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1 //===----- CGOpenMPRuntime.cpp - Interface to OpenMP Runtimes -------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This provides a class for OpenMP runtime code generation.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "CGOpenMPRuntime.h"
15 #include "CodeGenFunction.h"
16 #include "clang/AST/Decl.h"
17 #include "llvm/ADT/ArrayRef.h"
18 #include "llvm/IR/DerivedTypes.h"
19 #include "llvm/IR/GlobalValue.h"
20 #include "llvm/IR/Value.h"
21 #include "llvm/Support/raw_ostream.h"
22 #include <cassert>
23 
24 using namespace clang;
25 using namespace CodeGen;
26 
CGOpenMPRuntime(CodeGenModule & CGM)27 CGOpenMPRuntime::CGOpenMPRuntime(CodeGenModule &CGM)
28     : CGM(CGM), DefaultOpenMPPSource(nullptr) {
29   IdentTy = llvm::StructType::create(
30       "ident_t", CGM.Int32Ty /* reserved_1 */, CGM.Int32Ty /* flags */,
31       CGM.Int32Ty /* reserved_2 */, CGM.Int32Ty /* reserved_3 */,
32       CGM.Int8PtrTy /* psource */, NULL);
33   // Build void (*kmpc_micro)(kmp_int32 *global_tid, kmp_int32 *bound_tid,...)
34   llvm::Type *MicroParams[] = {llvm::PointerType::getUnqual(CGM.Int32Ty),
35                                llvm::PointerType::getUnqual(CGM.Int32Ty)};
36   Kmpc_MicroTy = llvm::FunctionType::get(CGM.VoidTy, MicroParams, true);
37 }
38 
39 llvm::Value *
GetOrCreateDefaultOpenMPLocation(OpenMPLocationFlags Flags)40 CGOpenMPRuntime::GetOrCreateDefaultOpenMPLocation(OpenMPLocationFlags Flags) {
41   llvm::Value *Entry = OpenMPDefaultLocMap.lookup(Flags);
42   if (!Entry) {
43     if (!DefaultOpenMPPSource) {
44       // Initialize default location for psource field of ident_t structure of
45       // all ident_t objects. Format is ";file;function;line;column;;".
46       // Taken from
47       // http://llvm.org/svn/llvm-project/openmp/trunk/runtime/src/kmp_str.c
48       DefaultOpenMPPSource =
49           CGM.GetAddrOfConstantCString(";unknown;unknown;0;0;;");
50       DefaultOpenMPPSource =
51           llvm::ConstantExpr::getBitCast(DefaultOpenMPPSource, CGM.Int8PtrTy);
52     }
53     llvm::GlobalVariable *DefaultOpenMPLocation = cast<llvm::GlobalVariable>(
54         CGM.CreateRuntimeVariable(IdentTy, ".kmpc_default_loc.addr"));
55     DefaultOpenMPLocation->setUnnamedAddr(true);
56     DefaultOpenMPLocation->setConstant(true);
57     DefaultOpenMPLocation->setLinkage(llvm::GlobalValue::PrivateLinkage);
58 
59     llvm::Constant *Zero = llvm::ConstantInt::get(CGM.Int32Ty, 0, true);
60     llvm::Constant *Values[] = {Zero,
61                                 llvm::ConstantInt::get(CGM.Int32Ty, Flags),
62                                 Zero, Zero, DefaultOpenMPPSource};
63     llvm::Constant *Init = llvm::ConstantStruct::get(IdentTy, Values);
64     DefaultOpenMPLocation->setInitializer(Init);
65     return DefaultOpenMPLocation;
66   }
67   return Entry;
68 }
69 
EmitOpenMPUpdateLocation(CodeGenFunction & CGF,SourceLocation Loc,OpenMPLocationFlags Flags)70 llvm::Value *CGOpenMPRuntime::EmitOpenMPUpdateLocation(
71     CodeGenFunction &CGF, SourceLocation Loc, OpenMPLocationFlags Flags) {
72   // If no debug info is generated - return global default location.
73   if (CGM.getCodeGenOpts().getDebugInfo() == CodeGenOptions::NoDebugInfo ||
74       Loc.isInvalid())
75     return GetOrCreateDefaultOpenMPLocation(Flags);
76 
77   assert(CGF.CurFn && "No function in current CodeGenFunction.");
78 
79   llvm::Value *LocValue = nullptr;
80   OpenMPLocMapTy::iterator I = OpenMPLocMap.find(CGF.CurFn);
81   if (I != OpenMPLocMap.end()) {
82     LocValue = I->second;
83   } else {
84     // Generate "ident_t .kmpc_loc.addr;"
85     llvm::AllocaInst *AI = CGF.CreateTempAlloca(IdentTy, ".kmpc_loc.addr");
86     AI->setAlignment(CGM.getDataLayout().getPrefTypeAlignment(IdentTy));
87     OpenMPLocMap[CGF.CurFn] = AI;
88     LocValue = AI;
89 
90     CGBuilderTy::InsertPointGuard IPG(CGF.Builder);
91     CGF.Builder.SetInsertPoint(CGF.AllocaInsertPt);
92     CGF.Builder.CreateMemCpy(LocValue, GetOrCreateDefaultOpenMPLocation(Flags),
93                              llvm::ConstantExpr::getSizeOf(IdentTy),
94                              CGM.PointerAlignInBytes);
95   }
96 
97   // char **psource = &.kmpc_loc_<flags>.addr.psource;
98   llvm::Value *PSource =
99       CGF.Builder.CreateConstInBoundsGEP2_32(LocValue, 0, IdentField_PSource);
100 
101   auto OMPDebugLoc = OpenMPDebugLocMap.lookup(Loc.getRawEncoding());
102   if (OMPDebugLoc == nullptr) {
103     SmallString<128> Buffer2;
104     llvm::raw_svector_ostream OS2(Buffer2);
105     // Build debug location
106     PresumedLoc PLoc = CGF.getContext().getSourceManager().getPresumedLoc(Loc);
107     OS2 << ";" << PLoc.getFilename() << ";";
108     if (const FunctionDecl *FD =
109             dyn_cast_or_null<FunctionDecl>(CGF.CurFuncDecl)) {
110       OS2 << FD->getQualifiedNameAsString();
111     }
112     OS2 << ";" << PLoc.getLine() << ";" << PLoc.getColumn() << ";;";
113     OMPDebugLoc = CGF.Builder.CreateGlobalStringPtr(OS2.str());
114     OpenMPDebugLocMap[Loc.getRawEncoding()] = OMPDebugLoc;
115   }
116   // *psource = ";<File>;<Function>;<Line>;<Column>;;";
117   CGF.Builder.CreateStore(OMPDebugLoc, PSource);
118 
119   return LocValue;
120 }
121 
GetOpenMPGlobalThreadNum(CodeGenFunction & CGF,SourceLocation Loc)122 llvm::Value *CGOpenMPRuntime::GetOpenMPGlobalThreadNum(CodeGenFunction &CGF,
123                                                        SourceLocation Loc) {
124   assert(CGF.CurFn && "No function in current CodeGenFunction.");
125 
126   llvm::Value *GTid = nullptr;
127   OpenMPGtidMapTy::iterator I = OpenMPGtidMap.find(CGF.CurFn);
128   if (I != OpenMPGtidMap.end()) {
129     GTid = I->second;
130   } else {
131     // Generate "int32 .kmpc_global_thread_num.addr;"
132     CGBuilderTy::InsertPointGuard IPG(CGF.Builder);
133     CGF.Builder.SetInsertPoint(CGF.AllocaInsertPt);
134     llvm::Value *Args[] = {EmitOpenMPUpdateLocation(CGF, Loc)};
135     GTid = CGF.EmitRuntimeCall(
136         CreateRuntimeFunction(OMPRTL__kmpc_global_thread_num), Args);
137     OpenMPGtidMap[CGF.CurFn] = GTid;
138   }
139   return GTid;
140 }
141 
FunctionFinished(CodeGenFunction & CGF)142 void CGOpenMPRuntime::FunctionFinished(CodeGenFunction &CGF) {
143   assert(CGF.CurFn && "No function in current CodeGenFunction.");
144   if (OpenMPGtidMap.count(CGF.CurFn))
145     OpenMPGtidMap.erase(CGF.CurFn);
146   if (OpenMPLocMap.count(CGF.CurFn))
147     OpenMPLocMap.erase(CGF.CurFn);
148 }
149 
getIdentTyPointerTy()150 llvm::Type *CGOpenMPRuntime::getIdentTyPointerTy() {
151   return llvm::PointerType::getUnqual(IdentTy);
152 }
153 
getKmpc_MicroPointerTy()154 llvm::Type *CGOpenMPRuntime::getKmpc_MicroPointerTy() {
155   return llvm::PointerType::getUnqual(Kmpc_MicroTy);
156 }
157 
158 llvm::Constant *
CreateRuntimeFunction(OpenMPRTLFunction Function)159 CGOpenMPRuntime::CreateRuntimeFunction(OpenMPRTLFunction Function) {
160   llvm::Constant *RTLFn = nullptr;
161   switch (Function) {
162   case OMPRTL__kmpc_fork_call: {
163     // Build void __kmpc_fork_call(ident_t *loc, kmp_int32 argc, kmpc_micro
164     // microtask, ...);
165     llvm::Type *TypeParams[] = {getIdentTyPointerTy(), CGM.Int32Ty,
166                                 getKmpc_MicroPointerTy()};
167     llvm::FunctionType *FnTy =
168         llvm::FunctionType::get(CGM.VoidTy, TypeParams, true);
169     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_fork_call");
170     break;
171   }
172   case OMPRTL__kmpc_global_thread_num: {
173     // Build kmp_int32 __kmpc_global_thread_num(ident_t *loc);
174     llvm::Type *TypeParams[] = {getIdentTyPointerTy()};
175     llvm::FunctionType *FnTy =
176         llvm::FunctionType::get(CGM.Int32Ty, TypeParams, false);
177     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_global_thread_num");
178     break;
179   }
180   }
181   return RTLFn;
182 }
183