[OPENMP] Codegen for 'reduction' clause in 'parallel' directive.

Emit a code for reduction clause. Next code should be emitted for reductions:

static kmp_critical_name lock = { 0 };

void reduce_func(void *lhs[<n>], void *rhs[<n>]) {
  ...
  *(Type<i> *)lhs[i] = RedOp<i>(*(Type<i> *)lhs[i], *(Type<i> *)rhs[i]);
  ...
}

... void *RedList[<n>] = {&<RHSExprs>[0], ..., &<RHSExprs>[<n> - 1]};
switch (__kmpc_reduce{_nowait}(<loc>, <gtid>, <n>, sizeof(RedList), RedList, reduce_func, &<lock>)) {
case 1:
  ...
  <LHSExprs>[i] = RedOp<i>(*<LHSExprs>[i], *<RHSExprs>[i]);
  ...
  __kmpc_end_reduce{_nowait}(<loc>, <gtid>, &<lock>);
  break;
case 2:
  ...
  Atomic(<LHSExprs>[i] = RedOp<i>(*<LHSExprs>[i], *<RHSExprs>[i]));
  ...
  break;
default:
  ;
}
Reduction variables are a kind of a private variables, they have private copies, but initial values are chosen in accordance with the reduction operation.

Differential Revision: http://reviews.llvm.org/D8915

llvm-svn: 234583

2 files changed, 18 insertions, 0 deletions

diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
index e40b1d9599e..447ca4831b9 100644
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -1917,6 +1917,18 @@ void OMPClauseReader::VisitOMPReductionClause(OMPReductionClause *C) {
   for (unsigned i = 0; i != NumVars; ++i)
     Vars.push_back(Reader->Reader.ReadSubExpr());
   C->setVarRefs(Vars);
+  Vars.clear();
+  for (unsigned i = 0; i != NumVars; ++i)
+    Vars.push_back(Reader->Reader.ReadSubExpr());
+  C->setLHSExprs(Vars);
+  Vars.clear();
+  for (unsigned i = 0; i != NumVars; ++i)
+    Vars.push_back(Reader->Reader.ReadSubExpr());
+  C->setRHSExprs(Vars);
+  Vars.clear();
+  for (unsigned i = 0; i != NumVars; ++i)
+    Vars.push_back(Reader->Reader.ReadSubExpr());
+  C->setReductionOps(Vars);
 }
 
 void OMPClauseReader::VisitOMPLinearClause(OMPLinearClause *C) {
diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp
index 97ed06ff638..a422f7a64f8 100644
--- a/clang/lib/Serialization/ASTWriterStmt.cpp
+++ b/clang/lib/Serialization/ASTWriterStmt.cpp
@@ -1815,6 +1815,12 @@ void OMPClauseWriter::VisitOMPReductionClause(OMPReductionClause *C) {
   Writer->Writer.AddDeclarationNameInfo(C->getNameInfo(), Record);
   for (auto *VE : C->varlists())
     Writer->Writer.AddStmt(VE);
+  for (auto *E : C->lhs_exprs())
+    Writer->Writer.AddStmt(E);
+  for (auto *E : C->rhs_exprs())
+    Writer->Writer.AddStmt(E);
+  for (auto *E : C->reduction_ops())
+    Writer->Writer.AddStmt(E);
 }
 
 void OMPClauseWriter::VisitOMPLinearClause(OMPLinearClause *C) {