1 | /* |
2 | * Copyright 2016 Google Inc. |
3 | * |
4 | * Use of this source code is governed by a BSD-style license that can be |
5 | * found in the LICENSE file. |
6 | */ |
7 | |
8 | #ifndef SKSL_PREFIXEXPRESSION |
9 | #define SKSL_PREFIXEXPRESSION |
10 | |
11 | #include "src/sksl/SkSLCompiler.h" |
12 | #include "src/sksl/SkSLIRGenerator.h" |
13 | #include "src/sksl/SkSLLexer.h" |
14 | #include "src/sksl/ir/SkSLExpression.h" |
15 | #include "src/sksl/ir/SkSLFloatLiteral.h" |
16 | |
17 | namespace SkSL { |
18 | |
19 | /** |
20 | * An expression modified by a unary operator appearing before it, such as '!flag'. |
21 | */ |
22 | struct PrefixExpression : public Expression { |
23 | PrefixExpression(Token::Kind op, std::unique_ptr<Expression> operand) |
24 | : INHERITED(operand->fOffset, kPrefix_Kind, operand->fType) |
25 | , fOperand(std::move(operand)) |
26 | , fOperator(op) {} |
27 | |
28 | bool isConstant() const override { |
29 | return fOperator == Token::MINUS && fOperand->isConstant(); |
30 | } |
31 | |
32 | bool hasProperty(Property property) const override { |
33 | if (property == Property::kSideEffects && (fOperator == Token::PLUSPLUS || |
34 | fOperator == Token::MINUSMINUS)) { |
35 | return true; |
36 | } |
37 | return fOperand->hasProperty(property); |
38 | } |
39 | |
40 | std::unique_ptr<Expression> constantPropagate(const IRGenerator& irGenerator, |
41 | const DefinitionMap& definitions) override { |
42 | if (fOperand->fKind == Expression::kFloatLiteral_Kind) { |
43 | return std::unique_ptr<Expression>(new FloatLiteral( |
44 | irGenerator.fContext, |
45 | fOffset, |
46 | -((FloatLiteral&) *fOperand).fValue)); |
47 | |
48 | } |
49 | return nullptr; |
50 | } |
51 | |
52 | SKSL_FLOAT getFVecComponent(int index) const override { |
53 | SkASSERT(fOperator == Token::Kind::MINUS); |
54 | return -fOperand->getFVecComponent(index); |
55 | } |
56 | |
57 | SKSL_INT getIVecComponent(int index) const override { |
58 | SkASSERT(fOperator == Token::Kind::MINUS); |
59 | return -fOperand->getIVecComponent(index); |
60 | } |
61 | |
62 | SKSL_FLOAT getMatComponent(int col, int row) const override { |
63 | SkASSERT(fOperator == Token::Kind::MINUS); |
64 | return -fOperand->getMatComponent(col, row); |
65 | } |
66 | |
67 | std::unique_ptr<Expression> clone() const override { |
68 | return std::unique_ptr<Expression>(new PrefixExpression(fOperator, fOperand->clone())); |
69 | } |
70 | |
71 | #ifdef SK_DEBUG |
72 | String description() const override { |
73 | return Compiler::OperatorName(fOperator) + fOperand->description(); |
74 | } |
75 | #endif |
76 | |
77 | std::unique_ptr<Expression> fOperand; |
78 | const Token::Kind fOperator; |
79 | |
80 | typedef Expression INHERITED; |
81 | }; |
82 | |
83 | } // namespace |
84 | |
85 | #endif |
86 | |