[OPENMP] Codegen for 'atomic update' construct.

Adds atomic update codegen for the following forms of expressions:

x binop= expr;
x++;
++x;
x--;
--x;
x = x binop expr;
x = expr binop x;
If x and expr are integer and binop is associative or x is a LHS in a RHS of the assignment expression, and atomics are allowed for type of x on the target platform atomicrmw instruction is emitted.
Otherwise compare-and-swap sequence is emitted:

bb:
...
atomic load <x>
cont:
<expected> = phi [ <x>, label %bb ], [ <new_failed>, %cont ]
<desired> = <expected> binop <expr>
<res> = cmpxchg atomic &<x>, desired, expected
<new_failed> = <res>.field1;
br <res>field2, label %exit, label %cont
exit:
...

Differential Revision: http://reviews.llvm.org/D8536

llvm-svn: 233513

2 files changed, 4 insertions, 4 deletions

diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
index c7b49dee2ec..b31d9e756a6 100644
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -2157,11 +2157,11 @@ void ASTStmtReader::VisitOMPAtomicDirective(OMPAtomicDirective *D) {
   // The NumClauses field was read in ReadStmtFromStream.
   ++Idx;
   VisitOMPExecutableDirective(D);
-  D->setOpKind(static_cast<BinaryOperatorKind>(Record[Idx++]));
   D->setX(Reader.ReadSubExpr());
-  D->setXRVal(Reader.ReadSubExpr());
   D->setV(Reader.ReadSubExpr());
   D->setExpr(Reader.ReadSubExpr());
+  D->setUpdateExpr(Reader.ReadSubExpr());
+  D->IsXLHSInRHSPart = Record[Idx++] != 0;
 }
 
 void ASTStmtReader::VisitOMPTargetDirective(OMPTargetDirective *D) {
diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp
index 6e647c31950..daebc52c96b 100644
--- a/clang/lib/Serialization/ASTWriterStmt.cpp
+++ b/clang/lib/Serialization/ASTWriterStmt.cpp
@@ -2005,11 +2005,11 @@ void ASTStmtWriter::VisitOMPAtomicDirective(OMPAtomicDirective *D) {
   VisitStmt(D);
   Record.push_back(D->getNumClauses());
   VisitOMPExecutableDirective(D);
-  Record.push_back(D->getOpKind());
   Writer.AddStmt(D->getX());
-  Writer.AddStmt(D->getXRVal());
   Writer.AddStmt(D->getV());
   Writer.AddStmt(D->getExpr());
+  Writer.AddStmt(D->getUpdateExpr());
+  Record.push_back(D->isXLHSInRHSPart() ? 1 : 0);
   Code = serialization::STMT_OMP_ATOMIC_DIRECTIVE;
 }