1 //===--- CGStmtOpenMP.cpp - Emit LLVM Code from Statements ----------------===//
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 contains code to emit OpenMP nodes as LLVM code.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "CGOpenMPRuntime.h"
15 #include "CodeGenFunction.h"
16 #include "CodeGenModule.h"
17 #include "clang/AST/Stmt.h"
18 #include "clang/AST/StmtOpenMP.h"
19 using namespace clang;
20 using namespace CodeGen;
21 
22 //===----------------------------------------------------------------------===//
23 //                              OpenMP Directive Emission
24 //===----------------------------------------------------------------------===//
25 
26 void CodeGenFunction::EmitOMPParallelDirective(const OMPParallelDirective &S) {
27   const CapturedStmt *CS = cast<CapturedStmt>(S.getAssociatedStmt());
28   llvm::Value *CapturedStruct = GenerateCapturedStmtArgument(*CS);
29 
30   llvm::Value *OutlinedFn;
31   {
32     CodeGenFunction CGF(CGM, true);
33     CGCapturedStmtInfo CGInfo(*CS, CS->getCapturedRegionKind());
34     CGF.CapturedStmtInfo = &CGInfo;
35     OutlinedFn = CGF.GenerateCapturedStmtFunction(
36         CS->getCapturedDecl(), CS->getCapturedRecordDecl(), CS->getLocStart());
37   }
38 
39   // Build call __kmpc_fork_call(loc, 1, microtask, captured_struct/*context*/)
40   llvm::Value *Args[] = {
41       CGM.getOpenMPRuntime().EmitOpenMPUpdateLocation(*this, S.getLocStart()),
42       Builder.getInt32(1), // Number of arguments after 'microtask' argument
43       // (there is only one additional argument - 'context')
44       Builder.CreateBitCast(OutlinedFn,
45                             CGM.getOpenMPRuntime().getKmpc_MicroPointerTy()),
46       EmitCastToVoidPtr(CapturedStruct)};
47   llvm::Constant *RTLFn = CGM.getOpenMPRuntime().CreateRuntimeFunction(
48       CGOpenMPRuntime::OMPRTL__kmpc_fork_call);
49   EmitRuntimeCall(RTLFn, Args);
50 }
51 
52 void CodeGenFunction::EmitOMPSimdDirective(const OMPSimdDirective &S) {
53   const CapturedStmt *CS = cast<CapturedStmt>(S.getAssociatedStmt());
54   const Stmt *Body = CS->getCapturedStmt();
55   LoopStack.setParallel();
56   LoopStack.setVectorizerEnable(true);
57   for (auto C : S.clauses()) {
58     switch (C->getClauseKind()) {
59     case OMPC_safelen: {
60       RValue Len = EmitAnyExpr(cast<OMPSafelenClause>(C)->getSafelen(),
61                                AggValueSlot::ignored(), true);
62       llvm::ConstantInt *Val = cast<llvm::ConstantInt>(Len.getScalarVal());
63       LoopStack.setVectorizerWidth(Val->getZExtValue());
64       // In presence of finite 'safelen', it may be unsafe to mark all
65       // the memory instructions parallel, because loop-carried
66       // dependences of 'safelen' iterations are possible.
67       LoopStack.setParallel(false);
68       break;
69     }
70     default:
71       // Not handled yet
72       ;
73     }
74   }
75   EmitStmt(Body);
76 }
77 
78 void CodeGenFunction::EmitOMPForDirective(const OMPForDirective &) {
79   llvm_unreachable("Not supported yet.");
80 }
81