1 //===- llvm/VectorBuilder.h - Builder for VP Intrinsics ---------*- 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 VectorBuilder class, which is used as a convenient way
10 // to create VP intrinsics as if they were LLVM instructions with a consistent
11 // and simplified interface.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_IR_VECTORBUILDER_H
16 #define LLVM_IR_VECTORBUILDER_H
17 
18 #include <llvm/IR/IRBuilder.h>
19 #include <llvm/IR/InstrTypes.h>
20 #include <llvm/IR/Instruction.h>
21 #include <llvm/IR/Value.h>
22 
23 namespace llvm {
24 
25 class VectorBuilder {
26 public:
27   enum class Behavior {
28     // Abort if the requested VP intrinsic could not be created.
29     // This is useful for strict consistency.
30     ReportAndAbort = 0,
31 
32     // Return a default-initialized value if the requested VP intrinsic could
33     // not be created.
34     // This is useful for a defensive fallback to non-VP code.
35     SilentlyReturnNone = 1,
36   };
37 
38 private:
39   IRBuilderBase &Builder;
40   Behavior ErrorHandling;
41 
42   // Explicit mask parameter.
43   Value *Mask;
44   // Explicit vector length parameter.
45   Value *ExplicitVectorLength;
46   // Compile-time vector length.
47   ElementCount StaticVectorLength;
48 
49   // Get mask/evl value handles for the current configuration.
50   Value &requestMask();
51   Value &requestEVL();
52 
53   void handleError(const char *ErrorMsg) const;
54   template <typename RetType>
55   RetType returnWithError(const char *ErrorMsg) const {
56     handleError(ErrorMsg);
57     return RetType();
58   }
59 
60 public:
61   VectorBuilder(IRBuilderBase &Builder,
62                 Behavior ErrorHandling = Behavior::ReportAndAbort)
63       : Builder(Builder), ErrorHandling(ErrorHandling), Mask(nullptr),
64         ExplicitVectorLength(nullptr),
65         StaticVectorLength(ElementCount::getFixed(0)) {}
66 
67   Module &getModule() const;
68   LLVMContext &getContext() const { return Builder.getContext(); }
69 
70   // All-true mask for the currently configured explicit vector length.
71   Value *getAllTrueMask();
72 
73   VectorBuilder &setMask(Value *NewMask) {
74     Mask = NewMask;
75     return *this;
76   }
77   VectorBuilder &setEVL(Value *NewExplicitVectorLength) {
78     ExplicitVectorLength = NewExplicitVectorLength;
79     return *this;
80   }
81   VectorBuilder &setStaticVL(unsigned NewFixedVL) {
82     StaticVectorLength = ElementCount::getFixed(NewFixedVL);
83     return *this;
84   }
85   // TODO: setStaticVL(ElementCount) for scalable types.
86 
87   // Emit a VP intrinsic call that mimics a regular instruction.
88   // This operation behaves according to the VectorBuilderBehavior.
89   // \p Opcode      The functional instruction opcode of the emitted intrinsic.
90   // \p ReturnTy    The return type of the operation.
91   // \p VecOpArray  The operand list.
92   Value *createVectorInstruction(unsigned Opcode, Type *ReturnTy,
93                                  ArrayRef<Value *> VecOpArray,
94                                  const Twine &Name = Twine());
95 };
96 
97 } // namespace llvm
98 
99 #endif // LLVM_IR_VECTORBUILDER_H
100