1 //===- CodeGen/ValueTypes.h - Low-Level Target independ. types --*- 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 file defines the set of low-level target independent types which various
10 // values in the code generator are.  This allows the target specific behavior
11 // of instructions to be described to target independent passes.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_CODEGEN_VALUETYPES_H
16 #define LLVM_CODEGEN_VALUETYPES_H
17 
18 #include "llvm/Support/Compiler.h"
19 #include "llvm/Support/MachineValueType.h"
20 #include "llvm/Support/MathExtras.h"
21 #include "llvm/Support/TypeSize.h"
22 #include <cassert>
23 #include <cstdint>
24 #include <string>
25 
26 namespace llvm {
27 
28   class LLVMContext;
29   class Type;
30 
31   /// Extended Value Type. Capable of holding value types which are not native
32   /// for any processor (such as the i12345 type), as well as the types an MVT
33   /// can represent.
34   struct EVT {
35   private:
36     MVT V = MVT::INVALID_SIMPLE_VALUE_TYPE;
37     Type *LLVMTy = nullptr;
38 
39   public:
40     constexpr EVT() = default;
41     constexpr EVT(MVT::SimpleValueType SVT) : V(SVT) {}
42     constexpr EVT(MVT S) : V(S) {}
43 
44     bool operator==(EVT VT) const {
45       return !(*this != VT);
46     }
47     bool operator!=(EVT VT) const {
48       if (V.SimpleTy != VT.V.SimpleTy)
49         return true;
50       if (V.SimpleTy == MVT::INVALID_SIMPLE_VALUE_TYPE)
51         return LLVMTy != VT.LLVMTy;
52       return false;
53     }
54 
55     /// Returns the EVT that represents a floating-point type with the given
56     /// number of bits. There are two floating-point types with 128 bits - this
57     /// returns f128 rather than ppcf128.
58     static EVT getFloatingPointVT(unsigned BitWidth) {
59       return MVT::getFloatingPointVT(BitWidth);
60     }
61 
62     /// Returns the EVT that represents an integer with the given number of
63     /// bits.
64     static EVT getIntegerVT(LLVMContext &Context, unsigned BitWidth) {
65       MVT M = MVT::getIntegerVT(BitWidth);
66       if (M.SimpleTy != MVT::INVALID_SIMPLE_VALUE_TYPE)
67         return M;
68       return getExtendedIntegerVT(Context, BitWidth);
69     }
70 
71     /// Returns the EVT that represents a vector NumElements in length, where
72     /// each element is of type VT.
73     static EVT getVectorVT(LLVMContext &Context, EVT VT, unsigned NumElements,
74                            bool IsScalable = false) {
75       MVT M = MVT::getVectorVT(VT.V, NumElements, IsScalable);
76       if (M.SimpleTy != MVT::INVALID_SIMPLE_VALUE_TYPE)
77         return M;
78 
79       assert(!IsScalable && "We don't support extended scalable types yet");
80       return getExtendedVectorVT(Context, VT, NumElements);
81     }
82 
83     /// Returns the EVT that represents a vector EC.Min elements in length,
84     /// where each element is of type VT.
85     static EVT getVectorVT(LLVMContext &Context, EVT VT, ElementCount EC) {
86       MVT M = MVT::getVectorVT(VT.V, EC);
87       if (M.SimpleTy != MVT::INVALID_SIMPLE_VALUE_TYPE)
88         return M;
89       assert (!EC.Scalable && "We don't support extended scalable types yet");
90       return getExtendedVectorVT(Context, VT, EC.Min);
91     }
92 
93     /// Return a vector with the same number of elements as this vector, but
94     /// with the element type converted to an integer type with the same
95     /// bitwidth.
96     EVT changeVectorElementTypeToInteger() const {
97       if (!isSimple()) {
98         assert (!isScalableVector() &&
99                 "We don't support extended scalable types yet");
100         return changeExtendedVectorElementTypeToInteger();
101       }
102       MVT EltTy = getSimpleVT().getVectorElementType();
103       unsigned BitWidth = EltTy.getSizeInBits();
104       MVT IntTy = MVT::getIntegerVT(BitWidth);
105       MVT VecTy = MVT::getVectorVT(IntTy, getVectorNumElements(),
106                                    isScalableVector());
107       assert(VecTy.SimpleTy != MVT::INVALID_SIMPLE_VALUE_TYPE &&
108              "Simple vector VT not representable by simple integer vector VT!");
109       return VecTy;
110     }
111 
112     /// Return the type converted to an equivalently sized integer or vector
113     /// with integer element type. Similar to changeVectorElementTypeToInteger,
114     /// but also handles scalars.
115     EVT changeTypeToInteger() {
116       if (isVector())
117         return changeVectorElementTypeToInteger();
118 
119       if (isSimple())
120         return MVT::getIntegerVT(getSizeInBits());
121 
122       return changeExtendedTypeToInteger();
123     }
124 
125     /// Test if the given EVT is simple (as opposed to being extended).
126     bool isSimple() const {
127       return V.SimpleTy != MVT::INVALID_SIMPLE_VALUE_TYPE;
128     }
129 
130     /// Test if the given EVT is extended (as opposed to being simple).
131     bool isExtended() const {
132       return !isSimple();
133     }
134 
135     /// Return true if this is a FP or a vector FP type.
136     bool isFloatingPoint() const {
137       return isSimple() ? V.isFloatingPoint() : isExtendedFloatingPoint();
138     }
139 
140     /// Return true if this is an integer or a vector integer type.
141     bool isInteger() const {
142       return isSimple() ? V.isInteger() : isExtendedInteger();
143     }
144 
145     /// Return true if this is an integer, but not a vector.
146     bool isScalarInteger() const {
147       return isSimple() ? V.isScalarInteger() : isExtendedScalarInteger();
148     }
149 
150     /// Return true if this is a vector value type.
151     bool isVector() const {
152       return isSimple() ? V.isVector() : isExtendedVector();
153     }
154 
155     /// Return true if this is a vector type where the runtime
156     /// length is machine dependent
157     bool isScalableVector() const {
158       // FIXME: We don't support extended scalable types yet, because the
159       // matching IR type doesn't exist. Once it has been added, this can
160       // be changed to call isExtendedScalableVector.
161       if (!isSimple())
162         return false;
163       return V.isScalableVector();
164     }
165 
166     /// Return true if this is a 16-bit vector type.
167     bool is16BitVector() const {
168       return isSimple() ? V.is16BitVector() : isExtended16BitVector();
169     }
170 
171     /// Return true if this is a 32-bit vector type.
172     bool is32BitVector() const {
173       return isSimple() ? V.is32BitVector() : isExtended32BitVector();
174     }
175 
176     /// Return true if this is a 64-bit vector type.
177     bool is64BitVector() const {
178       return isSimple() ? V.is64BitVector() : isExtended64BitVector();
179     }
180 
181     /// Return true if this is a 128-bit vector type.
182     bool is128BitVector() const {
183       return isSimple() ? V.is128BitVector() : isExtended128BitVector();
184     }
185 
186     /// Return true if this is a 256-bit vector type.
187     bool is256BitVector() const {
188       return isSimple() ? V.is256BitVector() : isExtended256BitVector();
189     }
190 
191     /// Return true if this is a 512-bit vector type.
192     bool is512BitVector() const {
193       return isSimple() ? V.is512BitVector() : isExtended512BitVector();
194     }
195 
196     /// Return true if this is a 1024-bit vector type.
197     bool is1024BitVector() const {
198       return isSimple() ? V.is1024BitVector() : isExtended1024BitVector();
199     }
200 
201     /// Return true if this is a 2048-bit vector type.
202     bool is2048BitVector() const {
203       return isSimple() ? V.is2048BitVector() : isExtended2048BitVector();
204     }
205 
206     /// Return true if this is an overloaded type for TableGen.
207     bool isOverloaded() const {
208       return (V==MVT::iAny || V==MVT::fAny || V==MVT::vAny || V==MVT::iPTRAny);
209     }
210 
211     /// Return true if the bit size is a multiple of 8.
212     bool isByteSized() const {
213       return getSizeInBits().isByteSized();
214     }
215 
216     /// Return true if the size is a power-of-two number of bytes.
217     bool isRound() const {
218       if (isScalableVector())
219         return false;
220       unsigned BitSize = getSizeInBits();
221       return BitSize >= 8 && !(BitSize & (BitSize - 1));
222     }
223 
224     /// Return true if this has the same number of bits as VT.
225     bool bitsEq(EVT VT) const {
226       if (EVT::operator==(VT)) return true;
227       return getSizeInBits() == VT.getSizeInBits();
228     }
229 
230     /// Return true if this has more bits than VT.
231     bool bitsGT(EVT VT) const {
232       if (EVT::operator==(VT)) return false;
233       return getSizeInBits() > VT.getSizeInBits();
234     }
235 
236     /// Return true if this has no less bits than VT.
237     bool bitsGE(EVT VT) const {
238       if (EVT::operator==(VT)) return true;
239       return getSizeInBits() >= VT.getSizeInBits();
240     }
241 
242     /// Return true if this has less bits than VT.
243     bool bitsLT(EVT VT) const {
244       if (EVT::operator==(VT)) return false;
245       return getSizeInBits() < VT.getSizeInBits();
246     }
247 
248     /// Return true if this has no more bits than VT.
249     bool bitsLE(EVT VT) const {
250       if (EVT::operator==(VT)) return true;
251       return getSizeInBits() <= VT.getSizeInBits();
252     }
253 
254     /// Return the SimpleValueType held in the specified simple EVT.
255     MVT getSimpleVT() const {
256       assert(isSimple() && "Expected a SimpleValueType!");
257       return V;
258     }
259 
260     /// If this is a vector type, return the element type, otherwise return
261     /// this.
262     EVT getScalarType() const {
263       return isVector() ? getVectorElementType() : *this;
264     }
265 
266     /// Given a vector type, return the type of each element.
267     EVT getVectorElementType() const {
268       assert(isVector() && "Invalid vector type!");
269       if (isSimple())
270         return V.getVectorElementType();
271       return getExtendedVectorElementType();
272     }
273 
274     /// Given a vector type, return the number of elements it contains.
275     unsigned getVectorNumElements() const {
276       assert(isVector() && "Invalid vector type!");
277       if (isSimple())
278         return V.getVectorNumElements();
279       return getExtendedVectorNumElements();
280     }
281 
282     // Given a (possibly scalable) vector type, return the ElementCount
283     ElementCount getVectorElementCount() const {
284       assert((isVector()) && "Invalid vector type!");
285       if (isSimple())
286         return V.getVectorElementCount();
287 
288       assert(!isScalableVector() &&
289              "We don't support extended scalable types yet");
290       return {getExtendedVectorNumElements(), false};
291     }
292 
293     /// Return the size of the specified value type in bits.
294     ///
295     /// If the value type is a scalable vector type, the scalable property will
296     /// be set and the runtime size will be a positive integer multiple of the
297     /// base size.
298     TypeSize getSizeInBits() const {
299       if (isSimple())
300         return V.getSizeInBits();
301       return getExtendedSizeInBits();
302     }
303 
304     TypeSize getScalarSizeInBits() const {
305       return getScalarType().getSizeInBits();
306     }
307 
308     /// Return the number of bytes overwritten by a store of the specified value
309     /// type.
310     ///
311     /// If the value type is a scalable vector type, the scalable property will
312     /// be set and the runtime size will be a positive integer multiple of the
313     /// base size.
314     TypeSize getStoreSize() const {
315       TypeSize BaseSize = getSizeInBits();
316       return {(BaseSize.getKnownMinSize() + 7) / 8, BaseSize.isScalable()};
317     }
318 
319     /// Return the number of bits overwritten by a store of the specified value
320     /// type.
321     ///
322     /// If the value type is a scalable vector type, the scalable property will
323     /// be set and the runtime size will be a positive integer multiple of the
324     /// base size.
325     TypeSize getStoreSizeInBits() const {
326       return getStoreSize() * 8;
327     }
328 
329     /// Rounds the bit-width of the given integer EVT up to the nearest power of
330     /// two (and at least to eight), and returns the integer EVT with that
331     /// number of bits.
332     EVT getRoundIntegerType(LLVMContext &Context) const {
333       assert(isInteger() && !isVector() && "Invalid integer type!");
334       unsigned BitWidth = getSizeInBits();
335       if (BitWidth <= 8)
336         return EVT(MVT::i8);
337       return getIntegerVT(Context, 1 << Log2_32_Ceil(BitWidth));
338     }
339 
340     /// Finds the smallest simple value type that is greater than or equal to
341     /// half the width of this EVT. If no simple value type can be found, an
342     /// extended integer value type of half the size (rounded up) is returned.
343     EVT getHalfSizedIntegerVT(LLVMContext &Context) const {
344       assert(isInteger() && !isVector() && "Invalid integer type!");
345       unsigned EVTSize = getSizeInBits();
346       for (unsigned IntVT = MVT::FIRST_INTEGER_VALUETYPE;
347           IntVT <= MVT::LAST_INTEGER_VALUETYPE; ++IntVT) {
348         EVT HalfVT = EVT((MVT::SimpleValueType)IntVT);
349         if (HalfVT.getSizeInBits() * 2 >= EVTSize)
350           return HalfVT;
351       }
352       return getIntegerVT(Context, (EVTSize + 1) / 2);
353     }
354 
355     /// Return a VT for an integer vector type with the size of the
356     /// elements doubled. The typed returned may be an extended type.
357     EVT widenIntegerVectorElementType(LLVMContext &Context) const {
358       EVT EltVT = getVectorElementType();
359       EltVT = EVT::getIntegerVT(Context, 2 * EltVT.getSizeInBits());
360       return EVT::getVectorVT(Context, EltVT, getVectorElementCount());
361     }
362 
363     // Return a VT for a vector type with the same element type but
364     // half the number of elements. The type returned may be an
365     // extended type.
366     EVT getHalfNumVectorElementsVT(LLVMContext &Context) const {
367       EVT EltVT = getVectorElementType();
368       auto EltCnt = getVectorElementCount();
369       assert(!(EltCnt.Min & 1) && "Splitting vector, but not in half!");
370       return EVT::getVectorVT(Context, EltVT, EltCnt / 2);
371     }
372 
373     /// Returns true if the given vector is a power of 2.
374     bool isPow2VectorType() const {
375       unsigned NElts = getVectorNumElements();
376       return !(NElts & (NElts - 1));
377     }
378 
379     /// Widens the length of the given vector EVT up to the nearest power of 2
380     /// and returns that type.
381     EVT getPow2VectorType(LLVMContext &Context) const {
382       if (!isPow2VectorType()) {
383         unsigned NElts = getVectorNumElements();
384         unsigned Pow2NElts = 1 <<  Log2_32_Ceil(NElts);
385         return EVT::getVectorVT(Context, getVectorElementType(), Pow2NElts,
386                                 isScalableVector());
387       }
388       else {
389         return *this;
390       }
391     }
392 
393     /// This function returns value type as a string, e.g. "i32".
394     std::string getEVTString() const;
395 
396     /// This method returns an LLVM type corresponding to the specified EVT.
397     /// For integer types, this returns an unsigned type. Note that this will
398     /// abort for types that cannot be represented.
399     Type *getTypeForEVT(LLVMContext &Context) const;
400 
401     /// Return the value type corresponding to the specified type.
402     /// This returns all pointers as iPTR.  If HandleUnknown is true, unknown
403     /// types are returned as Other, otherwise they are invalid.
404     static EVT getEVT(Type *Ty, bool HandleUnknown = false);
405 
406     intptr_t getRawBits() const {
407       if (isSimple())
408         return V.SimpleTy;
409       else
410         return (intptr_t)(LLVMTy);
411     }
412 
413     /// A meaningless but well-behaved order, useful for constructing
414     /// containers.
415     struct compareRawBits {
416       bool operator()(EVT L, EVT R) const {
417         if (L.V.SimpleTy == R.V.SimpleTy)
418           return L.LLVMTy < R.LLVMTy;
419         else
420           return L.V.SimpleTy < R.V.SimpleTy;
421       }
422     };
423 
424   private:
425     // Methods for handling the Extended-type case in functions above.
426     // These are all out-of-line to prevent users of this header file
427     // from having a dependency on Type.h.
428     EVT changeExtendedTypeToInteger() const;
429     EVT changeExtendedVectorElementTypeToInteger() const;
430     static EVT getExtendedIntegerVT(LLVMContext &C, unsigned BitWidth);
431     static EVT getExtendedVectorVT(LLVMContext &C, EVT VT,
432                                    unsigned NumElements);
433     bool isExtendedFloatingPoint() const LLVM_READONLY;
434     bool isExtendedInteger() const LLVM_READONLY;
435     bool isExtendedScalarInteger() const LLVM_READONLY;
436     bool isExtendedVector() const LLVM_READONLY;
437     bool isExtended16BitVector() const LLVM_READONLY;
438     bool isExtended32BitVector() const LLVM_READONLY;
439     bool isExtended64BitVector() const LLVM_READONLY;
440     bool isExtended128BitVector() const LLVM_READONLY;
441     bool isExtended256BitVector() const LLVM_READONLY;
442     bool isExtended512BitVector() const LLVM_READONLY;
443     bool isExtended1024BitVector() const LLVM_READONLY;
444     bool isExtended2048BitVector() const LLVM_READONLY;
445     EVT getExtendedVectorElementType() const;
446     unsigned getExtendedVectorNumElements() const LLVM_READONLY;
447     TypeSize getExtendedSizeInBits() const LLVM_READONLY;
448   };
449 
450 } // end namespace llvm
451 
452 #endif // LLVM_CODEGEN_VALUETYPES_H
453