VT, Expand);
847     }
848   }
849 
850   for (MVT VT : MVT::fp_valuetypes()) {
851     MVT IntVT = MVT::getIntegerVT(VT.getFixedSizeInBits());
852     if (IntVT.isValid()) {
853       setOperationAction(ISD::ATOMIC_SWAP, VT, Promote);
854       AddPromotedToType(ISD::ATOMIC_SWAP, VT, IntVT);
855     }
856   }
857 
858   // Set default actions for various operations.
859   for (MVT VT : MVT::all_valuetypes()) {
860     // Default all indexed load / store to expand.
861     for (unsigned IM = (unsigned)ISD::PRE_INC;
862          IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) {
863       setIndexedLoadAction(IM, VT, Expand);
864       setIndexedStoreAction(IM, VT, Expand);
865       setIndexedMaskedLoadAction(IM, VT, Expand);
866       setIndexedMaskedStoreAction(IM, VT, Expand);
867     }
868 
869     // Most backends expect to see the node which just returns the value loaded.
870     setOperationAction(ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS, VT, Expand);
871 
872     // These operations default to expand.
873     setOperationAction({ISD::FGETSIGN,       ISD::CONCAT_VECTORS,
874                         ISD::FMINNUM,        ISD::FMAXNUM,
875                         ISD::FMINNUM_IEEE,   ISD::FMAXNUM_IEEE,
876                         ISD::FMINIMUM,       ISD::FMAXIMUM,
877                         ISD::FMAD,           ISD::SMIN,
878                         ISD::SMAX,           ISD::UMIN,
879                         ISD::UMAX,           ISD::ABS,
880                         ISD::FSHL,           ISD::FSHR,
881                         ISD::SADDSAT,        ISD::UADDSAT,
882                         ISD::SSUBSAT,        ISD::USUBSAT,
883                         ISD::SSHLSAT,        ISD::USHLSAT,
884                         ISD::SMULFIX,        ISD::SMULFIXSAT,
885                         ISD::UMULFIX,        ISD::UMULFIXSAT,
886                         ISD::SDIVFIX,        ISD::SDIVFIXSAT,
887                         ISD::UDIVFIX,        ISD::UDIVFIXSAT,
888                         ISD::FP_TO_SINT_SAT, ISD::FP_TO_UINT_SAT,
889                         ISD::IS_FPCLASS},
890                        VT, Expand);
891 
892     // Overflow operations default to expand
893     setOperationAction({ISD::SADDO, ISD::SSUBO, ISD::UADDO, ISD::USUBO,
894                         ISD::SMULO, ISD::UMULO},
895                        VT, Expand);
896 
897     // Carry-using overflow operations default to expand.
898     setOperationAction({ISD::UADDO_CARRY, ISD::USUBO_CARRY, ISD::SETCCCARRY,
899                         ISD::SADDO_CARRY, ISD::SSUBO_CARRY},
900                        VT, Expand);
901 
902     // ADDC/ADDE/SUBC/SUBE default to expand.
903     setOperationAction({ISD::ADDC, ISD::ADDE, ISD::SUBC, ISD::SUBE}, VT,
904                        Expand);
905 
906     // Halving adds
907     setOperationAction(
908         {ISD::AVGFLOORS, ISD::AVGFLOORU, ISD::AVGCEILS, ISD::AVGCEILU}, VT,
909         Expand);
910 
911     // Absolute difference
912     setOperationAction({ISD::ABDS, ISD::ABDU}, VT, Expand);
913 
914     // These default to Expand so they will be expanded to CTLZ/CTTZ by default.
915     setOperationAction({ISD::CTLZ_ZERO_UNDEF, ISD::CTTZ_ZERO_UNDEF}, VT,
916                        Expand);
917 
918     setOperationAction({ISD::BITREVERSE, ISD::PARITY}, VT, Expand);
919 
920     // These library functions default to expand.
921     setOperationAction({ISD::FROUND, ISD::FPOWI, ISD::FLDEXP, ISD::FFREXP}, VT,
922                        Expand);
923 
924     // These operations default to expand for vector types.
925     if (VT.isVector())
926       setOperationAction(
927           {ISD::FCOPYSIGN, ISD::SIGN_EXTEND_INREG, ISD::ANY_EXTEND_VECTOR_INREG,
928            ISD::SIGN_EXTEND_VECTOR_INREG, ISD::ZERO_EXTEND_VECTOR_INREG,
929            ISD::SPLAT_VECTOR, ISD::LRINT, ISD::LLRINT},
930           VT, Expand);
931 
932       // Constrained floating-point operations default to expand.
933 #define DAG_INSTRUCTION(NAME, NARG, ROUND_MODE, INTRINSIC, DAGN)               \
934     setOperationAction(ISD::STRICT_##DAGN, VT, Expand);
935 #include "llvm/IR/ConstrainedOps.def"
936 
937     // For most targets @llvm.get.dynamic.area.offset just returns 0.
938     setOperationAction(ISD::GET_DYNAMIC_AREA_OFFSET, VT, Expand);
939 
940     // Vector reduction default to expand.
941     setOperationAction(
942         {ISD::VECREDUCE_FADD, ISD::VECREDUCE_FMUL, ISD::VECREDUCE_ADD,
943          ISD::VECREDUCE_MUL, ISD::VECREDUCE_AND, ISD::VECREDUCE_OR,
944          ISD::VECREDUCE_XOR, ISD::VECREDUCE_SMAX, ISD::VECREDUCE_SMIN,
945          ISD::VECREDUCE_UMAX, ISD::VECREDUCE_UMIN, ISD::VECREDUCE_FMAX,
946          ISD::VECREDUCE_FMIN, ISD::VECREDUCE_FMAXIMUM, ISD::VECREDUCE_FMINIMUM,
947          ISD::VECREDUCE_SEQ_FADD, ISD::VECREDUCE_SEQ_FMUL},
948         VT, Expand);
949 
950     // Named vector shuffles default to expand.
951     setOperationAction(ISD::VECTOR_SPLICE, VT, Expand);
952 
953     // VP operations default to expand.
954 #define BEGIN_REGISTER_VP_SDNODE(SDOPC, ...)                                   \
955     setOperationAction(ISD::SDOPC, VT, Expand);
956 #include "llvm/IR/VPIntrinsics.def"
957 
958     // FP environment operations default to expand.
959     setOperationAction(ISD::GET_FPENV, VT, Expand);
960     setOperationAction(ISD::SET_FPENV, VT, Expand);
961     setOperationAction(ISD::RESET_FPENV, VT, Expand);
962   }
963 
964   // Most targets ignore the @llvm.prefetch intrinsic.
965   setOperationAction(ISD::PREFETCH, MVT::Other, Expand);
966 
967   // Most targets also ignore the @llvm.readcyclecounter intrinsic.
968   setOperationAction(ISD::READCYCLECOUNTER, MVT::i64, Expand);
969 
970   // Most targets also ignore the @llvm.readsteadycounter intrinsic.
971   setOperationAction(ISD::READSTEADYCOUNTER, MVT::i64, Expand);
972 
973   // ConstantFP nodes default to expand.  Targets can either change this to
974   // Legal, in which case all fp constants are legal, or use isFPImmLegal()
975   // to optimize expansions for certain constants.
976   setOperationAction(ISD::ConstantFP,
977                      {MVT::bf16, MVT::f16, MVT::f32, MVT::f64, MVT::f80, MVT::f128},
978                      Expand);
979 
980   // These library functions default to expand.
981   setOperationAction({ISD::FCBRT, ISD::FLOG, ISD::FLOG2, ISD::FLOG10, ISD::FEXP,
982                       ISD::FEXP2, ISD::FEXP10, ISD::FFLOOR, ISD::FNEARBYINT,
983                       ISD::FCEIL, ISD::FRINT, ISD::FTRUNC, ISD::LROUND,
984                       ISD::LLROUND, ISD::LRINT, ISD::LLRINT, ISD::FROUNDEVEN},
985                      {MVT::f32, MVT::f64, MVT::f128}, Expand);
986 
987   // Default ISD::TRAP to expand (which turns it into abort).
988   setOperationAction(ISD::TRAP, MVT::Other, Expand);
989 
990   // On most systems, DEBUGTRAP and TRAP have no difference. The "Expand"
991   // here is to inform DAG Legalizer to replace DEBUGTRAP with TRAP.
992   setOperationAction(ISD::DEBUGTRAP, MVT::Other, Expand);
993 
994   setOperationAction(ISD::UBSANTRAP, MVT::Other, Expand);
995 
996   setOperationAction(ISD::GET_FPENV_MEM, MVT::Other, Expand);
997   setOperationAction(ISD::SET_FPENV_MEM, MVT::Other, Expand);
998 
999   for (MVT VT : {MVT::i8, MVT::i16, MVT::i32, MVT::i64}) {
1000     setOperationAction(ISD::GET_FPMODE, VT, Expand);
1001     setOperationAction(ISD::SET_FPMODE, VT, Expand);
1002   }
1003   setOperationAction(ISD::RESET_FPMODE, MVT::Other, Expand);
1004 }
1005 
1006 MVT TargetLoweringBase::getScalarShiftAmountTy(const DataLayout &DL,
1007                                                EVT) const {
1008   return MVT::getIntegerVT(DL.getPointerSizeInBits(0));
1009 }
1010 
1011 EVT TargetLoweringBase::getShiftAmountTy(EVT LHSTy, const DataLayout &DL,
1012                                          bool LegalTypes) const {
1013   assert(LHSTy.isInteger() && "Shift amount is not an integer type!");
1014   if (LHSTy.isVector())
1015     return LHSTy;
1016   MVT ShiftVT =
1017       LegalTypes ? getScalarShiftAmountTy(DL, LHSTy) : getPointerTy(DL);
1018   // If any possible shift value won't fit in the prefered type, just use
1019   // something safe. Assume it will be legalized when the shift is expanded.
1020   if (ShiftVT.getSizeInBits() < Log2_32_Ceil(LHSTy.getSizeInBits()))
1021     ShiftVT = MVT::i32;
1022   assert(ShiftVT.getSizeInBits() >= Log2_32_Ceil(LHSTy.getSizeInBits()) &&
1023          "ShiftVT is still too small!");
1024   return ShiftVT;
1025 }
1026 
1027 bool TargetLoweringBase::canOpTrap(unsigned Op, EVT VT) const {
1028   assert(isTypeLegal(VT));
1029   switch (Op) {
1030   default:
1031     return false;
1032   case ISD::SDIV:
1033   case ISD::UDIV:
1034   case ISD::SREM:
1035   case ISD::UREM:
1036     return true;
1037   }
1038 }
1039 
1040 bool TargetLoweringBase::isFreeAddrSpaceCast(unsigned SrcAS,
1041                                              unsigned DestAS) const {
1042   return TM.isNoopAddrSpaceCast(SrcAS, DestAS);
1043 }
1044 
1045 void TargetLoweringBase::setJumpIsExpensive(bool isExpensive) {
1046   // If the command-line option was specified, ignore this request.
1047   if (!JumpIsExpensiveOverride.getNumOccurrences())
1048     JumpIsExpensive = isExpensive;
1049 }
1050 
1051 TargetLoweringBase::LegalizeKind
1052 TargetLoweringBase::getTypeConversion(LLVMContext &Context, EVT VT) const {
1053   // If this is a simple type, use the ComputeRegisterProp mechanism.
1054   if (VT.isSimple()) {
1055     MVT SVT = VT.getSimpleVT();
1056     assert((unsigned)SVT.SimpleTy < std::size(TransformToType));
1057     MVT NVT = TransformToType[SVT.SimpleTy];
1058     LegalizeTypeAction LA = ValueTypeActions.getTypeAction(SVT);
1059 
1060     assert((LA == TypeLegal || LA == TypeSoftenFloat ||
1061             LA == TypeSoftPromoteHalf ||
1062             (NVT.isVector() ||
1063              ValueTypeActions.getTypeAction(NVT) != TypePromoteInteger)) &&
1064            "Promote may not follow Expand or Promote");
1065 
1066     if (LA == TypeSplitVector)
1067       return LegalizeKind(LA, EVT(SVT).getHalfNumVectorElementsVT(Context));
1068     if (LA == TypeScalarizeVector)
1069       return LegalizeKind(LA, SVT.getVectorElementType());
1070     return LegalizeKind(LA, NVT);
1071   }
1072 
1073   // Handle Extended Scalar Types.
1074   if (!VT.isVector()) {
1075     assert(VT.isInteger() && "Float types must be simple");
1076     unsigned BitSize = VT.getSizeInBits();
1077     // First promote to a power-of-two size, then expand if necessary.
1078     if (BitSize < 8 || !isPowerOf2_32(BitSize)) {
1079       EVT NVT = VT.getRoundIntegerType(Context);
1080       assert(NVT != VT && "Unable to round integer VT");
1081       LegalizeKind NextStep = getTypeConversion(Context, NVT);
1082       // Avoid multi-step promotion.
1083       if (NextStep.first == TypePromoteInteger)
1084         return NextStep;
1085       // Return rounded integer type.
1086       return LegalizeKind(TypePromoteInteger, NVT);
1087     }
1088 
1089     return LegalizeKind(TypeExpandInteger,
1090                         EVT::getIntegerVT(Context, VT.getSizeInBits() / 2));
1091   }
1092 
1093   // Handle vector types.
1094   ElementCount NumElts = VT.getVectorElementCount();
1095   EVT EltVT = VT.getVectorElementType();
1096 
1097   // Vectors with only one element are always scalarized.
1098   if (NumElts.isScalar())
1099     return LegalizeKind(TypeScalarizeVector, EltVT);
1100 
1101   // Try to widen vector elements until the element type is a power of two and
1102   // promote it to a legal type later on, for example:
1103   // <3 x i8> -> <4 x i8> -> <4 x i32>
1104   if (EltVT.isInteger()) {
1105     // Vectors with a number of elements that is not a power of two are always
1106     // widened, for example <3 x i8> -> <4 x i8>.
1107     if (!VT.isPow2VectorType()) {
1108       NumElts = NumElts.coefficientNextPowerOf2();
1109       EVT NVT = EVT::getVectorVT(Context, EltVT, NumElts);
1110       return LegalizeKind(TypeWidenVector, NVT);
1111     }
1112 
1113     // Examine the element type.
1114     LegalizeKind LK = getTypeConversion(Context, EltVT);
1115 
1116     // If type is to be expanded, split the vector.
1117     //  <4 x i140> -> <2 x i140>
1118     if (LK.first == TypeExpandInteger) {
1119       if (VT.getVectorElementCount().isScalable())
1120         return LegalizeKind(TypeScalarizeScalableVector, EltVT);
1121       return LegalizeKind(TypeSplitVector,
1122                           VT.getHalfNumVectorElementsVT(Context));
1123     }
1124 
1125     // Promote the integer element types until a legal vector type is found
1126     // or until the element integer type is too big. If a legal type was not
1127     // found, fallback to the usual mechanism of widening/splitting the
1128     // vector.
1129     EVT OldEltVT = EltVT;
1130     while (true) {
1131       // Increase the bitwidth of the element to the next pow-of-two
1132       // (which is greater than 8 bits).
1133       EltVT = EVT::getIntegerVT(Context, 1 + EltVT.getSizeInBits())
1134                   .getRoundIntegerType(Context);
1135 
1136       // Stop trying when getting a non-simple element type.
1137       // Note that vector elements may be greater than legal vector element
1138       // types. Example: X86 XMM registers hold 64bit element on 32bit
1139       // systems.
1140       if (!EltVT.isSimple())
1141         break;
1142 
1143       // Build a new vector type and check if it is legal.
1144       MVT NVT = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
1145       // Found a legal promoted vector type.
1146       if (NVT != MVT() && ValueTypeActions.getTypeAction(NVT) == TypeLegal)
1147         return LegalizeKind(TypePromoteInteger,
1148                             EVT::getVectorVT(Context, EltVT, NumElts));
1149     }
1150 
1151     // Reset the type to the unexpanded type if we did not find a legal vector
1152     // type with a promoted vector element type.
1153     EltVT = OldEltVT;
1154   }
1155 
1156   // Try to widen the vector until a legal type is found.
1157   // If there is no wider legal type, split the vector.
1158   while (true) {
1159     // Round up to the next power of 2.
1160     NumElts = NumElts.coefficientNextPowerOf2();
1161 
1162     // If there is no simple vector type with this many elements then there
1163     // cannot be a larger legal vector type.  Note that this assumes that
1164     // there are no skipped intermediate vector types in the simple types.
1165     if (!EltVT.isSimple())
1166       break;
1167     MVT LargerVector = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
1168     if (LargerVector == MVT())
1169       break;
1170 
1171     // If this type is legal then widen the vector.
1172     if (ValueTypeActions.getTypeAction(LargerVector) == TypeLegal)
1173       return LegalizeKind(TypeWidenVector, LargerVector);
1174   }
1175 
1176   // Widen odd vectors to next power of two.
1177   if (!VT.isPow2VectorType()) {
1178     EVT NVT = VT.getPow2VectorType(Context);
1179     return LegalizeKind(TypeWidenVector, NVT);
1180   }
1181 
1182   if (VT.getVectorElementCount() == ElementCount::getScalable(1))
1183     return LegalizeKind(TypeScalarizeScalableVector, EltVT);
1184 
1185   // Vectors with illegal element types are expanded.
1186   EVT NVT = EVT::getVectorVT(Context, EltVT,
1187                              VT.getVectorElementCount().divideCoefficientBy(2));
1188   return LegalizeKind(TypeSplitVector, NVT);
1189 }
1190 
1191 static unsigned getVectorTypeBreakdownMVT(MVT VT, MVT &IntermediateVT,
1192                                           unsigned &NumIntermediates,
1193                                           MVT &RegisterVT,
1194                                           TargetLoweringBase *TLI) {
1195   // Figure out the right, legal destination reg to copy into.
1196   ElementCount EC = VT.getVectorElementCount();
1197   MVT EltTy = VT.getVectorElementType();
1198 
1199   unsigned NumVectorRegs = 1;
1200 
1201   // Scalable vectors cannot be scalarized, so splitting or widening is
1202   // required.
1203   if (VT.isScalableVector() && !isPowerOf2_32(EC.getKnownMinValue()))
1204     llvm_unreachable(
1205         "Splitting or widening of non-power-of-2 MVTs is not implemented.");
1206 
1207   // FIXME: We don't support non-power-of-2-sized vectors for now.
1208   // Ideally we could break down into LHS/RHS like LegalizeDAG does.
1209   if (!isPowerOf2_32(EC.getKnownMinValue())) {
1210     // Split EC to unit size (scalable property is preserved).
1211     NumVectorRegs = EC.getKnownMinValue();
1212     EC = ElementCount::getFixed(1);
1213   }
1214 
1215   // Divide the input until we get to a supported size. This will
1216   // always end up with an EC that represent a scalar or a scalable
1217   // scalar.
1218   while (EC.getKnownMinValue() > 1 &&
1219          !TLI->isTypeLegal(MVT::getVectorVT(EltTy, EC))) {
1220     EC = EC.divideCoefficientBy(2);
1221     NumVectorRegs <<= 1;
1222   }
1223 
1224   NumIntermediates = NumVectorRegs;
1225 
1226   MVT NewVT = MVT::getVectorVT(EltTy, EC);
1227   if (!TLI->isTypeLegal(NewVT))
1228     NewVT = EltTy;
1229   IntermediateVT = NewVT;
1230 
1231   unsigned LaneSizeInBits = NewVT.getScalarSizeInBits();
1232 
1233   // Convert sizes such as i33 to i64.
1234   LaneSizeInBits = llvm::bit_ceil(LaneSizeInBits);
1235 
1236   MVT DestVT = TLI->getRegisterType(NewVT);
1237   RegisterVT = DestVT;
1238   if (EVT(DestVT).bitsLT(NewVT))    // Value is expanded, e.g. i64 -> i16.
1239     return NumVectorRegs * (LaneSizeInBits / DestVT.getScalarSizeInBits());
1240 
1241   // Otherwise, promotion or legal types use the same number of registers as
1242   // the vector decimated to the appropriate level.
1243   return NumVectorRegs;
1244 }
1245 
1246 /// isLegalRC - Return true if the value types that can be represented by the
1247 /// specified register class are all legal.
1248 bool TargetLoweringBase::isLegalRC(const TargetRegisterInfo &TRI,
1249                                    const TargetRegisterClass &RC) const {
1250   for (const auto *I = TRI.legalclasstypes_begin(RC); *I != MVT::Other; ++I)
1251     if (isTypeLegal(*I))
1252       return true;
1253   return false;
1254 }
1255 
1256 /// Replace/modify any TargetFrameIndex operands with a targte-dependent
1257 /// sequence of memory operands that is recognized by PrologEpilogInserter.
1258 MachineBasicBlock *
1259 TargetLoweringBase::emitPatchPoint(MachineInstr &InitialMI,
1260                                    MachineBasicBlock *MBB) const {
1261   MachineInstr *MI = &InitialMI;
1262   MachineFunction &MF = *MI->getMF();
1263   MachineFrameInfo &MFI = MF.getFrameInfo();
1264 
1265   // We're handling multiple types of operands here:
1266   // PATCHPOINT MetaArgs - live-in, read only, direct
1267   // STATEPOINT Deopt Spill - live-through, read only, indirect
1268   // STATEPOINT Deopt Alloca - live-through, read only, direct
1269   // (We're currently conservative and mark the deopt slots read/write in
1270   // practice.)
1271   // STATEPOINT GC Spill - live-through, read/write, indirect
1272   // STATEPOINT GC Alloca - live-through, read/write, direct
1273   // The live-in vs live-through is handled already (the live through ones are
1274   // all stack slots), but we need to handle the different type of stackmap
1275   // operands and memory effects here.
1276 
1277   if (llvm::none_of(MI->operands(),
1278                     [](MachineOperand &Operand) { return Operand.isFI(); }))
1279     return MBB;
1280 
1281   MachineInstrBuilder MIB = BuildMI(MF, MI->getDebugLoc(), MI->getDesc());
1282 
1283   // Inherit previous memory operands.
1284   MIB.cloneMemRefs(*MI);
1285 
1286   for (unsigned i = 0; i < MI->getNumOperands(); ++i) {
1287     MachineOperand &MO = MI->getOperand(i);
1288     if (!MO.isFI()) {
1289       // Index of Def operand this Use it tied to.
1290       // Since Defs are coming before Uses, if Use is tied, then
1291       // index of Def must be smaller that index of that Use.
1292       // Also, Defs preserve their position in new MI.
1293       unsigned TiedTo = i;
1294       if (MO.isReg() && MO.isTied())
1295         TiedTo = MI->findTiedOperandIdx(i);
1296       MIB.add(MO);
1297       if (TiedTo < i)
1298         MIB->tieOperands(TiedTo, MIB->getNumOperands() - 1);
1299       continue;
1300     }
1301 
1302     // foldMemoryOperand builds a new MI after replacing a single FI operand
1303     // with the canonical set of five x86 addressing-mode operands.
1304     int FI = MO.getIndex();
1305 
1306     // Add frame index operands recognized by stackmaps.cpp
1307     if (MFI.isStatepointSpillSlotObjectIndex(FI)) {
1308       // indirect-mem-ref tag, size, #FI, offset.
1309       // Used for spills inserted by StatepointLowering.  This codepath is not
1310       // used for patchpoints/stackmaps at all, for these spilling is done via
1311       // foldMemoryOperand callback only.
1312       assert(MI->getOpcode() == TargetOpcode::STATEPOINT && "sanity");
1313       MIB.addImm(StackMaps::IndirectMemRefOp);
1314       MIB.addImm(MFI.getObjectSize(FI));
1315       MIB.add(MO);
1316       MIB.addImm(0);
1317     } else {
1318       // direct-mem-ref tag, #FI, offset.
1319       // Used by patchpoint, and direct alloca arguments to statepoints
1320       MIB.addImm(StackMaps::DirectMemRefOp);
1321       MIB.add(MO);
1322       MIB.addImm(0);
1323     }
1324 
1325     assert(MIB->mayLoad() && "Folded a stackmap use to a non-load!");
1326 
1327     // Add a new memory operand for this FI.
1328     assert(MFI.getObjectOffset(FI) != -1);
1329 
1330     // Note: STATEPOINT MMOs are added during SelectionDAG.  STACKMAP, and
1331     // PATCHPOINT should be updated to do the same. (TODO)
1332     if (MI->getOpcode() != TargetOpcode::STATEPOINT) {
1333       auto Flags = MachineMemOperand::MOLoad;
1334       MachineMemOperand *MMO = MF.getMachineMemOperand(
1335           MachinePointerInfo::getFixedStack(MF, FI), Flags,
1336           MF.getDataLayout().getPointerSize(), MFI.getObjectAlign(FI));
1337       MIB->addMemOperand(MF, MMO);
1338     }
1339   }
1340   MBB->insert(MachineBasicBlock::iterator(MI), MIB);
1341   MI->eraseFromParent();
1342   return MBB;
1343 }
1344 
1345 /// findRepresentativeClass - Return the largest legal super-reg register class
1346 /// of the register class for the specified type and its associated "cost".
1347 // This function is in TargetLowering because it uses RegClassForVT which would
1348 // need to be moved to TargetRegisterInfo and would necessitate moving
1349 // isTypeLegal over as well - a massive change that would just require
1350 // TargetLowering having a TargetRegisterInfo class member that it would use.
1351 std::pair<const TargetRegisterClass *, uint8_t>
1352 TargetLoweringBase::findRepresentativeClass(const TargetRegisterInfo *TRI,
1353                                             MVT VT) const {
1354   const TargetRegisterClass *RC = RegClassForVT[VT.SimpleTy];
1355   if (!RC)
1356     return std::make_pair(RC, 0);
1357 
1358   // Compute the set of all super-register classes.
1359   BitVector SuperRegRC(TRI->getNumRegClasses());
1360   for (SuperRegClassIterator RCI(RC, TRI); RCI.isValid(); ++RCI)
1361     SuperRegRC.setBitsInMask(RCI.getMask());
1362 
1363   // Find the first legal register class with the largest spill size.
1364   const TargetRegisterClass *BestRC = RC;
1365   for (unsigned i : SuperRegRC.set_bits()) {
1366     const TargetRegisterClass *SuperRC = TRI->getRegClass(i);
1367     // We want the largest possible spill size.
1368     if (TRI->getSpillSize(*SuperRC) <= TRI->getSpillSize(*BestRC))
1369       continue;
1370     if (!isLegalRC(*TRI, *SuperRC))
1371       continue;
1372     BestRC = SuperRC;
1373   }
1374   return std::make_pair(BestRC, 1);
1375 }
1376 
1377 /// computeRegisterProperties - Once all of the register classes are added,
1378 /// this allows us to compute derived properties we expose.
1379 void TargetLoweringBase::computeRegisterProperties(
1380     const TargetRegisterInfo *TRI) {
1381   static_assert(MVT::VALUETYPE_SIZE <= MVT::MAX_ALLOWED_VALUETYPE,
1382                 "Too many value types for ValueTypeActions to hold!");
1383 
1384   // Everything defaults to needing one register.
1385   for (unsigned i = 0; i != MVT::VALUETYPE_SIZE; ++i) {
1386     NumRegistersForVT[i] = 1;
1387     RegisterTypeForVT[i] = TransformToType[i] = (MVT::SimpleValueType)i;
1388   }
1389   // ...except isVoid, which doesn't need any registers.
1390   NumRegistersForVT[MVT::isVoid] = 0;
1391 
1392   // Find the largest integer register class.
1393   unsigned LargestIntReg = MVT::LAST_INTEGER_VALUETYPE;
1394   for (; RegClassForVT[LargestIntReg] == nullptr; --LargestIntReg)
1395     assert(LargestIntReg != MVT::i1 && "No integer registers defined!");
1396 
1397   // Every integer value type larger than this largest register takes twice as
1398   // many registers to represent as the previous ValueType.
1399   for (unsigned ExpandedReg = LargestIntReg + 1;
1400        ExpandedReg <= MVT::LAST_INTEGER_VALUETYPE; ++ExpandedReg) {
1401     NumRegistersForVT[ExpandedReg] = 2*NumRegistersForVT[ExpandedReg-1];
1402     RegisterTypeForVT[ExpandedReg] = (MVT::SimpleValueType)LargestIntReg;
1403     TransformToType[ExpandedReg] = (MVT::SimpleValueType)(ExpandedReg - 1);
1404     ValueTypeActions.setTypeAction((MVT::SimpleValueType)ExpandedReg,
1405                                    TypeExpandInteger);
1406   }
1407 
1408   // Inspect all of the ValueType's smaller than the largest integer
1409   // register to see which ones need promotion.
1410   unsigned LegalIntReg = LargestIntReg;
1411   for (unsigned IntReg = LargestIntReg - 1;
1412        IntReg >= (unsigned)MVT::i1; --IntReg) {
1413     MVT IVT = (MVT::SimpleValueType)IntReg;
1414     if (isTypeLegal(IVT)) {
1415       LegalIntReg = IntReg;
1416     } else {
1417       RegisterTypeForVT[IntReg] = TransformToType[IntReg] =
1418         (MVT::SimpleValueType)LegalIntReg;
1419       ValueTypeActions.setTypeAction(IVT, TypePromoteInteger);
1420     }
1421   }
1422 
1423   // ppcf128 type is really two f64's.
1424   if (!isTypeLegal(MVT::ppcf128)) {
1425     if (isTypeLegal(MVT::f64)) {
1426       NumRegistersForVT[MVT::ppcf128] = 2*NumRegistersForVT[MVT::f64];
1427       RegisterTypeForVT[MVT::ppcf128] = MVT::f64;
1428       TransformToType[MVT::ppcf128] = MVT::f64;
1429       ValueTypeActions.setTypeAction(MVT::ppcf128, TypeExpandFloat);
1430     } else {
1431       NumRegistersForVT[MVT::ppcf128] = NumRegistersForVT[MVT::i128];
1432       RegisterTypeForVT[MVT::ppcf128] = RegisterTypeForVT[MVT::i128];
1433       TransformToType[MVT::ppcf128] = MVT::i128;
1434       ValueTypeActions.setTypeAction(MVT::ppcf128, TypeSoftenFloat);
1435     }
1436   }
1437 
1438   // Decide how to handle f128. If the target does not have native f128 support,
1439   // expand it to i128 and we will be generating soft float library calls.
1440   if (!isTypeLegal(MVT::f128)) {
1441     NumRegistersForVT[MVT::f128] = NumRegistersForVT[MVT::i128];
1442     RegisterTypeForVT[MVT::f128] = RegisterTypeForVT[MVT::i128];
1443     TransformToType[MVT::f128] = MVT::i128;
1444     ValueTypeActions.setTypeAction(MVT::f128, TypeSoftenFloat);
1445   }
1446 
1447   // Decide how to handle f80. If the target does not have native f80 support,
1448   // expand it to i96 and we will be generating soft float library calls.
1449   if (!isTypeLegal(MVT::f80)) {
1450     NumRegistersForVT[MVT::f80] = 3*NumRegistersForVT[MVT::i32];
1451     RegisterTypeForVT[MVT::f80] = RegisterTypeForVT[MVT::i32];
1452     TransformToType[MVT::f80] = MVT::i32;
1453     ValueTypeActions.setTypeAction(MVT::f80, TypeSoftenFloat);
1454   }
1455 
1456   // Decide how to handle f64. If the target does not have native f64 support,
1457   // expand it to i64 and we will be generating soft float library calls.
1458   if (!isTypeLegal(MVT::f64)) {
1459     NumRegistersForVT[MVT::f64] = NumRegistersForVT[MVT::i64];
1460     RegisterTypeForVT[MVT::f64] = RegisterTypeForVT[MVT::i64];
1461     TransformToType[MVT::f64] = MVT::i64;
1462     ValueTypeActions.setTypeAction(MVT::f64, TypeSoftenFloat);
1463   }
1464 
1465   // Decide how to handle f32. If the target does not have native f32 support,
1466   // expand it to i32 and we will be generating soft float library calls.
1467   if (!isTypeLegal(MVT::f32)) {
1468     NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::i32];
1469     RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::i32];
1470     TransformToType[MVT::f32] = MVT::i32;
1471     ValueTypeActions.setTypeAction(MVT::f32, TypeSoftenFloat);
1472   }
1473 
1474   // Decide how to handle f16. If the target does not have native f16 support,
1475   // promote it to f32, because there are no f16 library calls (except for
1476   // conversions).
1477   if (!isTypeLegal(MVT::f16)) {
1478     // Allow targets to control how we legalize half.
1479     bool SoftPromoteHalfType = softPromoteHalfType();
1480     bool UseFPRegsForHalfType = !SoftPromoteHalfType || useFPRegsForHalfType();
1481 
1482     if (!UseFPRegsForHalfType) {
1483       NumRegistersForVT[MVT::f16] = NumRegistersForVT[MVT::i16];
1484       RegisterTypeForVT[MVT::f16] = RegisterTypeForVT[MVT::i16];
1485     } else {
1486       NumRegistersForVT[MVT::f16] = NumRegistersForVT[MVT::f32];
1487       RegisterTypeForVT[MVT::f16] = RegisterTypeForVT[MVT::f32];
1488     }
1489     TransformToType[MVT::f16] = MVT::f32;
1490     if (SoftPromoteHalfType) {
1491       ValueTypeActions.setTypeAction(MVT::f16, TypeSoftPromoteHalf);
1492     } else {
1493       ValueTypeActions.setTypeAction(MVT::f16, TypePromoteFloat);
1494     }
1495   }
1496 
1497   // Decide how to handle bf16. If the target does not have native bf16 support,
1498   // promote it to f32, because there are no bf16 library calls (except for
1499   // converting from f32 to bf16).
1500   if (!isTypeLegal(MVT::bf16)) {
1501     NumRegistersForVT[MVT::bf16] = NumRegistersForVT[MVT::f32];
1502     RegisterTypeForVT[MVT::bf16] = RegisterTypeForVT[MVT::f32];
1503     TransformToType[MVT::bf16] = MVT::f32;
1504     ValueTypeActions.setTypeAction(MVT::bf16, TypeSoftPromoteHalf);
1505   }
1506 
1507   // Loop over all of the vector value types to see which need transformations.
1508   for (unsigned i = MVT::FIRST_VECTOR_VALUETYPE;
1509        i <= (unsigned)MVT::LAST_VECTOR_VALUETYPE; ++i) {
1510     MVT VT = (MVT::SimpleValueType) i;
1511     if (isTypeLegal(VT))
1512       continue;
1513 
1514     MVT EltVT = VT.getVectorElementType();
1515     ElementCount EC = VT.getVectorElementCount();
1516     bool IsLegalWiderType = false;
1517     bool IsScalable = VT.isScalableVector();
1518     LegalizeTypeAction PreferredAction = getPreferredVectorAction(VT);
1519     switch (PreferredAction) {
1520     case TypePromoteInteger: {
1521       MVT::SimpleValueType EndVT = IsScalable ?
1522                                    MVT::LAST_INTEGER_SCALABLE_VECTOR_VALUETYPE :
1523                                    MVT::LAST_INTEGER_FIXEDLEN_VECTOR_VALUETYPE;
1524       // Try to promote the elements of integer vectors. If no legal
1525       // promotion was found, fall through to the widen-vector method.
1526       for (unsigned nVT = i + 1;
1527            (MVT::SimpleValueType)nVT <= EndVT; ++nVT) {
1528         MVT SVT = (MVT::SimpleValueType) nVT;
1529         // Promote vectors of integers to vectors with the same number
1530         // of elements, with a wider element type.
1531         if (SVT.getScalarSizeInBits() > EltVT.getFixedSizeInBits() &&
1532             SVT.getVectorElementCount() == EC && isTypeLegal(SVT)) {
1533           TransformToType[i] = SVT;
1534           RegisterTypeForVT[i] = SVT;
1535           NumRegistersForVT[i] = 1;
1536           ValueTypeActions.setTypeAction(VT, TypePromoteInteger);
1537           IsLegalWiderType = true;
1538           break;
1539         }
1540       }
1541       if (IsLegalWiderType)
1542         break;
1543       [[fallthrough]];
1544     }
1545 
1546     case TypeWidenVector:
1547       if (isPowerOf2_32(EC.getKnownMinValue())) {
1548         // Try to widen the vector.
1549         for (unsigned nVT = i + 1; nVT <= MVT::LAST_VECTOR_VALUETYPE; ++nVT) {
1550           MVT SVT = (MVT::SimpleValueType) nVT;
1551           if (SVT.getVectorElementType() == EltVT &&
1552               SVT.isScalableVector() == IsScalable &&
1553               SVT.getVectorElementCount().getKnownMinValue() >
1554                   EC.getKnownMinValue() &&
1555               isTypeLegal(SVT)) {
1556             TransformToType[i] = SVT;
1557             RegisterTypeForVT[i] = SVT;
1558             NumRegistersForVT[i] = 1;
1559             ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1560             IsLegalWiderType = true;
1561             break;
1562           }
1563         }
1564         if (IsLegalWiderType)
1565           break;
1566       } else {
1567         // Only widen to the next power of 2 to keep consistency with EVT.
1568         MVT NVT = VT.getPow2VectorType();
1569         if (isTypeLegal(NVT)) {
1570           TransformToType[i] = NVT;
1571           ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1572           RegisterTypeForVT[i] = NVT;
1573           NumRegistersForVT[i] = 1;
1574           break;
1575         }
1576       }
1577       [[fallthrough]];
1578 
1579     case TypeSplitVector:
1580     case TypeScalarizeVector: {
1581       MVT IntermediateVT;
1582       MVT RegisterVT;
1583       unsigned NumIntermediates;
1584       unsigned NumRegisters = getVectorTypeBreakdownMVT(VT, IntermediateVT,
1585           NumIntermediates, RegisterVT, this);
1586       NumRegistersForVT[i] = NumRegisters;
1587       assert(NumRegistersForVT[i] == NumRegisters &&
1588              "NumRegistersForVT size cannot represent NumRegisters!");
1589       RegisterTypeForVT[i] = RegisterVT;
1590 
1591       MVT NVT = VT.getPow2VectorType();
1592       if (NVT == VT) {
1593         // Type is already a power of 2.  The default action is to split.
1594         TransformToType[i] = MVT::Other;
1595         if (PreferredAction == TypeScalarizeVector)
1596           ValueTypeActions.setTypeAction(VT, TypeScalarizeVector);
1597         else if (PreferredAction == TypeSplitVector)
1598           ValueTypeActions.setTypeAction(VT, TypeSplitVector);
1599         else if (EC.getKnownMinValue() > 1)
1600           ValueTypeActions.setTypeAction(VT, TypeSplitVector);
1601         else
1602           ValueTypeActions.setTypeAction(VT, EC.isScalable()
1603                                                  ? TypeScalarizeScalableVector
1604                                                  : TypeScalarizeVector);
1605       } else {
1606         TransformToType[i] = NVT;
1607         ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1608       }
1609       break;
1610     }
1611     default:
1612       llvm_unreachable("Unknown vector legalization action!");
1613     }
1614   }
1615 
1616   // Determine the 'representative' register class for each value type.
1617   // An representative register class is the largest (meaning one which is
1618   // not a sub-register class / subreg register class) legal register class for
1619   // a group of value types. For example, on i386, i8, i16, and i32
1620   // representative would be GR32; while on x86_64 it's GR64.
1621   for (unsigned i = 0; i != MVT::VALUETYPE_SIZE; ++i) {
1622     const TargetRegisterClass* RRC;
1623     uint8_t Cost;
1624     std::tie(RRC, Cost) = findRepresentativeClass(TRI, (MVT::SimpleValueType)i);
1625     RepRegClassForVT[i] = RRC;
1626     RepRegClassCostForVT[i] = Cost;
1627   }
1628 }
1629 
1630 EVT TargetLoweringBase::getSetCCResultType(const DataLayout &DL, LLVMContext &,
1631                                            EVT VT) const {
1632   assert(!VT.isVector() && "No default SetCC type for vectors!");
1633   return getPointerTy(DL).SimpleTy;
1634 }
1635 
1636 MVT::SimpleValueType TargetLoweringBase::getCmpLibcallReturnType() const {
1637   return MVT::i32; // return the default value
1638 }
1639 
1640 /// getVectorTypeBreakdown - Vector types are broken down into some number of
1641 /// legal first class types.  For example, MVT::v8f32 maps to 2 MVT::v4f32
1642 /// with Altivec or SSE1, or 8 promoted MVT::f64 values with the X86 FP stack.
1643 /// Similarly, MVT::v2i64 turns into 4 MVT::i32 values with both PPC and X86.
1644 ///
1645 /// This method returns the number of registers needed, and the VT for each
1646 /// register.  It also returns the VT and quantity of the intermediate values
1647 /// before they are promoted/expanded.
1648 unsigned TargetLoweringBase::getVectorTypeBreakdown(LLVMContext &Context,
1649                                                     EVT VT, EVT &IntermediateVT,
1650                                                     unsigned &NumIntermediates,
1651                                                     MVT &RegisterVT) const {
1652   ElementCount EltCnt = VT.getVectorElementCount();
1653 
1654   // If there is a wider vector type with the same element type as this one,
1655   // or a promoted vector type that has the same number of elements which
1656   // are wider, then we should convert to that legal vector type.
1657   // This handles things like <2 x float> -> <4 x float> and
1658   // <4 x i1> -> <4 x i32>.
1659   LegalizeTypeAction TA = getTypeAction(Context, VT);
1660   if (!EltCnt.isScalar() &&
1661       (TA == TypeWidenVector || TA == TypePromoteInteger)) {
1662     EVT RegisterEVT = getTypeToTransformTo(Context, VT);
1663     if (isTypeLegal(RegisterEVT)) {
1664       IntermediateVT = RegisterEVT;
1665       RegisterVT = RegisterEVT.getSimpleVT();
1666       NumIntermediates = 1;
1667       return 1;
1668     }
1669   }
1670 
1671   // Figure out the right, legal destination reg to copy into.
1672   EVT EltTy = VT.getVectorElementType();
1673 
1674   unsigned NumVectorRegs = 1;
1675 
1676   // Scalable vectors cannot be scalarized, so handle the legalisation of the
1677   // types like done elsewhere in SelectionDAG.
1678   if (EltCnt.isScalable()) {
1679     LegalizeKind LK;
1680     EVT PartVT = VT;
1681     do {
1682       // Iterate until we've found a legal (part) type to hold VT.
1683       LK = getTypeConversion(Context, PartVT);
1684       PartVT = LK.second;
1685     } while (LK.first != TypeLegal);
1686 
1687     if (!PartVT.isVector()) {
1688       report_fatal_error(
1689           "Don't know how to legalize this scalable vector type");
1690     }
1691 
1692     NumIntermediates =
1693         divideCeil(VT.getVectorElementCount().getKnownMinValue(),
1694                    PartVT.getVectorElementCount().getKnownMinValue());
1695     IntermediateVT = PartVT;
1696     RegisterVT = getRegisterType(Context, IntermediateVT);
1697     return NumIntermediates;
1698   }
1699 
1700   // FIXME: We don't support non-power-of-2-sized vectors for now.  Ideally
1701   // we could break down into LHS/RHS like LegalizeDAG does.
1702   if (!isPowerOf2_32(EltCnt.getKnownMinValue())) {
1703     NumVectorRegs = EltCnt.getKnownMinValue();
1704     EltCnt = ElementCount::getFixed(1);
1705   }
1706 
1707   // Divide the input until we get to a supported size.  This will always
1708   // end with a scalar if the target doesn't support vectors.
1709   while (EltCnt.getKnownMinValue() > 1 &&
1710          !isTypeLegal(EVT::getVectorVT(Context, EltTy, EltCnt))) {
1711     EltCnt = EltCnt.divideCoefficientBy(2);
1712     NumVectorRegs <<= 1;
1713   }
1714 
1715   NumIntermediates = NumVectorRegs;
1716 
1717   EVT NewVT = EVT::getVectorVT(Context, EltTy, EltCnt);
1718   if (!isTypeLegal(NewVT))
1719     NewVT = EltTy;
1720   IntermediateVT = NewVT;
1721 
1722   MVT DestVT = getRegisterType(Context, NewVT);
1723   RegisterVT = DestVT;
1724 
1725   if (EVT(DestVT).bitsLT(NewVT)) {  // Value is expanded, e.g. i64 -> i16.
1726     TypeSize NewVTSize = NewVT.getSizeInBits();
1727     // Convert sizes such as i33 to i64.
1728     if (!llvm::has_single_bit<uint32_t>(NewVTSize.getKnownMinValue()))
1729       NewVTSize = NewVTSize.coefficientNextPowerOf2();
1730     return NumVectorRegs*(NewVTSize/DestVT.getSizeInBits());
1731   }
1732 
1733   // Otherwise, promotion or legal types use the same number of registers as
1734   // the vector decimated to the appropriate level.
1735   return NumVectorRegs;
1736 }
1737 
1738 bool TargetLoweringBase::isSuitableForJumpTable(const SwitchInst *SI,
1739                                                 uint64_t NumCases,
1740                                                 uint64_t Range,
1741                                                 ProfileSummaryInfo *PSI,
1742                                                 BlockFrequencyInfo *BFI) const {
1743   // FIXME: This function check the maximum table size and density, but the
1744   // minimum size is not checked. It would be nice if the minimum size is
1745   // also combined within this function. Currently, the minimum size check is
1746   // performed in findJumpTable() in SelectionDAGBuiler and
1747   // getEstimatedNumberOfCaseClusters() in BasicTTIImpl.
1748   const bool OptForSize =
1749       SI->getParent()->getParent()->hasOptSize() ||
1750       llvm::shouldOptimizeForSize(SI->getParent(), PSI, BFI);
1751   const unsigned MinDensity = getMinimumJumpTableDensity(OptForSize);
1752   const unsigned MaxJumpTableSize = getMaximumJumpTableSize();
1753 
1754   // Check whether the number of cases is small enough and
1755   // the range is dense enough for a jump table.
1756   return (OptForSize || Range <= MaxJumpTableSize) &&
1757          (NumCases * 100 >= Range * MinDensity);
1758 }
1759 
1760 MVT TargetLoweringBase::getPreferredSwitchConditionType(LLVMContext &Context,
1761                                                         EVT ConditionVT) const {
1762   return getRegisterType(Context, ConditionVT);
1763 }
1764 
1765 /// Get the EVTs and ArgFlags collections that represent the legalized return
1766 /// type of the given function.  This does not require a DAG or a return value,
1767 /// and is suitable for use before any DAGs for the function are constructed.
1768 /// TODO: Move this out of TargetLowering.cpp.
1769 void llvm::GetReturnInfo(CallingConv::ID CC, Type *ReturnType,
1770                          AttributeList attr,
1771                          SmallVectorImpl<ISD::OutputArg> &Outs,
1772                          const TargetLowering &TLI, const DataLayout &DL) {
1773   SmallVector<EVT, 4> ValueVTs;
1774   ComputeValueVTs(TLI, DL, ReturnType, ValueVTs);
1775   unsigned NumValues = ValueVTs.size();
1776   if (NumValues == 0) return;
1777 
1778   for (unsigned j = 0, f = NumValues; j != f; ++j) {
1779     EVT VT = ValueVTs[j];
1780     ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
1781 
1782     if (attr.hasRetAttr(Attribute::SExt))
1783       ExtendKind = ISD::SIGN_EXTEND;
1784     else if (attr.hasRetAttr(Attribute::ZExt))
1785       ExtendKind = ISD::ZERO_EXTEND;
1786 
1787     if (ExtendKind != ISD::ANY_EXTEND && VT.isInteger())
1788       VT = TLI.getTypeForExtReturn(ReturnType->getContext(), VT, ExtendKind);
1789 
1790     unsigned NumParts =
1791         TLI.getNumRegistersForCallingConv(ReturnType->getContext(), CC, VT);
1792     MVT PartVT =
1793         TLI.getRegisterTypeForCallingConv(ReturnType->getContext(), CC, VT);
1794 
1795     // 'inreg' on function refers to return value
1796     ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy();
1797     if (attr.hasRetAttr(Attribute::InReg))
1798       Flags.setInReg();
1799 
1800     // Propagate extension type if any
1801     if (attr.hasRetAttr(Attribute::SExt))
1802       Flags.setSExt();
1803     else if (attr.hasRetAttr(Attribute::ZExt))
1804       Flags.setZExt();
1805 
1806     for (unsigned i = 0; i < NumParts; ++i)
1807       Outs.push_back(ISD::OutputArg(Flags, PartVT, VT, /*isfixed=*/true, 0, 0));
1808   }
1809 }
1810 
1811 /// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
1812 /// function arguments in the caller parameter area.  This is the actual
1813 /// alignment, not its logarithm.
1814 uint64_t TargetLoweringBase::getByValTypeAlignment(Type *Ty,
1815                                                    const DataLayout &DL) const {
1816   return DL.getABITypeAlign(Ty).value();
1817 }
1818 
1819 bool TargetLoweringBase::allowsMemoryAccessForAlignment(
1820     LLVMContext &Context, const DataLayout &DL, EVT VT, unsigned AddrSpace,
1821     Align Alignment, MachineMemOperand::Flags Flags, unsigned *Fast) const {
1822   // Check if the specified alignment is sufficient based on the data layout.
1823   // TODO: While using the data layout works in practice, a better solution
1824   // would be to implement this check directly (make this a virtual function).
1825   // For example, the ABI alignment may change based on software platform while
1826   // this function should only be affected by hardware implementation.
1827   Type *Ty = VT.getTypeForEVT(Context);
1828   if (VT.isZeroSized() || Alignment >= DL.getABITypeAlign(Ty)) {
1829     // Assume that an access that meets the ABI-specified alignment is fast.
1830     if (Fast != nullptr)
1831       *Fast = 1;
1832     return true;
1833   }
1834 
1835   // This is a misaligned access.
1836   return allowsMisalignedMemoryAccesses(VT, AddrSpace, Alignment, Flags, Fast);
1837 }
1838 
1839 bool TargetLoweringBase::allowsMemoryAccessForAlignment(
1840     LLVMContext &Context, const DataLayout &DL, EVT VT,
1841     const MachineMemOperand &MMO, unsigned *Fast) const {
1842   return allowsMemoryAccessForAlignment(Context, DL, VT, MMO.getAddrSpace(),
1843                                         MMO.getAlign(), MMO.getFlags(), Fast);
1844 }
1845 
1846 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1847                                             const DataLayout &DL, EVT VT,
1848                                             unsigned AddrSpace, Align Alignment,
1849                                             MachineMemOperand::Flags Flags,
1850                                             unsigned *Fast) const {
1851   return allowsMemoryAccessForAlignment(Context, DL, VT, AddrSpace, Alignment,
1852                                         Flags, Fast);
1853 }
1854 
1855 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1856                                             const DataLayout &DL, EVT VT,
1857                                             const MachineMemOperand &MMO,
1858                                             unsigned *Fast) const {
1859   return allowsMemoryAccess(Context, DL, VT, MMO.getAddrSpace(), MMO.getAlign(),
1860                             MMO.getFlags(), Fast);
1861 }
1862 
1863 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1864                                             const DataLayout &DL, LLT Ty,
1865                                             const MachineMemOperand &MMO,
1866                                             unsigned *Fast) const {
1867   EVT VT = getApproximateEVTForLLT(Ty, DL, Context);
1868   return allowsMemoryAccess(Context, DL, VT, MMO.getAddrSpace(), MMO.getAlign(),
1869                             MMO.getFlags(), Fast);
1870 }
1871 
1872 //===----------------------------------------------------------------------===//
1873 //  TargetTransformInfo Helpers
1874 //===----------------------------------------------------------------------===//
1875 
1876 int TargetLoweringBase::InstructionOpcodeToISD(unsigned Opcode) const {
1877   enum InstructionOpcodes {
1878 #define HANDLE_INST(NUM, OPCODE, CLASS) OPCODE = NUM,
1879 #define LAST_OTHER_INST(NUM) InstructionOpcodesCount = NUM
1880 #include "llvm/IR/Instruction.def"
1881   };
1882   switch (static_cast<InstructionOpcodes>(Opcode)) {
1883   case Ret:            return 0;
1884   case Br:             return 0;
1885   case Switch:         return 0;
1886   case IndirectBr:     return 0;
1887   case Invoke:         return 0;
1888   case CallBr:         return 0;
1889   case Resume:         return 0;
1890   case Unreachable:    return 0;
1891   case CleanupRet:     return 0;
1892   case CatchRet:       return 0;
1893   case CatchPad:       return 0;
1894   case CatchSwitch:    return 0;
1895   case CleanupPad:     return 0;
1896   case FNeg:           return ISD::FNEG;
1897   case Add:            return ISD::ADD;
1898   case FAdd:           return ISD::FADD;
1899   case Sub:            return ISD::SUB;
1900   case FSub:           return ISD::FSUB;
1901   case Mul:            return ISD::MUL;
1902   case FMul:           return ISD::FMUL;
1903   case UDiv:           return ISD::UDIV;
1904   case SDiv:           return ISD::SDIV;
1905   case FDiv:           return ISD::FDIV;
1906   case URem:           return ISD::UREM;
1907   case SRem:           return ISD::SREM;
1908   case FRem:           return ISD::FREM;
1909   case Shl:            return ISD::SHL;
1910   case LShr:           return ISD::SRL;
1911   case AShr:           return ISD::SRA;
1912   case And:            return ISD::AND;
1913   case Or:             return ISD::OR;
1914   case Xor:            return ISD::XOR;
1915   case Alloca:         return 0;
1916   case Load:           return ISD::LOAD;
1917   case Store:          return ISD::STORE;
1918   case GetElementPtr:  return 0;
1919   case Fence:          return 0;
1920   case AtomicCmpXchg:  return 0;
1921   case AtomicRMW:      return 0;
1922   case Trunc:          return ISD::TRUNCATE;
1923   case ZExt:           return ISD::ZERO_EXTEND;
1924   case SExt:           return ISD::SIGN_EXTEND;
1925   case FPToUI:         return ISD::FP_TO_UINT;
1926   case FPToSI:         return ISD::FP_TO_SINT;
1927   case UIToFP:         return ISD::UINT_TO_FP;
1928   case SIToFP:         return ISD::SINT_TO_FP;
1929   case FPTrunc:        return ISD::FP_ROUND;
1930   case FPExt:          return ISD::FP_EXTEND;
1931   case PtrToInt:       return ISD::BITCAST;
1932   case IntToPtr:       return ISD::BITCAST;
1933   case BitCast:        return ISD::BITCAST;
1934   case AddrSpaceCast:  return ISD::ADDRSPACECAST;
1935   case ICmp:           return ISD::SETCC;
1936   case FCmp:           return ISD::SETCC;
1937   case PHI:            return 0;
1938   case Call:           return 0;
1939   case Select:         return ISD::SELECT;
1940   case UserOp1:        return 0;
1941   case UserOp2:        return 0;
1942   case VAArg:          return 0;
1943   case ExtractElement: return ISD::EXTRACT_VECTOR_ELT;
1944   case InsertElement:  return ISD::INSERT_VECTOR_ELT;
1945   case ShuffleVector:  return ISD::VECTOR_SHUFFLE;
1946   case ExtractValue:   return ISD::MERGE_VALUES;
1947   case InsertValue:    return ISD::MERGE_VALUES;
1948   case LandingPad:     return 0;
1949   case Freeze:         return ISD::FREEZE;
1950   }
1951 
1952   llvm_unreachable("Unknown instruction type encountered!");
1953 }
1954 
1955 Value *
1956 TargetLoweringBase::getDefaultSafeStackPointerLocation(IRBuilderBase &IRB,
1957                                                        bool UseTLS) const {
1958   // compiler-rt provides a variable with a magic name.  Targets that do not
1959   // link with compiler-rt may also provide such a variable.
1960   Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1961   const char *UnsafeStackPtrVar = "__safestack_unsafe_stack_ptr";
1962   auto UnsafeStackPtr =
1963       dyn_cast_or_null<GlobalVariable>(M->getNamedValue(UnsafeStackPtrVar));
1964 
1965   Type *StackPtrTy = PointerType::getUnqual(M->getContext());
1966 
1967   if (!UnsafeStackPtr) {
1968     auto TLSModel = UseTLS ?
1969         GlobalValue::InitialExecTLSModel :
1970         GlobalValue::NotThreadLocal;
1971     // The global variable is not defined yet, define it ourselves.
1972     // We use the initial-exec TLS model because we do not support the
1973     // variable living anywhere other than in the main executable.
1974     UnsafeStackPtr = new GlobalVariable(
1975         *M, StackPtrTy, false, GlobalValue::ExternalLinkage, nullptr,
1976         UnsafeStackPtrVar, nullptr, TLSModel);
1977   } else {
1978     // The variable exists, check its type and attributes.
1979     if (UnsafeStackPtr->getValueType() != StackPtrTy)
1980       report_fatal_error(Twine(UnsafeStackPtrVar) + " must have void* type");
1981     if (UseTLS != UnsafeStackPtr->isThreadLocal())
1982       report_fatal_error(Twine(UnsafeStackPtrVar) + " must " +
1983                          (UseTLS ? "" : "not ") + "be thread-local");
1984   }
1985   return UnsafeStackPtr;
1986 }
1987 
1988 Value *
1989 TargetLoweringBase::getSafeStackPointerLocation(IRBuilderBase &IRB) const {
1990   if (!TM.getTargetTriple().isAndroid())
1991     return getDefaultSafeStackPointerLocation(IRB, true);
1992 
1993   // Android provides a libc function to retrieve the address of the current
1994   // thread's unsafe stack pointer.
1995   Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1996   auto *PtrTy = PointerType::getUnqual(M->getContext());
1997   FunctionCallee Fn =
1998       M->getOrInsertFunction("__safestack_pointer_address", PtrTy);
1999   return IRB.CreateCall(Fn);
2000 }
2001 
2002 //===----------------------------------------------------------------------===//
2003 //  Loop Strength Reduction hooks
2004 //===----------------------------------------------------------------------===//
2005 
2006 /// isLegalAddressingMode - Return true if the addressing mode represented
2007 /// by AM is legal for this target, for a load/store of the specified type.
2008 bool TargetLoweringBase::isLegalAddressingMode(const DataLayout &DL,
2009                                                const AddrMode &AM, Type *Ty,
2010                                                unsigned AS, Instruction *I) const {
2011   // The default implementation of this implements a conservative RISCy, r+r and
2012   // r+i addr mode.
2013 
2014   // Allows a sign-extended 16-bit immediate field.
2015   if (AM.BaseOffs <= -(1LL << 16) || AM.BaseOffs >= (1LL << 16)-1)
2016     return false;
2017 
2018   // No global is ever allowed as a base.
2019   if (AM.BaseGV)
2020     return false;
2021 
2022   // Only support r+r,
2023   switch (AM.Scale) {
2024   case 0:  // "r+i" or just "i", depending on HasBaseReg.
2025     break;
2026   case 1:
2027     if (AM.HasBaseReg && AM.BaseOffs)  // "r+r+i" is not allowed.
2028       return false;
2029     // Otherwise we have r+r or r+i.
2030     break;
2031   case 2:
2032     if (AM.HasBaseReg || AM.BaseOffs)  // 2*r+r  or  2*r+i is not allowed.
2033       return false;
2034     // Allow 2*r as r+r.
2035     break;
2036   default: // Don't allow n * r
2037     return false;
2038   }
2039 
2040   return true;
2041 }
2042 
2043 //===----------------------------------------------------------------------===//
2044 //  Stack Protector
2045 //===----------------------------------------------------------------------===//
2046 
2047 // For OpenBSD return its special guard variable. Otherwise return nullptr,
2048 // so that SelectionDAG handle SSP.
2049 Value *TargetLoweringBase::getIRStackGuard(IRBuilderBase &IRB) const {
2050   if (getTargetMachine().getTargetTriple().isOSOpenBSD()) {
2051     Module &M = *IRB.GetInsertBlock()->getParent()->getParent();
2052     PointerType *PtrTy = PointerType::getUnqual(M.getContext());
2053     Constant *C = M.getOrInsertGlobal("__guard_local", PtrTy);
2054     if (GlobalVariable *G = dyn_cast_or_null<GlobalVariable>(C))
2055       G->setVisibility(GlobalValue::HiddenVisibility);
2056     return C;
2057   }
2058   return nullptr;
2059 }
2060 
2061 // Currently only support "standard" __stack_chk_guard.
2062 // TODO: add LOAD_STACK_GUARD support.
2063 void TargetLoweringBase::insertSSPDeclarations(Module &M) const {
2064   if (!M.getNamedValue("__stack_chk_guard")) {
2065     auto *GV = new GlobalVariable(M, PointerType::getUnqual(M.getContext()),
2066                                   false, GlobalVariable::ExternalLinkage,
2067                                   nullptr, "__stack_chk_guard");
2068 
2069     // FreeBSD has "__stack_chk_guard" defined externally on libc.so
2070     if (M.getDirectAccessExternalData() &&
2071         !TM.getTargetTriple().isWindowsGNUEnvironment() &&
2072         !TM.getTargetTriple().isOSFreeBSD() &&
2073         (!TM.getTargetTriple().isOSDarwin() ||
2074          TM.getRelocationModel() == Reloc::Static))
2075       GV->setDSOLocal(true);
2076   }
2077 }
2078 
2079 // Currently only support "standard" __stack_chk_guard.
2080 // TODO: add LOAD_STACK_GUARD support.
2081 Value *TargetLoweringBase::getSDagStackGuard(const Module &M) const {
2082   return M.getNamedValue("__stack_chk_guard");
2083 }
2084 
2085 Function *TargetLoweringBase::getSSPStackGuardCheck(const Module &M) const {
2086   return nullptr;
2087 }
2088 
2089 unsigned TargetLoweringBase::getMinimumJumpTableEntries() const {
2090   return MinimumJumpTableEntries;
2091 }
2092 
2093 void TargetLoweringBase::setMinimumJumpTableEntries(unsigned Val) {
2094   MinimumJumpTableEntries = Val;
2095 }
2096 
2097 unsigned TargetLoweringBase::getMinimumJumpTableDensity(bool OptForSize) const {
2098   return OptForSize ? OptsizeJumpTableDensity : JumpTableDensity;
2099 }
2100 
2101 unsigned TargetLoweringBase::getMaximumJumpTableSize() const {
2102   return MaximumJumpTableSize;
2103 }
2104 
2105 void TargetLoweringBase::setMaximumJumpTableSize(unsigned Val) {
2106   MaximumJumpTableSize = Val;
2107 }
2108 
2109 bool TargetLoweringBase::isJumpTableRelative() const {
2110   return getTargetMachine().isPositionIndependent();
2111 }
2112 
2113 Align TargetLoweringBase::getPrefLoopAlignment(MachineLoop *ML) const {
2114   if (TM.Options.LoopAlignment)
2115     return Align(TM.Options.LoopAlignment);
2116   return PrefLoopAlignment;
2117 }
2118 
2119 unsigned TargetLoweringBase::getMaxPermittedBytesForAlignment(
2120     MachineBasicBlock *MBB) const {
2121   return MaxBytesForAlignment;
2122 }
2123 
2124 //===----------------------------------------------------------------------===//
2125 //  Reciprocal Estimates
2126 //===----------------------------------------------------------------------===//
2127 
2128 /// Get the reciprocal estimate attribute string for a function that will
2129 /// override the target defaults.
2130 static StringRef getRecipEstimateForFunc(MachineFunction &MF) {
2131   const Function &F = MF.getFunction();
2132   return F.getFnAttribute("reciprocal-estimates").getValueAsString();
2133 }
2134 
2135 /// Construct a string for the given reciprocal operation of the given type.
2136 /// This string should match the corresponding option to the front-end's
2137 /// "-mrecip" flag assuming those strings have been passed through in an
2138 /// attribute string. For example, "vec-divf" for a division of a vXf32.
2139 static std::string getReciprocalOpName(bool IsSqrt, EVT VT) {
2140   std::string Name = VT.isVector() ? "vec-" : "";
2141 
2142   Name += IsSqrt ? "sqrt" : "div";
2143 
2144   // TODO: Handle other float types?
2145   if (VT.getScalarType() == MVT::f64) {
2146     Name += "d";
2147   } else if (VT.getScalarType() == MVT::f16) {
2148     Name += "h";
2149   } else {
2150     assert(VT.getScalarType() == MVT::f32 &&
2151            "Unexpected FP type for reciprocal estimate");
2152     Name += "f";
2153   }
2154 
2155   return Name;
2156 }
2157 
2158 /// Return the character position and value (a single numeric character) of a
2159 /// customized refinement operation in the input string if it exists. Return
2160 /// false if there is no customized refinement step count.
2161 static bool parseRefinementStep(StringRef In, size_t &Position,
2162                                 uint8_t &Value) {
2163   const char RefStepToken = ':';
2164   Position = In.find(RefStepToken);
2165   if (Position == StringRef::npos)
2166     return false;
2167 
2168   StringRef RefStepString = In.substr(Position + 1);
2169   // Allow exactly one numeric character for the additional refinement
2170   // step parameter.
2171   if (RefStepString.size() == 1) {
2172     char RefStepChar = RefStepString[0];
2173     if (isDigit(RefStepChar)) {
2174       Value = RefStepChar - '0';
2175       return true;
2176     }
2177   }
2178   report_fatal_error("Invalid refinement step for -recip.");
2179 }
2180 
2181 /// For the input attribute string, return one of the ReciprocalEstimate enum
2182 /// status values (enabled, disabled, or not specified) for this operation on
2183 /// the specified data type.
2184 static int getOpEnabled(bool IsSqrt, EVT VT, StringRef Override) {
2185   if (Override.empty())
2186     return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2187 
2188   SmallVector<StringRef, 4> OverrideVector;
2189   Override.split(OverrideVector, ',');
2190   unsigned NumArgs = OverrideVector.size();
2191 
2192   // Check if "all", "none", or "default" was specified.
2193   if (NumArgs == 1) {
2194     // Look for an optional setting of the number of refinement steps needed
2195     // for this type of reciprocal operation.
2196     size_t RefPos;
2197     uint8_t RefSteps;
2198     if (parseRefinementStep(Override, RefPos, RefSteps)) {
2199       // Split the string for further processing.
2200       Override = Override.substr(0, RefPos);
2201     }
2202 
2203     // All reciprocal types are enabled.
2204     if (Override == "all")
2205       return TargetLoweringBase::ReciprocalEstimate::Enabled;
2206 
2207     // All reciprocal types are disabled.
2208     if (Override == "none")
2209       return TargetLoweringBase::ReciprocalEstimate::Disabled;
2210 
2211     // Target defaults for enablement are used.
2212     if (Override == "default")
2213       return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2214   }
2215 
2216   // The attribute string may omit the size suffix ('f'/'d').
2217   std::string VTName = getReciprocalOpName(IsSqrt, VT);
2218   std::string VTNameNoSize = VTName;
2219   VTNameNoSize.pop_back();
2220   static const char DisabledPrefix = '!';
2221 
2222   for (StringRef RecipType : OverrideVector) {
2223     size_t RefPos;
2224     uint8_t RefSteps;
2225     if (parseRefinementStep(RecipType, RefPos, RefSteps))
2226       RecipType = RecipType.substr(0, RefPos);
2227 
2228     // Ignore the disablement token for string matching.
2229     bool IsDisabled = RecipType[0] == DisabledPrefix;
2230     if (IsDisabled)
2231       RecipType = RecipType.substr(1);
2232 
2233     if (RecipType.equals(VTName) || RecipType.equals(VTNameNoSize))
2234       return IsDisabled ? TargetLoweringBase::ReciprocalEstimate::Disabled
2235                         : TargetLoweringBase::ReciprocalEstimate::Enabled;
2236   }
2237 
2238   return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2239 }
2240 
2241 /// For the input attribute string, return the customized refinement step count
2242 /// for this operation on the specified data type. If the step count does not
2243 /// exist, return the ReciprocalEstimate enum value for unspecified.
2244 static int getOpRefinementSteps(bool IsSqrt, EVT VT, StringRef Override) {
2245   if (Override.empty())
2246     return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2247 
2248   SmallVector<StringRef, 4> OverrideVector;
2249   Override.split(OverrideVector, ',');
2250   unsigned NumArgs = OverrideVector.size();
2251 
2252   // Check if "all", "default", or "none" was specified.
2253   if (NumArgs == 1) {
2254     // Look for an optional setting of the number of refinement steps needed
2255     // for this type of reciprocal operation.
2256     size_t RefPos;
2257     uint8_t RefSteps;
2258     if (!parseRefinementStep(Override, RefPos, RefSteps))
2259       return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2260 
2261     // Split the string for further processing.
2262     Override = Override.substr(0, RefPos);
2263     assert(Override != "none" &&
2264            "Disabled reciprocals, but specifed refinement steps?");
2265 
2266     // If this is a general override, return the specified number of steps.
2267     if (Override == "all" || Override == "default")
2268       return RefSteps;
2269   }
2270 
2271   // The attribute string may omit the size suffix ('f'/'d').
2272   std::string VTName = getReciprocalOpName(IsSqrt, VT);
2273   std::string VTNameNoSize = VTName;
2274   VTNameNoSize.pop_back();
2275 
2276   for (StringRef RecipType : OverrideVector) {
2277     size_t RefPos;
2278     uint8_t RefSteps;
2279     if (!parseRefinementStep(RecipType, RefPos, RefSteps))
2280       continue;
2281 
2282     RecipType = RecipType.substr(0, RefPos);
2283     if (RecipType.equals(VTName) || RecipType.equals(VTNameNoSize))
2284       return RefSteps;
2285   }
2286 
2287   return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2288 }
2289 
2290 int TargetLoweringBase::getRecipEstimateSqrtEnabled(EVT VT,
2291                                                     MachineFunction &MF) const {
2292   return getOpEnabled(true, VT, getRecipEstimateForFunc(MF));
2293 }
2294 
2295 int TargetLoweringBase::getRecipEstimateDivEnabled(EVT VT,
2296                                                    MachineFunction &MF) const {
2297   return getOpEnabled(false, VT, getRecipEstimateForFunc(MF));
2298 }
2299 
2300 int TargetLoweringBase::getSqrtRefinementSteps(EVT VT,
2301                                                MachineFunction &MF) const {
2302   return getOpRefinementSteps(true, VT, getRecipEstimateForFunc(MF));
2303 }
2304 
2305 int TargetLoweringBase::getDivRefinementSteps(EVT VT,
2306                                               MachineFunction &MF) const {
2307   return getOpRefinementSteps(false, VT, getRecipEstimateForFunc(MF));
2308 }
2309 
2310 bool TargetLoweringBase::isLoadBitCastBeneficial(
2311     EVT LoadVT, EVT BitcastVT, const SelectionDAG &DAG,
2312     const MachineMemOperand &MMO) const {
2313   // Single-element vectors are scalarized, so we should generally avoid having
2314   // any memory operations on such types, as they would get scalarized too.
2315   if (LoadVT.isFixedLengthVector() && BitcastVT.isFixedLengthVector() &&
2316       BitcastVT.getVectorNumElements() == 1)
2317     return false;
2318 
2319   // Don't do if we could do an indexed load on the original type, but not on
2320   // the new one.
2321   if (!LoadVT.isSimple() || !BitcastVT.isSimple())
2322     return true;
2323 
2324   MVT LoadMVT = LoadVT.getSimpleVT();
2325 
2326   // Don't bother doing this if it's just going to be promoted again later, as
2327   // doing so might interfere with other combines.
2328   if (getOperationAction(ISD::LOAD, LoadMVT) == Promote &&
2329       getTypeToPromoteTo(ISD::LOAD, LoadMVT) == BitcastVT.getSimpleVT())
2330     return false;
2331 
2332   unsigned Fast = 0;
2333   return allowsMemoryAccess(*DAG.getContext(), DAG.getDataLayout(), BitcastVT,
2334                             MMO, &Fast) &&
2335          Fast;
2336 }
2337 
2338 void TargetLoweringBase::finalizeLowering(MachineFunction &MF) const {
2339   MF.getRegInfo().freezeReservedRegs(MF);
2340 }
2341 
2342 MachineMemOperand::Flags TargetLoweringBase::getLoadMemOperandFlags(
2343     const LoadInst &LI, const DataLayout &DL, AssumptionCache *AC,
2344     const TargetLibraryInfo *LibInfo) const {
2345   MachineMemOperand::Flags Flags = MachineMemOperand::MOLoad;
2346   if (LI.isVolatile())
2347     Flags |= MachineMemOperand::MOVolatile;
2348 
2349   if (LI.hasMetadata(LLVMContext::MD_nontemporal))
2350     Flags |= MachineMemOperand::MONonTemporal;
2351 
2352   if (LI.hasMetadata(LLVMContext::MD_invariant_load))
2353     Flags |= MachineMemOperand::MOInvariant;
2354 
2355   if (isDereferenceableAndAlignedPointer(LI.getPointerOperand(), LI.getType(),
2356                                          LI.getAlign(), DL, &LI, AC,
2357                                          /*DT=*/nullptr, LibInfo))
2358     Flags |= MachineMemOperand::MODereferenceable;
2359 
2360   Flags |= getTargetMMOFlags(LI);
2361   return Flags;
2362 }
2363 
2364 MachineMemOperand::Flags
2365 TargetLoweringBase::getStoreMemOperandFlags(const StoreInst &SI,
2366                                             const DataLayout &DL) const {
2367   MachineMemOperand::Flags Flags = MachineMemOperand::MOStore;
2368 
2369   if (SI.isVolatile())
2370     Flags |= MachineMemOperand::MOVolatile;
2371 
2372   if (SI.hasMetadata(LLVMContext::MD_nontemporal))
2373     Flags |= MachineMemOperand::MONonTemporal;
2374 
2375   // FIXME: Not preserving dereferenceable
2376   Flags |= getTargetMMOFlags(SI);
2377   return Flags;
2378 }
2379 
2380 MachineMemOperand::Flags
2381 TargetLoweringBase::getAtomicMemOperandFlags(const Instruction &AI,
2382                                              const DataLayout &DL) const {
2383   auto Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOStore;
2384 
2385   if (const AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(&AI)) {
2386     if (RMW->isVolatile())
2387       Flags |= MachineMemOperand::MOVolatile;
2388   } else if (const AtomicCmpXchgInst *CmpX = dyn_cast<AtomicCmpXchgInst>(&AI)) {
2389     if (CmpX->isVolatile())
2390       Flags |= MachineMemOperand::MOVolatile;
2391   } else
2392     llvm_unreachable("not an atomic instruction");
2393 
2394   // FIXME: Not preserving dereferenceable
2395   Flags |= getTargetMMOFlags(AI);
2396   return Flags;
2397 }
2398 
2399 Instruction *TargetLoweringBase::emitLeadingFence(IRBuilderBase &Builder,
2400                                                   Instruction *Inst,
2401                                                   AtomicOrdering Ord) const {
2402   if (isReleaseOrStronger(Ord) && Inst->hasAtomicStore())
2403     return Builder.CreateFence(Ord);
2404   else
2405     return nullptr;
2406 }
2407 
2408 Instruction *TargetLoweringBase::emitTrailingFence(IRBuilderBase &Builder,
2409                                                    Instruction *Inst,
2410                                                    AtomicOrdering Ord) const {
2411   if (isAcquireOrStronger(Ord))
2412     return Builder.CreateFence(Ord);
2413   else
2414     return nullptr;
2415 }
2416 
2417 //===----------------------------------------------------------------------===//
2418 //  GlobalISel Hooks
2419 //===----------------------------------------------------------------------===//
2420 
2421 bool TargetLoweringBase::shouldLocalize(const MachineInstr &MI,
2422                                         const TargetTransformInfo *TTI) const {
2423   auto &MF = *MI.getMF();
2424   auto &MRI = MF.getRegInfo();
2425   // Assuming a spill and reload of a value has a cost of 1 instruction each,
2426   // this helper function computes the maximum number of uses we should consider
2427   // for remat. E.g. on arm64 global addresses take 2 insts to materialize. We
2428   // break even in terms of code size when the original MI has 2 users vs
2429   // choosing to potentially spill. Any more than 2 users we we have a net code
2430   // size increase. This doesn't take into account register pressure though.
2431   auto maxUses = [](unsigned RematCost) {
2432     // A cost of 1 means remats are basically free.
2433     if (RematCost == 1)
2434       return std::numeric_limits<unsigned>::max();
2435     if (RematCost == 2)
2436       return 2U;
2437 
2438     // Remat is too expensive, only sink if there's one user.
2439     if (RematCost > 2)
2440       return 1U;
2441     llvm_unreachable("Unexpected remat cost");
2442   };
2443 
2444   switch (MI.getOpcode()) {
2445   default:
2446     return false;
2447   // Constants-like instructions should be close to their users.
2448   // We don't want long live-ranges for them.
2449   case TargetOpcode::G_CONSTANT:
2450   case TargetOpcode::G_FCONSTANT:
2451   case TargetOpcode::G_FRAME_INDEX:
2452   case TargetOpcode::G_INTTOPTR:
2453     return true;
2454   case TargetOpcode::G_GLOBAL_VALUE: {
2455     unsigned RematCost = TTI->getGISelRematGlobalCost();
2456     Register Reg = MI.getOperand(0).getReg();
2457     unsigned MaxUses = maxUses(RematCost);
2458     if (MaxUses == UINT_MAX)
2459       return true; // Remats are "free" so always localize.
2460     return MRI.hasAtMostUserInstrs(Reg, MaxUses);
2461   }
2462   }
2463 }
2464