Do not change the size of function arguments. PR 1489.

llvm-svn: 37496

1 files changed, 9 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index ac89b179e13..f97ee721515 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -3993,7 +3993,15 @@ TargetLowering::LowerCallTo(SDOperand Chain, const Type *RetTy,
         Op = DAG.getNode(ExtOp, getTypeToTransformTo(VT), Op);
       } else {
         assert(MVT::isFloatingPoint(VT) && "Not int or FP?");
-        Op = DAG.getNode(ISD::FP_EXTEND, getTypeToTransformTo(VT), Op);
+        // A true promotion would change the size of the argument.
+        // Instead, pretend this is an int.  If FP objects are not
+        // passed the same as ints, the original type should be Legal
+        // and we should not get here.
+        Op = DAG.getNode(ISD::BIT_CONVERT, 
+                         VT==MVT::f32 ? MVT::i32 :
+                         (VT==MVT::f64 ? MVT::i64 :
+                          MVT::Other),
+                         Op);
       }
       Ops.push_back(Op);
       Ops.push_back(DAG.getConstant(Flags, MVT::i32));