[SelectionDAG] Add a helper function for creating a boolean constant based on the target's boolean content

Many in SimplifySetCC and FoldSetCC try to create true or false constants. Some of them query getBooleanContents to figure out whether to use all ones or just 1 for true. But many places do not check and just use 1 without ensuring the VT has an i1 scalar type. Note sure if those places only trigger before type legalization so they only see an i1
type?

To cleanup the inconsistency and reduce some duplicated code, this patch adds a getBoolConstant method to SelectionDAG that takes are of querying getBooleanContents and doing the right thing.

Differential Revision: https://reviews.llvm.org/D43037

llvm-svn: 324634

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/include/llvm/CodeGen/SelectionDAG.h b/llvm/include/llvm/CodeGen/SelectionDAG.h
index 28a34597401..cf8618b76e2 100644
--- a/llvm/include/llvm/CodeGen/SelectionDAG.h
+++ b/llvm/include/llvm/CodeGen/SelectionDAG.h
@@ -570,6 +570,10 @@ public:
                             bool isOpaque = false) {
     return getConstant(Val, DL, VT, true, isOpaque);
   }
+
+  /// \brief Create a true or false constant of type \p VT using the target's
+  /// BooleanContent for type \p OpVT.
+  SDValue getBoolConstant(bool V, const SDLoc &DL, EVT VT, EVT OpVT);
   /// @}
 
   /// \brief Create a ConstantFPSDNode wrapping a constant value.