xref: /llvm-project/llvm/lib/CodeGen/TargetLoweringBase.cpp (revision 11fcae69dbea4860e20ab799ecca9b0432d7f19d)
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) {
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   }
311 
312   return UNKNOWN_LIBCALL;
313 }
314 
315 /// getFPROUND - Return the FPROUND_*_* value for the given types, or
316 /// UNKNOWN_LIBCALL if there is none.
317 RTLIB::Libcall RTLIB::getFPROUND(EVT OpVT, EVT RetVT) {
318   if (RetVT == MVT::f16) {
319     if (OpVT == MVT::f32)
320       return FPROUND_F32_F16;
321     if (OpVT == MVT::f64)
322       return FPROUND_F64_F16;
323     if (OpVT == MVT::f80)
324       return FPROUND_F80_F16;
325     if (OpVT == MVT::f128)
326       return FPROUND_F128_F16;
327     if (OpVT == MVT::ppcf128)
328       return FPROUND_PPCF128_F16;
329   } else if (RetVT == MVT::bf16) {
330     if (OpVT == MVT::f32)
331       return FPROUND_F32_BF16;
332     if (OpVT == MVT::f64)
333       return FPROUND_F64_BF16;
334   } else if (RetVT == MVT::f32) {
335     if (OpVT == MVT::f64)
336       return FPROUND_F64_F32;
337     if (OpVT == MVT::f80)
338       return FPROUND_F80_F32;
339     if (OpVT == MVT::f128)
340       return FPROUND_F128_F32;
341     if (OpVT == MVT::ppcf128)
342       return FPROUND_PPCF128_F32;
343   } else if (RetVT == MVT::f64) {
344     if (OpVT == MVT::f80)
345       return FPROUND_F80_F64;
346     if (OpVT == MVT::f128)
347       return FPROUND_F128_F64;
348     if (OpVT == MVT::ppcf128)
349       return FPROUND_PPCF128_F64;
350   } else if (RetVT == MVT::f80) {
351     if (OpVT == MVT::f128)
352       return FPROUND_F128_F80;
353   }
354 
355   return UNKNOWN_LIBCALL;
356 }
357 
358 /// getFPTOSINT - Return the FPTOSINT_*_* value for the given types, or
359 /// UNKNOWN_LIBCALL if there is none.
360 RTLIB::Libcall RTLIB::getFPTOSINT(EVT OpVT, EVT RetVT) {
361   if (OpVT == MVT::f16) {
362     if (RetVT == MVT::i32)
363       return FPTOSINT_F16_I32;
364     if (RetVT == MVT::i64)
365       return FPTOSINT_F16_I64;
366     if (RetVT == MVT::i128)
367       return FPTOSINT_F16_I128;
368   } else if (OpVT == MVT::f32) {
369     if (RetVT == MVT::i32)
370       return FPTOSINT_F32_I32;
371     if (RetVT == MVT::i64)
372       return FPTOSINT_F32_I64;
373     if (RetVT == MVT::i128)
374       return FPTOSINT_F32_I128;
375   } else if (OpVT == MVT::f64) {
376     if (RetVT == MVT::i32)
377       return FPTOSINT_F64_I32;
378     if (RetVT == MVT::i64)
379       return FPTOSINT_F64_I64;
380     if (RetVT == MVT::i128)
381       return FPTOSINT_F64_I128;
382   } else if (OpVT == MVT::f80) {
383     if (RetVT == MVT::i32)
384       return FPTOSINT_F80_I32;
385     if (RetVT == MVT::i64)
386       return FPTOSINT_F80_I64;
387     if (RetVT == MVT::i128)
388       return FPTOSINT_F80_I128;
389   } else if (OpVT == MVT::f128) {
390     if (RetVT == MVT::i32)
391       return FPTOSINT_F128_I32;
392     if (RetVT == MVT::i64)
393       return FPTOSINT_F128_I64;
394     if (RetVT == MVT::i128)
395       return FPTOSINT_F128_I128;
396   } else if (OpVT == MVT::ppcf128) {
397     if (RetVT == MVT::i32)
398       return FPTOSINT_PPCF128_I32;
399     if (RetVT == MVT::i64)
400       return FPTOSINT_PPCF128_I64;
401     if (RetVT == MVT::i128)
402       return FPTOSINT_PPCF128_I128;
403   }
404   return UNKNOWN_LIBCALL;
405 }
406 
407 /// getFPTOUINT - Return the FPTOUINT_*_* value for the given types, or
408 /// UNKNOWN_LIBCALL if there is none.
409 RTLIB::Libcall RTLIB::getFPTOUINT(EVT OpVT, EVT RetVT) {
410   if (OpVT == MVT::f16) {
411     if (RetVT == MVT::i32)
412       return FPTOUINT_F16_I32;
413     if (RetVT == MVT::i64)
414       return FPTOUINT_F16_I64;
415     if (RetVT == MVT::i128)
416       return FPTOUINT_F16_I128;
417   } else if (OpVT == MVT::f32) {
418     if (RetVT == MVT::i32)
419       return FPTOUINT_F32_I32;
420     if (RetVT == MVT::i64)
421       return FPTOUINT_F32_I64;
422     if (RetVT == MVT::i128)
423       return FPTOUINT_F32_I128;
424   } else if (OpVT == MVT::f64) {
425     if (RetVT == MVT::i32)
426       return FPTOUINT_F64_I32;
427     if (RetVT == MVT::i64)
428       return FPTOUINT_F64_I64;
429     if (RetVT == MVT::i128)
430       return FPTOUINT_F64_I128;
431   } else if (OpVT == MVT::f80) {
432     if (RetVT == MVT::i32)
433       return FPTOUINT_F80_I32;
434     if (RetVT == MVT::i64)
435       return FPTOUINT_F80_I64;
436     if (RetVT == MVT::i128)
437       return FPTOUINT_F80_I128;
438   } else if (OpVT == MVT::f128) {
439     if (RetVT == MVT::i32)
440       return FPTOUINT_F128_I32;
441     if (RetVT == MVT::i64)
442       return FPTOUINT_F128_I64;
443     if (RetVT == MVT::i128)
444       return FPTOUINT_F128_I128;
445   } else if (OpVT == MVT::ppcf128) {
446     if (RetVT == MVT::i32)
447       return FPTOUINT_PPCF128_I32;
448     if (RetVT == MVT::i64)
449       return FPTOUINT_PPCF128_I64;
450     if (RetVT == MVT::i128)
451       return FPTOUINT_PPCF128_I128;
452   }
453   return UNKNOWN_LIBCALL;
454 }
455 
456 /// getSINTTOFP - Return the SINTTOFP_*_* value for the given types, or
457 /// UNKNOWN_LIBCALL if there is none.
458 RTLIB::Libcall RTLIB::getSINTTOFP(EVT OpVT, EVT RetVT) {
459   if (OpVT == MVT::i32) {
460     if (RetVT == MVT::f16)
461       return SINTTOFP_I32_F16;
462     if (RetVT == MVT::f32)
463       return SINTTOFP_I32_F32;
464     if (RetVT == MVT::f64)
465       return SINTTOFP_I32_F64;
466     if (RetVT == MVT::f80)
467       return SINTTOFP_I32_F80;
468     if (RetVT == MVT::f128)
469       return SINTTOFP_I32_F128;
470     if (RetVT == MVT::ppcf128)
471       return SINTTOFP_I32_PPCF128;
472   } else if (OpVT == MVT::i64) {
473     if (RetVT == MVT::f16)
474       return SINTTOFP_I64_F16;
475     if (RetVT == MVT::f32)
476       return SINTTOFP_I64_F32;
477     if (RetVT == MVT::f64)
478       return SINTTOFP_I64_F64;
479     if (RetVT == MVT::f80)
480       return SINTTOFP_I64_F80;
481     if (RetVT == MVT::f128)
482       return SINTTOFP_I64_F128;
483     if (RetVT == MVT::ppcf128)
484       return SINTTOFP_I64_PPCF128;
485   } else if (OpVT == MVT::i128) {
486     if (RetVT == MVT::f16)
487       return SINTTOFP_I128_F16;
488     if (RetVT == MVT::f32)
489       return SINTTOFP_I128_F32;
490     if (RetVT == MVT::f64)
491       return SINTTOFP_I128_F64;
492     if (RetVT == MVT::f80)
493       return SINTTOFP_I128_F80;
494     if (RetVT == MVT::f128)
495       return SINTTOFP_I128_F128;
496     if (RetVT == MVT::ppcf128)
497       return SINTTOFP_I128_PPCF128;
498   }
499   return UNKNOWN_LIBCALL;
500 }
501 
502 /// getUINTTOFP - Return the UINTTOFP_*_* value for the given types, or
503 /// UNKNOWN_LIBCALL if there is none.
504 RTLIB::Libcall RTLIB::getUINTTOFP(EVT OpVT, EVT RetVT) {
505   if (OpVT == MVT::i32) {
506     if (RetVT == MVT::f16)
507       return UINTTOFP_I32_F16;
508     if (RetVT == MVT::f32)
509       return UINTTOFP_I32_F32;
510     if (RetVT == MVT::f64)
511       return UINTTOFP_I32_F64;
512     if (RetVT == MVT::f80)
513       return UINTTOFP_I32_F80;
514     if (RetVT == MVT::f128)
515       return UINTTOFP_I32_F128;
516     if (RetVT == MVT::ppcf128)
517       return UINTTOFP_I32_PPCF128;
518   } else if (OpVT == MVT::i64) {
519     if (RetVT == MVT::f16)
520       return UINTTOFP_I64_F16;
521     if (RetVT == MVT::f32)
522       return UINTTOFP_I64_F32;
523     if (RetVT == MVT::f64)
524       return UINTTOFP_I64_F64;
525     if (RetVT == MVT::f80)
526       return UINTTOFP_I64_F80;
527     if (RetVT == MVT::f128)
528       return UINTTOFP_I64_F128;
529     if (RetVT == MVT::ppcf128)
530       return UINTTOFP_I64_PPCF128;
531   } else if (OpVT == MVT::i128) {
532     if (RetVT == MVT::f16)
533       return UINTTOFP_I128_F16;
534     if (RetVT == MVT::f32)
535       return UINTTOFP_I128_F32;
536     if (RetVT == MVT::f64)
537       return UINTTOFP_I128_F64;
538     if (RetVT == MVT::f80)
539       return UINTTOFP_I128_F80;
540     if (RetVT == MVT::f128)
541       return UINTTOFP_I128_F128;
542     if (RetVT == MVT::ppcf128)
543       return UINTTOFP_I128_PPCF128;
544   }
545   return UNKNOWN_LIBCALL;
546 }
547 
548 RTLIB::Libcall RTLIB::getPOWI(EVT RetVT) {
549   return getFPLibCall(RetVT, POWI_F32, POWI_F64, POWI_F80, POWI_F128,
550                       POWI_PPCF128);
551 }
552 
553 RTLIB::Libcall RTLIB::getLDEXP(EVT RetVT) {
554   return getFPLibCall(RetVT, LDEXP_F32, LDEXP_F64, LDEXP_F80, LDEXP_F128,
555                       LDEXP_PPCF128);
556 }
557 
558 RTLIB::Libcall RTLIB::getFREXP(EVT RetVT) {
559   return getFPLibCall(RetVT, FREXP_F32, FREXP_F64, FREXP_F80, FREXP_F128,
560                       FREXP_PPCF128);
561 }
562 
563 RTLIB::Libcall RTLIB::getOutlineAtomicHelper(const Libcall (&LC)[5][4],
564                                              AtomicOrdering Order,
565                                              uint64_t MemSize) {
566   unsigned ModeN, ModelN;
567   switch (MemSize) {
568   case 1:
569     ModeN = 0;
570     break;
571   case 2:
572     ModeN = 1;
573     break;
574   case 4:
575     ModeN = 2;
576     break;
577   case 8:
578     ModeN = 3;
579     break;
580   case 16:
581     ModeN = 4;
582     break;
583   default:
584     return RTLIB::UNKNOWN_LIBCALL;
585   }
586 
587   switch (Order) {
588   case AtomicOrdering::Monotonic:
589     ModelN = 0;
590     break;
591   case AtomicOrdering::Acquire:
592     ModelN = 1;
593     break;
594   case AtomicOrdering::Release:
595     ModelN = 2;
596     break;
597   case AtomicOrdering::AcquireRelease:
598   case AtomicOrdering::SequentiallyConsistent:
599     ModelN = 3;
600     break;
601   default:
602     return UNKNOWN_LIBCALL;
603   }
604 
605   return LC[ModeN][ModelN];
606 }
607 
608 RTLIB::Libcall RTLIB::getOUTLINE_ATOMIC(unsigned Opc, AtomicOrdering Order,
609                                         MVT VT) {
610   if (!VT.isScalarInteger())
611     return UNKNOWN_LIBCALL;
612   uint64_t MemSize = VT.getScalarSizeInBits() / 8;
613 
614 #define LCALLS(A, B)                                                           \
615   { A##B##_RELAX, A##B##_ACQ, A##B##_REL, A##B##_ACQ_REL }
616 #define LCALL5(A)                                                              \
617   LCALLS(A, 1), LCALLS(A, 2), LCALLS(A, 4), LCALLS(A, 8), LCALLS(A, 16)
618   switch (Opc) {
619   case ISD::ATOMIC_CMP_SWAP: {
620     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_CAS)};
621     return getOutlineAtomicHelper(LC, Order, MemSize);
622   }
623   case ISD::ATOMIC_SWAP: {
624     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_SWP)};
625     return getOutlineAtomicHelper(LC, Order, MemSize);
626   }
627   case ISD::ATOMIC_LOAD_ADD: {
628     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDADD)};
629     return getOutlineAtomicHelper(LC, Order, MemSize);
630   }
631   case ISD::ATOMIC_LOAD_OR: {
632     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDSET)};
633     return getOutlineAtomicHelper(LC, Order, MemSize);
634   }
635   case ISD::ATOMIC_LOAD_CLR: {
636     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDCLR)};
637     return getOutlineAtomicHelper(LC, Order, MemSize);
638   }
639   case ISD::ATOMIC_LOAD_XOR: {
640     const Libcall LC[5][4] = {LCALL5(OUTLINE_ATOMIC_LDEOR)};
641     return getOutlineAtomicHelper(LC, Order, MemSize);
642   }
643   default:
644     return UNKNOWN_LIBCALL;
645   }
646 #undef LCALLS
647 #undef LCALL5
648 }
649 
650 RTLIB::Libcall RTLIB::getSYNC(unsigned Opc, MVT VT) {
651 #define OP_TO_LIBCALL(Name, Enum)                                              \
652   case Name:                                                                   \
653     switch (VT.SimpleTy) {                                                     \
654     default:                                                                   \
655       return UNKNOWN_LIBCALL;                                                  \
656     case MVT::i8:                                                              \
657       return Enum##_1;                                                         \
658     case MVT::i16:                                                             \
659       return Enum##_2;                                                         \
660     case MVT::i32:                                                             \
661       return Enum##_4;                                                         \
662     case MVT::i64:                                                             \
663       return Enum##_8;                                                         \
664     case MVT::i128:                                                            \
665       return Enum##_16;                                                        \
666     }
667 
668   switch (Opc) {
669     OP_TO_LIBCALL(ISD::ATOMIC_SWAP, SYNC_LOCK_TEST_AND_SET)
670     OP_TO_LIBCALL(ISD::ATOMIC_CMP_SWAP, SYNC_VAL_COMPARE_AND_SWAP)
671     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_ADD, SYNC_FETCH_AND_ADD)
672     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_SUB, SYNC_FETCH_AND_SUB)
673     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_AND, SYNC_FETCH_AND_AND)
674     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_OR, SYNC_FETCH_AND_OR)
675     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_XOR, SYNC_FETCH_AND_XOR)
676     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_NAND, SYNC_FETCH_AND_NAND)
677     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_MAX, SYNC_FETCH_AND_MAX)
678     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_UMAX, SYNC_FETCH_AND_UMAX)
679     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_MIN, SYNC_FETCH_AND_MIN)
680     OP_TO_LIBCALL(ISD::ATOMIC_LOAD_UMIN, SYNC_FETCH_AND_UMIN)
681   }
682 
683 #undef OP_TO_LIBCALL
684 
685   return UNKNOWN_LIBCALL;
686 }
687 
688 RTLIB::Libcall RTLIB::getMEMCPY_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
689   switch (ElementSize) {
690   case 1:
691     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_1;
692   case 2:
693     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_2;
694   case 4:
695     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_4;
696   case 8:
697     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_8;
698   case 16:
699     return MEMCPY_ELEMENT_UNORDERED_ATOMIC_16;
700   default:
701     return UNKNOWN_LIBCALL;
702   }
703 }
704 
705 RTLIB::Libcall RTLIB::getMEMMOVE_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
706   switch (ElementSize) {
707   case 1:
708     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_1;
709   case 2:
710     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_2;
711   case 4:
712     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_4;
713   case 8:
714     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_8;
715   case 16:
716     return MEMMOVE_ELEMENT_UNORDERED_ATOMIC_16;
717   default:
718     return UNKNOWN_LIBCALL;
719   }
720 }
721 
722 RTLIB::Libcall RTLIB::getMEMSET_ELEMENT_UNORDERED_ATOMIC(uint64_t ElementSize) {
723   switch (ElementSize) {
724   case 1:
725     return MEMSET_ELEMENT_UNORDERED_ATOMIC_1;
726   case 2:
727     return MEMSET_ELEMENT_UNORDERED_ATOMIC_2;
728   case 4:
729     return MEMSET_ELEMENT_UNORDERED_ATOMIC_4;
730   case 8:
731     return MEMSET_ELEMENT_UNORDERED_ATOMIC_8;
732   case 16:
733     return MEMSET_ELEMENT_UNORDERED_ATOMIC_16;
734   default:
735     return UNKNOWN_LIBCALL;
736   }
737 }
738 
739 /// InitCmpLibcallCCs - Set default comparison libcall CC.
740 static void InitCmpLibcallCCs(ISD::CondCode *CCs) {
741   std::fill(CCs, CCs + RTLIB::UNKNOWN_LIBCALL, ISD::SETCC_INVALID);
742   CCs[RTLIB::OEQ_F32] = ISD::SETEQ;
743   CCs[RTLIB::OEQ_F64] = ISD::SETEQ;
744   CCs[RTLIB::OEQ_F128] = ISD::SETEQ;
745   CCs[RTLIB::OEQ_PPCF128] = ISD::SETEQ;
746   CCs[RTLIB::UNE_F32] = ISD::SETNE;
747   CCs[RTLIB::UNE_F64] = ISD::SETNE;
748   CCs[RTLIB::UNE_F128] = ISD::SETNE;
749   CCs[RTLIB::UNE_PPCF128] = ISD::SETNE;
750   CCs[RTLIB::OGE_F32] = ISD::SETGE;
751   CCs[RTLIB::OGE_F64] = ISD::SETGE;
752   CCs[RTLIB::OGE_F128] = ISD::SETGE;
753   CCs[RTLIB::OGE_PPCF128] = ISD::SETGE;
754   CCs[RTLIB::OLT_F32] = ISD::SETLT;
755   CCs[RTLIB::OLT_F64] = ISD::SETLT;
756   CCs[RTLIB::OLT_F128] = ISD::SETLT;
757   CCs[RTLIB::OLT_PPCF128] = ISD::SETLT;
758   CCs[RTLIB::OLE_F32] = ISD::SETLE;
759   CCs[RTLIB::OLE_F64] = ISD::SETLE;
760   CCs[RTLIB::OLE_F128] = ISD::SETLE;
761   CCs[RTLIB::OLE_PPCF128] = ISD::SETLE;
762   CCs[RTLIB::OGT_F32] = ISD::SETGT;
763   CCs[RTLIB::OGT_F64] = ISD::SETGT;
764   CCs[RTLIB::OGT_F128] = ISD::SETGT;
765   CCs[RTLIB::OGT_PPCF128] = ISD::SETGT;
766   CCs[RTLIB::UO_F32] = ISD::SETNE;
767   CCs[RTLIB::UO_F64] = ISD::SETNE;
768   CCs[RTLIB::UO_F128] = ISD::SETNE;
769   CCs[RTLIB::UO_PPCF128] = ISD::SETNE;
770 }
771 
772 /// NOTE: The TargetMachine owns TLOF.
773 TargetLoweringBase::TargetLoweringBase(const TargetMachine &tm) : TM(tm) {
774   initActions();
775 
776   // Perform these initializations only once.
777   MaxStoresPerMemset = MaxStoresPerMemcpy = MaxStoresPerMemmove =
778       MaxLoadsPerMemcmp = 8;
779   MaxGluedStoresPerMemcpy = 0;
780   MaxStoresPerMemsetOptSize = MaxStoresPerMemcpyOptSize =
781       MaxStoresPerMemmoveOptSize = MaxLoadsPerMemcmpOptSize = 4;
782   HasMultipleConditionRegisters = false;
783   HasExtractBitsInsn = false;
784   JumpIsExpensive = JumpIsExpensiveOverride;
785   PredictableSelectIsExpensive = false;
786   EnableExtLdPromotion = false;
787   StackPointerRegisterToSaveRestore = 0;
788   BooleanContents = UndefinedBooleanContent;
789   BooleanFloatContents = UndefinedBooleanContent;
790   BooleanVectorContents = UndefinedBooleanContent;
791   SchedPreferenceInfo = Sched::ILP;
792   GatherAllAliasesMaxDepth = 18;
793   IsStrictFPEnabled = DisableStrictNodeMutation;
794   MaxBytesForAlignment = 0;
795   MaxAtomicSizeInBitsSupported = 0;
796 
797   // Assume that even with libcalls, no target supports wider than 128 bit
798   // division.
799   MaxDivRemBitWidthSupported = 128;
800 
801   MaxLargeFPConvertBitWidthSupported = llvm::IntegerType::MAX_INT_BITS;
802 
803   MinCmpXchgSizeInBits = 0;
804   SupportsUnalignedAtomics = false;
805 
806   std::fill(std::begin(LibcallRoutineNames), std::end(LibcallRoutineNames), nullptr);
807 
808   InitLibcalls(TM.getTargetTriple());
809   InitCmpLibcallCCs(CmpLibcallCCs);
810 }
811 
812 void TargetLoweringBase::initActions() {
813   // All operations default to being supported.
814   memset(OpActions, 0, sizeof(OpActions));
815   memset(LoadExtActions, 0, sizeof(LoadExtActions));
816   memset(TruncStoreActions, 0, sizeof(TruncStoreActions));
817   memset(IndexedModeActions, 0, sizeof(IndexedModeActions));
818   memset(CondCodeActions, 0, sizeof(CondCodeActions));
819   std::fill(std::begin(RegClassForVT), std::end(RegClassForVT), nullptr);
820   std::fill(std::begin(TargetDAGCombineArray),
821             std::end(TargetDAGCombineArray), 0);
822 
823   // We're somewhat special casing MVT::i2 and MVT::i4. Ideally we want to
824   // remove this and targets should individually set these types if not legal.
825   for (ISD::NodeType NT : enum_seq(ISD::DELETED_NODE, ISD::BUILTIN_OP_END,
826                                    force_iteration_on_noniterable_enum)) {
827     for (MVT VT : {MVT::i2, MVT::i4})
828       OpActions[(unsigned)VT.SimpleTy][NT] = Expand;
829   }
830   for (MVT AVT : MVT::all_valuetypes()) {
831     for (MVT VT : {MVT::i2, MVT::i4, MVT::v128i2, MVT::v64i4}) {
832       setTruncStoreAction(AVT, VT, Expand);
833       setLoadExtAction(ISD::EXTLOAD, AVT, VT, Expand);
834       setLoadExtAction(ISD::ZEXTLOAD, AVT, VT, Expand);
835     }
836   }
837   for (unsigned IM = (unsigned)ISD::PRE_INC;
838        IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) {
839     for (MVT VT : {MVT::i2, MVT::i4}) {
840       setIndexedLoadAction(IM, VT, Expand);
841       setIndexedStoreAction(IM, VT, Expand);
842       setIndexedMaskedLoadAction(IM, VT, Expand);
843       setIndexedMaskedStoreAction(IM, VT, Expand);
844     }
845   }
846 
847   for (MVT VT : MVT::fp_valuetypes()) {
848     MVT IntVT = MVT::getIntegerVT(VT.getFixedSizeInBits());
849     if (IntVT.isValid()) {
850       setOperationAction(ISD::ATOMIC_SWAP, VT, Promote);
851       AddPromotedToType(ISD::ATOMIC_SWAP, VT, IntVT);
852     }
853   }
854 
855   // Set default actions for various operations.
856   for (MVT VT : MVT::all_valuetypes()) {
857     // Default all indexed load / store to expand.
858     for (unsigned IM = (unsigned)ISD::PRE_INC;
859          IM != (unsigned)ISD::LAST_INDEXED_MODE; ++IM) {
860       setIndexedLoadAction(IM, VT, Expand);
861       setIndexedStoreAction(IM, VT, Expand);
862       setIndexedMaskedLoadAction(IM, VT, Expand);
863       setIndexedMaskedStoreAction(IM, VT, Expand);
864     }
865 
866     // Most backends expect to see the node which just returns the value loaded.
867     setOperationAction(ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS, VT, Expand);
868 
869     // These operations default to expand.
870     setOperationAction({ISD::FGETSIGN,       ISD::CONCAT_VECTORS,
871                         ISD::FMINNUM,        ISD::FMAXNUM,
872                         ISD::FMINNUM_IEEE,   ISD::FMAXNUM_IEEE,
873                         ISD::FMINIMUM,       ISD::FMAXIMUM,
874                         ISD::FMAD,           ISD::SMIN,
875                         ISD::SMAX,           ISD::UMIN,
876                         ISD::UMAX,           ISD::ABS,
877                         ISD::FSHL,           ISD::FSHR,
878                         ISD::SADDSAT,        ISD::UADDSAT,
879                         ISD::SSUBSAT,        ISD::USUBSAT,
880                         ISD::SSHLSAT,        ISD::USHLSAT,
881                         ISD::SMULFIX,        ISD::SMULFIXSAT,
882                         ISD::UMULFIX,        ISD::UMULFIXSAT,
883                         ISD::SDIVFIX,        ISD::SDIVFIXSAT,
884                         ISD::UDIVFIX,        ISD::UDIVFIXSAT,
885                         ISD::FP_TO_SINT_SAT, ISD::FP_TO_UINT_SAT,
886                         ISD::IS_FPCLASS},
887                        VT, Expand);
888 
889     // Overflow operations default to expand
890     setOperationAction({ISD::SADDO, ISD::SSUBO, ISD::UADDO, ISD::USUBO,
891                         ISD::SMULO, ISD::UMULO},
892                        VT, Expand);
893 
894     // Carry-using overflow operations default to expand.
895     setOperationAction({ISD::UADDO_CARRY, ISD::USUBO_CARRY, ISD::SETCCCARRY,
896                         ISD::SADDO_CARRY, ISD::SSUBO_CARRY},
897                        VT, Expand);
898 
899     // ADDC/ADDE/SUBC/SUBE default to expand.
900     setOperationAction({ISD::ADDC, ISD::ADDE, ISD::SUBC, ISD::SUBE}, VT,
901                        Expand);
902 
903     // Halving adds
904     setOperationAction(
905         {ISD::AVGFLOORS, ISD::AVGFLOORU, ISD::AVGCEILS, ISD::AVGCEILU}, VT,
906         Expand);
907 
908     // Absolute difference
909     setOperationAction({ISD::ABDS, ISD::ABDU}, VT, Expand);
910 
911     // These default to Expand so they will be expanded to CTLZ/CTTZ by default.
912     setOperationAction({ISD::CTLZ_ZERO_UNDEF, ISD::CTTZ_ZERO_UNDEF}, VT,
913                        Expand);
914 
915     setOperationAction({ISD::BITREVERSE, ISD::PARITY}, VT, Expand);
916 
917     // These library functions default to expand.
918     setOperationAction({ISD::FROUND, ISD::FPOWI, ISD::FLDEXP, ISD::FFREXP}, VT,
919                        Expand);
920 
921     // These operations default to expand for vector types.
922     if (VT.isVector())
923       setOperationAction(
924           {ISD::FCOPYSIGN, ISD::SIGN_EXTEND_INREG, ISD::ANY_EXTEND_VECTOR_INREG,
925            ISD::SIGN_EXTEND_VECTOR_INREG, ISD::ZERO_EXTEND_VECTOR_INREG,
926            ISD::SPLAT_VECTOR, ISD::LRINT, ISD::LLRINT},
927           VT, Expand);
928 
929       // Constrained floating-point operations default to expand.
930 #define DAG_INSTRUCTION(NAME, NARG, ROUND_MODE, INTRINSIC, DAGN)               \
931     setOperationAction(ISD::STRICT_##DAGN, VT, Expand);
932 #include "llvm/IR/ConstrainedOps.def"
933 
934     // For most targets @llvm.get.dynamic.area.offset just returns 0.
935     setOperationAction(ISD::GET_DYNAMIC_AREA_OFFSET, VT, Expand);
936 
937     // Vector reduction default to expand.
938     setOperationAction(
939         {ISD::VECREDUCE_FADD, ISD::VECREDUCE_FMUL, ISD::VECREDUCE_ADD,
940          ISD::VECREDUCE_MUL, ISD::VECREDUCE_AND, ISD::VECREDUCE_OR,
941          ISD::VECREDUCE_XOR, ISD::VECREDUCE_SMAX, ISD::VECREDUCE_SMIN,
942          ISD::VECREDUCE_UMAX, ISD::VECREDUCE_UMIN, ISD::VECREDUCE_FMAX,
943          ISD::VECREDUCE_FMIN, ISD::VECREDUCE_FMAXIMUM, ISD::VECREDUCE_FMINIMUM,
944          ISD::VECREDUCE_SEQ_FADD, ISD::VECREDUCE_SEQ_FMUL},
945         VT, Expand);
946 
947     // Named vector shuffles default to expand.
948     setOperationAction(ISD::VECTOR_SPLICE, VT, Expand);
949 
950     // VP operations default to expand.
951 #define BEGIN_REGISTER_VP_SDNODE(SDOPC, ...)                                   \
952     setOperationAction(ISD::SDOPC, VT, Expand);
953 #include "llvm/IR/VPIntrinsics.def"
954 
955     // FP environment operations default to expand.
956     setOperationAction(ISD::GET_FPENV, VT, Expand);
957     setOperationAction(ISD::SET_FPENV, VT, Expand);
958     setOperationAction(ISD::RESET_FPENV, VT, Expand);
959   }
960 
961   // Most targets ignore the @llvm.prefetch intrinsic.
962   setOperationAction(ISD::PREFETCH, MVT::Other, Expand);
963 
964   // Most targets also ignore the @llvm.readcyclecounter intrinsic.
965   setOperationAction(ISD::READCYCLECOUNTER, MVT::i64, Expand);
966 
967   // Most targets also ignore the @llvm.readsteadycounter intrinsic.
968   setOperationAction(ISD::READSTEADYCOUNTER, MVT::i64, Expand);
969 
970   // ConstantFP nodes default to expand.  Targets can either change this to
971   // Legal, in which case all fp constants are legal, or use isFPImmLegal()
972   // to optimize expansions for certain constants.
973   setOperationAction(ISD::ConstantFP,
974                      {MVT::bf16, MVT::f16, MVT::f32, MVT::f64, MVT::f80, MVT::f128},
975                      Expand);
976 
977   // These library functions default to expand.
978   setOperationAction({ISD::FCBRT, ISD::FLOG, ISD::FLOG2, ISD::FLOG10, ISD::FEXP,
979                       ISD::FEXP2, ISD::FEXP10, ISD::FFLOOR, ISD::FNEARBYINT,
980                       ISD::FCEIL, ISD::FRINT, ISD::FTRUNC, ISD::LROUND,
981                       ISD::LLROUND, ISD::LRINT, ISD::LLRINT, ISD::FROUNDEVEN},
982                      {MVT::f32, MVT::f64, MVT::f128}, Expand);
983 
984   // Default ISD::TRAP to expand (which turns it into abort).
985   setOperationAction(ISD::TRAP, MVT::Other, Expand);
986 
987   // On most systems, DEBUGTRAP and TRAP have no difference. The "Expand"
988   // here is to inform DAG Legalizer to replace DEBUGTRAP with TRAP.
989   setOperationAction(ISD::DEBUGTRAP, MVT::Other, Expand);
990 
991   setOperationAction(ISD::UBSANTRAP, MVT::Other, Expand);
992 
993   setOperationAction(ISD::GET_FPENV_MEM, MVT::Other, Expand);
994   setOperationAction(ISD::SET_FPENV_MEM, MVT::Other, Expand);
995 
996   for (MVT VT : {MVT::i8, MVT::i16, MVT::i32, MVT::i64}) {
997     setOperationAction(ISD::GET_FPMODE, VT, Expand);
998     setOperationAction(ISD::SET_FPMODE, VT, Expand);
999   }
1000   setOperationAction(ISD::RESET_FPMODE, MVT::Other, Expand);
1001 }
1002 
1003 MVT TargetLoweringBase::getScalarShiftAmountTy(const DataLayout &DL,
1004                                                EVT) const {
1005   return MVT::getIntegerVT(DL.getPointerSizeInBits(0));
1006 }
1007 
1008 EVT TargetLoweringBase::getShiftAmountTy(EVT LHSTy, const DataLayout &DL,
1009                                          bool LegalTypes) const {
1010   assert(LHSTy.isInteger() && "Shift amount is not an integer type!");
1011   if (LHSTy.isVector())
1012     return LHSTy;
1013   MVT ShiftVT =
1014       LegalTypes ? getScalarShiftAmountTy(DL, LHSTy) : getPointerTy(DL);
1015   // If any possible shift value won't fit in the prefered type, just use
1016   // something safe. Assume it will be legalized when the shift is expanded.
1017   if (ShiftVT.getSizeInBits() < Log2_32_Ceil(LHSTy.getSizeInBits()))
1018     ShiftVT = MVT::i32;
1019   assert(ShiftVT.getSizeInBits() >= Log2_32_Ceil(LHSTy.getSizeInBits()) &&
1020          "ShiftVT is still too small!");
1021   return ShiftVT;
1022 }
1023 
1024 bool TargetLoweringBase::canOpTrap(unsigned Op, EVT VT) const {
1025   assert(isTypeLegal(VT));
1026   switch (Op) {
1027   default:
1028     return false;
1029   case ISD::SDIV:
1030   case ISD::UDIV:
1031   case ISD::SREM:
1032   case ISD::UREM:
1033     return true;
1034   }
1035 }
1036 
1037 bool TargetLoweringBase::isFreeAddrSpaceCast(unsigned SrcAS,
1038                                              unsigned DestAS) const {
1039   return TM.isNoopAddrSpaceCast(SrcAS, DestAS);
1040 }
1041 
1042 void TargetLoweringBase::setJumpIsExpensive(bool isExpensive) {
1043   // If the command-line option was specified, ignore this request.
1044   if (!JumpIsExpensiveOverride.getNumOccurrences())
1045     JumpIsExpensive = isExpensive;
1046 }
1047 
1048 TargetLoweringBase::LegalizeKind
1049 TargetLoweringBase::getTypeConversion(LLVMContext &Context, EVT VT) const {
1050   // If this is a simple type, use the ComputeRegisterProp mechanism.
1051   if (VT.isSimple()) {
1052     MVT SVT = VT.getSimpleVT();
1053     assert((unsigned)SVT.SimpleTy < std::size(TransformToType));
1054     MVT NVT = TransformToType[SVT.SimpleTy];
1055     LegalizeTypeAction LA = ValueTypeActions.getTypeAction(SVT);
1056 
1057     assert((LA == TypeLegal || LA == TypeSoftenFloat ||
1058             LA == TypeSoftPromoteHalf ||
1059             (NVT.isVector() ||
1060              ValueTypeActions.getTypeAction(NVT) != TypePromoteInteger)) &&
1061            "Promote may not follow Expand or Promote");
1062 
1063     if (LA == TypeSplitVector)
1064       return LegalizeKind(LA, EVT(SVT).getHalfNumVectorElementsVT(Context));
1065     if (LA == TypeScalarizeVector)
1066       return LegalizeKind(LA, SVT.getVectorElementType());
1067     return LegalizeKind(LA, NVT);
1068   }
1069 
1070   // Handle Extended Scalar Types.
1071   if (!VT.isVector()) {
1072     assert(VT.isInteger() && "Float types must be simple");
1073     unsigned BitSize = VT.getSizeInBits();
1074     // First promote to a power-of-two size, then expand if necessary.
1075     if (BitSize < 8 || !isPowerOf2_32(BitSize)) {
1076       EVT NVT = VT.getRoundIntegerType(Context);
1077       assert(NVT != VT && "Unable to round integer VT");
1078       LegalizeKind NextStep = getTypeConversion(Context, NVT);
1079       // Avoid multi-step promotion.
1080       if (NextStep.first == TypePromoteInteger)
1081         return NextStep;
1082       // Return rounded integer type.
1083       return LegalizeKind(TypePromoteInteger, NVT);
1084     }
1085 
1086     return LegalizeKind(TypeExpandInteger,
1087                         EVT::getIntegerVT(Context, VT.getSizeInBits() / 2));
1088   }
1089 
1090   // Handle vector types.
1091   ElementCount NumElts = VT.getVectorElementCount();
1092   EVT EltVT = VT.getVectorElementType();
1093 
1094   // Vectors with only one element are always scalarized.
1095   if (NumElts.isScalar())
1096     return LegalizeKind(TypeScalarizeVector, EltVT);
1097 
1098   // Try to widen vector elements until the element type is a power of two and
1099   // promote it to a legal type later on, for example:
1100   // <3 x i8> -> <4 x i8> -> <4 x i32>
1101   if (EltVT.isInteger()) {
1102     // Vectors with a number of elements that is not a power of two are always
1103     // widened, for example <3 x i8> -> <4 x i8>.
1104     if (!VT.isPow2VectorType()) {
1105       NumElts = NumElts.coefficientNextPowerOf2();
1106       EVT NVT = EVT::getVectorVT(Context, EltVT, NumElts);
1107       return LegalizeKind(TypeWidenVector, NVT);
1108     }
1109 
1110     // Examine the element type.
1111     LegalizeKind LK = getTypeConversion(Context, EltVT);
1112 
1113     // If type is to be expanded, split the vector.
1114     //  <4 x i140> -> <2 x i140>
1115     if (LK.first == TypeExpandInteger) {
1116       if (VT.getVectorElementCount().isScalable())
1117         return LegalizeKind(TypeScalarizeScalableVector, EltVT);
1118       return LegalizeKind(TypeSplitVector,
1119                           VT.getHalfNumVectorElementsVT(Context));
1120     }
1121 
1122     // Promote the integer element types until a legal vector type is found
1123     // or until the element integer type is too big. If a legal type was not
1124     // found, fallback to the usual mechanism of widening/splitting the
1125     // vector.
1126     EVT OldEltVT = EltVT;
1127     while (true) {
1128       // Increase the bitwidth of the element to the next pow-of-two
1129       // (which is greater than 8 bits).
1130       EltVT = EVT::getIntegerVT(Context, 1 + EltVT.getSizeInBits())
1131                   .getRoundIntegerType(Context);
1132 
1133       // Stop trying when getting a non-simple element type.
1134       // Note that vector elements may be greater than legal vector element
1135       // types. Example: X86 XMM registers hold 64bit element on 32bit
1136       // systems.
1137       if (!EltVT.isSimple())
1138         break;
1139 
1140       // Build a new vector type and check if it is legal.
1141       MVT NVT = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
1142       // Found a legal promoted vector type.
1143       if (NVT != MVT() && ValueTypeActions.getTypeAction(NVT) == TypeLegal)
1144         return LegalizeKind(TypePromoteInteger,
1145                             EVT::getVectorVT(Context, EltVT, NumElts));
1146     }
1147 
1148     // Reset the type to the unexpanded type if we did not find a legal vector
1149     // type with a promoted vector element type.
1150     EltVT = OldEltVT;
1151   }
1152 
1153   // Try to widen the vector until a legal type is found.
1154   // If there is no wider legal type, split the vector.
1155   while (true) {
1156     // Round up to the next power of 2.
1157     NumElts = NumElts.coefficientNextPowerOf2();
1158 
1159     // If there is no simple vector type with this many elements then there
1160     // cannot be a larger legal vector type.  Note that this assumes that
1161     // there are no skipped intermediate vector types in the simple types.
1162     if (!EltVT.isSimple())
1163       break;
1164     MVT LargerVector = MVT::getVectorVT(EltVT.getSimpleVT(), NumElts);
1165     if (LargerVector == MVT())
1166       break;
1167 
1168     // If this type is legal then widen the vector.
1169     if (ValueTypeActions.getTypeAction(LargerVector) == TypeLegal)
1170       return LegalizeKind(TypeWidenVector, LargerVector);
1171   }
1172 
1173   // Widen odd vectors to next power of two.
1174   if (!VT.isPow2VectorType()) {
1175     EVT NVT = VT.getPow2VectorType(Context);
1176     return LegalizeKind(TypeWidenVector, NVT);
1177   }
1178 
1179   if (VT.getVectorElementCount() == ElementCount::getScalable(1))
1180     return LegalizeKind(TypeScalarizeScalableVector, EltVT);
1181 
1182   // Vectors with illegal element types are expanded.
1183   EVT NVT = EVT::getVectorVT(Context, EltVT,
1184                              VT.getVectorElementCount().divideCoefficientBy(2));
1185   return LegalizeKind(TypeSplitVector, NVT);
1186 }
1187 
1188 static unsigned getVectorTypeBreakdownMVT(MVT VT, MVT &IntermediateVT,
1189                                           unsigned &NumIntermediates,
1190                                           MVT &RegisterVT,
1191                                           TargetLoweringBase *TLI) {
1192   // Figure out the right, legal destination reg to copy into.
1193   ElementCount EC = VT.getVectorElementCount();
1194   MVT EltTy = VT.getVectorElementType();
1195 
1196   unsigned NumVectorRegs = 1;
1197 
1198   // Scalable vectors cannot be scalarized, so splitting or widening is
1199   // required.
1200   if (VT.isScalableVector() && !isPowerOf2_32(EC.getKnownMinValue()))
1201     llvm_unreachable(
1202         "Splitting or widening of non-power-of-2 MVTs is not implemented.");
1203 
1204   // FIXME: We don't support non-power-of-2-sized vectors for now.
1205   // Ideally we could break down into LHS/RHS like LegalizeDAG does.
1206   if (!isPowerOf2_32(EC.getKnownMinValue())) {
1207     // Split EC to unit size (scalable property is preserved).
1208     NumVectorRegs = EC.getKnownMinValue();
1209     EC = ElementCount::getFixed(1);
1210   }
1211 
1212   // Divide the input until we get to a supported size. This will
1213   // always end up with an EC that represent a scalar or a scalable
1214   // scalar.
1215   while (EC.getKnownMinValue() > 1 &&
1216          !TLI->isTypeLegal(MVT::getVectorVT(EltTy, EC))) {
1217     EC = EC.divideCoefficientBy(2);
1218     NumVectorRegs <<= 1;
1219   }
1220 
1221   NumIntermediates = NumVectorRegs;
1222 
1223   MVT NewVT = MVT::getVectorVT(EltTy, EC);
1224   if (!TLI->isTypeLegal(NewVT))
1225     NewVT = EltTy;
1226   IntermediateVT = NewVT;
1227 
1228   unsigned LaneSizeInBits = NewVT.getScalarSizeInBits();
1229 
1230   // Convert sizes such as i33 to i64.
1231   LaneSizeInBits = llvm::bit_ceil(LaneSizeInBits);
1232 
1233   MVT DestVT = TLI->getRegisterType(NewVT);
1234   RegisterVT = DestVT;
1235   if (EVT(DestVT).bitsLT(NewVT))    // Value is expanded, e.g. i64 -> i16.
1236     return NumVectorRegs * (LaneSizeInBits / DestVT.getScalarSizeInBits());
1237 
1238   // Otherwise, promotion or legal types use the same number of registers as
1239   // the vector decimated to the appropriate level.
1240   return NumVectorRegs;
1241 }
1242 
1243 /// isLegalRC - Return true if the value types that can be represented by the
1244 /// specified register class are all legal.
1245 bool TargetLoweringBase::isLegalRC(const TargetRegisterInfo &TRI,
1246                                    const TargetRegisterClass &RC) const {
1247   for (const auto *I = TRI.legalclasstypes_begin(RC); *I != MVT::Other; ++I)
1248     if (isTypeLegal(*I))
1249       return true;
1250   return false;
1251 }
1252 
1253 /// Replace/modify any TargetFrameIndex operands with a targte-dependent
1254 /// sequence of memory operands that is recognized by PrologEpilogInserter.
1255 MachineBasicBlock *
1256 TargetLoweringBase::emitPatchPoint(MachineInstr &InitialMI,
1257                                    MachineBasicBlock *MBB) const {
1258   MachineInstr *MI = &InitialMI;
1259   MachineFunction &MF = *MI->getMF();
1260   MachineFrameInfo &MFI = MF.getFrameInfo();
1261 
1262   // We're handling multiple types of operands here:
1263   // PATCHPOINT MetaArgs - live-in, read only, direct
1264   // STATEPOINT Deopt Spill - live-through, read only, indirect
1265   // STATEPOINT Deopt Alloca - live-through, read only, direct
1266   // (We're currently conservative and mark the deopt slots read/write in
1267   // practice.)
1268   // STATEPOINT GC Spill - live-through, read/write, indirect
1269   // STATEPOINT GC Alloca - live-through, read/write, direct
1270   // The live-in vs live-through is handled already (the live through ones are
1271   // all stack slots), but we need to handle the different type of stackmap
1272   // operands and memory effects here.
1273 
1274   if (llvm::none_of(MI->operands(),
1275                     [](MachineOperand &Operand) { return Operand.isFI(); }))
1276     return MBB;
1277 
1278   MachineInstrBuilder MIB = BuildMI(MF, MI->getDebugLoc(), MI->getDesc());
1279 
1280   // Inherit previous memory operands.
1281   MIB.cloneMemRefs(*MI);
1282 
1283   for (unsigned i = 0; i < MI->getNumOperands(); ++i) {
1284     MachineOperand &MO = MI->getOperand(i);
1285     if (!MO.isFI()) {
1286       // Index of Def operand this Use it tied to.
1287       // Since Defs are coming before Uses, if Use is tied, then
1288       // index of Def must be smaller that index of that Use.
1289       // Also, Defs preserve their position in new MI.
1290       unsigned TiedTo = i;
1291       if (MO.isReg() && MO.isTied())
1292         TiedTo = MI->findTiedOperandIdx(i);
1293       MIB.add(MO);
1294       if (TiedTo < i)
1295         MIB->tieOperands(TiedTo, MIB->getNumOperands() - 1);
1296       continue;
1297     }
1298 
1299     // foldMemoryOperand builds a new MI after replacing a single FI operand
1300     // with the canonical set of five x86 addressing-mode operands.
1301     int FI = MO.getIndex();
1302 
1303     // Add frame index operands recognized by stackmaps.cpp
1304     if (MFI.isStatepointSpillSlotObjectIndex(FI)) {
1305       // indirect-mem-ref tag, size, #FI, offset.
1306       // Used for spills inserted by StatepointLowering.  This codepath is not
1307       // used for patchpoints/stackmaps at all, for these spilling is done via
1308       // foldMemoryOperand callback only.
1309       assert(MI->getOpcode() == TargetOpcode::STATEPOINT && "sanity");
1310       MIB.addImm(StackMaps::IndirectMemRefOp);
1311       MIB.addImm(MFI.getObjectSize(FI));
1312       MIB.add(MO);
1313       MIB.addImm(0);
1314     } else {
1315       // direct-mem-ref tag, #FI, offset.
1316       // Used by patchpoint, and direct alloca arguments to statepoints
1317       MIB.addImm(StackMaps::DirectMemRefOp);
1318       MIB.add(MO);
1319       MIB.addImm(0);
1320     }
1321 
1322     assert(MIB->mayLoad() && "Folded a stackmap use to a non-load!");
1323 
1324     // Add a new memory operand for this FI.
1325     assert(MFI.getObjectOffset(FI) != -1);
1326 
1327     // Note: STATEPOINT MMOs are added during SelectionDAG.  STACKMAP, and
1328     // PATCHPOINT should be updated to do the same. (TODO)
1329     if (MI->getOpcode() != TargetOpcode::STATEPOINT) {
1330       auto Flags = MachineMemOperand::MOLoad;
1331       MachineMemOperand *MMO = MF.getMachineMemOperand(
1332           MachinePointerInfo::getFixedStack(MF, FI), Flags,
1333           MF.getDataLayout().getPointerSize(), MFI.getObjectAlign(FI));
1334       MIB->addMemOperand(MF, MMO);
1335     }
1336   }
1337   MBB->insert(MachineBasicBlock::iterator(MI), MIB);
1338   MI->eraseFromParent();
1339   return MBB;
1340 }
1341 
1342 /// findRepresentativeClass - Return the largest legal super-reg register class
1343 /// of the register class for the specified type and its associated "cost".
1344 // This function is in TargetLowering because it uses RegClassForVT which would
1345 // need to be moved to TargetRegisterInfo and would necessitate moving
1346 // isTypeLegal over as well - a massive change that would just require
1347 // TargetLowering having a TargetRegisterInfo class member that it would use.
1348 std::pair<const TargetRegisterClass *, uint8_t>
1349 TargetLoweringBase::findRepresentativeClass(const TargetRegisterInfo *TRI,
1350                                             MVT VT) const {
1351   const TargetRegisterClass *RC = RegClassForVT[VT.SimpleTy];
1352   if (!RC)
1353     return std::make_pair(RC, 0);
1354 
1355   // Compute the set of all super-register classes.
1356   BitVector SuperRegRC(TRI->getNumRegClasses());
1357   for (SuperRegClassIterator RCI(RC, TRI); RCI.isValid(); ++RCI)
1358     SuperRegRC.setBitsInMask(RCI.getMask());
1359 
1360   // Find the first legal register class with the largest spill size.
1361   const TargetRegisterClass *BestRC = RC;
1362   for (unsigned i : SuperRegRC.set_bits()) {
1363     const TargetRegisterClass *SuperRC = TRI->getRegClass(i);
1364     // We want the largest possible spill size.
1365     if (TRI->getSpillSize(*SuperRC) <= TRI->getSpillSize(*BestRC))
1366       continue;
1367     if (!isLegalRC(*TRI, *SuperRC))
1368       continue;
1369     BestRC = SuperRC;
1370   }
1371   return std::make_pair(BestRC, 1);
1372 }
1373 
1374 /// computeRegisterProperties - Once all of the register classes are added,
1375 /// this allows us to compute derived properties we expose.
1376 void TargetLoweringBase::computeRegisterProperties(
1377     const TargetRegisterInfo *TRI) {
1378   static_assert(MVT::VALUETYPE_SIZE <= MVT::MAX_ALLOWED_VALUETYPE,
1379                 "Too many value types for ValueTypeActions to hold!");
1380 
1381   // Everything defaults to needing one register.
1382   for (unsigned i = 0; i != MVT::VALUETYPE_SIZE; ++i) {
1383     NumRegistersForVT[i] = 1;
1384     RegisterTypeForVT[i] = TransformToType[i] = (MVT::SimpleValueType)i;
1385   }
1386   // ...except isVoid, which doesn't need any registers.
1387   NumRegistersForVT[MVT::isVoid] = 0;
1388 
1389   // Find the largest integer register class.
1390   unsigned LargestIntReg = MVT::LAST_INTEGER_VALUETYPE;
1391   for (; RegClassForVT[LargestIntReg] == nullptr; --LargestIntReg)
1392     assert(LargestIntReg != MVT::i1 && "No integer registers defined!");
1393 
1394   // Every integer value type larger than this largest register takes twice as
1395   // many registers to represent as the previous ValueType.
1396   for (unsigned ExpandedReg = LargestIntReg + 1;
1397        ExpandedReg <= MVT::LAST_INTEGER_VALUETYPE; ++ExpandedReg) {
1398     NumRegistersForVT[ExpandedReg] = 2*NumRegistersForVT[ExpandedReg-1];
1399     RegisterTypeForVT[ExpandedReg] = (MVT::SimpleValueType)LargestIntReg;
1400     TransformToType[ExpandedReg] = (MVT::SimpleValueType)(ExpandedReg - 1);
1401     ValueTypeActions.setTypeAction((MVT::SimpleValueType)ExpandedReg,
1402                                    TypeExpandInteger);
1403   }
1404 
1405   // Inspect all of the ValueType's smaller than the largest integer
1406   // register to see which ones need promotion.
1407   unsigned LegalIntReg = LargestIntReg;
1408   for (unsigned IntReg = LargestIntReg - 1;
1409        IntReg >= (unsigned)MVT::i1; --IntReg) {
1410     MVT IVT = (MVT::SimpleValueType)IntReg;
1411     if (isTypeLegal(IVT)) {
1412       LegalIntReg = IntReg;
1413     } else {
1414       RegisterTypeForVT[IntReg] = TransformToType[IntReg] =
1415         (MVT::SimpleValueType)LegalIntReg;
1416       ValueTypeActions.setTypeAction(IVT, TypePromoteInteger);
1417     }
1418   }
1419 
1420   // ppcf128 type is really two f64's.
1421   if (!isTypeLegal(MVT::ppcf128)) {
1422     if (isTypeLegal(MVT::f64)) {
1423       NumRegistersForVT[MVT::ppcf128] = 2*NumRegistersForVT[MVT::f64];
1424       RegisterTypeForVT[MVT::ppcf128] = MVT::f64;
1425       TransformToType[MVT::ppcf128] = MVT::f64;
1426       ValueTypeActions.setTypeAction(MVT::ppcf128, TypeExpandFloat);
1427     } else {
1428       NumRegistersForVT[MVT::ppcf128] = NumRegistersForVT[MVT::i128];
1429       RegisterTypeForVT[MVT::ppcf128] = RegisterTypeForVT[MVT::i128];
1430       TransformToType[MVT::ppcf128] = MVT::i128;
1431       ValueTypeActions.setTypeAction(MVT::ppcf128, TypeSoftenFloat);
1432     }
1433   }
1434 
1435   // Decide how to handle f128. If the target does not have native f128 support,
1436   // expand it to i128 and we will be generating soft float library calls.
1437   if (!isTypeLegal(MVT::f128)) {
1438     NumRegistersForVT[MVT::f128] = NumRegistersForVT[MVT::i128];
1439     RegisterTypeForVT[MVT::f128] = RegisterTypeForVT[MVT::i128];
1440     TransformToType[MVT::f128] = MVT::i128;
1441     ValueTypeActions.setTypeAction(MVT::f128, TypeSoftenFloat);
1442   }
1443 
1444   // Decide how to handle f80. If the target does not have native f80 support,
1445   // expand it to i96 and we will be generating soft float library calls.
1446   if (!isTypeLegal(MVT::f80)) {
1447     NumRegistersForVT[MVT::f80] = 3*NumRegistersForVT[MVT::i32];
1448     RegisterTypeForVT[MVT::f80] = RegisterTypeForVT[MVT::i32];
1449     TransformToType[MVT::f80] = MVT::i32;
1450     ValueTypeActions.setTypeAction(MVT::f80, TypeSoftenFloat);
1451   }
1452 
1453   // Decide how to handle f64. If the target does not have native f64 support,
1454   // expand it to i64 and we will be generating soft float library calls.
1455   if (!isTypeLegal(MVT::f64)) {
1456     NumRegistersForVT[MVT::f64] = NumRegistersForVT[MVT::i64];
1457     RegisterTypeForVT[MVT::f64] = RegisterTypeForVT[MVT::i64];
1458     TransformToType[MVT::f64] = MVT::i64;
1459     ValueTypeActions.setTypeAction(MVT::f64, TypeSoftenFloat);
1460   }
1461 
1462   // Decide how to handle f32. If the target does not have native f32 support,
1463   // expand it to i32 and we will be generating soft float library calls.
1464   if (!isTypeLegal(MVT::f32)) {
1465     NumRegistersForVT[MVT::f32] = NumRegistersForVT[MVT::i32];
1466     RegisterTypeForVT[MVT::f32] = RegisterTypeForVT[MVT::i32];
1467     TransformToType[MVT::f32] = MVT::i32;
1468     ValueTypeActions.setTypeAction(MVT::f32, TypeSoftenFloat);
1469   }
1470 
1471   // Decide how to handle f16. If the target does not have native f16 support,
1472   // promote it to f32, because there are no f16 library calls (except for
1473   // conversions).
1474   if (!isTypeLegal(MVT::f16)) {
1475     // Allow targets to control how we legalize half.
1476     bool SoftPromoteHalfType = softPromoteHalfType();
1477     bool UseFPRegsForHalfType = !SoftPromoteHalfType || useFPRegsForHalfType();
1478 
1479     if (!UseFPRegsForHalfType) {
1480       NumRegistersForVT[MVT::f16] = NumRegistersForVT[MVT::i16];
1481       RegisterTypeForVT[MVT::f16] = RegisterTypeForVT[MVT::i16];
1482     } else {
1483       NumRegistersForVT[MVT::f16] = NumRegistersForVT[MVT::f32];
1484       RegisterTypeForVT[MVT::f16] = RegisterTypeForVT[MVT::f32];
1485     }
1486     TransformToType[MVT::f16] = MVT::f32;
1487     if (SoftPromoteHalfType) {
1488       ValueTypeActions.setTypeAction(MVT::f16, TypeSoftPromoteHalf);
1489     } else {
1490       ValueTypeActions.setTypeAction(MVT::f16, TypePromoteFloat);
1491     }
1492   }
1493 
1494   // Decide how to handle bf16. If the target does not have native bf16 support,
1495   // promote it to f32, because there are no bf16 library calls (except for
1496   // converting from f32 to bf16).
1497   if (!isTypeLegal(MVT::bf16)) {
1498     NumRegistersForVT[MVT::bf16] = NumRegistersForVT[MVT::f32];
1499     RegisterTypeForVT[MVT::bf16] = RegisterTypeForVT[MVT::f32];
1500     TransformToType[MVT::bf16] = MVT::f32;
1501     ValueTypeActions.setTypeAction(MVT::bf16, TypeSoftPromoteHalf);
1502   }
1503 
1504   // Loop over all of the vector value types to see which need transformations.
1505   for (unsigned i = MVT::FIRST_VECTOR_VALUETYPE;
1506        i <= (unsigned)MVT::LAST_VECTOR_VALUETYPE; ++i) {
1507     MVT VT = (MVT::SimpleValueType) i;
1508     if (isTypeLegal(VT))
1509       continue;
1510 
1511     MVT EltVT = VT.getVectorElementType();
1512     ElementCount EC = VT.getVectorElementCount();
1513     bool IsLegalWiderType = false;
1514     bool IsScalable = VT.isScalableVector();
1515     LegalizeTypeAction PreferredAction = getPreferredVectorAction(VT);
1516     switch (PreferredAction) {
1517     case TypePromoteInteger: {
1518       MVT::SimpleValueType EndVT = IsScalable ?
1519                                    MVT::LAST_INTEGER_SCALABLE_VECTOR_VALUETYPE :
1520                                    MVT::LAST_INTEGER_FIXEDLEN_VECTOR_VALUETYPE;
1521       // Try to promote the elements of integer vectors. If no legal
1522       // promotion was found, fall through to the widen-vector method.
1523       for (unsigned nVT = i + 1;
1524            (MVT::SimpleValueType)nVT <= EndVT; ++nVT) {
1525         MVT SVT = (MVT::SimpleValueType) nVT;
1526         // Promote vectors of integers to vectors with the same number
1527         // of elements, with a wider element type.
1528         if (SVT.getScalarSizeInBits() > EltVT.getFixedSizeInBits() &&
1529             SVT.getVectorElementCount() == EC && isTypeLegal(SVT)) {
1530           TransformToType[i] = SVT;
1531           RegisterTypeForVT[i] = SVT;
1532           NumRegistersForVT[i] = 1;
1533           ValueTypeActions.setTypeAction(VT, TypePromoteInteger);
1534           IsLegalWiderType = true;
1535           break;
1536         }
1537       }
1538       if (IsLegalWiderType)
1539         break;
1540       [[fallthrough]];
1541     }
1542 
1543     case TypeWidenVector:
1544       if (isPowerOf2_32(EC.getKnownMinValue())) {
1545         // Try to widen the vector.
1546         for (unsigned nVT = i + 1; nVT <= MVT::LAST_VECTOR_VALUETYPE; ++nVT) {
1547           MVT SVT = (MVT::SimpleValueType) nVT;
1548           if (SVT.getVectorElementType() == EltVT &&
1549               SVT.isScalableVector() == IsScalable &&
1550               SVT.getVectorElementCount().getKnownMinValue() >
1551                   EC.getKnownMinValue() &&
1552               isTypeLegal(SVT)) {
1553             TransformToType[i] = SVT;
1554             RegisterTypeForVT[i] = SVT;
1555             NumRegistersForVT[i] = 1;
1556             ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1557             IsLegalWiderType = true;
1558             break;
1559           }
1560         }
1561         if (IsLegalWiderType)
1562           break;
1563       } else {
1564         // Only widen to the next power of 2 to keep consistency with EVT.
1565         MVT NVT = VT.getPow2VectorType();
1566         if (isTypeLegal(NVT)) {
1567           TransformToType[i] = NVT;
1568           ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1569           RegisterTypeForVT[i] = NVT;
1570           NumRegistersForVT[i] = 1;
1571           break;
1572         }
1573       }
1574       [[fallthrough]];
1575 
1576     case TypeSplitVector:
1577     case TypeScalarizeVector: {
1578       MVT IntermediateVT;
1579       MVT RegisterVT;
1580       unsigned NumIntermediates;
1581       unsigned NumRegisters = getVectorTypeBreakdownMVT(VT, IntermediateVT,
1582           NumIntermediates, RegisterVT, this);
1583       NumRegistersForVT[i] = NumRegisters;
1584       assert(NumRegistersForVT[i] == NumRegisters &&
1585              "NumRegistersForVT size cannot represent NumRegisters!");
1586       RegisterTypeForVT[i] = RegisterVT;
1587 
1588       MVT NVT = VT.getPow2VectorType();
1589       if (NVT == VT) {
1590         // Type is already a power of 2.  The default action is to split.
1591         TransformToType[i] = MVT::Other;
1592         if (PreferredAction == TypeScalarizeVector)
1593           ValueTypeActions.setTypeAction(VT, TypeScalarizeVector);
1594         else if (PreferredAction == TypeSplitVector)
1595           ValueTypeActions.setTypeAction(VT, TypeSplitVector);
1596         else if (EC.getKnownMinValue() > 1)
1597           ValueTypeActions.setTypeAction(VT, TypeSplitVector);
1598         else
1599           ValueTypeActions.setTypeAction(VT, EC.isScalable()
1600                                                  ? TypeScalarizeScalableVector
1601                                                  : TypeScalarizeVector);
1602       } else {
1603         TransformToType[i] = NVT;
1604         ValueTypeActions.setTypeAction(VT, TypeWidenVector);
1605       }
1606       break;
1607     }
1608     default:
1609       llvm_unreachable("Unknown vector legalization action!");
1610     }
1611   }
1612 
1613   // Determine the 'representative' register class for each value type.
1614   // An representative register class is the largest (meaning one which is
1615   // not a sub-register class / subreg register class) legal register class for
1616   // a group of value types. For example, on i386, i8, i16, and i32
1617   // representative would be GR32; while on x86_64 it's GR64.
1618   for (unsigned i = 0; i != MVT::VALUETYPE_SIZE; ++i) {
1619     const TargetRegisterClass* RRC;
1620     uint8_t Cost;
1621     std::tie(RRC, Cost) = findRepresentativeClass(TRI, (MVT::SimpleValueType)i);
1622     RepRegClassForVT[i] = RRC;
1623     RepRegClassCostForVT[i] = Cost;
1624   }
1625 }
1626 
1627 EVT TargetLoweringBase::getSetCCResultType(const DataLayout &DL, LLVMContext &,
1628                                            EVT VT) const {
1629   assert(!VT.isVector() && "No default SetCC type for vectors!");
1630   return getPointerTy(DL).SimpleTy;
1631 }
1632 
1633 MVT::SimpleValueType TargetLoweringBase::getCmpLibcallReturnType() const {
1634   return MVT::i32; // return the default value
1635 }
1636 
1637 /// getVectorTypeBreakdown - Vector types are broken down into some number of
1638 /// legal first class types.  For example, MVT::v8f32 maps to 2 MVT::v4f32
1639 /// with Altivec or SSE1, or 8 promoted MVT::f64 values with the X86 FP stack.
1640 /// Similarly, MVT::v2i64 turns into 4 MVT::i32 values with both PPC and X86.
1641 ///
1642 /// This method returns the number of registers needed, and the VT for each
1643 /// register.  It also returns the VT and quantity of the intermediate values
1644 /// before they are promoted/expanded.
1645 unsigned TargetLoweringBase::getVectorTypeBreakdown(LLVMContext &Context,
1646                                                     EVT VT, EVT &IntermediateVT,
1647                                                     unsigned &NumIntermediates,
1648                                                     MVT &RegisterVT) const {
1649   ElementCount EltCnt = VT.getVectorElementCount();
1650 
1651   // If there is a wider vector type with the same element type as this one,
1652   // or a promoted vector type that has the same number of elements which
1653   // are wider, then we should convert to that legal vector type.
1654   // This handles things like <2 x float> -> <4 x float> and
1655   // <4 x i1> -> <4 x i32>.
1656   LegalizeTypeAction TA = getTypeAction(Context, VT);
1657   if (!EltCnt.isScalar() &&
1658       (TA == TypeWidenVector || TA == TypePromoteInteger)) {
1659     EVT RegisterEVT = getTypeToTransformTo(Context, VT);
1660     if (isTypeLegal(RegisterEVT)) {
1661       IntermediateVT = RegisterEVT;
1662       RegisterVT = RegisterEVT.getSimpleVT();
1663       NumIntermediates = 1;
1664       return 1;
1665     }
1666   }
1667 
1668   // Figure out the right, legal destination reg to copy into.
1669   EVT EltTy = VT.getVectorElementType();
1670 
1671   unsigned NumVectorRegs = 1;
1672 
1673   // Scalable vectors cannot be scalarized, so handle the legalisation of the
1674   // types like done elsewhere in SelectionDAG.
1675   if (EltCnt.isScalable()) {
1676     LegalizeKind LK;
1677     EVT PartVT = VT;
1678     do {
1679       // Iterate until we've found a legal (part) type to hold VT.
1680       LK = getTypeConversion(Context, PartVT);
1681       PartVT = LK.second;
1682     } while (LK.first != TypeLegal);
1683 
1684     if (!PartVT.isVector()) {
1685       report_fatal_error(
1686           "Don't know how to legalize this scalable vector type");
1687     }
1688 
1689     NumIntermediates =
1690         divideCeil(VT.getVectorElementCount().getKnownMinValue(),
1691                    PartVT.getVectorElementCount().getKnownMinValue());
1692     IntermediateVT = PartVT;
1693     RegisterVT = getRegisterType(Context, IntermediateVT);
1694     return NumIntermediates;
1695   }
1696 
1697   // FIXME: We don't support non-power-of-2-sized vectors for now.  Ideally
1698   // we could break down into LHS/RHS like LegalizeDAG does.
1699   if (!isPowerOf2_32(EltCnt.getKnownMinValue())) {
1700     NumVectorRegs = EltCnt.getKnownMinValue();
1701     EltCnt = ElementCount::getFixed(1);
1702   }
1703 
1704   // Divide the input until we get to a supported size.  This will always
1705   // end with a scalar if the target doesn't support vectors.
1706   while (EltCnt.getKnownMinValue() > 1 &&
1707          !isTypeLegal(EVT::getVectorVT(Context, EltTy, EltCnt))) {
1708     EltCnt = EltCnt.divideCoefficientBy(2);
1709     NumVectorRegs <<= 1;
1710   }
1711 
1712   NumIntermediates = NumVectorRegs;
1713 
1714   EVT NewVT = EVT::getVectorVT(Context, EltTy, EltCnt);
1715   if (!isTypeLegal(NewVT))
1716     NewVT = EltTy;
1717   IntermediateVT = NewVT;
1718 
1719   MVT DestVT = getRegisterType(Context, NewVT);
1720   RegisterVT = DestVT;
1721 
1722   if (EVT(DestVT).bitsLT(NewVT)) {  // Value is expanded, e.g. i64 -> i16.
1723     TypeSize NewVTSize = NewVT.getSizeInBits();
1724     // Convert sizes such as i33 to i64.
1725     if (!llvm::has_single_bit<uint32_t>(NewVTSize.getKnownMinValue()))
1726       NewVTSize = NewVTSize.coefficientNextPowerOf2();
1727     return NumVectorRegs*(NewVTSize/DestVT.getSizeInBits());
1728   }
1729 
1730   // Otherwise, promotion or legal types use the same number of registers as
1731   // the vector decimated to the appropriate level.
1732   return NumVectorRegs;
1733 }
1734 
1735 bool TargetLoweringBase::isSuitableForJumpTable(const SwitchInst *SI,
1736                                                 uint64_t NumCases,
1737                                                 uint64_t Range,
1738                                                 ProfileSummaryInfo *PSI,
1739                                                 BlockFrequencyInfo *BFI) const {
1740   // FIXME: This function check the maximum table size and density, but the
1741   // minimum size is not checked. It would be nice if the minimum size is
1742   // also combined within this function. Currently, the minimum size check is
1743   // performed in findJumpTable() in SelectionDAGBuiler and
1744   // getEstimatedNumberOfCaseClusters() in BasicTTIImpl.
1745   const bool OptForSize =
1746       SI->getParent()->getParent()->hasOptSize() ||
1747       llvm::shouldOptimizeForSize(SI->getParent(), PSI, BFI);
1748   const unsigned MinDensity = getMinimumJumpTableDensity(OptForSize);
1749   const unsigned MaxJumpTableSize = getMaximumJumpTableSize();
1750 
1751   // Check whether the number of cases is small enough and
1752   // the range is dense enough for a jump table.
1753   return (OptForSize || Range <= MaxJumpTableSize) &&
1754          (NumCases * 100 >= Range * MinDensity);
1755 }
1756 
1757 MVT TargetLoweringBase::getPreferredSwitchConditionType(LLVMContext &Context,
1758                                                         EVT ConditionVT) const {
1759   return getRegisterType(Context, ConditionVT);
1760 }
1761 
1762 /// Get the EVTs and ArgFlags collections that represent the legalized return
1763 /// type of the given function.  This does not require a DAG or a return value,
1764 /// and is suitable for use before any DAGs for the function are constructed.
1765 /// TODO: Move this out of TargetLowering.cpp.
1766 void llvm::GetReturnInfo(CallingConv::ID CC, Type *ReturnType,
1767                          AttributeList attr,
1768                          SmallVectorImpl<ISD::OutputArg> &Outs,
1769                          const TargetLowering &TLI, const DataLayout &DL) {
1770   SmallVector<EVT, 4> ValueVTs;
1771   ComputeValueVTs(TLI, DL, ReturnType, ValueVTs);
1772   unsigned NumValues = ValueVTs.size();
1773   if (NumValues == 0) return;
1774 
1775   for (unsigned j = 0, f = NumValues; j != f; ++j) {
1776     EVT VT = ValueVTs[j];
1777     ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
1778 
1779     if (attr.hasRetAttr(Attribute::SExt))
1780       ExtendKind = ISD::SIGN_EXTEND;
1781     else if (attr.hasRetAttr(Attribute::ZExt))
1782       ExtendKind = ISD::ZERO_EXTEND;
1783 
1784     if (ExtendKind != ISD::ANY_EXTEND && VT.isInteger())
1785       VT = TLI.getTypeForExtReturn(ReturnType->getContext(), VT, ExtendKind);
1786 
1787     unsigned NumParts =
1788         TLI.getNumRegistersForCallingConv(ReturnType->getContext(), CC, VT);
1789     MVT PartVT =
1790         TLI.getRegisterTypeForCallingConv(ReturnType->getContext(), CC, VT);
1791 
1792     // 'inreg' on function refers to return value
1793     ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy();
1794     if (attr.hasRetAttr(Attribute::InReg))
1795       Flags.setInReg();
1796 
1797     // Propagate extension type if any
1798     if (attr.hasRetAttr(Attribute::SExt))
1799       Flags.setSExt();
1800     else if (attr.hasRetAttr(Attribute::ZExt))
1801       Flags.setZExt();
1802 
1803     for (unsigned i = 0; i < NumParts; ++i)
1804       Outs.push_back(ISD::OutputArg(Flags, PartVT, VT, /*isfixed=*/true, 0, 0));
1805   }
1806 }
1807 
1808 /// getByValTypeAlignment - Return the desired alignment for ByVal aggregate
1809 /// function arguments in the caller parameter area.  This is the actual
1810 /// alignment, not its logarithm.
1811 uint64_t TargetLoweringBase::getByValTypeAlignment(Type *Ty,
1812                                                    const DataLayout &DL) const {
1813   return DL.getABITypeAlign(Ty).value();
1814 }
1815 
1816 bool TargetLoweringBase::allowsMemoryAccessForAlignment(
1817     LLVMContext &Context, const DataLayout &DL, EVT VT, unsigned AddrSpace,
1818     Align Alignment, MachineMemOperand::Flags Flags, unsigned *Fast) const {
1819   // Check if the specified alignment is sufficient based on the data layout.
1820   // TODO: While using the data layout works in practice, a better solution
1821   // would be to implement this check directly (make this a virtual function).
1822   // For example, the ABI alignment may change based on software platform while
1823   // this function should only be affected by hardware implementation.
1824   Type *Ty = VT.getTypeForEVT(Context);
1825   if (VT.isZeroSized() || Alignment >= DL.getABITypeAlign(Ty)) {
1826     // Assume that an access that meets the ABI-specified alignment is fast.
1827     if (Fast != nullptr)
1828       *Fast = 1;
1829     return true;
1830   }
1831 
1832   // This is a misaligned access.
1833   return allowsMisalignedMemoryAccesses(VT, AddrSpace, Alignment, Flags, Fast);
1834 }
1835 
1836 bool TargetLoweringBase::allowsMemoryAccessForAlignment(
1837     LLVMContext &Context, const DataLayout &DL, EVT VT,
1838     const MachineMemOperand &MMO, unsigned *Fast) const {
1839   return allowsMemoryAccessForAlignment(Context, DL, VT, MMO.getAddrSpace(),
1840                                         MMO.getAlign(), MMO.getFlags(), Fast);
1841 }
1842 
1843 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1844                                             const DataLayout &DL, EVT VT,
1845                                             unsigned AddrSpace, Align Alignment,
1846                                             MachineMemOperand::Flags Flags,
1847                                             unsigned *Fast) const {
1848   return allowsMemoryAccessForAlignment(Context, DL, VT, AddrSpace, Alignment,
1849                                         Flags, Fast);
1850 }
1851 
1852 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1853                                             const DataLayout &DL, EVT VT,
1854                                             const MachineMemOperand &MMO,
1855                                             unsigned *Fast) const {
1856   return allowsMemoryAccess(Context, DL, VT, MMO.getAddrSpace(), MMO.getAlign(),
1857                             MMO.getFlags(), Fast);
1858 }
1859 
1860 bool TargetLoweringBase::allowsMemoryAccess(LLVMContext &Context,
1861                                             const DataLayout &DL, LLT Ty,
1862                                             const MachineMemOperand &MMO,
1863                                             unsigned *Fast) const {
1864   EVT VT = getApproximateEVTForLLT(Ty, DL, Context);
1865   return allowsMemoryAccess(Context, DL, VT, MMO.getAddrSpace(), MMO.getAlign(),
1866                             MMO.getFlags(), Fast);
1867 }
1868 
1869 //===----------------------------------------------------------------------===//
1870 //  TargetTransformInfo Helpers
1871 //===----------------------------------------------------------------------===//
1872 
1873 int TargetLoweringBase::InstructionOpcodeToISD(unsigned Opcode) const {
1874   enum InstructionOpcodes {
1875 #define HANDLE_INST(NUM, OPCODE, CLASS) OPCODE = NUM,
1876 #define LAST_OTHER_INST(NUM) InstructionOpcodesCount = NUM
1877 #include "llvm/IR/Instruction.def"
1878   };
1879   switch (static_cast<InstructionOpcodes>(Opcode)) {
1880   case Ret:            return 0;
1881   case Br:             return 0;
1882   case Switch:         return 0;
1883   case IndirectBr:     return 0;
1884   case Invoke:         return 0;
1885   case CallBr:         return 0;
1886   case Resume:         return 0;
1887   case Unreachable:    return 0;
1888   case CleanupRet:     return 0;
1889   case CatchRet:       return 0;
1890   case CatchPad:       return 0;
1891   case CatchSwitch:    return 0;
1892   case CleanupPad:     return 0;
1893   case FNeg:           return ISD::FNEG;
1894   case Add:            return ISD::ADD;
1895   case FAdd:           return ISD::FADD;
1896   case Sub:            return ISD::SUB;
1897   case FSub:           return ISD::FSUB;
1898   case Mul:            return ISD::MUL;
1899   case FMul:           return ISD::FMUL;
1900   case UDiv:           return ISD::UDIV;
1901   case SDiv:           return ISD::SDIV;
1902   case FDiv:           return ISD::FDIV;
1903   case URem:           return ISD::UREM;
1904   case SRem:           return ISD::SREM;
1905   case FRem:           return ISD::FREM;
1906   case Shl:            return ISD::SHL;
1907   case LShr:           return ISD::SRL;
1908   case AShr:           return ISD::SRA;
1909   case And:            return ISD::AND;
1910   case Or:             return ISD::OR;
1911   case Xor:            return ISD::XOR;
1912   case Alloca:         return 0;
1913   case Load:           return ISD::LOAD;
1914   case Store:          return ISD::STORE;
1915   case GetElementPtr:  return 0;
1916   case Fence:          return 0;
1917   case AtomicCmpXchg:  return 0;
1918   case AtomicRMW:      return 0;
1919   case Trunc:          return ISD::TRUNCATE;
1920   case ZExt:           return ISD::ZERO_EXTEND;
1921   case SExt:           return ISD::SIGN_EXTEND;
1922   case FPToUI:         return ISD::FP_TO_UINT;
1923   case FPToSI:         return ISD::FP_TO_SINT;
1924   case UIToFP:         return ISD::UINT_TO_FP;
1925   case SIToFP:         return ISD::SINT_TO_FP;
1926   case FPTrunc:        return ISD::FP_ROUND;
1927   case FPExt:          return ISD::FP_EXTEND;
1928   case PtrToInt:       return ISD::BITCAST;
1929   case IntToPtr:       return ISD::BITCAST;
1930   case BitCast:        return ISD::BITCAST;
1931   case AddrSpaceCast:  return ISD::ADDRSPACECAST;
1932   case ICmp:           return ISD::SETCC;
1933   case FCmp:           return ISD::SETCC;
1934   case PHI:            return 0;
1935   case Call:           return 0;
1936   case Select:         return ISD::SELECT;
1937   case UserOp1:        return 0;
1938   case UserOp2:        return 0;
1939   case VAArg:          return 0;
1940   case ExtractElement: return ISD::EXTRACT_VECTOR_ELT;
1941   case InsertElement:  return ISD::INSERT_VECTOR_ELT;
1942   case ShuffleVector:  return ISD::VECTOR_SHUFFLE;
1943   case ExtractValue:   return ISD::MERGE_VALUES;
1944   case InsertValue:    return ISD::MERGE_VALUES;
1945   case LandingPad:     return 0;
1946   case Freeze:         return ISD::FREEZE;
1947   }
1948 
1949   llvm_unreachable("Unknown instruction type encountered!");
1950 }
1951 
1952 Value *
1953 TargetLoweringBase::getDefaultSafeStackPointerLocation(IRBuilderBase &IRB,
1954                                                        bool UseTLS) const {
1955   // compiler-rt provides a variable with a magic name.  Targets that do not
1956   // link with compiler-rt may also provide such a variable.
1957   Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1958   const char *UnsafeStackPtrVar = "__safestack_unsafe_stack_ptr";
1959   auto UnsafeStackPtr =
1960       dyn_cast_or_null<GlobalVariable>(M->getNamedValue(UnsafeStackPtrVar));
1961 
1962   Type *StackPtrTy = PointerType::getUnqual(M->getContext());
1963 
1964   if (!UnsafeStackPtr) {
1965     auto TLSModel = UseTLS ?
1966         GlobalValue::InitialExecTLSModel :
1967         GlobalValue::NotThreadLocal;
1968     // The global variable is not defined yet, define it ourselves.
1969     // We use the initial-exec TLS model because we do not support the
1970     // variable living anywhere other than in the main executable.
1971     UnsafeStackPtr = new GlobalVariable(
1972         *M, StackPtrTy, false, GlobalValue::ExternalLinkage, nullptr,
1973         UnsafeStackPtrVar, nullptr, TLSModel);
1974   } else {
1975     // The variable exists, check its type and attributes.
1976     if (UnsafeStackPtr->getValueType() != StackPtrTy)
1977       report_fatal_error(Twine(UnsafeStackPtrVar) + " must have void* type");
1978     if (UseTLS != UnsafeStackPtr->isThreadLocal())
1979       report_fatal_error(Twine(UnsafeStackPtrVar) + " must " +
1980                          (UseTLS ? "" : "not ") + "be thread-local");
1981   }
1982   return UnsafeStackPtr;
1983 }
1984 
1985 Value *
1986 TargetLoweringBase::getSafeStackPointerLocation(IRBuilderBase &IRB) const {
1987   if (!TM.getTargetTriple().isAndroid())
1988     return getDefaultSafeStackPointerLocation(IRB, true);
1989 
1990   // Android provides a libc function to retrieve the address of the current
1991   // thread's unsafe stack pointer.
1992   Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1993   auto *PtrTy = PointerType::getUnqual(M->getContext());
1994   FunctionCallee Fn =
1995       M->getOrInsertFunction("__safestack_pointer_address", PtrTy);
1996   return IRB.CreateCall(Fn);
1997 }
1998 
1999 //===----------------------------------------------------------------------===//
2000 //  Loop Strength Reduction hooks
2001 //===----------------------------------------------------------------------===//
2002 
2003 /// isLegalAddressingMode - Return true if the addressing mode represented
2004 /// by AM is legal for this target, for a load/store of the specified type.
2005 bool TargetLoweringBase::isLegalAddressingMode(const DataLayout &DL,
2006                                                const AddrMode &AM, Type *Ty,
2007                                                unsigned AS, Instruction *I) const {
2008   // The default implementation of this implements a conservative RISCy, r+r and
2009   // r+i addr mode.
2010 
2011   // Allows a sign-extended 16-bit immediate field.
2012   if (AM.BaseOffs <= -(1LL << 16) || AM.BaseOffs >= (1LL << 16)-1)
2013     return false;
2014 
2015   // No global is ever allowed as a base.
2016   if (AM.BaseGV)
2017     return false;
2018 
2019   // Only support r+r,
2020   switch (AM.Scale) {
2021   case 0:  // "r+i" or just "i", depending on HasBaseReg.
2022     break;
2023   case 1:
2024     if (AM.HasBaseReg && AM.BaseOffs)  // "r+r+i" is not allowed.
2025       return false;
2026     // Otherwise we have r+r or r+i.
2027     break;
2028   case 2:
2029     if (AM.HasBaseReg || AM.BaseOffs)  // 2*r+r  or  2*r+i is not allowed.
2030       return false;
2031     // Allow 2*r as r+r.
2032     break;
2033   default: // Don't allow n * r
2034     return false;
2035   }
2036 
2037   return true;
2038 }
2039 
2040 //===----------------------------------------------------------------------===//
2041 //  Stack Protector
2042 //===----------------------------------------------------------------------===//
2043 
2044 // For OpenBSD return its special guard variable. Otherwise return nullptr,
2045 // so that SelectionDAG handle SSP.
2046 Value *TargetLoweringBase::getIRStackGuard(IRBuilderBase &IRB) const {
2047   if (getTargetMachine().getTargetTriple().isOSOpenBSD()) {
2048     Module &M = *IRB.GetInsertBlock()->getParent()->getParent();
2049     PointerType *PtrTy = PointerType::getUnqual(M.getContext());
2050     Constant *C = M.getOrInsertGlobal("__guard_local", PtrTy);
2051     if (GlobalVariable *G = dyn_cast_or_null<GlobalVariable>(C))
2052       G->setVisibility(GlobalValue::HiddenVisibility);
2053     return C;
2054   }
2055   return nullptr;
2056 }
2057 
2058 // Currently only support "standard" __stack_chk_guard.
2059 // TODO: add LOAD_STACK_GUARD support.
2060 void TargetLoweringBase::insertSSPDeclarations(Module &M) const {
2061   if (!M.getNamedValue("__stack_chk_guard")) {
2062     auto *GV = new GlobalVariable(M, PointerType::getUnqual(M.getContext()),
2063                                   false, GlobalVariable::ExternalLinkage,
2064                                   nullptr, "__stack_chk_guard");
2065 
2066     // FreeBSD has "__stack_chk_guard" defined externally on libc.so
2067     if (M.getDirectAccessExternalData() &&
2068         !TM.getTargetTriple().isWindowsGNUEnvironment() &&
2069         !TM.getTargetTriple().isOSFreeBSD() &&
2070         (!TM.getTargetTriple().isOSDarwin() ||
2071          TM.getRelocationModel() == Reloc::Static))
2072       GV->setDSOLocal(true);
2073   }
2074 }
2075 
2076 // Currently only support "standard" __stack_chk_guard.
2077 // TODO: add LOAD_STACK_GUARD support.
2078 Value *TargetLoweringBase::getSDagStackGuard(const Module &M) const {
2079   return M.getNamedValue("__stack_chk_guard");
2080 }
2081 
2082 Function *TargetLoweringBase::getSSPStackGuardCheck(const Module &M) const {
2083   return nullptr;
2084 }
2085 
2086 unsigned TargetLoweringBase::getMinimumJumpTableEntries() const {
2087   return MinimumJumpTableEntries;
2088 }
2089 
2090 void TargetLoweringBase::setMinimumJumpTableEntries(unsigned Val) {
2091   MinimumJumpTableEntries = Val;
2092 }
2093 
2094 unsigned TargetLoweringBase::getMinimumJumpTableDensity(bool OptForSize) const {
2095   return OptForSize ? OptsizeJumpTableDensity : JumpTableDensity;
2096 }
2097 
2098 unsigned TargetLoweringBase::getMaximumJumpTableSize() const {
2099   return MaximumJumpTableSize;
2100 }
2101 
2102 void TargetLoweringBase::setMaximumJumpTableSize(unsigned Val) {
2103   MaximumJumpTableSize = Val;
2104 }
2105 
2106 bool TargetLoweringBase::isJumpTableRelative() const {
2107   return getTargetMachine().isPositionIndependent();
2108 }
2109 
2110 Align TargetLoweringBase::getPrefLoopAlignment(MachineLoop *ML) const {
2111   if (TM.Options.LoopAlignment)
2112     return Align(TM.Options.LoopAlignment);
2113   return PrefLoopAlignment;
2114 }
2115 
2116 unsigned TargetLoweringBase::getMaxPermittedBytesForAlignment(
2117     MachineBasicBlock *MBB) const {
2118   return MaxBytesForAlignment;
2119 }
2120 
2121 //===----------------------------------------------------------------------===//
2122 //  Reciprocal Estimates
2123 //===----------------------------------------------------------------------===//
2124 
2125 /// Get the reciprocal estimate attribute string for a function that will
2126 /// override the target defaults.
2127 static StringRef getRecipEstimateForFunc(MachineFunction &MF) {
2128   const Function &F = MF.getFunction();
2129   return F.getFnAttribute("reciprocal-estimates").getValueAsString();
2130 }
2131 
2132 /// Construct a string for the given reciprocal operation of the given type.
2133 /// This string should match the corresponding option to the front-end's
2134 /// "-mrecip" flag assuming those strings have been passed through in an
2135 /// attribute string. For example, "vec-divf" for a division of a vXf32.
2136 static std::string getReciprocalOpName(bool IsSqrt, EVT VT) {
2137   std::string Name = VT.isVector() ? "vec-" : "";
2138 
2139   Name += IsSqrt ? "sqrt" : "div";
2140 
2141   // TODO: Handle other float types?
2142   if (VT.getScalarType() == MVT::f64) {
2143     Name += "d";
2144   } else if (VT.getScalarType() == MVT::f16) {
2145     Name += "h";
2146   } else {
2147     assert(VT.getScalarType() == MVT::f32 &&
2148            "Unexpected FP type for reciprocal estimate");
2149     Name += "f";
2150   }
2151 
2152   return Name;
2153 }
2154 
2155 /// Return the character position and value (a single numeric character) of a
2156 /// customized refinement operation in the input string if it exists. Return
2157 /// false if there is no customized refinement step count.
2158 static bool parseRefinementStep(StringRef In, size_t &Position,
2159                                 uint8_t &Value) {
2160   const char RefStepToken = ':';
2161   Position = In.find(RefStepToken);
2162   if (Position == StringRef::npos)
2163     return false;
2164 
2165   StringRef RefStepString = In.substr(Position + 1);
2166   // Allow exactly one numeric character for the additional refinement
2167   // step parameter.
2168   if (RefStepString.size() == 1) {
2169     char RefStepChar = RefStepString[0];
2170     if (isDigit(RefStepChar)) {
2171       Value = RefStepChar - '0';
2172       return true;
2173     }
2174   }
2175   report_fatal_error("Invalid refinement step for -recip.");
2176 }
2177 
2178 /// For the input attribute string, return one of the ReciprocalEstimate enum
2179 /// status values (enabled, disabled, or not specified) for this operation on
2180 /// the specified data type.
2181 static int getOpEnabled(bool IsSqrt, EVT VT, StringRef Override) {
2182   if (Override.empty())
2183     return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2184 
2185   SmallVector<StringRef, 4> OverrideVector;
2186   Override.split(OverrideVector, ',');
2187   unsigned NumArgs = OverrideVector.size();
2188 
2189   // Check if "all", "none", or "default" was specified.
2190   if (NumArgs == 1) {
2191     // Look for an optional setting of the number of refinement steps needed
2192     // for this type of reciprocal operation.
2193     size_t RefPos;
2194     uint8_t RefSteps;
2195     if (parseRefinementStep(Override, RefPos, RefSteps)) {
2196       // Split the string for further processing.
2197       Override = Override.substr(0, RefPos);
2198     }
2199 
2200     // All reciprocal types are enabled.
2201     if (Override == "all")
2202       return TargetLoweringBase::ReciprocalEstimate::Enabled;
2203 
2204     // All reciprocal types are disabled.
2205     if (Override == "none")
2206       return TargetLoweringBase::ReciprocalEstimate::Disabled;
2207 
2208     // Target defaults for enablement are used.
2209     if (Override == "default")
2210       return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2211   }
2212 
2213   // The attribute string may omit the size suffix ('f'/'d').
2214   std::string VTName = getReciprocalOpName(IsSqrt, VT);
2215   std::string VTNameNoSize = VTName;
2216   VTNameNoSize.pop_back();
2217   static const char DisabledPrefix = '!';
2218 
2219   for (StringRef RecipType : OverrideVector) {
2220     size_t RefPos;
2221     uint8_t RefSteps;
2222     if (parseRefinementStep(RecipType, RefPos, RefSteps))
2223       RecipType = RecipType.substr(0, RefPos);
2224 
2225     // Ignore the disablement token for string matching.
2226     bool IsDisabled = RecipType[0] == DisabledPrefix;
2227     if (IsDisabled)
2228       RecipType = RecipType.substr(1);
2229 
2230     if (RecipType.equals(VTName) || RecipType.equals(VTNameNoSize))
2231       return IsDisabled ? TargetLoweringBase::ReciprocalEstimate::Disabled
2232                         : TargetLoweringBase::ReciprocalEstimate::Enabled;
2233   }
2234 
2235   return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2236 }
2237 
2238 /// For the input attribute string, return the customized refinement step count
2239 /// for this operation on the specified data type. If the step count does not
2240 /// exist, return the ReciprocalEstimate enum value for unspecified.
2241 static int getOpRefinementSteps(bool IsSqrt, EVT VT, StringRef Override) {
2242   if (Override.empty())
2243     return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2244 
2245   SmallVector<StringRef, 4> OverrideVector;
2246   Override.split(OverrideVector, ',');
2247   unsigned NumArgs = OverrideVector.size();
2248 
2249   // Check if "all", "default", or "none" was specified.
2250   if (NumArgs == 1) {
2251     // Look for an optional setting of the number of refinement steps needed
2252     // for this type of reciprocal operation.
2253     size_t RefPos;
2254     uint8_t RefSteps;
2255     if (!parseRefinementStep(Override, RefPos, RefSteps))
2256       return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2257 
2258     // Split the string for further processing.
2259     Override = Override.substr(0, RefPos);
2260     assert(Override != "none" &&
2261            "Disabled reciprocals, but specifed refinement steps?");
2262 
2263     // If this is a general override, return the specified number of steps.
2264     if (Override == "all" || Override == "default")
2265       return RefSteps;
2266   }
2267 
2268   // The attribute string may omit the size suffix ('f'/'d').
2269   std::string VTName = getReciprocalOpName(IsSqrt, VT);
2270   std::string VTNameNoSize = VTName;
2271   VTNameNoSize.pop_back();
2272 
2273   for (StringRef RecipType : OverrideVector) {
2274     size_t RefPos;
2275     uint8_t RefSteps;
2276     if (!parseRefinementStep(RecipType, RefPos, RefSteps))
2277       continue;
2278 
2279     RecipType = RecipType.substr(0, RefPos);
2280     if (RecipType.equals(VTName) || RecipType.equals(VTNameNoSize))
2281       return RefSteps;
2282   }
2283 
2284   return TargetLoweringBase::ReciprocalEstimate::Unspecified;
2285 }
2286 
2287 int TargetLoweringBase::getRecipEstimateSqrtEnabled(EVT VT,
2288                                                     MachineFunction &MF) const {
2289   return getOpEnabled(true, VT, getRecipEstimateForFunc(MF));
2290 }
2291 
2292 int TargetLoweringBase::getRecipEstimateDivEnabled(EVT VT,
2293                                                    MachineFunction &MF) const {
2294   return getOpEnabled(false, VT, getRecipEstimateForFunc(MF));
2295 }
2296 
2297 int TargetLoweringBase::getSqrtRefinementSteps(EVT VT,
2298                                                MachineFunction &MF) const {
2299   return getOpRefinementSteps(true, VT, getRecipEstimateForFunc(MF));
2300 }
2301 
2302 int TargetLoweringBase::getDivRefinementSteps(EVT VT,
2303                                               MachineFunction &MF) const {
2304   return getOpRefinementSteps(false, VT, getRecipEstimateForFunc(MF));
2305 }
2306 
2307 bool TargetLoweringBase::isLoadBitCastBeneficial(
2308     EVT LoadVT, EVT BitcastVT, const SelectionDAG &DAG,
2309     const MachineMemOperand &MMO) const {
2310   // Single-element vectors are scalarized, so we should generally avoid having
2311   // any memory operations on such types, as they would get scalarized too.
2312   if (LoadVT.isFixedLengthVector() && BitcastVT.isFixedLengthVector() &&
2313       BitcastVT.getVectorNumElements() == 1)
2314     return false;
2315 
2316   // Don't do if we could do an indexed load on the original type, but not on
2317   // the new one.
2318   if (!LoadVT.isSimple() || !BitcastVT.isSimple())
2319     return true;
2320 
2321   MVT LoadMVT = LoadVT.getSimpleVT();
2322 
2323   // Don't bother doing this if it's just going to be promoted again later, as
2324   // doing so might interfere with other combines.
2325   if (getOperationAction(ISD::LOAD, LoadMVT) == Promote &&
2326       getTypeToPromoteTo(ISD::LOAD, LoadMVT) == BitcastVT.getSimpleVT())
2327     return false;
2328 
2329   unsigned Fast = 0;
2330   return allowsMemoryAccess(*DAG.getContext(), DAG.getDataLayout(), BitcastVT,
2331                             MMO, &Fast) &&
2332          Fast;
2333 }
2334 
2335 void TargetLoweringBase::finalizeLowering(MachineFunction &MF) const {
2336   MF.getRegInfo().freezeReservedRegs(MF);
2337 }
2338 
2339 MachineMemOperand::Flags TargetLoweringBase::getLoadMemOperandFlags(
2340     const LoadInst &LI, const DataLayout &DL, AssumptionCache *AC,
2341     const TargetLibraryInfo *LibInfo) const {
2342   MachineMemOperand::Flags Flags = MachineMemOperand::MOLoad;
2343   if (LI.isVolatile())
2344     Flags |= MachineMemOperand::MOVolatile;
2345 
2346   if (LI.hasMetadata(LLVMContext::MD_nontemporal))
2347     Flags |= MachineMemOperand::MONonTemporal;
2348 
2349   if (LI.hasMetadata(LLVMContext::MD_invariant_load))
2350     Flags |= MachineMemOperand::MOInvariant;
2351 
2352   if (isDereferenceableAndAlignedPointer(LI.getPointerOperand(), LI.getType(),
2353                                          LI.getAlign(), DL, &LI, AC,
2354                                          /*DT=*/nullptr, LibInfo))
2355     Flags |= MachineMemOperand::MODereferenceable;
2356 
2357   Flags |= getTargetMMOFlags(LI);
2358   return Flags;
2359 }
2360 
2361 MachineMemOperand::Flags
2362 TargetLoweringBase::getStoreMemOperandFlags(const StoreInst &SI,
2363                                             const DataLayout &DL) const {
2364   MachineMemOperand::Flags Flags = MachineMemOperand::MOStore;
2365 
2366   if (SI.isVolatile())
2367     Flags |= MachineMemOperand::MOVolatile;
2368 
2369   if (SI.hasMetadata(LLVMContext::MD_nontemporal))
2370     Flags |= MachineMemOperand::MONonTemporal;
2371 
2372   // FIXME: Not preserving dereferenceable
2373   Flags |= getTargetMMOFlags(SI);
2374   return Flags;
2375 }
2376 
2377 MachineMemOperand::Flags
2378 TargetLoweringBase::getAtomicMemOperandFlags(const Instruction &AI,
2379                                              const DataLayout &DL) const {
2380   auto Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOStore;
2381 
2382   if (const AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(&AI)) {
2383     if (RMW->isVolatile())
2384       Flags |= MachineMemOperand::MOVolatile;
2385   } else if (const AtomicCmpXchgInst *CmpX = dyn_cast<AtomicCmpXchgInst>(&AI)) {
2386     if (CmpX->isVolatile())
2387       Flags |= MachineMemOperand::MOVolatile;
2388   } else
2389     llvm_unreachable("not an atomic instruction");
2390 
2391   // FIXME: Not preserving dereferenceable
2392   Flags |= getTargetMMOFlags(AI);
2393   return Flags;
2394 }
2395 
2396 Instruction *TargetLoweringBase::emitLeadingFence(IRBuilderBase &Builder,
2397                                                   Instruction *Inst,
2398                                                   AtomicOrdering Ord) const {
2399   if (isReleaseOrStronger(Ord) && Inst->hasAtomicStore())
2400     return Builder.CreateFence(Ord);
2401   else
2402     return nullptr;
2403 }
2404 
2405 Instruction *TargetLoweringBase::emitTrailingFence(IRBuilderBase &Builder,
2406                                                    Instruction *Inst,
2407                                                    AtomicOrdering Ord) const {
2408   if (isAcquireOrStronger(Ord))
2409     return Builder.CreateFence(Ord);
2410   else
2411     return nullptr;
2412 }
2413 
2414 //===----------------------------------------------------------------------===//
2415 //  GlobalISel Hooks
2416 //===----------------------------------------------------------------------===//
2417 
2418 bool TargetLoweringBase::shouldLocalize(const MachineInstr &MI,
2419                                         const TargetTransformInfo *TTI) const {
2420   auto &MF = *MI.getMF();
2421   auto &MRI = MF.getRegInfo();
2422   // Assuming a spill and reload of a value has a cost of 1 instruction each,
2423   // this helper function computes the maximum number of uses we should consider
2424   // for remat. E.g. on arm64 global addresses take 2 insts to materialize. We
2425   // break even in terms of code size when the original MI has 2 users vs
2426   // choosing to potentially spill. Any more than 2 users we we have a net code
2427   // size increase. This doesn't take into account register pressure though.
2428   auto maxUses = [](unsigned RematCost) {
2429     // A cost of 1 means remats are basically free.
2430     if (RematCost == 1)
2431       return std::numeric_limits<unsigned>::max();
2432     if (RematCost == 2)
2433       return 2U;
2434 
2435     // Remat is too expensive, only sink if there's one user.
2436     if (RematCost > 2)
2437       return 1U;
2438     llvm_unreachable("Unexpected remat cost");
2439   };
2440 
2441   switch (MI.getOpcode()) {
2442   default:
2443     return false;
2444   // Constants-like instructions should be close to their users.
2445   // We don't want long live-ranges for them.
2446   case TargetOpcode::G_CONSTANT:
2447   case TargetOpcode::G_FCONSTANT:
2448   case TargetOpcode::G_FRAME_INDEX:
2449   case TargetOpcode::G_INTTOPTR:
2450     return true;
2451   case TargetOpcode::G_GLOBAL_VALUE: {
2452     unsigned RematCost = TTI->getGISelRematGlobalCost();
2453     Register Reg = MI.getOperand(0).getReg();
2454     unsigned MaxUses = maxUses(RematCost);
2455     if (MaxUses == UINT_MAX)
2456       return true; // Remats are "free" so always localize.
2457     return MRI.hasAtMostUserInstrs(Reg, MaxUses);
2458   }
2459   }
2460 }
2461