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

1 files changed, 9 insertions, 0 deletions

diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp
index ee328e2351a..d527fcd382d 100644
--- a/clang/lib/Serialization/ASTWriterStmt.cpp
+++ b/clang/lib/Serialization/ASTWriterStmt.cpp
@@ -794,6 +794,15 @@ void ASTStmtWriter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) {
   Code = serialization::EXPR_SHUFFLE_VECTOR;
 }
 
+void ASTStmtWriter::VisitConvertVectorExpr(ConvertVectorExpr *E) {
+  VisitExpr(E);
+  Writer.AddSourceLocation(E->getBuiltinLoc(), Record);
+  Writer.AddSourceLocation(E->getRParenLoc(), Record);
+  Writer.AddTypeSourceInfo(E->getTypeSourceInfo(), Record);
+  Writer.AddStmt(E->getSrcExpr());
+  Code = serialization::EXPR_CONVERT_VECTOR;
+}
+
 void ASTStmtWriter::VisitBlockExpr(BlockExpr *E) {
   VisitExpr(E);
   Writer.AddDeclRef(E->getBlockDecl(), Record);