Add the intrinsic __builtin_convertvector

LLVM supports applying conversion instructions to vectors of the same number of
elements (fptrunc, fptosi, etc.) but there had been no way for a Clang user to
cause such instructions to be generated when using builtin vector types.

C-style casting on vectors is already defined in terms of bitcasts, and so
cannot be used for these conversions as well (without leading to a very
confusing set of semantics). As a result, this adds a __builtin_convertvector
intrinsic (patterned after the OpenCL __builtin_astype intrinsic). This is
intended to aid the creation of vector intrinsic headers that create generic IR
instead of target-dependent intrinsics (in other words, this is a generic
_mm_cvtepi32_ps). As noted in the documentation, the action of
__builtin_convertvector is defined in terms of the action of a C-style cast on
each vector element.

llvm-svn: 190915

6 files changed, 16 insertions, 0 deletions

diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index ea91fbec4f8..a3a36da65f4 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -2843,6 +2843,7 @@ bool Expr::HasSideEffects(const ASTContext &Ctx) const {
   case SubstNonTypeTemplateParmExprClass:
   case MaterializeTemporaryExprClass:
   case ShuffleVectorExprClass:
+  case ConvertVectorExprClass:
   case AsTypeExprClass:
     // These have a side-effect if any subexpression does.
     break;
diff --git a/clang/lib/AST/ExprClassification.cpp b/clang/lib/AST/ExprClassification.cpp
index 1c91af7d47f..4640d7d37d6 100644
--- a/clang/lib/AST/ExprClassification.cpp
+++ b/clang/lib/AST/ExprClassification.cpp
@@ -155,6 +155,7 @@ static Cl::Kinds ClassifyInternal(ASTContext &Ctx, const Expr *E) {
   case Expr::OffsetOfExprClass:
   case Expr::CXXThrowExprClass:
   case Expr::ShuffleVectorExprClass:
+  case Expr::ConvertVectorExprClass:
   case Expr::IntegerLiteralClass:
   case Expr::CharacterLiteralClass:
   case Expr::AddrLabelExprClass:
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 8ca33cbd20c..0fb6d427610 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -8145,6 +8145,7 @@ static ICEDiag CheckICE(const Expr* E, const ASTContext &Ctx) {
   case Expr::ObjCSubscriptRefExprClass:
   case Expr::ObjCIsaExprClass:
   case Expr::ShuffleVectorExprClass:
+  case Expr::ConvertVectorExprClass:
   case Expr::BlockExprClass:
   case Expr::NoStmtClass:
   case Expr::OpaqueValueExprClass:
diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
index a87bf1123e8..3b32bdfb2ba 100644
--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
@@ -2603,6 +2603,7 @@ recurse:
   case Expr::OffsetOfExprClass:
   case Expr::PredefinedExprClass:
   case Expr::ShuffleVectorExprClass:
+  case Expr::ConvertVectorExprClass:
   case Expr::StmtExprClass:
   case Expr::UnaryTypeTraitExprClass:
   case Expr::BinaryTypeTraitExprClass:
diff --git a/clang/lib/AST/StmtPrinter.cpp b/clang/lib/AST/StmtPrinter.cpp
index 98b56bcbc7c..ee3852a3e98 100644
--- a/clang/lib/AST/StmtPrinter.cpp
+++ b/clang/lib/AST/StmtPrinter.cpp
@@ -1088,6 +1088,14 @@ void StmtPrinter::VisitShuffleVectorExpr(ShuffleVectorExpr *Node) {
   OS << ")";
 }
 
+void StmtPrinter::VisitConvertVectorExpr(ConvertVectorExpr *Node) {
+  OS << "__builtin_convertvector(";
+  PrintExpr(Node->getSrcExpr());
+  OS << ", ";
+  Node->getType().print(OS, Policy);
+  OS << ")";
+}
+
 void StmtPrinter::VisitInitListExpr(InitListExpr* Node) {
   if (Node->getSyntacticForm()) {
     Visit(Node->getSyntacticForm());
diff --git a/clang/lib/AST/StmtProfile.cpp b/clang/lib/AST/StmtProfile.cpp
index 77c34c41aaf..9591127b8af 100644
--- a/clang/lib/AST/StmtProfile.cpp
+++ b/clang/lib/AST/StmtProfile.cpp
@@ -454,6 +454,10 @@ void StmtProfiler::VisitShuffleVectorExpr(const ShuffleVectorExpr *S) {
   VisitExpr(S);
 }
 
+void StmtProfiler::VisitConvertVectorExpr(const ConvertVectorExpr *S) {
+  VisitExpr(S);
+}
+
 void StmtProfiler::VisitChooseExpr(const ChooseExpr *S) {
   VisitExpr(S);
 }