[cuda] Allow using integral non-type template parameters as launch_bounds attribute arguments.

 - Changed CUDALaunchBounds arguments from integers to Expr* so they can
   be saved in AST for instantiation.
 - Added support for template instantiation of launch_bounds attrubute.
 - Moved evaluation of launch_bounds arguments to NVPTXTargetCodeGenInfo::
   SetTargetAttributes() where it can be done after template instantiation.
 - Added a warning on negative launch_bounds arguments.
 - Amended test cases.

Differential Revision: http://reviews.llvm.org/D8985

llvm-svn: 235452

1 files changed, 32 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 6936539f1ca..8f2e95a6152 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -202,6 +202,31 @@ static void instantiateDependentEnableIfAttr(
   New->addAttr(EIA);
 }
 
+// Constructs and adds to New a new instance of CUDALaunchBoundsAttr using
+// template A as the base and arguments from TemplateArgs.
+static void instantiateDependentCUDALaunchBoundsAttr(
+    Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
+    const CUDALaunchBoundsAttr &Attr, Decl *New) {
+  // The alignment expression is a constant expression.
+  EnterExpressionEvaluationContext Unevaluated(S, Sema::ConstantEvaluated);
+
+  ExprResult Result = S.SubstExpr(Attr.getMaxThreads(), TemplateArgs);
+  if (Result.isInvalid())
+    return;
+  Expr *MaxThreads = Result.getAs<Expr>();
+
+  Expr *MinBlocks = nullptr;
+  if (Attr.getMinBlocks()) {
+    Result = S.SubstExpr(Attr.getMinBlocks(), TemplateArgs);
+    if (Result.isInvalid())
+      return;
+    MinBlocks = Result.getAs<Expr>();
+  }
+
+  S.AddLaunchBoundsAttr(Attr.getLocation(), New, MaxThreads, MinBlocks,
+                        Attr.getSpellingListIndex());
+}
+
 void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
                             const Decl *Tmpl, Decl *New,
                             LateInstantiatedAttrVec *LateAttrs,
@@ -233,6 +258,13 @@ void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
       continue;
     }
 
+    if (const CUDALaunchBoundsAttr *CUDALaunchBounds =
+            dyn_cast<CUDALaunchBoundsAttr>(TmplAttr)) {
+      instantiateDependentCUDALaunchBoundsAttr(*this, TemplateArgs,
+                                               *CUDALaunchBounds, New);
+      continue;
+    }
+
     // Existing DLL attribute on the instantiation takes precedence.
     if (TmplAttr->getKind() == attr::DLLExport ||
         TmplAttr->getKind() == attr::DLLImport) {