[Sema,CodeGen] Remove comment from SemaChecking about a builtin_shufflevector form that it doesn't support. Remove CodeGen support for the same form since it could never have been used due to the missing support in Sema.

I couldn't find any documentation that this form existed either. Nor is there documentation for one of the remaining two forms, but there is a testcase that uses it.

llvm-svn: 269879

2 files changed, 3 insertions, 20 deletions

diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
index 8f122963a1f..0e49ce6aaf3 100644
--- a/clang/lib/CodeGen/CGExprScalar.cpp
+++ b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -984,8 +984,7 @@ Value *ScalarExprEmitter::VisitExpr(Expr *E) {
 
 Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) {
   // Vector Mask Case
-  if (E->getNumSubExprs() == 2 ||
-      (E->getNumSubExprs() == 3 && E->getExpr(2)->getType()->isVectorType())) {
+  if (E->getNumSubExprs() == 2) {
     Value *LHS = CGF.EmitScalarExpr(E->getExpr(0));
     Value *RHS = CGF.EmitScalarExpr(E->getExpr(1));
     Value *Mask;
@@ -993,22 +992,7 @@ Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) {
     llvm::VectorType *LTy = cast<llvm::VectorType>(LHS->getType());
     unsigned LHSElts = LTy->getNumElements();
 
-    if (E->getNumSubExprs() == 3) {
-      Mask = CGF.EmitScalarExpr(E->getExpr(2));
-
-      // Shuffle LHS & RHS into one input vector.
-      SmallVector<llvm::Constant*, 32> concat;
-      for (unsigned i = 0; i != LHSElts; ++i) {
-        concat.push_back(Builder.getInt32(2*i));
-        concat.push_back(Builder.getInt32(2*i+1));
-      }
-
-      Value* CV = llvm::ConstantVector::get(concat);
-      LHS = Builder.CreateShuffleVector(LHS, RHS, CV, "concat");
-      LHSElts *= 2;
-    } else {
-      Mask = RHS;
-    }
+    Mask = RHS;
 
     llvm::VectorType *MTy = cast<llvm::VectorType>(Mask->getType());
 
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 31a20cb806a..dc91b93f202 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -3136,8 +3136,7 @@ ExprResult Sema::SemaBuiltinShuffleVector(CallExpr *TheCall) {
 
   // Determine which of the following types of shufflevector we're checking:
   // 1) unary, vector mask: (lhs, mask)
-  // 2) binary, vector mask: (lhs, rhs, mask)
-  // 3) binary, scalar mask: (lhs, rhs, index, ..., index)
+  // 2) binary, scalar mask: (lhs, rhs, index, ..., index)
   QualType resType = TheCall->getArg(0)->getType();
   unsigned numElements = 0;