zenilib: zenilib/jni/external/angle/src/third_party/compiler/ArrayBoundsClamper.cpp Source File

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ArrayBoundsClamper.cpp
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1 /*
2 * Copyright (C) 2012 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE, INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26 #include "third_party/compiler/ArrayBoundsClamper.h"
27
28 // The built-in 'clamp' instruction only accepts floats and returns a float. I
29 // iterated a few times with our driver team who examined the output from our
30 // compiler - they said the multiple casts generates more code than a single
31 // function call. An inline ternary operator might have been better, but since
32 // the index value might be an expression itself, we'd have to make temporary
33 // variables to avoid evaluating the expression multiple times. And making
34 // temporary variables was difficult because ANGLE would then need to make more
35 // brutal changes to the expression tree.
36
37 const char* kIntClampBegin = "// BEGIN: Generated code for array bounds clamping\n\n";
38 const char* kIntClampEnd = "// END: Generated code for array bounds clamping\n\n";
39 const char* kIntClampDefinition = "int webgl_int_clamp(int value, int minValue, int maxValue) { return ((value < minValue) ? minValue : ((value > maxValue) ? maxValue : value)); }\n\n";
40
41 namespace {
42
43 class ArrayBoundsClamperMarker : public TIntermTraverser {
44 public:
45 ArrayBoundsClamperMarker()
46 : mNeedsClamp(false)
47 {
48 }
49
50 virtual bool visitBinary(Visit visit, TIntermBinary* node)
51 {
52 if (node->getOp() == EOpIndexIndirect)
53 {
54 TIntermTyped* left = node->getLeft();
55 if (left->isArray() || left->isVector() || left->isMatrix())
56 {
57 node->setAddIndexClamp();
58 mNeedsClamp = true;
59 }
60 }
61 return true;
62 }
63
64 bool GetNeedsClamp() { return mNeedsClamp; }
65
66 private:
67 bool mNeedsClamp;
68 };
69
70 } // anonymous namespace
71
72 ArrayBoundsClamper::ArrayBoundsClamper()
73 : mClampingStrategy(SH_CLAMP_WITH_CLAMP_INTRINSIC)
74 , mArrayBoundsClampDefinitionNeeded(false)
75 {
76 }
77
78 void ArrayBoundsClamper::SetClampingStrategy(ShArrayIndexClampingStrategy clampingStrategy)
79 {
80 mClampingStrategy = clampingStrategy;
81 }
82
83 void ArrayBoundsClamper::MarkIndirectArrayBoundsForClamping(TIntermNode* root)
84 {
85 ASSERT(root);
86
87 ArrayBoundsClamperMarker clamper;
88 root->traverse(&clamper);
89 if (clamper.GetNeedsClamp())
90 {
91 SetArrayBoundsClampDefinitionNeeded();
92 }
93 }
94
95 void ArrayBoundsClamper::OutputClampingFunctionDefinition(TInfoSinkBase& out) const
96 {
97 if (!mArrayBoundsClampDefinitionNeeded)
98 {
99 return;
100 }
101 if (mClampingStrategy != SH_CLAMP_WITH_USER_DEFINED_INT_CLAMP_FUNCTION)
102 {
103 return;
104 }
105 out << kIntClampBegin << kIntClampDefinition << kIntClampEnd;
106 }
ArrayBoundsClamper::MarkIndirectArrayBoundsForClamping
void MarkIndirectArrayBoundsForClamping(TIntermNode *root)
Definition: ArrayBoundsClamper.cpp:83
kIntClampBegin
const char * kIntClampBegin
Definition: ArrayBoundsClamper.cpp:37
Visit
Visit
Definition: intermediate.h:524
TIntermOperator::getOp
TOperator getOp() const
Definition: intermediate.h:389
left
GLint left
Definition: glew.h:7291
kIntClampDefinition
const char * kIntClampDefinition
Definition: ArrayBoundsClamper.cpp:39
TIntermBinary::getLeft
TIntermTyped * getLeft() const
Definition: intermediate.h:413
ArrayBoundsClamper::ArrayBoundsClamper
ArrayBoundsClamper()
Definition: ArrayBoundsClamper.cpp:72
ArrayBoundsClamper.h
SH_CLAMP_WITH_CLAMP_INTRINSIC
Definition: ShaderLang.h:177
TIntermTyped
Definition: intermediate.h:245
SH_CLAMP_WITH_USER_DEFINED_INT_CLAMP_FUNCTION
Definition: ShaderLang.h:180
ArrayBoundsClamper::SetClampingStrategy
void SetClampingStrategy(ShArrayIndexClampingStrategy clampingStrategy)
Definition: ArrayBoundsClamper.cpp:78
TIntermTyped::isMatrix
bool isMatrix() const
Definition: intermediate.h:259
TIntermBinary
Definition: intermediate.h:404
ShArrayIndexClampingStrategy
ShArrayIndexClampingStrategy
Definition: ShaderLang.h:175
TIntermTyped::isVector
bool isVector() const
Definition: intermediate.h:261
kIntClampEnd
const char * kIntClampEnd
Definition: ArrayBoundsClamper.cpp:38
TInfoSinkBase
Definition: InfoSink.h:38
EOpIndexIndirect
Definition: intermediate.h:87
ASSERT
#define ASSERT(expression)
Definition: debug.h:36
TIntermTraverser::visitBinary
virtual bool visitBinary(Visit visit, TIntermBinary *)
Definition: intermediate.h:554
TIntermNode::traverse
virtual void traverse(TIntermTraverser *)=0
TIntermTraverser
Definition: intermediate.h:539
ArrayBoundsClamper::OutputClampingFunctionDefinition
void OutputClampingFunctionDefinition(TInfoSinkBase &out) const
Definition: ArrayBoundsClamper.cpp:95
TIntermBinary::setAddIndexClamp
void setAddIndexClamp()
Definition: intermediate.h:417
TIntermTyped::isArray
bool isArray() const
Definition: intermediate.h:260
TIntermNode
Definition: intermediate.h:206
false
#define false
Definition: ftrandom.c:50