Don't try to make BUILD_VECTOR operands have the same

type as the vector element type: allow them to be of
a wider integer type than the element type all the way
through the system, and not just as far as LegalizeDAG.
This should be safe because it used to be this way
(the old type legalizer would produce such nodes), so
backends should be able to handle it.  In fact only
targets which have legal vector types with an illegal
promoted element type will ever see this (eg: <4 x i16>
on ppc).  This fixes a regression with the new type
legalizer (vec_splat.ll).  Also, treat SCALAR_TO_VECTOR
the same as BUILD_VECTOR.  After all, it is just a
special case of BUILD_VECTOR.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69467 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 1 deletions

diff --git a/include/llvm/CodeGen/SelectionDAGNodes.h b/include/llvm/CodeGen/SelectionDAGNodes.h
index 3ae26fd..5670668 100644
--- a/include/llvm/CodeGen/SelectionDAGNodes.h
+++ b/include/llvm/CodeGen/SelectionDAGNodes.h
@@ -328,7 +328,10 @@ namespace ISD {
 
     /// SCALAR_TO_VECTOR(VAL) - This represents the operation of loading a
     /// scalar value into element 0 of the resultant vector type.  The top
-    /// elements 1 to N-1 of the N-element vector are undefined.
+    /// elements 1 to N-1 of the N-element vector are undefined.  The type
+    /// of the operand must match the vector element type, except when they
+    /// are integer types.  In this case the operand is allowed to be wider
+    /// than the vector element type, and is implicitly truncated to it.
     SCALAR_TO_VECTOR,
 
     // MULHU/MULHS - Multiply high - Multiply two integers of type iN, producing