1 /*
2  * Copyright 2015, The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef BCC_RS_UTILS_H
18 #define BCC_RS_UTILS_H
19 
20 #include "rsDefines.h"
21 
22 #include <llvm/IR/Type.h>
23 #include <llvm/IR/DerivedTypes.h>
24 #include <llvm/ADT/StringRef.h>
25 
26 #include <string>
27 
28 namespace {
29 
getUnsuffixedStructName(const llvm::StructType * T)30 static inline llvm::StringRef getUnsuffixedStructName(const llvm::StructType *T) {
31 #ifdef FORCE_BUILD_LLVM_DISABLE_NDEBUG
32   // Bug: 22926131
33   // When building with assertions enabled, LLVM cannot read the name of a
34   // literal (anonymous) structure, because they shouldn't actually ever have
35   // a name. Unfortunately, due to past definitions of RenderScript object
36   // types as anonymous structures typedef-ed to their proper typename,
37   // we had been relying on accessing this information. LLVM bitcode retains
38   // the typedef-ed name for such anonymous structures. There is a
39   // corresponding (safe) fix to the RenderScript headers to actually name
40   // these types the same as their typedef name to simplify things. That
41   // fixes this issue going forward, but it won't allow us to compile legacy
42   // code properly. In that case, we just have non-assert builds ignore the
43   // fact that anonymous structures shouldn't have their name read, and do it
44   // anyway. Note that RSCompilerDriver.cpp checks the compiler version
45   // number (from llvm-rs-cc) to ensure that we are only ever building modern
46   // code when we have assertions enabled. Legacy code can only be compiled
47   // correctly with a non-asserting compiler.
48   //
49   // Note that the whole reason for looking at the "unsuffixed" name of the
50   // type is because LLVM suffixes duplicate typedefs of the same anonymous
51   // structure. In the new case, where all of the RS object types have a
52   // proper name, they won't have a dotted suffix at all. We still need
53   // to look at the old unsuffixed version to handle legacy code properly.
54   if (T->isLiteral()) {
55     return "";
56   }
57 #endif
58 
59   // Get just the object type name with no suffix.
60   size_t LastDot = T->getName().rfind('.');
61   if (LastDot == strlen("struct")) {
62     // If we get back to just the "struct" part, we know that we had a
63     // raw typename (i.e. struct.rs_element with no ".[0-9]+" suffix on it.
64     // In that case, we will want to create our slice such that it contains
65     // the entire name.
66     LastDot = T->getName().size();
67   }
68   return T->getStructName().slice(0, LastDot);
69 }
70 
71 const char kAllocationTypeName[] = "struct.rs_allocation";
72 const char kElementTypeName[]    = "struct.rs_element";
73 const char kSamplerTypeName[]    = "struct.rs_sampler";
74 const char kScriptTypeName[]     = "struct.rs_script";
75 const char kTypeTypeName[]       = "struct.rs_type";
76 
77 // Returns the RsDataType for a given input LLVM type.
78 // This is only used to distinguish the associated RS object types (i.e.
79 // rs_allocation, rs_element, rs_sampler, rs_script, and rs_type).
80 // All other types are reported back as RS_TYPE_NONE, since no special
81 // handling would be necessary.
getRsDataTypeForType(const llvm::Type * T)82 static inline enum RsDataType getRsDataTypeForType(const llvm::Type *T) {
83   if (T->isStructTy()) {
84     const llvm::StringRef StructName = getUnsuffixedStructName(llvm::dyn_cast<const llvm::StructType>(T));
85     if (StructName.equals(kAllocationTypeName)) {
86       return RS_TYPE_ALLOCATION;
87     } else if (StructName.equals(kElementTypeName)) {
88       return RS_TYPE_ELEMENT;
89     } else if (StructName.equals(kSamplerTypeName)) {
90       return RS_TYPE_SAMPLER;
91     } else if (StructName.equals(kScriptTypeName)) {
92       return RS_TYPE_SCRIPT;
93     } else if (StructName.equals(kTypeTypeName)) {
94       return RS_TYPE_TYPE;
95     }
96   }
97   return RS_TYPE_NONE;
98 }
99 
100 // Returns true if the input type is one of our RenderScript object types
101 // (allocation, element, sampler, script, type) and false if it is not.
isRsObjectType(const llvm::Type * T)102 static inline bool isRsObjectType(const llvm::Type *T) {
103   return getRsDataTypeForType(T) != RS_TYPE_NONE;
104 }
105 
106 }  // end namespace
107 
108 // When we have a general reduction kernel with no combiner function,
109 // we will synthesize a combiner function from the accumulator
110 // function.  Given the accumulator function name, what should be the
111 // name of the combiner function?
nameReduceCombinerFromAccumulator(llvm::StringRef accumName)112 static inline std::string nameReduceCombinerFromAccumulator(llvm::StringRef accumName) {
113   return std::string(accumName) + ".combiner";
114 }
115 
116 #endif // BCC_RS_UTILS_H
117