Generalize BuildVectorSDNode::isConstantSplat to use APInts and handle

arbitrary vector sizes.  Add an optional MinSplatBits parameter to specify
a minimum for the splat element size.  Update the PPC target to use the
revised interface.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65899 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 12 insertions, 7 deletions

diff --git a/include/llvm/CodeGen/SelectionDAGNodes.h b/include/llvm/CodeGen/SelectionDAGNodes.h
index b10c865..e945b98 100644
--- a/include/llvm/CodeGen/SelectionDAGNodes.h
+++ b/include/llvm/CodeGen/SelectionDAGNodes.h
@@ -1933,13 +1933,18 @@ public:
 /// BUILD_VECTORs.
 class BuildVectorSDNode : public SDNode {
 public:
-  /// isConstantSplat - check if this is a constant splat, and if so, return
-  /// the splat element value in SplatBits.  Any undefined bits in that value
-  /// are set to zero, and the corresponding bits in the SplatUndef mask are
-  /// set.  The SplatSize value is set to the splat element size in bytes.
-  /// HasAnyUndefs is set to true if any bits in the vector are undefined.
-  bool isConstantSplat(unsigned &SplatBits, unsigned &SplatUndef,
-                       unsigned &SplatSize, bool &HasAnyUndefs);
+  /// isConstantSplat - Check if this is a constant splat, and if so, find the
+  /// smallest element size that splats the vector.  If MinSplatBits is
+  /// nonzero, the element size must be at least that large.  Note that the
+  /// splat element may be the entire vector (i.e., a one element vector).
+  /// Returns the splat element value in SplatValue.  Any undefined bits in
+  /// that value are zero, and the corresponding bits in the SplatUndef mask
+  /// are set.  The SplatBitSize value is set to the splat element size in
+  /// bits.  HasAnyUndefs is set to true if any bits in the vector are
+  /// undefined.
+  bool isConstantSplat(APInt &SplatValue, APInt &SplatUndef,
+                       unsigned &SplatBitSize, bool &HasAnyUndefs,
+                       unsigned MinSplatBits = 0);
 
   static inline bool classof(const BuildVectorSDNode *) { return true; }
   static inline bool classof(const SDNode *N) {