1 //===- MveEmitter.cpp - Generate arm_mve.h for use with clang -*- C++ -*-=====//
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 set of linked tablegen backends is responsible for emitting the bits
10 // and pieces that implement <arm_mve.h>, which is defined by the ACLE standard
11 // and provides a set of types and functions for (more or less) direct access
12 // to the MVE instruction set, including the scalar shifts as well as the
13 // vector instructions.
14 //
15 // MVE's standard intrinsic functions are unusual in that they have a system of
16 // polymorphism. For example, the function vaddq() can behave like vaddq_u16(),
17 // vaddq_f32(), vaddq_s8(), etc., depending on the types of the vector
18 // arguments you give it.
19 //
20 // This constrains the implementation strategies. The usual approach to making
21 // the user-facing functions polymorphic would be to either use
22 // __attribute__((overloadable)) to make a set of vaddq() functions that are
23 // all inline wrappers on the underlying clang builtins, or to define a single
24 // vaddq() macro which expands to an instance of _Generic.
25 //
26 // The inline-wrappers approach would work fine for most intrinsics, except for
27 // the ones that take an argument required to be a compile-time constant,
28 // because if you wrap an inline function around a call to a builtin, the
29 // constant nature of the argument is not passed through.
30 //
31 // The _Generic approach can be made to work with enough effort, but it takes a
32 // lot of machinery, because of the design feature of _Generic that even the
33 // untaken branches are required to pass all front-end validity checks such as
34 // type-correctness. You can work around that by nesting further _Generics all
35 // over the place to coerce things to the right type in untaken branches, but
36 // what you get out is complicated, hard to guarantee its correctness, and
37 // worst of all, gives _completely unreadable_ error messages if the user gets
38 // the types wrong for an intrinsic call.
39 //
40 // Therefore, my strategy is to introduce a new __attribute__ that allows a
41 // function to be mapped to a clang builtin even though it doesn't have the
42 // same name, and then declare all the user-facing MVE function names with that
43 // attribute, mapping each one directly to the clang builtin. And the
44 // polymorphic ones have __attribute__((overloadable)) as well. So once the
45 // compiler has resolved the overload, it knows the internal builtin ID of the
46 // selected function, and can check the immediate arguments against that; and
47 // if the user gets the types wrong in a call to a polymorphic intrinsic, they
48 // get a completely clear error message showing all the declarations of that
49 // function in the header file and explaining why each one doesn't fit their
50 // call.
51 //
52 // The downside of this is that if every clang builtin has to correspond
53 // exactly to a user-facing ACLE intrinsic, then you can't save work in the
54 // frontend by doing it in the header file: CGBuiltin.cpp has to do the entire
55 // job of converting an ACLE intrinsic call into LLVM IR. So the Tablegen
56 // description for an MVE intrinsic has to contain a full description of the
57 // sequence of IRBuilder calls that clang will need to make.
58 //
59 //===----------------------------------------------------------------------===//
60 
61 #include "llvm/ADT/APInt.h"
62 #include "llvm/ADT/StringRef.h"
63 #include "llvm/Support/Casting.h"
64 #include "llvm/Support/raw_ostream.h"
65 #include "llvm/TableGen/Error.h"
66 #include "llvm/TableGen/Record.h"
67 #include "llvm/TableGen/StringToOffsetTable.h"
68 #include <cassert>
69 #include <cstddef>
70 #include <cstdint>
71 #include <list>
72 #include <map>
73 #include <memory>
74 #include <set>
75 #include <string>
76 #include <vector>
77 
78 using namespace llvm;
79 
80 namespace {
81 
82 class MveEmitter;
83 class Result;
84 
85 // -----------------------------------------------------------------------------
86 // A system of classes to represent all the types we'll need to deal with in
87 // the prototypes of intrinsics.
88 //
89 // Query methods include finding out the C name of a type; the "LLVM name" in
90 // the sense of a C++ code snippet that can be used in the codegen function;
91 // the suffix that represents the type in the ACLE intrinsic naming scheme
92 // (e.g. 's32' represents int32_t in intrinsics such as vaddq_s32); whether the
93 // type is floating-point related (hence should be under #ifdef in the MVE
94 // header so that it isn't included in integer-only MVE mode); and the type's
95 // size in bits. Not all subtypes support all these queries.
96 
97 class Type {
98 public:
99   enum class TypeKind {
100     // Void appears as a return type (for store intrinsics, which are pure
101     // side-effect). It's also used as the parameter type in the Tablegen
102     // when an intrinsic doesn't need to come in various suffixed forms like
103     // vfooq_s8,vfooq_u16,vfooq_f32.
104     Void,
105 
106     // Scalar is used for ordinary int and float types of all sizes.
107     Scalar,
108 
109     // Vector is used for anything that occupies exactly one MVE vector
110     // register, i.e. {uint,int,float}NxM_t.
111     Vector,
112 
113     // MultiVector is used for the {uint,int,float}NxMxK_t types used by the
114     // interleaving load/store intrinsics v{ld,st}{2,4}q.
115     MultiVector,
116 
117     // Predicate is used by all the predicated intrinsics. Its C
118     // representation is mve_pred16_t (which is just an alias for uint16_t).
119     // But we give more detail here, by indicating that a given predicate
120     // instruction is logically regarded as a vector of i1 containing the
121     // same number of lanes as the input vector type. So our Predicate type
122     // comes with a lane count, which we use to decide which kind of <n x i1>
123     // we'll invoke the pred_i2v IR intrinsic to translate it into.
124     Predicate,
125 
126     // Pointer is used for pointer types (obviously), and comes with a flag
127     // indicating whether it's a pointer to a const or mutable instance of
128     // the pointee type.
129     Pointer,
130   };
131 
132 private:
133   const TypeKind TKind;
134 
135 protected:
136   Type(TypeKind K) : TKind(K) {}
137 
138 public:
139   TypeKind typeKind() const { return TKind; }
140   virtual ~Type() = default;
141   virtual bool requiresFloat() const = 0;
142   virtual unsigned sizeInBits() const = 0;
143   virtual std::string cName() const = 0;
144   virtual std::string llvmName() const {
145     PrintFatalError("no LLVM type name available for type " + cName());
146   }
147   virtual std::string acleSuffix(std::string) const {
148     PrintFatalError("no ACLE suffix available for this type");
149   }
150 };
151 
152 enum class ScalarTypeKind { SignedInt, UnsignedInt, Float };
153 inline std::string toLetter(ScalarTypeKind kind) {
154   switch (kind) {
155   case ScalarTypeKind::SignedInt:
156     return "s";
157   case ScalarTypeKind::UnsignedInt:
158     return "u";
159   case ScalarTypeKind::Float:
160     return "f";
161   }
162   llvm_unreachable("Unhandled ScalarTypeKind enum");
163 }
164 inline std::string toCPrefix(ScalarTypeKind kind) {
165   switch (kind) {
166   case ScalarTypeKind::SignedInt:
167     return "int";
168   case ScalarTypeKind::UnsignedInt:
169     return "uint";
170   case ScalarTypeKind::Float:
171     return "float";
172   }
173   llvm_unreachable("Unhandled ScalarTypeKind enum");
174 }
175 
176 class VoidType : public Type {
177 public:
178   VoidType() : Type(TypeKind::Void) {}
179   unsigned sizeInBits() const override { return 0; }
180   bool requiresFloat() const override { return false; }
181   std::string cName() const override { return "void"; }
182 
183   static bool classof(const Type *T) { return T->typeKind() == TypeKind::Void; }
184   std::string acleSuffix(std::string) const override { return ""; }
185 };
186 
187 class PointerType : public Type {
188   const Type *Pointee;
189   bool Const;
190 
191 public:
192   PointerType(const Type *Pointee, bool Const)
193       : Type(TypeKind::Pointer), Pointee(Pointee), Const(Const) {}
194   unsigned sizeInBits() const override { return 32; }
195   bool requiresFloat() const override { return Pointee->requiresFloat(); }
196   std::string cName() const override {
197     std::string Name = Pointee->cName();
198 
199     // The syntax for a pointer in C is different when the pointee is
200     // itself a pointer. The MVE intrinsics don't contain any double
201     // pointers, so we don't need to worry about that wrinkle.
202     assert(!isa<PointerType>(Pointee) && "Pointer to pointer not supported");
203 
204     if (Const)
205       Name = "const " + Name;
206     return Name + " *";
207   }
208   std::string llvmName() const override {
209     return "llvm::PointerType::getUnqual(" + Pointee->llvmName() + ")";
210   }
211 
212   static bool classof(const Type *T) {
213     return T->typeKind() == TypeKind::Pointer;
214   }
215 };
216 
217 // Base class for all the types that have a name of the form
218 // [prefix][numbers]_t, like int32_t, uint16x8_t, float32x4x2_t.
219 //
220 // For this sub-hierarchy we invent a cNameBase() method which returns the
221 // whole name except for the trailing "_t", so that Vector and MultiVector can
222 // append an extra "x2" or whatever to their element type's cNameBase(). Then
223 // the main cName() query method puts "_t" on the end for the final type name.
224 
225 class CRegularNamedType : public Type {
226   using Type::Type;
227   virtual std::string cNameBase() const = 0;
228 
229 public:
230   std::string cName() const override { return cNameBase() + "_t"; }
231 };
232 
233 class ScalarType : public CRegularNamedType {
234   ScalarTypeKind Kind;
235   unsigned Bits;
236   std::string NameOverride;
237 
238 public:
239   ScalarType(const Record *Record) : CRegularNamedType(TypeKind::Scalar) {
240     Kind = StringSwitch<ScalarTypeKind>(Record->getValueAsString("kind"))
241                .Case("s", ScalarTypeKind::SignedInt)
242                .Case("u", ScalarTypeKind::UnsignedInt)
243                .Case("f", ScalarTypeKind::Float);
244     Bits = Record->getValueAsInt("size");
245     NameOverride = std::string(Record->getValueAsString("nameOverride"));
246   }
247   unsigned sizeInBits() const override { return Bits; }
248   ScalarTypeKind kind() const { return Kind; }
249   std::string suffix() const { return toLetter(Kind) + utostr(Bits); }
250   std::string cNameBase() const override {
251     return toCPrefix(Kind) + utostr(Bits);
252   }
253   std::string cName() const override {
254     if (NameOverride.empty())
255       return CRegularNamedType::cName();
256     return NameOverride;
257   }
258   std::string llvmName() const override {
259     if (Kind == ScalarTypeKind::Float) {
260       if (Bits == 16)
261         return "HalfTy";
262       if (Bits == 32)
263         return "FloatTy";
264       if (Bits == 64)
265         return "DoubleTy";
266       PrintFatalError("bad size for floating type");
267     }
268     return "Int" + utostr(Bits) + "Ty";
269   }
270   std::string acleSuffix(std::string overrideLetter) const override {
271     return "_" + (overrideLetter.size() ? overrideLetter : toLetter(Kind))
272                + utostr(Bits);
273   }
274   bool isInteger() const { return Kind != ScalarTypeKind::Float; }
275   bool requiresFloat() const override { return !isInteger(); }
276   bool hasNonstandardName() const { return !NameOverride.empty(); }
277 
278   static bool classof(const Type *T) {
279     return T->typeKind() == TypeKind::Scalar;
280   }
281 };
282 
283 class VectorType : public CRegularNamedType {
284   const ScalarType *Element;
285   unsigned Lanes;
286 
287 public:
288   VectorType(const ScalarType *Element, unsigned Lanes)
289       : CRegularNamedType(TypeKind::Vector), Element(Element), Lanes(Lanes) {}
290   unsigned sizeInBits() const override { return Lanes * Element->sizeInBits(); }
291   unsigned lanes() const { return Lanes; }
292   bool requiresFloat() const override { return Element->requiresFloat(); }
293   std::string cNameBase() const override {
294     return Element->cNameBase() + "x" + utostr(Lanes);
295   }
296   std::string llvmName() const override {
297     return "llvm::VectorType::get(" + Element->llvmName() + ", " +
298            utostr(Lanes) + ")";
299   }
300 
301   static bool classof(const Type *T) {
302     return T->typeKind() == TypeKind::Vector;
303   }
304 };
305 
306 class MultiVectorType : public CRegularNamedType {
307   const VectorType *Element;
308   unsigned Registers;
309 
310 public:
311   MultiVectorType(unsigned Registers, const VectorType *Element)
312       : CRegularNamedType(TypeKind::MultiVector), Element(Element),
313         Registers(Registers) {}
314   unsigned sizeInBits() const override {
315     return Registers * Element->sizeInBits();
316   }
317   unsigned registers() const { return Registers; }
318   bool requiresFloat() const override { return Element->requiresFloat(); }
319   std::string cNameBase() const override {
320     return Element->cNameBase() + "x" + utostr(Registers);
321   }
322 
323   // MultiVectorType doesn't override llvmName, because we don't expect to do
324   // automatic code generation for the MVE intrinsics that use it: the {vld2,
325   // vld4, vst2, vst4} family are the only ones that use these types, so it was
326   // easier to hand-write the codegen for dealing with these structs than to
327   // build in lots of extra automatic machinery that would only be used once.
328 
329   static bool classof(const Type *T) {
330     return T->typeKind() == TypeKind::MultiVector;
331   }
332 };
333 
334 class PredicateType : public CRegularNamedType {
335   unsigned Lanes;
336 
337 public:
338   PredicateType(unsigned Lanes)
339       : CRegularNamedType(TypeKind::Predicate), Lanes(Lanes) {}
340   unsigned sizeInBits() const override { return 16; }
341   std::string cNameBase() const override { return "mve_pred16"; }
342   bool requiresFloat() const override { return false; };
343   std::string llvmName() const override {
344     // Use <4 x i1> instead of <2 x i1> for two-lane vector types. See
345     // the comment in llvm/lib/Target/ARM/ARMInstrMVE.td for further
346     // explanation.
347     unsigned ModifiedLanes = (Lanes == 2 ? 4 : Lanes);
348 
349     return "llvm::VectorType::get(Builder.getInt1Ty(), " +
350            utostr(ModifiedLanes) + ")";
351   }
352 
353   static bool classof(const Type *T) {
354     return T->typeKind() == TypeKind::Predicate;
355   }
356 };
357 
358 // -----------------------------------------------------------------------------
359 // Class to facilitate merging together the code generation for many intrinsics
360 // by means of varying a few constant or type parameters.
361 //
362 // Most obviously, the intrinsics in a single parametrised family will have
363 // code generation sequences that only differ in a type or two, e.g. vaddq_s8
364 // and vaddq_u16 will look the same apart from putting a different vector type
365 // in the call to CGM.getIntrinsic(). But also, completely different intrinsics
366 // will often code-generate in the same way, with only a different choice of
367 // _which_ IR intrinsic they lower to (e.g. vaddq_m_s8 and vmulq_m_s8), but
368 // marshalling the arguments and return values of the IR intrinsic in exactly
369 // the same way. And others might differ only in some other kind of constant,
370 // such as a lane index.
371 //
372 // So, when we generate the IR-building code for all these intrinsics, we keep
373 // track of every value that could possibly be pulled out of the code and
374 // stored ahead of time in a local variable. Then we group together intrinsics
375 // by textual equivalence of the code that would result if _all_ those
376 // parameters were stored in local variables. That gives us maximal sets that
377 // can be implemented by a single piece of IR-building code by changing
378 // parameter values ahead of time.
379 //
380 // After we've done that, we do a second pass in which we only allocate _some_
381 // of the parameters into local variables, by tracking which ones have the same
382 // values as each other (so that a single variable can be reused) and which
383 // ones are the same across the whole set (so that no variable is needed at
384 // all).
385 //
386 // Hence the class below. Its allocParam method is invoked during code
387 // generation by every method of a Result subclass (see below) that wants to
388 // give it the opportunity to pull something out into a switchable parameter.
389 // It returns a variable name for the parameter, or (if it's being used in the
390 // second pass once we've decided that some parameters don't need to be stored
391 // in variables after all) it might just return the input expression unchanged.
392 
393 struct CodeGenParamAllocator {
394   // Accumulated during code generation
395   std::vector<std::string> *ParamTypes = nullptr;
396   std::vector<std::string> *ParamValues = nullptr;
397 
398   // Provided ahead of time in pass 2, to indicate which parameters are being
399   // assigned to what. This vector contains an entry for each call to
400   // allocParam expected during code gen (which we counted up in pass 1), and
401   // indicates the number of the parameter variable that should be returned, or
402   // -1 if this call shouldn't allocate a parameter variable at all.
403   //
404   // We rely on the recursive code generation working identically in passes 1
405   // and 2, so that the same list of calls to allocParam happen in the same
406   // order. That guarantees that the parameter numbers recorded in pass 1 will
407   // match the entries in this vector that store what MveEmitter::EmitBuiltinCG
408   // decided to do about each one in pass 2.
409   std::vector<int> *ParamNumberMap = nullptr;
410 
411   // Internally track how many things we've allocated
412   unsigned nparams = 0;
413 
414   std::string allocParam(StringRef Type, StringRef Value) {
415     unsigned ParamNumber;
416 
417     if (!ParamNumberMap) {
418       // In pass 1, unconditionally assign a new parameter variable to every
419       // value we're asked to process.
420       ParamNumber = nparams++;
421     } else {
422       // In pass 2, consult the map provided by the caller to find out which
423       // variable we should be keeping things in.
424       int MapValue = (*ParamNumberMap)[nparams++];
425       if (MapValue < 0)
426         return std::string(Value);
427       ParamNumber = MapValue;
428     }
429 
430     // If we've allocated a new parameter variable for the first time, store
431     // its type and value to be retrieved after codegen.
432     if (ParamTypes && ParamTypes->size() == ParamNumber)
433       ParamTypes->push_back(std::string(Type));
434     if (ParamValues && ParamValues->size() == ParamNumber)
435       ParamValues->push_back(std::string(Value));
436 
437     // Unimaginative naming scheme for parameter variables.
438     return "Param" + utostr(ParamNumber);
439   }
440 };
441 
442 // -----------------------------------------------------------------------------
443 // System of classes that represent all the intermediate values used during
444 // code-generation for an intrinsic.
445 //
446 // The base class 'Result' can represent a value of the LLVM type 'Value', or
447 // sometimes 'Address' (for loads/stores, including an alignment requirement).
448 //
449 // In the case where the Tablegen provides a value in the codegen dag as a
450 // plain integer literal, the Result object we construct here will be one that
451 // returns true from hasIntegerConstantValue(). This allows the generated C++
452 // code to use the constant directly in contexts which can take a literal
453 // integer, such as Builder.CreateExtractValue(thing, 1), without going to the
454 // effort of calling llvm::ConstantInt::get() and then pulling the constant
455 // back out of the resulting llvm:Value later.
456 
457 class Result {
458 public:
459   // Convenient shorthand for the pointer type we'll be using everywhere.
460   using Ptr = std::shared_ptr<Result>;
461 
462 private:
463   Ptr Predecessor;
464   std::string VarName;
465   bool VarNameUsed = false;
466   unsigned Visited = 0;
467 
468 public:
469   virtual ~Result() = default;
470   using Scope = std::map<std::string, Ptr>;
471   virtual void genCode(raw_ostream &OS, CodeGenParamAllocator &) const = 0;
472   virtual bool hasIntegerConstantValue() const { return false; }
473   virtual uint32_t integerConstantValue() const { return 0; }
474   virtual bool hasIntegerValue() const { return false; }
475   virtual std::string getIntegerValue(const std::string &) {
476     llvm_unreachable("non-working Result::getIntegerValue called");
477   }
478   virtual std::string typeName() const { return "Value *"; }
479 
480   // Mostly, when a code-generation operation has a dependency on prior
481   // operations, it's because it uses the output values of those operations as
482   // inputs. But there's one exception, which is the use of 'seq' in Tablegen
483   // to indicate that operations have to be performed in sequence regardless of
484   // whether they use each others' output values.
485   //
486   // So, the actual generation of code is done by depth-first search, using the
487   // prerequisites() method to get a list of all the other Results that have to
488   // be computed before this one. That method divides into the 'predecessor',
489   // set by setPredecessor() while processing a 'seq' dag node, and the list
490   // returned by 'morePrerequisites', which each subclass implements to return
491   // a list of the Results it uses as input to whatever its own computation is
492   // doing.
493 
494   virtual void morePrerequisites(std::vector<Ptr> &output) const {}
495   std::vector<Ptr> prerequisites() const {
496     std::vector<Ptr> ToRet;
497     if (Predecessor)
498       ToRet.push_back(Predecessor);
499     morePrerequisites(ToRet);
500     return ToRet;
501   }
502 
503   void setPredecessor(Ptr p) {
504     // If the user has nested one 'seq' node inside another, and this
505     // method is called on the return value of the inner 'seq' (i.e.
506     // the final item inside it), then we can't link _this_ node to p,
507     // because it already has a predecessor. Instead, walk the chain
508     // until we find the first item in the inner seq, and link that to
509     // p, so that nesting seqs has the obvious effect of linking
510     // everything together into one long sequential chain.
511     Result *r = this;
512     while (r->Predecessor)
513       r = r->Predecessor.get();
514     r->Predecessor = p;
515   }
516 
517   // Each Result will be assigned a variable name in the output code, but not
518   // all those variable names will actually be used (e.g. the return value of
519   // Builder.CreateStore has void type, so nobody will want to refer to it). To
520   // prevent annoying compiler warnings, we track whether each Result's
521   // variable name was ever actually mentioned in subsequent statements, so
522   // that it can be left out of the final generated code.
523   std::string varname() {
524     VarNameUsed = true;
525     return VarName;
526   }
527   void setVarname(const StringRef s) { VarName = std::string(s); }
528   bool varnameUsed() const { return VarNameUsed; }
529 
530   // Emit code to generate this result as a Value *.
531   virtual std::string asValue() {
532     return varname();
533   }
534 
535   // Code generation happens in multiple passes. This method tracks whether a
536   // Result has yet been visited in a given pass, without the need for a
537   // tedious loop in between passes that goes through and resets a 'visited'
538   // flag back to false: you just set Pass=1 the first time round, and Pass=2
539   // the second time.
540   bool needsVisiting(unsigned Pass) {
541     bool ToRet = Visited < Pass;
542     Visited = Pass;
543     return ToRet;
544   }
545 };
546 
547 // Result subclass that retrieves one of the arguments to the clang builtin
548 // function. In cases where the argument has pointer type, we call
549 // EmitPointerWithAlignment and store the result in a variable of type Address,
550 // so that load and store IR nodes can know the right alignment. Otherwise, we
551 // call EmitScalarExpr.
552 //
553 // There are aggregate parameters in the MVE intrinsics API, but we don't deal
554 // with them in this Tablegen back end: they only arise in the vld2q/vld4q and
555 // vst2q/vst4q family, which is few enough that we just write the code by hand
556 // for those in CGBuiltin.cpp.
557 class BuiltinArgResult : public Result {
558 public:
559   unsigned ArgNum;
560   bool AddressType;
561   bool Immediate;
562   BuiltinArgResult(unsigned ArgNum, bool AddressType, bool Immediate)
563       : ArgNum(ArgNum), AddressType(AddressType), Immediate(Immediate) {}
564   void genCode(raw_ostream &OS, CodeGenParamAllocator &) const override {
565     OS << (AddressType ? "EmitPointerWithAlignment" : "EmitScalarExpr")
566        << "(E->getArg(" << ArgNum << "))";
567   }
568   std::string typeName() const override {
569     return AddressType ? "Address" : Result::typeName();
570   }
571   // Emit code to generate this result as a Value *.
572   std::string asValue() override {
573     if (AddressType)
574       return "(" + varname() + ".getPointer())";
575     return Result::asValue();
576   }
577   bool hasIntegerValue() const override { return Immediate; }
578   std::string getIntegerValue(const std::string &IntType) override {
579     return "GetIntegerConstantValue<" + IntType + ">(E->getArg(" +
580            utostr(ArgNum) + "), getContext())";
581   }
582 };
583 
584 // Result subclass for an integer literal appearing in Tablegen. This may need
585 // to be turned into an llvm::Result by means of llvm::ConstantInt::get(), or
586 // it may be used directly as an integer, depending on which IRBuilder method
587 // it's being passed to.
588 class IntLiteralResult : public Result {
589 public:
590   const ScalarType *IntegerType;
591   uint32_t IntegerValue;
592   IntLiteralResult(const ScalarType *IntegerType, uint32_t IntegerValue)
593       : IntegerType(IntegerType), IntegerValue(IntegerValue) {}
594   void genCode(raw_ostream &OS,
595                CodeGenParamAllocator &ParamAlloc) const override {
596     OS << "llvm::ConstantInt::get("
597        << ParamAlloc.allocParam("llvm::Type *", IntegerType->llvmName())
598        << ", ";
599     OS << ParamAlloc.allocParam(IntegerType->cName(), utostr(IntegerValue))
600        << ")";
601   }
602   bool hasIntegerConstantValue() const override { return true; }
603   uint32_t integerConstantValue() const override { return IntegerValue; }
604 };
605 
606 // Result subclass representing a cast between different integer types. We use
607 // our own ScalarType abstraction as the representation of the target type,
608 // which gives both size and signedness.
609 class IntCastResult : public Result {
610 public:
611   const ScalarType *IntegerType;
612   Ptr V;
613   IntCastResult(const ScalarType *IntegerType, Ptr V)
614       : IntegerType(IntegerType), V(V) {}
615   void genCode(raw_ostream &OS,
616                CodeGenParamAllocator &ParamAlloc) const override {
617     OS << "Builder.CreateIntCast(" << V->varname() << ", "
618        << ParamAlloc.allocParam("llvm::Type *", IntegerType->llvmName()) << ", "
619        << ParamAlloc.allocParam("bool",
620                                 IntegerType->kind() == ScalarTypeKind::SignedInt
621                                     ? "true"
622                                     : "false")
623        << ")";
624   }
625   void morePrerequisites(std::vector<Ptr> &output) const override {
626     output.push_back(V);
627   }
628 };
629 
630 // Result subclass representing a cast between different pointer types.
631 class PointerCastResult : public Result {
632 public:
633   const PointerType *PtrType;
634   Ptr V;
635   PointerCastResult(const PointerType *PtrType, Ptr V)
636       : PtrType(PtrType), V(V) {}
637   void genCode(raw_ostream &OS,
638                CodeGenParamAllocator &ParamAlloc) const override {
639     OS << "Builder.CreatePointerCast(" << V->asValue() << ", "
640        << ParamAlloc.allocParam("llvm::Type *", PtrType->llvmName()) << ")";
641   }
642   void morePrerequisites(std::vector<Ptr> &output) const override {
643     output.push_back(V);
644   }
645 };
646 
647 // Result subclass representing a call to an IRBuilder method. Each IRBuilder
648 // method we want to use will have a Tablegen record giving the method name and
649 // describing any important details of how to call it, such as whether a
650 // particular argument should be an integer constant instead of an llvm::Value.
651 class IRBuilderResult : public Result {
652 public:
653   StringRef CallPrefix;
654   std::vector<Ptr> Args;
655   std::set<unsigned> AddressArgs;
656   std::map<unsigned, std::string> IntegerArgs;
657   IRBuilderResult(StringRef CallPrefix, std::vector<Ptr> Args,
658                   std::set<unsigned> AddressArgs,
659                   std::map<unsigned, std::string> IntegerArgs)
660       : CallPrefix(CallPrefix), Args(Args), AddressArgs(AddressArgs),
661         IntegerArgs(IntegerArgs) {}
662   void genCode(raw_ostream &OS,
663                CodeGenParamAllocator &ParamAlloc) const override {
664     OS << CallPrefix;
665     const char *Sep = "";
666     for (unsigned i = 0, e = Args.size(); i < e; ++i) {
667       Ptr Arg = Args[i];
668       auto it = IntegerArgs.find(i);
669 
670       OS << Sep;
671       Sep = ", ";
672 
673       if (it != IntegerArgs.end()) {
674         if (Arg->hasIntegerConstantValue())
675           OS << "static_cast<" << it->second << ">("
676              << ParamAlloc.allocParam(it->second,
677                                       utostr(Arg->integerConstantValue()))
678              << ")";
679         else if (Arg->hasIntegerValue())
680           OS << ParamAlloc.allocParam(it->second,
681                                       Arg->getIntegerValue(it->second));
682       } else {
683         OS << Arg->varname();
684       }
685     }
686     OS << ")";
687   }
688   void morePrerequisites(std::vector<Ptr> &output) const override {
689     for (unsigned i = 0, e = Args.size(); i < e; ++i) {
690       Ptr Arg = Args[i];
691       if (IntegerArgs.find(i) != IntegerArgs.end())
692         continue;
693       output.push_back(Arg);
694     }
695   }
696 };
697 
698 // Result subclass representing making an Address out of a Value.
699 class AddressResult : public Result {
700 public:
701   Ptr Arg;
702   unsigned Align;
703   AddressResult(Ptr Arg, unsigned Align) : Arg(Arg), Align(Align) {}
704   void genCode(raw_ostream &OS,
705                CodeGenParamAllocator &ParamAlloc) const override {
706     OS << "Address(" << Arg->varname() << ", CharUnits::fromQuantity("
707        << Align << "))";
708   }
709   std::string typeName() const override {
710     return "Address";
711   }
712   void morePrerequisites(std::vector<Ptr> &output) const override {
713     output.push_back(Arg);
714   }
715 };
716 
717 // Result subclass representing a call to an IR intrinsic, which we first have
718 // to look up using an Intrinsic::ID constant and an array of types.
719 class IRIntrinsicResult : public Result {
720 public:
721   std::string IntrinsicID;
722   std::vector<const Type *> ParamTypes;
723   std::vector<Ptr> Args;
724   IRIntrinsicResult(StringRef IntrinsicID, std::vector<const Type *> ParamTypes,
725                     std::vector<Ptr> Args)
726       : IntrinsicID(std::string(IntrinsicID)), ParamTypes(ParamTypes),
727         Args(Args) {}
728   void genCode(raw_ostream &OS,
729                CodeGenParamAllocator &ParamAlloc) const override {
730     std::string IntNo = ParamAlloc.allocParam(
731         "Intrinsic::ID", "Intrinsic::" + IntrinsicID);
732     OS << "Builder.CreateCall(CGM.getIntrinsic(" << IntNo;
733     if (!ParamTypes.empty()) {
734       OS << ", llvm::SmallVector<llvm::Type *, " << ParamTypes.size() << "> {";
735       const char *Sep = "";
736       for (auto T : ParamTypes) {
737         OS << Sep << ParamAlloc.allocParam("llvm::Type *", T->llvmName());
738         Sep = ", ";
739       }
740       OS << "}";
741     }
742     OS << "), llvm::SmallVector<Value *, " << Args.size() << "> {";
743     const char *Sep = "";
744     for (auto Arg : Args) {
745       OS << Sep << Arg->asValue();
746       Sep = ", ";
747     }
748     OS << "})";
749   }
750   void morePrerequisites(std::vector<Ptr> &output) const override {
751     output.insert(output.end(), Args.begin(), Args.end());
752   }
753 };
754 
755 // Result subclass that specifies a type, for use in IRBuilder operations such
756 // as CreateBitCast that take a type argument.
757 class TypeResult : public Result {
758 public:
759   const Type *T;
760   TypeResult(const Type *T) : T(T) {}
761   void genCode(raw_ostream &OS, CodeGenParamAllocator &) const override {
762     OS << T->llvmName();
763   }
764   std::string typeName() const override {
765     return "llvm::Type *";
766   }
767 };
768 
769 // -----------------------------------------------------------------------------
770 // Class that describes a single ACLE intrinsic.
771 //
772 // A Tablegen record will typically describe more than one ACLE intrinsic, by
773 // means of setting the 'list<Type> Params' field to a list of multiple
774 // parameter types, so as to define vaddq_{s8,u8,...,f16,f32} all in one go.
775 // We'll end up with one instance of ACLEIntrinsic for *each* parameter type,
776 // rather than a single one for all of them. Hence, the constructor takes both
777 // a Tablegen record and the current value of the parameter type.
778 
779 class ACLEIntrinsic {
780   // Structure documenting that one of the intrinsic's arguments is required to
781   // be a compile-time constant integer, and what constraints there are on its
782   // value. Used when generating Sema checking code.
783   struct ImmediateArg {
784     enum class BoundsType { ExplicitRange, UInt };
785     BoundsType boundsType;
786     int64_t i1, i2;
787     StringRef ExtraCheckType, ExtraCheckArgs;
788     const Type *ArgType;
789   };
790 
791   // For polymorphic intrinsics, FullName is the explicit name that uniquely
792   // identifies this variant of the intrinsic, and ShortName is the name it
793   // shares with at least one other intrinsic.
794   std::string ShortName, FullName;
795 
796   // A very small number of intrinsics _only_ have a polymorphic
797   // variant (vuninitializedq taking an unevaluated argument).
798   bool PolymorphicOnly;
799 
800   // Another rarely-used flag indicating that the builtin doesn't
801   // evaluate its argument(s) at all.
802   bool NonEvaluating;
803 
804   const Type *ReturnType;
805   std::vector<const Type *> ArgTypes;
806   std::map<unsigned, ImmediateArg> ImmediateArgs;
807   Result::Ptr Code;
808 
809   std::map<std::string, std::string> CustomCodeGenArgs;
810 
811   // Recursive function that does the internals of code generation.
812   void genCodeDfs(Result::Ptr V, std::list<Result::Ptr> &Used,
813                   unsigned Pass) const {
814     if (!V->needsVisiting(Pass))
815       return;
816 
817     for (Result::Ptr W : V->prerequisites())
818       genCodeDfs(W, Used, Pass);
819 
820     Used.push_back(V);
821   }
822 
823 public:
824   const std::string &shortName() const { return ShortName; }
825   const std::string &fullName() const { return FullName; }
826   const Type *returnType() const { return ReturnType; }
827   const std::vector<const Type *> &argTypes() const { return ArgTypes; }
828   bool requiresFloat() const {
829     if (ReturnType->requiresFloat())
830       return true;
831     for (const Type *T : ArgTypes)
832       if (T->requiresFloat())
833         return true;
834     return false;
835   }
836   bool polymorphic() const { return ShortName != FullName; }
837   bool polymorphicOnly() const { return PolymorphicOnly; }
838   bool nonEvaluating() const { return NonEvaluating; }
839 
840   // External entry point for code generation, called from MveEmitter.
841   void genCode(raw_ostream &OS, CodeGenParamAllocator &ParamAlloc,
842                unsigned Pass) const {
843     if (!hasCode()) {
844       for (auto kv : CustomCodeGenArgs)
845         OS << "  " << kv.first << " = " << kv.second << ";\n";
846       OS << "  break; // custom code gen\n";
847       return;
848     }
849     std::list<Result::Ptr> Used;
850     genCodeDfs(Code, Used, Pass);
851 
852     unsigned varindex = 0;
853     for (Result::Ptr V : Used)
854       if (V->varnameUsed())
855         V->setVarname("Val" + utostr(varindex++));
856 
857     for (Result::Ptr V : Used) {
858       OS << "  ";
859       if (V == Used.back()) {
860         assert(!V->varnameUsed());
861         OS << "return "; // FIXME: what if the top-level thing is void?
862       } else if (V->varnameUsed()) {
863         std::string Type = V->typeName();
864         OS << V->typeName();
865         if (!StringRef(Type).endswith("*"))
866           OS << " ";
867         OS << V->varname() << " = ";
868       }
869       V->genCode(OS, ParamAlloc);
870       OS << ";\n";
871     }
872   }
873   bool hasCode() const { return Code != nullptr; }
874 
875   static std::string signedHexLiteral(const llvm::APInt &iOrig) {
876     llvm::APInt i = iOrig.trunc(64);
877     SmallString<40> s;
878     i.toString(s, 16, true, true);
879     return std::string(s.str());
880   }
881 
882   std::string genSema() const {
883     std::vector<std::string> SemaChecks;
884 
885     for (const auto &kv : ImmediateArgs) {
886       const ImmediateArg &IA = kv.second;
887 
888       llvm::APInt lo(128, 0), hi(128, 0);
889       switch (IA.boundsType) {
890       case ImmediateArg::BoundsType::ExplicitRange:
891         lo = IA.i1;
892         hi = IA.i2;
893         break;
894       case ImmediateArg::BoundsType::UInt:
895         lo = 0;
896         hi = llvm::APInt::getMaxValue(IA.i1).zext(128);
897         break;
898       }
899 
900       std::string Index = utostr(kv.first);
901 
902       // Emit a range check if the legal range of values for the
903       // immediate is smaller than the _possible_ range of values for
904       // its type.
905       unsigned ArgTypeBits = IA.ArgType->sizeInBits();
906       llvm::APInt ArgTypeRange = llvm::APInt::getMaxValue(ArgTypeBits).zext(128);
907       llvm::APInt ActualRange = (hi-lo).trunc(64).sext(128);
908       if (ActualRange.ult(ArgTypeRange))
909         SemaChecks.push_back("SemaBuiltinConstantArgRange(TheCall, " + Index +
910                              ", " + signedHexLiteral(lo) + ", " +
911                              signedHexLiteral(hi) + ")");
912 
913       if (!IA.ExtraCheckType.empty()) {
914         std::string Suffix;
915         if (!IA.ExtraCheckArgs.empty()) {
916           std::string tmp;
917           StringRef Arg = IA.ExtraCheckArgs;
918           if (Arg == "!lanesize") {
919             tmp = utostr(IA.ArgType->sizeInBits());
920             Arg = tmp;
921           }
922           Suffix = (Twine(", ") + Arg).str();
923         }
924         SemaChecks.push_back((Twine("SemaBuiltinConstantArg") +
925                               IA.ExtraCheckType + "(TheCall, " + Index +
926                               Suffix + ")")
927                                  .str());
928       }
929 
930       assert(!SemaChecks.empty());
931     }
932     if (SemaChecks.empty())
933       return "";
934     return (Twine("  return ") +
935             join(std::begin(SemaChecks), std::end(SemaChecks),
936                  " ||\n         ") +
937             ";\n")
938         .str();
939   }
940 
941   ACLEIntrinsic(MveEmitter &ME, Record *R, const Type *Param);
942 };
943 
944 // -----------------------------------------------------------------------------
945 // The top-level class that holds all the state from analyzing the entire
946 // Tablegen input.
947 
948 class MveEmitter {
949   // MveEmitter holds a collection of all the types we've instantiated.
950   VoidType Void;
951   std::map<std::string, std::unique_ptr<ScalarType>> ScalarTypes;
952   std::map<std::tuple<ScalarTypeKind, unsigned, unsigned>,
953            std::unique_ptr<VectorType>>
954       VectorTypes;
955   std::map<std::pair<std::string, unsigned>, std::unique_ptr<MultiVectorType>>
956       MultiVectorTypes;
957   std::map<unsigned, std::unique_ptr<PredicateType>> PredicateTypes;
958   std::map<std::string, std::unique_ptr<PointerType>> PointerTypes;
959 
960   // And all the ACLEIntrinsic instances we've created.
961   std::map<std::string, std::unique_ptr<ACLEIntrinsic>> ACLEIntrinsics;
962 
963 public:
964   // Methods to create a Type object, or return the right existing one from the
965   // maps stored in this object.
966   const VoidType *getVoidType() { return &Void; }
967   const ScalarType *getScalarType(StringRef Name) {
968     return ScalarTypes[std::string(Name)].get();
969   }
970   const ScalarType *getScalarType(Record *R) {
971     return getScalarType(R->getName());
972   }
973   const VectorType *getVectorType(const ScalarType *ST, unsigned Lanes) {
974     std::tuple<ScalarTypeKind, unsigned, unsigned> key(ST->kind(),
975                                                        ST->sizeInBits(), Lanes);
976     if (VectorTypes.find(key) == VectorTypes.end())
977       VectorTypes[key] = std::make_unique<VectorType>(ST, Lanes);
978     return VectorTypes[key].get();
979   }
980   const VectorType *getVectorType(const ScalarType *ST) {
981     return getVectorType(ST, 128 / ST->sizeInBits());
982   }
983   const MultiVectorType *getMultiVectorType(unsigned Registers,
984                                             const VectorType *VT) {
985     std::pair<std::string, unsigned> key(VT->cNameBase(), Registers);
986     if (MultiVectorTypes.find(key) == MultiVectorTypes.end())
987       MultiVectorTypes[key] = std::make_unique<MultiVectorType>(Registers, VT);
988     return MultiVectorTypes[key].get();
989   }
990   const PredicateType *getPredicateType(unsigned Lanes) {
991     unsigned key = Lanes;
992     if (PredicateTypes.find(key) == PredicateTypes.end())
993       PredicateTypes[key] = std::make_unique<PredicateType>(Lanes);
994     return PredicateTypes[key].get();
995   }
996   const PointerType *getPointerType(const Type *T, bool Const) {
997     PointerType PT(T, Const);
998     std::string key = PT.cName();
999     if (PointerTypes.find(key) == PointerTypes.end())
1000       PointerTypes[key] = std::make_unique<PointerType>(PT);
1001     return PointerTypes[key].get();
1002   }
1003 
1004   // Methods to construct a type from various pieces of Tablegen. These are
1005   // always called in the context of setting up a particular ACLEIntrinsic, so
1006   // there's always an ambient parameter type (because we're iterating through
1007   // the Params list in the Tablegen record for the intrinsic), which is used
1008   // to expand Tablegen classes like 'Vector' which mean something different in
1009   // each member of a parametric family.
1010   const Type *getType(Record *R, const Type *Param);
1011   const Type *getType(DagInit *D, const Type *Param);
1012   const Type *getType(Init *I, const Type *Param);
1013 
1014   // Functions that translate the Tablegen representation of an intrinsic's
1015   // code generation into a collection of Value objects (which will then be
1016   // reprocessed to read out the actual C++ code included by CGBuiltin.cpp).
1017   Result::Ptr getCodeForDag(DagInit *D, const Result::Scope &Scope,
1018                             const Type *Param);
1019   Result::Ptr getCodeForDagArg(DagInit *D, unsigned ArgNum,
1020                                const Result::Scope &Scope, const Type *Param);
1021   Result::Ptr getCodeForArg(unsigned ArgNum, const Type *ArgType, bool Promote,
1022                             bool Immediate);
1023 
1024   // Constructor and top-level functions.
1025 
1026   MveEmitter(RecordKeeper &Records);
1027 
1028   void EmitHeader(raw_ostream &OS);
1029   void EmitBuiltinDef(raw_ostream &OS);
1030   void EmitBuiltinSema(raw_ostream &OS);
1031   void EmitBuiltinCG(raw_ostream &OS);
1032   void EmitBuiltinAliases(raw_ostream &OS);
1033 };
1034 
1035 const Type *MveEmitter::getType(Init *I, const Type *Param) {
1036   if (auto Dag = dyn_cast<DagInit>(I))
1037     return getType(Dag, Param);
1038   if (auto Def = dyn_cast<DefInit>(I))
1039     return getType(Def->getDef(), Param);
1040 
1041   PrintFatalError("Could not convert this value into a type");
1042 }
1043 
1044 const Type *MveEmitter::getType(Record *R, const Type *Param) {
1045   // Pass to a subfield of any wrapper records. We don't expect more than one
1046   // of these: immediate operands are used as plain numbers rather than as
1047   // llvm::Value, so it's meaningless to promote their type anyway.
1048   if (R->isSubClassOf("Immediate"))
1049     R = R->getValueAsDef("type");
1050   else if (R->isSubClassOf("unpromoted"))
1051     R = R->getValueAsDef("underlying_type");
1052 
1053   if (R->getName() == "Void")
1054     return getVoidType();
1055   if (R->isSubClassOf("PrimitiveType"))
1056     return getScalarType(R);
1057   if (R->isSubClassOf("ComplexType"))
1058     return getType(R->getValueAsDag("spec"), Param);
1059 
1060   PrintFatalError(R->getLoc(), "Could not convert this record into a type");
1061 }
1062 
1063 const Type *MveEmitter::getType(DagInit *D, const Type *Param) {
1064   // The meat of the getType system: types in the Tablegen are represented by a
1065   // dag whose operators select sub-cases of this function.
1066 
1067   Record *Op = cast<DefInit>(D->getOperator())->getDef();
1068   if (!Op->isSubClassOf("ComplexTypeOp"))
1069     PrintFatalError(
1070         "Expected ComplexTypeOp as dag operator in type expression");
1071 
1072   if (Op->getName() == "CTO_Parameter") {
1073     if (isa<VoidType>(Param))
1074       PrintFatalError("Parametric type in unparametrised context");
1075     return Param;
1076   }
1077 
1078   if (Op->getName() == "CTO_Vec") {
1079     const Type *Element = getType(D->getArg(0), Param);
1080     if (D->getNumArgs() == 1) {
1081       return getVectorType(cast<ScalarType>(Element));
1082     } else {
1083       const Type *ExistingVector = getType(D->getArg(1), Param);
1084       return getVectorType(cast<ScalarType>(Element),
1085                            cast<VectorType>(ExistingVector)->lanes());
1086     }
1087   }
1088 
1089   if (Op->getName() == "CTO_Pred") {
1090     const Type *Element = getType(D->getArg(0), Param);
1091     return getPredicateType(128 / Element->sizeInBits());
1092   }
1093 
1094   if (Op->isSubClassOf("CTO_Tuple")) {
1095     unsigned Registers = Op->getValueAsInt("n");
1096     const Type *Element = getType(D->getArg(0), Param);
1097     return getMultiVectorType(Registers, cast<VectorType>(Element));
1098   }
1099 
1100   if (Op->isSubClassOf("CTO_Pointer")) {
1101     const Type *Pointee = getType(D->getArg(0), Param);
1102     return getPointerType(Pointee, Op->getValueAsBit("const"));
1103   }
1104 
1105   if (Op->getName() == "CTO_CopyKind") {
1106     const ScalarType *STSize = cast<ScalarType>(getType(D->getArg(0), Param));
1107     const ScalarType *STKind = cast<ScalarType>(getType(D->getArg(1), Param));
1108     for (const auto &kv : ScalarTypes) {
1109       const ScalarType *RT = kv.second.get();
1110       if (RT->kind() == STKind->kind() && RT->sizeInBits() == STSize->sizeInBits())
1111         return RT;
1112     }
1113     PrintFatalError("Cannot find a type to satisfy CopyKind");
1114   }
1115 
1116   if (Op->isSubClassOf("CTO_ScaleSize")) {
1117     const ScalarType *STKind = cast<ScalarType>(getType(D->getArg(0), Param));
1118     int Num = Op->getValueAsInt("num"), Denom = Op->getValueAsInt("denom");
1119     unsigned DesiredSize = STKind->sizeInBits() * Num / Denom;
1120     for (const auto &kv : ScalarTypes) {
1121       const ScalarType *RT = kv.second.get();
1122       if (RT->kind() == STKind->kind() && RT->sizeInBits() == DesiredSize)
1123         return RT;
1124     }
1125     PrintFatalError("Cannot find a type to satisfy ScaleSize");
1126   }
1127 
1128   PrintFatalError("Bad operator in type dag expression");
1129 }
1130 
1131 Result::Ptr MveEmitter::getCodeForDag(DagInit *D, const Result::Scope &Scope,
1132                                       const Type *Param) {
1133   Record *Op = cast<DefInit>(D->getOperator())->getDef();
1134 
1135   if (Op->getName() == "seq") {
1136     Result::Scope SubScope = Scope;
1137     Result::Ptr PrevV = nullptr;
1138     for (unsigned i = 0, e = D->getNumArgs(); i < e; ++i) {
1139       // We don't use getCodeForDagArg here, because the argument name
1140       // has different semantics in a seq
1141       Result::Ptr V =
1142           getCodeForDag(cast<DagInit>(D->getArg(i)), SubScope, Param);
1143       StringRef ArgName = D->getArgNameStr(i);
1144       if (!ArgName.empty())
1145         SubScope[std::string(ArgName)] = V;
1146       if (PrevV)
1147         V->setPredecessor(PrevV);
1148       PrevV = V;
1149     }
1150     return PrevV;
1151   } else if (Op->isSubClassOf("Type")) {
1152     if (D->getNumArgs() != 1)
1153       PrintFatalError("Type casts should have exactly one argument");
1154     const Type *CastType = getType(Op, Param);
1155     Result::Ptr Arg = getCodeForDagArg(D, 0, Scope, Param);
1156     if (const auto *ST = dyn_cast<ScalarType>(CastType)) {
1157       if (!ST->requiresFloat()) {
1158         if (Arg->hasIntegerConstantValue())
1159           return std::make_shared<IntLiteralResult>(
1160               ST, Arg->integerConstantValue());
1161         else
1162           return std::make_shared<IntCastResult>(ST, Arg);
1163       }
1164     } else if (const auto *PT = dyn_cast<PointerType>(CastType)) {
1165       return std::make_shared<PointerCastResult>(PT, Arg);
1166     }
1167     PrintFatalError("Unsupported type cast");
1168   } else if (Op->getName() == "address") {
1169     if (D->getNumArgs() != 2)
1170       PrintFatalError("'address' should have two arguments");
1171     Result::Ptr Arg = getCodeForDagArg(D, 0, Scope, Param);
1172     unsigned Alignment;
1173     if (auto *II = dyn_cast<IntInit>(D->getArg(1))) {
1174       Alignment = II->getValue();
1175     } else {
1176       PrintFatalError("'address' alignment argument should be an integer");
1177     }
1178     return std::make_shared<AddressResult>(Arg, Alignment);
1179   } else if (Op->getName() == "unsignedflag") {
1180     if (D->getNumArgs() != 1)
1181       PrintFatalError("unsignedflag should have exactly one argument");
1182     Record *TypeRec = cast<DefInit>(D->getArg(0))->getDef();
1183     if (!TypeRec->isSubClassOf("Type"))
1184       PrintFatalError("unsignedflag's argument should be a type");
1185     if (const auto *ST = dyn_cast<ScalarType>(getType(TypeRec, Param))) {
1186       return std::make_shared<IntLiteralResult>(
1187         getScalarType("u32"), ST->kind() == ScalarTypeKind::UnsignedInt);
1188     } else {
1189       PrintFatalError("unsignedflag's argument should be a scalar type");
1190     }
1191   } else {
1192     std::vector<Result::Ptr> Args;
1193     for (unsigned i = 0, e = D->getNumArgs(); i < e; ++i)
1194       Args.push_back(getCodeForDagArg(D, i, Scope, Param));
1195     if (Op->isSubClassOf("IRBuilderBase")) {
1196       std::set<unsigned> AddressArgs;
1197       std::map<unsigned, std::string> IntegerArgs;
1198       for (Record *sp : Op->getValueAsListOfDefs("special_params")) {
1199         unsigned Index = sp->getValueAsInt("index");
1200         if (sp->isSubClassOf("IRBuilderAddrParam")) {
1201           AddressArgs.insert(Index);
1202         } else if (sp->isSubClassOf("IRBuilderIntParam")) {
1203           IntegerArgs[Index] = std::string(sp->getValueAsString("type"));
1204         }
1205       }
1206       return std::make_shared<IRBuilderResult>(Op->getValueAsString("prefix"),
1207                                                Args, AddressArgs, IntegerArgs);
1208     } else if (Op->isSubClassOf("IRIntBase")) {
1209       std::vector<const Type *> ParamTypes;
1210       for (Record *RParam : Op->getValueAsListOfDefs("params"))
1211         ParamTypes.push_back(getType(RParam, Param));
1212       std::string IntName = std::string(Op->getValueAsString("intname"));
1213       if (Op->getValueAsBit("appendKind"))
1214         IntName += "_" + toLetter(cast<ScalarType>(Param)->kind());
1215       return std::make_shared<IRIntrinsicResult>(IntName, ParamTypes, Args);
1216     } else {
1217       PrintFatalError("Unsupported dag node " + Op->getName());
1218     }
1219   }
1220 }
1221 
1222 Result::Ptr MveEmitter::getCodeForDagArg(DagInit *D, unsigned ArgNum,
1223                                          const Result::Scope &Scope,
1224                                          const Type *Param) {
1225   Init *Arg = D->getArg(ArgNum);
1226   StringRef Name = D->getArgNameStr(ArgNum);
1227 
1228   if (!Name.empty()) {
1229     if (!isa<UnsetInit>(Arg))
1230       PrintFatalError(
1231           "dag operator argument should not have both a value and a name");
1232     auto it = Scope.find(std::string(Name));
1233     if (it == Scope.end())
1234       PrintFatalError("unrecognized variable name '" + Name + "'");
1235     return it->second;
1236   }
1237 
1238   if (auto *II = dyn_cast<IntInit>(Arg))
1239     return std::make_shared<IntLiteralResult>(getScalarType("u32"),
1240                                               II->getValue());
1241 
1242   if (auto *DI = dyn_cast<DagInit>(Arg))
1243     return getCodeForDag(DI, Scope, Param);
1244 
1245   if (auto *DI = dyn_cast<DefInit>(Arg)) {
1246     Record *Rec = DI->getDef();
1247     if (Rec->isSubClassOf("Type")) {
1248       const Type *T = getType(Rec, Param);
1249       return std::make_shared<TypeResult>(T);
1250     }
1251   }
1252 
1253   PrintFatalError("bad dag argument type for code generation");
1254 }
1255 
1256 Result::Ptr MveEmitter::getCodeForArg(unsigned ArgNum, const Type *ArgType,
1257                                       bool Promote, bool Immediate) {
1258   Result::Ptr V = std::make_shared<BuiltinArgResult>(
1259       ArgNum, isa<PointerType>(ArgType), Immediate);
1260 
1261   if (Promote) {
1262     if (const auto *ST = dyn_cast<ScalarType>(ArgType)) {
1263       if (ST->isInteger() && ST->sizeInBits() < 32)
1264         V = std::make_shared<IntCastResult>(getScalarType("u32"), V);
1265     } else if (const auto *PT = dyn_cast<PredicateType>(ArgType)) {
1266       V = std::make_shared<IntCastResult>(getScalarType("u32"), V);
1267       V = std::make_shared<IRIntrinsicResult>("arm_mve_pred_i2v",
1268                                               std::vector<const Type *>{PT},
1269                                               std::vector<Result::Ptr>{V});
1270     }
1271   }
1272 
1273   return V;
1274 }
1275 
1276 ACLEIntrinsic::ACLEIntrinsic(MveEmitter &ME, Record *R, const Type *Param)
1277     : ReturnType(ME.getType(R->getValueAsDef("ret"), Param)) {
1278   // Derive the intrinsic's full name, by taking the name of the
1279   // Tablegen record (or override) and appending the suffix from its
1280   // parameter type. (If the intrinsic is unparametrised, its
1281   // parameter type will be given as Void, which returns the empty
1282   // string for acleSuffix.)
1283   StringRef BaseName =
1284       (R->isSubClassOf("NameOverride") ? R->getValueAsString("basename")
1285                                        : R->getName());
1286   StringRef overrideLetter = R->getValueAsString("overrideKindLetter");
1287   FullName =
1288       (Twine(BaseName) + Param->acleSuffix(std::string(overrideLetter))).str();
1289 
1290   // Derive the intrinsic's polymorphic name, by removing components from the
1291   // full name as specified by its 'pnt' member ('polymorphic name type'),
1292   // which indicates how many type suffixes to remove, and any other piece of
1293   // the name that should be removed.
1294   Record *PolymorphicNameType = R->getValueAsDef("pnt");
1295   SmallVector<StringRef, 8> NameParts;
1296   StringRef(FullName).split(NameParts, '_');
1297   for (unsigned i = 0, e = PolymorphicNameType->getValueAsInt(
1298                            "NumTypeSuffixesToDiscard");
1299        i < e; ++i)
1300     NameParts.pop_back();
1301   if (!PolymorphicNameType->isValueUnset("ExtraSuffixToDiscard")) {
1302     StringRef ExtraSuffix =
1303         PolymorphicNameType->getValueAsString("ExtraSuffixToDiscard");
1304     auto it = NameParts.end();
1305     while (it != NameParts.begin()) {
1306       --it;
1307       if (*it == ExtraSuffix) {
1308         NameParts.erase(it);
1309         break;
1310       }
1311     }
1312   }
1313   ShortName = join(std::begin(NameParts), std::end(NameParts), "_");
1314 
1315   PolymorphicOnly = R->getValueAsBit("polymorphicOnly");
1316   NonEvaluating = R->getValueAsBit("nonEvaluating");
1317 
1318   // Process the intrinsic's argument list.
1319   DagInit *ArgsDag = R->getValueAsDag("args");
1320   Result::Scope Scope;
1321   for (unsigned i = 0, e = ArgsDag->getNumArgs(); i < e; ++i) {
1322     Init *TypeInit = ArgsDag->getArg(i);
1323 
1324     bool Promote = true;
1325     if (auto TypeDI = dyn_cast<DefInit>(TypeInit))
1326       if (TypeDI->getDef()->isSubClassOf("unpromoted"))
1327         Promote = false;
1328 
1329     // Work out the type of the argument, for use in the function prototype in
1330     // the header file.
1331     const Type *ArgType = ME.getType(TypeInit, Param);
1332     ArgTypes.push_back(ArgType);
1333 
1334     // If the argument is a subclass of Immediate, record the details about
1335     // what values it can take, for Sema checking.
1336     bool Immediate = false;
1337     if (auto TypeDI = dyn_cast<DefInit>(TypeInit)) {
1338       Record *TypeRec = TypeDI->getDef();
1339       if (TypeRec->isSubClassOf("Immediate")) {
1340         Immediate = true;
1341 
1342         Record *Bounds = TypeRec->getValueAsDef("bounds");
1343         ImmediateArg &IA = ImmediateArgs[i];
1344         if (Bounds->isSubClassOf("IB_ConstRange")) {
1345           IA.boundsType = ImmediateArg::BoundsType::ExplicitRange;
1346           IA.i1 = Bounds->getValueAsInt("lo");
1347           IA.i2 = Bounds->getValueAsInt("hi");
1348         } else if (Bounds->getName() == "IB_UEltValue") {
1349           IA.boundsType = ImmediateArg::BoundsType::UInt;
1350           IA.i1 = Param->sizeInBits();
1351         } else if (Bounds->getName() == "IB_LaneIndex") {
1352           IA.boundsType = ImmediateArg::BoundsType::ExplicitRange;
1353           IA.i1 = 0;
1354           IA.i2 = 128 / Param->sizeInBits() - 1;
1355         } else if (Bounds->isSubClassOf("IB_EltBit")) {
1356           IA.boundsType = ImmediateArg::BoundsType::ExplicitRange;
1357           IA.i1 = Bounds->getValueAsInt("base");
1358           const Type *T = ME.getType(Bounds->getValueAsDef("type"), Param);
1359           IA.i2 = IA.i1 + T->sizeInBits() - 1;
1360         } else {
1361           PrintFatalError("unrecognised ImmediateBounds subclass");
1362         }
1363 
1364         IA.ArgType = ArgType;
1365 
1366         if (!TypeRec->isValueUnset("extra")) {
1367           IA.ExtraCheckType = TypeRec->getValueAsString("extra");
1368           if (!TypeRec->isValueUnset("extraarg"))
1369             IA.ExtraCheckArgs = TypeRec->getValueAsString("extraarg");
1370         }
1371       }
1372     }
1373 
1374     // The argument will usually have a name in the arguments dag, which goes
1375     // into the variable-name scope that the code gen will refer to.
1376     StringRef ArgName = ArgsDag->getArgNameStr(i);
1377     if (!ArgName.empty())
1378       Scope[std::string(ArgName)] =
1379           ME.getCodeForArg(i, ArgType, Promote, Immediate);
1380   }
1381 
1382   // Finally, go through the codegen dag and translate it into a Result object
1383   // (with an arbitrary DAG of depended-on Results hanging off it).
1384   DagInit *CodeDag = R->getValueAsDag("codegen");
1385   Record *MainOp = cast<DefInit>(CodeDag->getOperator())->getDef();
1386   if (MainOp->isSubClassOf("CustomCodegen")) {
1387     // Or, if it's the special case of CustomCodegen, just accumulate
1388     // a list of parameters we're going to assign to variables before
1389     // breaking from the loop.
1390     CustomCodeGenArgs["CustomCodeGenType"] =
1391         (Twine("CustomCodeGen::") + MainOp->getValueAsString("type")).str();
1392     for (unsigned i = 0, e = CodeDag->getNumArgs(); i < e; ++i) {
1393       StringRef Name = CodeDag->getArgNameStr(i);
1394       if (Name.empty()) {
1395         PrintFatalError("Operands to CustomCodegen should have names");
1396       } else if (auto *II = dyn_cast<IntInit>(CodeDag->getArg(i))) {
1397         CustomCodeGenArgs[std::string(Name)] = itostr(II->getValue());
1398       } else if (auto *SI = dyn_cast<StringInit>(CodeDag->getArg(i))) {
1399         CustomCodeGenArgs[std::string(Name)] = std::string(SI->getValue());
1400       } else {
1401         PrintFatalError("Operands to CustomCodegen should be integers");
1402       }
1403     }
1404   } else {
1405     Code = ME.getCodeForDag(CodeDag, Scope, Param);
1406   }
1407 }
1408 
1409 MveEmitter::MveEmitter(RecordKeeper &Records) {
1410   // Construct the whole MveEmitter.
1411 
1412   // First, look up all the instances of PrimitiveType. This gives us the list
1413   // of vector typedefs we have to put in arm_mve.h, and also allows us to
1414   // collect all the useful ScalarType instances into a big list so that we can
1415   // use it for operations such as 'find the unsigned version of this signed
1416   // integer type'.
1417   for (Record *R : Records.getAllDerivedDefinitions("PrimitiveType"))
1418     ScalarTypes[std::string(R->getName())] = std::make_unique<ScalarType>(R);
1419 
1420   // Now go through the instances of Intrinsic, and for each one, iterate
1421   // through its list of type parameters making an ACLEIntrinsic for each one.
1422   for (Record *R : Records.getAllDerivedDefinitions("Intrinsic")) {
1423     for (Record *RParam : R->getValueAsListOfDefs("params")) {
1424       const Type *Param = getType(RParam, getVoidType());
1425       auto Intrinsic = std::make_unique<ACLEIntrinsic>(*this, R, Param);
1426       ACLEIntrinsics[Intrinsic->fullName()] = std::move(Intrinsic);
1427     }
1428   }
1429 }
1430 
1431 /// A wrapper on raw_string_ostream that contains its own buffer rather than
1432 /// having to point it at one elsewhere. (In other words, it works just like
1433 /// std::ostringstream; also, this makes it convenient to declare a whole array
1434 /// of them at once.)
1435 ///
1436 /// We have to set this up using multiple inheritance, to ensure that the
1437 /// string member has been constructed before raw_string_ostream's constructor
1438 /// is given a pointer to it.
1439 class string_holder {
1440 protected:
1441   std::string S;
1442 };
1443 class raw_self_contained_string_ostream : private string_holder,
1444                                           public raw_string_ostream {
1445 public:
1446   raw_self_contained_string_ostream()
1447       : string_holder(), raw_string_ostream(S) {}
1448 };
1449 
1450 void MveEmitter::EmitHeader(raw_ostream &OS) {
1451   // Accumulate pieces of the header file that will be enabled under various
1452   // different combinations of #ifdef. The index into parts[] is made up of
1453   // the following bit flags.
1454   constexpr unsigned Float = 1;
1455   constexpr unsigned UseUserNamespace = 2;
1456 
1457   constexpr unsigned NumParts = 4;
1458   raw_self_contained_string_ostream parts[NumParts];
1459 
1460   // Write typedefs for all the required vector types, and a few scalar
1461   // types that don't already have the name we want them to have.
1462 
1463   parts[0] << "typedef uint16_t mve_pred16_t;\n";
1464   parts[Float] << "typedef __fp16 float16_t;\n"
1465                   "typedef float float32_t;\n";
1466   for (const auto &kv : ScalarTypes) {
1467     const ScalarType *ST = kv.second.get();
1468     if (ST->hasNonstandardName())
1469       continue;
1470     raw_ostream &OS = parts[ST->requiresFloat() ? Float : 0];
1471     const VectorType *VT = getVectorType(ST);
1472 
1473     OS << "typedef __attribute__((__neon_vector_type__(" << VT->lanes()
1474        << "), __clang_arm_mve_strict_polymorphism)) " << ST->cName() << " "
1475        << VT->cName() << ";\n";
1476 
1477     // Every vector type also comes with a pair of multi-vector types for
1478     // the VLD2 and VLD4 instructions.
1479     for (unsigned n = 2; n <= 4; n += 2) {
1480       const MultiVectorType *MT = getMultiVectorType(n, VT);
1481       OS << "typedef struct { " << VT->cName() << " val[" << n << "]; } "
1482          << MT->cName() << ";\n";
1483     }
1484   }
1485   parts[0] << "\n";
1486   parts[Float] << "\n";
1487 
1488   // Write declarations for all the intrinsics.
1489 
1490   for (const auto &kv : ACLEIntrinsics) {
1491     const ACLEIntrinsic &Int = *kv.second;
1492 
1493     // We generate each intrinsic twice, under its full unambiguous
1494     // name and its shorter polymorphic name (if the latter exists).
1495     for (bool Polymorphic : {false, true}) {
1496       if (Polymorphic && !Int.polymorphic())
1497         continue;
1498       if (!Polymorphic && Int.polymorphicOnly())
1499         continue;
1500 
1501       // We also generate each intrinsic under a name like __arm_vfooq
1502       // (which is in C language implementation namespace, so it's
1503       // safe to define in any conforming user program) and a shorter
1504       // one like vfooq (which is in user namespace, so a user might
1505       // reasonably have used it for something already). If so, they
1506       // can #define __ARM_MVE_PRESERVE_USER_NAMESPACE before
1507       // including the header, which will suppress the shorter names
1508       // and leave only the implementation-namespace ones. Then they
1509       // have to write __arm_vfooq everywhere, of course.
1510 
1511       for (bool UserNamespace : {false, true}) {
1512         raw_ostream &OS = parts[(Int.requiresFloat() ? Float : 0) |
1513                                 (UserNamespace ? UseUserNamespace : 0)];
1514 
1515         // Make the name of the function in this declaration.
1516 
1517         std::string FunctionName =
1518             Polymorphic ? Int.shortName() : Int.fullName();
1519         if (!UserNamespace)
1520           FunctionName = "__arm_" + FunctionName;
1521 
1522         // Make strings for the types involved in the function's
1523         // prototype.
1524 
1525         std::string RetTypeName = Int.returnType()->cName();
1526         if (!StringRef(RetTypeName).endswith("*"))
1527           RetTypeName += " ";
1528 
1529         std::vector<std::string> ArgTypeNames;
1530         for (const Type *ArgTypePtr : Int.argTypes())
1531           ArgTypeNames.push_back(ArgTypePtr->cName());
1532         std::string ArgTypesString =
1533             join(std::begin(ArgTypeNames), std::end(ArgTypeNames), ", ");
1534 
1535         // Emit the actual declaration. All these functions are
1536         // declared 'static inline' without a body, which is fine
1537         // provided clang recognizes them as builtins, and has the
1538         // effect that this type signature is used in place of the one
1539         // that Builtins.def didn't provide. That's how we can get
1540         // structure types that weren't defined until this header was
1541         // included to be part of the type signature of a builtin that
1542         // was known to clang already.
1543         //
1544         // The declarations use __attribute__(__clang_arm_mve_alias),
1545         // so that each function declared will be recognized as the
1546         // appropriate MVE builtin in spite of its user-facing name.
1547         //
1548         // (That's better than making them all wrapper functions,
1549         // partly because it avoids any compiler error message citing
1550         // the wrapper function definition instead of the user's code,
1551         // and mostly because some MVE intrinsics have arguments
1552         // required to be compile-time constants, and that property
1553         // can't be propagated through a wrapper function. It can be
1554         // propagated through a macro, but macros can't be overloaded
1555         // on argument types very easily - you have to use _Generic,
1556         // which makes error messages very confusing when the user
1557         // gets it wrong.)
1558         //
1559         // Finally, the polymorphic versions of the intrinsics are
1560         // also defined with __attribute__(overloadable), so that when
1561         // the same name is defined with several type signatures, the
1562         // right thing happens. Each one of the overloaded
1563         // declarations is given a different builtin id, which
1564         // has exactly the effect we want: first clang resolves the
1565         // overload to the right function, then it knows which builtin
1566         // it's referring to, and then the Sema checking for that
1567         // builtin can check further things like the constant
1568         // arguments.
1569         //
1570         // One more subtlety is the newline just before the return
1571         // type name. That's a cosmetic tweak to make the error
1572         // messages legible if the user gets the types wrong in a call
1573         // to a polymorphic function: this way, clang will print just
1574         // the _final_ line of each declaration in the header, to show
1575         // the type signatures that would have been legal. So all the
1576         // confusing machinery with __attribute__ is left out of the
1577         // error message, and the user sees something that's more or
1578         // less self-documenting: "here's a list of actually readable
1579         // type signatures for vfooq(), and here's why each one didn't
1580         // match your call".
1581 
1582         OS << "static __inline__ __attribute__(("
1583            << (Polymorphic ? "overloadable, " : "")
1584            << "__clang_arm_mve_alias(__builtin_arm_mve_" << Int.fullName()
1585            << ")))\n"
1586            << RetTypeName << FunctionName << "(" << ArgTypesString << ");\n";
1587       }
1588     }
1589   }
1590   for (auto &part : parts)
1591     part << "\n";
1592 
1593   // Now we've finished accumulating bits and pieces into the parts[] array.
1594   // Put it all together to write the final output file.
1595 
1596   OS << "/*===---- arm_mve.h - ARM MVE intrinsics "
1597         "-----------------------------------===\n"
1598         " *\n"
1599         " *\n"
1600         " * Part of the LLVM Project, under the Apache License v2.0 with LLVM "
1601         "Exceptions.\n"
1602         " * See https://llvm.org/LICENSE.txt for license information.\n"
1603         " * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception\n"
1604         " *\n"
1605         " *===-------------------------------------------------------------"
1606         "----"
1607         "------===\n"
1608         " */\n"
1609         "\n"
1610         "#ifndef __ARM_MVE_H\n"
1611         "#define __ARM_MVE_H\n"
1612         "\n"
1613         "#if !__ARM_FEATURE_MVE\n"
1614         "#error \"MVE support not enabled\"\n"
1615         "#endif\n"
1616         "\n"
1617         "#include <stdint.h>\n"
1618         "\n"
1619         "#ifdef __cplusplus\n"
1620         "extern \"C\" {\n"
1621         "#endif\n"
1622         "\n";
1623 
1624   for (size_t i = 0; i < NumParts; ++i) {
1625     std::vector<std::string> conditions;
1626     if (i & Float)
1627       conditions.push_back("(__ARM_FEATURE_MVE & 2)");
1628     if (i & UseUserNamespace)
1629       conditions.push_back("(!defined __ARM_MVE_PRESERVE_USER_NAMESPACE)");
1630 
1631     std::string condition =
1632         join(std::begin(conditions), std::end(conditions), " && ");
1633     if (!condition.empty())
1634       OS << "#if " << condition << "\n\n";
1635     OS << parts[i].str();
1636     if (!condition.empty())
1637       OS << "#endif /* " << condition << " */\n\n";
1638   }
1639 
1640   OS << "#ifdef __cplusplus\n"
1641         "} /* extern \"C\" */\n"
1642         "#endif\n"
1643         "\n"
1644         "#endif /* __ARM_MVE_H */\n";
1645 }
1646 
1647 void MveEmitter::EmitBuiltinDef(raw_ostream &OS) {
1648   for (const auto &kv : ACLEIntrinsics) {
1649     const ACLEIntrinsic &Int = *kv.second;
1650     OS << "TARGET_HEADER_BUILTIN(__builtin_arm_mve_" << Int.fullName()
1651        << ", \"\", \"n\", \"arm_mve.h\", ALL_LANGUAGES, \"\")\n";
1652   }
1653 
1654   std::set<std::string> ShortNamesSeen;
1655 
1656   for (const auto &kv : ACLEIntrinsics) {
1657     const ACLEIntrinsic &Int = *kv.second;
1658     if (Int.polymorphic()) {
1659       StringRef Name = Int.shortName();
1660       if (ShortNamesSeen.find(std::string(Name)) == ShortNamesSeen.end()) {
1661         OS << "BUILTIN(__builtin_arm_mve_" << Name << ", \"vi.\", \"nt";
1662         if (Int.nonEvaluating())
1663           OS << "u"; // indicate that this builtin doesn't evaluate its args
1664         OS << "\")\n";
1665         ShortNamesSeen.insert(std::string(Name));
1666       }
1667     }
1668   }
1669 }
1670 
1671 void MveEmitter::EmitBuiltinSema(raw_ostream &OS) {
1672   std::map<std::string, std::set<std::string>> Checks;
1673 
1674   for (const auto &kv : ACLEIntrinsics) {
1675     const ACLEIntrinsic &Int = *kv.second;
1676     std::string Check = Int.genSema();
1677     if (!Check.empty())
1678       Checks[Check].insert(Int.fullName());
1679   }
1680 
1681   for (const auto &kv : Checks) {
1682     for (StringRef Name : kv.second)
1683       OS << "case ARM::BI__builtin_arm_mve_" << Name << ":\n";
1684     OS << kv.first;
1685   }
1686 }
1687 
1688 // Machinery for the grouping of intrinsics by similar codegen.
1689 //
1690 // The general setup is that 'MergeableGroup' stores the things that a set of
1691 // similarly shaped intrinsics have in common: the text of their code
1692 // generation, and the number and type of their parameter variables.
1693 // MergeableGroup is the key in a std::map whose value is a set of
1694 // OutputIntrinsic, which stores the ways in which a particular intrinsic
1695 // specializes the MergeableGroup's generic description: the function name and
1696 // the _values_ of the parameter variables.
1697 
1698 struct ComparableStringVector : std::vector<std::string> {
1699   // Infrastructure: a derived class of vector<string> which comes with an
1700   // ordering, so that it can be used as a key in maps and an element in sets.
1701   // There's no requirement on the ordering beyond being deterministic.
1702   bool operator<(const ComparableStringVector &rhs) const {
1703     if (size() != rhs.size())
1704       return size() < rhs.size();
1705     for (size_t i = 0, e = size(); i < e; ++i)
1706       if ((*this)[i] != rhs[i])
1707         return (*this)[i] < rhs[i];
1708     return false;
1709   }
1710 };
1711 
1712 struct OutputIntrinsic {
1713   const ACLEIntrinsic *Int;
1714   std::string Name;
1715   ComparableStringVector ParamValues;
1716   bool operator<(const OutputIntrinsic &rhs) const {
1717     if (Name != rhs.Name)
1718       return Name < rhs.Name;
1719     return ParamValues < rhs.ParamValues;
1720   }
1721 };
1722 struct MergeableGroup {
1723   std::string Code;
1724   ComparableStringVector ParamTypes;
1725   bool operator<(const MergeableGroup &rhs) const {
1726     if (Code != rhs.Code)
1727       return Code < rhs.Code;
1728     return ParamTypes < rhs.ParamTypes;
1729   }
1730 };
1731 
1732 void MveEmitter::EmitBuiltinCG(raw_ostream &OS) {
1733   // Pass 1: generate code for all the intrinsics as if every type or constant
1734   // that can possibly be abstracted out into a parameter variable will be.
1735   // This identifies the sets of intrinsics we'll group together into a single
1736   // piece of code generation.
1737 
1738   std::map<MergeableGroup, std::set<OutputIntrinsic>> MergeableGroupsPrelim;
1739 
1740   for (const auto &kv : ACLEIntrinsics) {
1741     const ACLEIntrinsic &Int = *kv.second;
1742 
1743     MergeableGroup MG;
1744     OutputIntrinsic OI;
1745 
1746     OI.Int = &Int;
1747     OI.Name = Int.fullName();
1748     CodeGenParamAllocator ParamAllocPrelim{&MG.ParamTypes, &OI.ParamValues};
1749     raw_string_ostream OS(MG.Code);
1750     Int.genCode(OS, ParamAllocPrelim, 1);
1751     OS.flush();
1752 
1753     MergeableGroupsPrelim[MG].insert(OI);
1754   }
1755 
1756   // Pass 2: for each of those groups, optimize the parameter variable set by
1757   // eliminating 'parameters' that are the same for all intrinsics in the
1758   // group, and merging together pairs of parameter variables that take the
1759   // same values as each other for all intrinsics in the group.
1760 
1761   std::map<MergeableGroup, std::set<OutputIntrinsic>> MergeableGroups;
1762 
1763   for (const auto &kv : MergeableGroupsPrelim) {
1764     const MergeableGroup &MG = kv.first;
1765     std::vector<int> ParamNumbers;
1766     std::map<ComparableStringVector, int> ParamNumberMap;
1767 
1768     // Loop over the parameters for this group.
1769     for (size_t i = 0, e = MG.ParamTypes.size(); i < e; ++i) {
1770       // Is this parameter the same for all intrinsics in the group?
1771       const OutputIntrinsic &OI_first = *kv.second.begin();
1772       bool Constant = all_of(kv.second, [&](const OutputIntrinsic &OI) {
1773         return OI.ParamValues[i] == OI_first.ParamValues[i];
1774       });
1775 
1776       // If so, record it as -1, meaning 'no parameter variable needed'. Then
1777       // the corresponding call to allocParam in pass 2 will not generate a
1778       // variable at all, and just use the value inline.
1779       if (Constant) {
1780         ParamNumbers.push_back(-1);
1781         continue;
1782       }
1783 
1784       // Otherwise, make a list of the values this parameter takes for each
1785       // intrinsic, and see if that value vector matches anything we already
1786       // have. We also record the parameter type, so that we don't accidentally
1787       // match up two parameter variables with different types. (Not that
1788       // there's much chance of them having textually equivalent values, but in
1789       // _principle_ it could happen.)
1790       ComparableStringVector key;
1791       key.push_back(MG.ParamTypes[i]);
1792       for (const auto &OI : kv.second)
1793         key.push_back(OI.ParamValues[i]);
1794 
1795       auto Found = ParamNumberMap.find(key);
1796       if (Found != ParamNumberMap.end()) {
1797         // Yes, an existing parameter variable can be reused for this.
1798         ParamNumbers.push_back(Found->second);
1799         continue;
1800       }
1801 
1802       // No, we need a new parameter variable.
1803       int ExistingIndex = ParamNumberMap.size();
1804       ParamNumberMap[key] = ExistingIndex;
1805       ParamNumbers.push_back(ExistingIndex);
1806     }
1807 
1808     // Now we're ready to do the pass 2 code generation, which will emit the
1809     // reduced set of parameter variables we've just worked out.
1810 
1811     for (const auto &OI_prelim : kv.second) {
1812       const ACLEIntrinsic *Int = OI_prelim.Int;
1813 
1814       MergeableGroup MG;
1815       OutputIntrinsic OI;
1816 
1817       OI.Int = OI_prelim.Int;
1818       OI.Name = OI_prelim.Name;
1819       CodeGenParamAllocator ParamAlloc{&MG.ParamTypes, &OI.ParamValues,
1820                                        &ParamNumbers};
1821       raw_string_ostream OS(MG.Code);
1822       Int->genCode(OS, ParamAlloc, 2);
1823       OS.flush();
1824 
1825       MergeableGroups[MG].insert(OI);
1826     }
1827   }
1828 
1829   // Output the actual C++ code.
1830 
1831   for (const auto &kv : MergeableGroups) {
1832     const MergeableGroup &MG = kv.first;
1833 
1834     // List of case statements in the main switch on BuiltinID, and an open
1835     // brace.
1836     const char *prefix = "";
1837     for (const auto &OI : kv.second) {
1838       OS << prefix << "case ARM::BI__builtin_arm_mve_" << OI.Name << ":";
1839       prefix = "\n";
1840     }
1841     OS << " {\n";
1842 
1843     if (!MG.ParamTypes.empty()) {
1844       // If we've got some parameter variables, then emit their declarations...
1845       for (size_t i = 0, e = MG.ParamTypes.size(); i < e; ++i) {
1846         StringRef Type = MG.ParamTypes[i];
1847         OS << "  " << Type;
1848         if (!Type.endswith("*"))
1849           OS << " ";
1850         OS << " Param" << utostr(i) << ";\n";
1851       }
1852 
1853       // ... and an inner switch on BuiltinID that will fill them in with each
1854       // individual intrinsic's values.
1855       OS << "  switch (BuiltinID) {\n";
1856       for (const auto &OI : kv.second) {
1857         OS << "  case ARM::BI__builtin_arm_mve_" << OI.Name << ":\n";
1858         for (size_t i = 0, e = MG.ParamTypes.size(); i < e; ++i)
1859           OS << "    Param" << utostr(i) << " = " << OI.ParamValues[i] << ";\n";
1860         OS << "    break;\n";
1861       }
1862       OS << "  }\n";
1863     }
1864 
1865     // And finally, output the code, and close the outer pair of braces. (The
1866     // code will always end with a 'return' statement, so we need not insert a
1867     // 'break' here.)
1868     OS << MG.Code << "}\n";
1869   }
1870 }
1871 
1872 void MveEmitter::EmitBuiltinAliases(raw_ostream &OS) {
1873   // Build a sorted table of:
1874   // - intrinsic id number
1875   // - full name
1876   // - polymorphic name or -1
1877   StringToOffsetTable StringTable;
1878   OS << "struct IntrinToName {\n"
1879         "  uint32_t Id;\n"
1880         "  int32_t FullName;\n"
1881         "  int32_t ShortName;\n"
1882         "};\n";
1883   OS << "static const IntrinToName Map[] = {\n";
1884   for (const auto &kv : ACLEIntrinsics) {
1885     const ACLEIntrinsic &Int = *kv.second;
1886     int32_t ShortNameOffset =
1887         Int.polymorphic() ? StringTable.GetOrAddStringOffset(Int.shortName())
1888                           : -1;
1889     OS << "  { ARM::BI__builtin_arm_mve_" << Int.fullName() << ", "
1890        << StringTable.GetOrAddStringOffset(Int.fullName()) << ", "
1891        << ShortNameOffset << "},\n";
1892   }
1893   OS << "};\n\n";
1894 
1895   OS << "static const char IntrinNames[] = {\n";
1896   StringTable.EmitString(OS);
1897   OS << "};\n\n";
1898 
1899   OS << "auto It = std::lower_bound(std::begin(Map), "
1900         "std::end(Map), BuiltinID,\n"
1901         "  [](const IntrinToName &L, unsigned Id) {\n"
1902         "    return L.Id < Id;\n"
1903         "  });\n";
1904   OS << "if (It == std::end(Map) || It->Id != BuiltinID)\n"
1905         "  return false;\n";
1906   OS << "StringRef FullName(&IntrinNames[It->FullName]);\n";
1907   OS << "if (AliasName == FullName)\n"
1908         "  return true;\n";
1909   OS << "if (It->ShortName == -1)\n"
1910         "  return false;\n";
1911   OS << "StringRef ShortName(&IntrinNames[It->ShortName]);\n";
1912   OS << "return AliasName == ShortName;\n";
1913 }
1914 
1915 } // namespace
1916 
1917 namespace clang {
1918 
1919 void EmitMveHeader(RecordKeeper &Records, raw_ostream &OS) {
1920   MveEmitter(Records).EmitHeader(OS);
1921 }
1922 
1923 void EmitMveBuiltinDef(RecordKeeper &Records, raw_ostream &OS) {
1924   MveEmitter(Records).EmitBuiltinDef(OS);
1925 }
1926 
1927 void EmitMveBuiltinSema(RecordKeeper &Records, raw_ostream &OS) {
1928   MveEmitter(Records).EmitBuiltinSema(OS);
1929 }
1930 
1931 void EmitMveBuiltinCG(RecordKeeper &Records, raw_ostream &OS) {
1932   MveEmitter(Records).EmitBuiltinCG(OS);
1933 }
1934 
1935 void EmitMveBuiltinAliases(RecordKeeper &Records, raw_ostream &OS) {
1936   MveEmitter(Records).EmitBuiltinAliases(OS);
1937 }
1938 
1939 } // end namespace clang
1940