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 <assert.h>
23 
24 using namespace clang;
25 using namespace CodeGen;
26 
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 *
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[] = {
61       Zero, llvm::ConstantInt::get(CGM.Int32Ty, Flags), Zero,
62       Zero, DefaultOpenMPPSource
63     };
64     llvm::Constant *Init = llvm::ConstantStruct::get(IdentTy, Values);
65     DefaultOpenMPLocation->setInitializer(Init);
66     return DefaultOpenMPLocation;
67   }
68   return Entry;
69 }
70 
71 llvm::Value *CGOpenMPRuntime::EmitOpenMPUpdateLocation(
72     CodeGenFunction &CGF, SourceLocation Loc, OpenMPLocationFlags Flags) {
73   // If no debug info is generated - return global default location.
74   if (CGM.getCodeGenOpts().getDebugInfo() == CodeGenOptions::NoDebugInfo ||
75       Loc.isInvalid())
76     return GetOrCreateDefaultOpenMPLocation(Flags);
77 
78   assert(CGF.CurFn && "No function in current CodeGenFunction.");
79 
80   llvm::Value *LocValue = nullptr;
81   OpenMPLocMapTy::iterator I = OpenMPLocMap.find(CGF.CurFn);
82   if (I != OpenMPLocMap.end()) {
83     LocValue = I->second;
84   } else {
85     // Generate "ident_t .kmpc_loc.addr;"
86     llvm::AllocaInst *AI = CGF.CreateTempAlloca(IdentTy, ".kmpc_loc.addr");
87     AI->setAlignment(CGM.getDataLayout().getPrefTypeAlignment(IdentTy));
88     OpenMPLocMap[CGF.CurFn] = AI;
89     LocValue = AI;
90 
91     CGBuilderTy::InsertPointGuard IPG(CGF.Builder);
92     CGF.Builder.SetInsertPoint(CGF.AllocaInsertPt);
93     CGF.Builder.CreateMemCpy(LocValue, GetOrCreateDefaultOpenMPLocation(Flags),
94                              llvm::ConstantExpr::getSizeOf(IdentTy),
95                              CGM.PointerAlignInBytes);
96   }
97 
98   // char **psource = &.kmpc_loc_<flags>.addr.psource;
99   llvm::Value *PSource =
100       CGF.Builder.CreateConstInBoundsGEP2_32(LocValue, 0, IdentField_PSource);
101 
102   auto OMPDebugLoc = OpenMPDebugLocMap.lookup(Loc.getRawEncoding());
103   if (OMPDebugLoc == nullptr) {
104     SmallString<128> Buffer2;
105     llvm::raw_svector_ostream OS2(Buffer2);
106     // Build debug location
107     PresumedLoc PLoc = CGF.getContext().getSourceManager().getPresumedLoc(Loc);
108     OS2 << ";" << PLoc.getFilename() << ";";
109     if (const FunctionDecl *FD =
110             dyn_cast_or_null<FunctionDecl>(CGF.CurFuncDecl)) {
111       OS2 << FD->getQualifiedNameAsString();
112     }
113     OS2 << ";" << PLoc.getLine() << ";" << PLoc.getColumn() << ";;";
114     OMPDebugLoc = CGF.Builder.CreateGlobalStringPtr(OS2.str());
115     OpenMPDebugLocMap[Loc.getRawEncoding()] = OMPDebugLoc;
116   }
117   // *psource = ";<File>;<Function>;<Line>;<Column>;;";
118   CGF.Builder.CreateStore(OMPDebugLoc, PSource);
119 
120   return LocValue;
121 }
122 
123 llvm::Value *CGOpenMPRuntime::GetOpenMPGlobalThreadNum(CodeGenFunction &CGF,
124                                                        SourceLocation Loc) {
125   assert(CGF.CurFn && "No function in current CodeGenFunction.");
126 
127   llvm::Value *GTid = nullptr;
128   OpenMPGtidMapTy::iterator I = OpenMPGtidMap.find(CGF.CurFn);
129   if (I != OpenMPGtidMap.end()) {
130     GTid = I->second;
131   } else {
132     // Generate "int32 .kmpc_global_thread_num.addr;"
133     CGBuilderTy::InsertPointGuard IPG(CGF.Builder);
134     CGF.Builder.SetInsertPoint(CGF.AllocaInsertPt);
135     llvm::Value *Args[] = { EmitOpenMPUpdateLocation(CGF, Loc) };
136     GTid = CGF.EmitRuntimeCall(
137         CreateRuntimeFunction(OMPRTL__kmpc_global_thread_num), Args);
138     OpenMPGtidMap[CGF.CurFn] = GTid;
139   }
140   return GTid;
141 }
142 
143 void CGOpenMPRuntime::FunctionFinished(CodeGenFunction &CGF) {
144   assert(CGF.CurFn && "No function in current CodeGenFunction.");
145   if (OpenMPGtidMap.count(CGF.CurFn))
146     OpenMPGtidMap.erase(CGF.CurFn);
147   if (OpenMPLocMap.count(CGF.CurFn))
148     OpenMPLocMap.erase(CGF.CurFn);
149 }
150 
151 llvm::Type *CGOpenMPRuntime::getIdentTyPointerTy() {
152   return llvm::PointerType::getUnqual(IdentTy);
153 }
154 
155 llvm::Type *CGOpenMPRuntime::getKmpc_MicroPointerTy() {
156   return llvm::PointerType::getUnqual(Kmpc_MicroTy);
157 }
158 
159 llvm::Constant *
160 CGOpenMPRuntime::CreateRuntimeFunction(OpenMPRTLFunction Function) {
161   llvm::Constant *RTLFn = nullptr;
162   switch (Function) {
163   case OMPRTL__kmpc_fork_call: {
164     // Build void __kmpc_fork_call(ident_t *loc, kmp_int32 argc, kmpc_micro
165     // microtask, ...);
166     llvm::Type *TypeParams[] = { getIdentTyPointerTy(), CGM.Int32Ty,
167                                  getKmpc_MicroPointerTy() };
168     llvm::FunctionType *FnTy =
169         llvm::FunctionType::get(CGM.VoidTy, TypeParams, true);
170     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_fork_call");
171     break;
172   }
173   case OMPRTL__kmpc_global_thread_num: {
174     // Build kmp_int32 __kmpc_global_thread_num(ident_t *loc);
175     llvm::Type *TypeParams[] = { getIdentTyPointerTy() };
176     llvm::FunctionType *FnTy =
177         llvm::FunctionType::get(CGM.Int32Ty, TypeParams, false);
178     RTLFn = CGM.CreateRuntimeFunction(FnTy, "__kmpc_global_thread_num");
179     break;
180   }
181   }
182   return RTLFn;
183 }
184