[OPENMP 4.1] Add codegen for 'simdlen' clause.

Add emission of metadata for simd loops in presence of 'simdlen' clause.
If 'simdlen' clause is provided without 'safelen' clause, the vectorizer width for the loop is set to value of 'simdlen' clause + all read/write ops in loop are marked with '!llvm.mem.parallel_loop_access' metadata.
If 'simdlen' clause is provided along with 'safelen' clause, the vectorizer width for the loop is set to value of 'simdlen' clause + all read/write ops in loop are not marked with '!llvm.mem.parallel_loop_access' metadata.
If 'safelen' clause is provided without 'simdlen' clause, the vectorizer width for the loop is set to value of 'safelen' clause + all read/write ops in loop are not marked with '!llvm.mem.parallel_loop_access' metadata.

llvm-svn: 245697

1 files changed, 14 insertions, 4 deletions

diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
index daa3dca7ce4..4bc5276fcdf 100644
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -739,10 +739,20 @@ emitPrivateLinearVars(CodeGenFunction &CGF, const OMPExecutableDirective &D,
   }
 }
 
-static void emitSafelenClause(CodeGenFunction &CGF,
-                              const OMPExecutableDirective &D) {
+static void emitSimdlenSafelenClause(CodeGenFunction &CGF,
+                                     const OMPExecutableDirective &D) {
   if (auto *C =
-          cast_or_null<OMPSafelenClause>(D.getSingleClause(OMPC_safelen))) {
+          cast_or_null<OMPSimdlenClause>(D.getSingleClause(OMPC_simdlen))) {
+    RValue Len = CGF.EmitAnyExpr(C->getSimdlen(), AggValueSlot::ignored(),
+                                 /*ignoreResult=*/true);
+    llvm::ConstantInt *Val = cast<llvm::ConstantInt>(Len.getScalarVal());
+    CGF.LoopStack.setVectorizeWidth(Val->getZExtValue());
+    // In presence of finite 'safelen', it may be unsafe to mark all
+    // the memory instructions parallel, because loop-carried
+    // dependences of 'safelen' iterations are possible.
+    CGF.LoopStack.setParallel(!D.getSingleClause(OMPC_safelen));
+  } else if (auto *C = cast_or_null<OMPSafelenClause>(
+                 D.getSingleClause(OMPC_safelen))) {
     RValue Len = CGF.EmitAnyExpr(C->getSafelen(), AggValueSlot::ignored(),
                                  /*ignoreResult=*/true);
     llvm::ConstantInt *Val = cast<llvm::ConstantInt>(Len.getScalarVal());
@@ -758,7 +768,7 @@ void CodeGenFunction::EmitOMPSimdInit(const OMPLoopDirective &D) {
   // Walk clauses and process safelen/lastprivate.
   LoopStack.setParallel();
   LoopStack.setVectorizeEnable(true);
-  emitSafelenClause(*this, D);
+  emitSimdlenSafelenClause(*this, D);
 }
 
 void CodeGenFunction::EmitOMPSimdFinal(const OMPLoopDirective &D) {