From: Craig Topper <craig.topper@gmail.com>
Date: Tue, 10 Jan 2017 07:42:57 +0000 (+0000)
Subject: [DAGCombiner] Merge together duplicate checks for folding fold (select C, 1, X) ... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=7b6c6fbcbbcd0ab113a0c6ce333eac0b378209cb;p=llvm

[DAGCombiner] Merge together duplicate checks for folding fold (select C, 1, X) -> (or C, X)  and  folding (select C, X, 0) -> (and C, X). Also be consistent about checking that both the condition and the result type are i1. NFC

I guess previously we just assumed if the result type was i1, then the condition type must also be i1?

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291548 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 5a30c85ec8c..4b0ce6f27e7 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -5361,8 +5361,9 @@ SDValue DAGCombiner::visitSELECT(SDNode *N) {
     // fold (select false, X, Y) -> Y
     return !N0C->isNullValue() ? N1 : N2;
   }
-  // fold (select C, 1, X) -> (or C, X)
-  if (VT == MVT::i1 && isOneConstant(N1))
+  // fold (select X, X, Y) -> (or X, Y)
+  // fold (select X, 1, Y) -> (or C, Y)
+  if (VT == VT0 && VT == MVT::i1 && (N0 == N1 || isOneConstant(N1)))
     return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N2);
 
   if (SDValue V = foldSelectOfConstants(N))
@@ -5380,16 +5381,9 @@ SDValue DAGCombiner::visitSELECT(SDNode *N) {
     AddToWorklist(NOTNode.getNode());
     return DAG.getNode(ISD::OR, SDLoc(N), VT, NOTNode, N1);
   }
-  // fold (select C, X, 0) -> (and C, X)
-  if (VT == MVT::i1 && isNullConstant(N2))
-    return DAG.getNode(ISD::AND, SDLoc(N), VT, N0, N1);
-  // fold (select X, X, Y) -> (or X, Y)
-  // fold (select X, 1, Y) -> (or X, Y)
-  if (VT == MVT::i1 && (N0 == N1 || isOneConstant(N1)))
-    return DAG.getNode(ISD::OR, SDLoc(N), VT, N0, N2);
   // fold (select X, Y, X) -> (and X, Y)
   // fold (select X, Y, 0) -> (and X, Y)
-  if (VT == MVT::i1 && (N0 == N2 || isNullConstant(N2)))
+  if (VT == VT0 && VT == MVT::i1 && (N0 == N2 || isNullConstant(N2)))
     return DAG.getNode(ISD::AND, SDLoc(N), VT, N0, N1);
 
   // If we can fold this based on the true/false value, do so.