Move vector bitcast handling in constant expressions from the expression

evaluator into constant initializer handling / IRGen. The practical consequence
of this is that the bitcast now lives in the constant's definition, rather than
in its uses.

The code in the constant expression evaluator was producing vectors of the wrong
type and size (and possibly of the wrong value for a big-endian int-to-vector
bitcast). We were getting away with this only because we don't yet support
constant-folding of any expressions which inspect vector values.

llvm-svn: 145981

1 files changed, 1 insertions, 31 deletions

diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 438bef5de87..6a290a6c834 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -2502,11 +2502,9 @@ static bool EvaluateVector(const Expr* E, APValue& Result, EvalInfo &Info) {
 
 bool VectorExprEvaluator::VisitCastExpr(const CastExpr* E) {
   const VectorType *VTy = E->getType()->castAs<VectorType>();
-  QualType EltTy = VTy->getElementType();
   unsigned NElts = VTy->getNumElements();
-  unsigned EltWidth = Info.Ctx.getTypeSize(EltTy);
 
-  const Expr* SE = E->getSubExpr();
+  const Expr *SE = E->getSubExpr();
   QualType SETy = SE->getType();
 
   switch (E->getCastKind()) {
@@ -2530,34 +2528,6 @@ bool VectorExprEvaluator::VisitCastExpr(const CastExpr* E) {
     SmallVector<APValue, 4> Elts(NElts, Val);
     return Success(Elts, E);
   }
-  case CK_BitCast: {
-    // FIXME: this is wrong for any cast other than a no-op cast.
-    if (SETy->isVectorType())
-      return Visit(SE);
-
-    if (!SETy->isIntegerType())
-      return Error(E);
-
-    APSInt Init;
-    if (!EvaluateInteger(SE, Init, Info))
-      return Error(E);
-
-    assert((EltTy->isIntegerType() || EltTy->isRealFloatingType()) &&
-           "Vectors must be composed of ints or floats");
-
-    SmallVector<APValue, 4> Elts;
-    for (unsigned i = 0; i != NElts; ++i) {
-      APSInt Tmp = Init.extOrTrunc(EltWidth);
-
-      if (EltTy->isIntegerType())
-        Elts.push_back(APValue(Tmp));
-      else
-        Elts.push_back(APValue(APFloat(Tmp)));
-
-      Init >>= EltWidth;
-    }
-    return Success(Elts, E);
-  }
   default:
     return ExprEvaluatorBaseTy::VisitCastExpr(E);
   }