From d1521ef40ce3e1241c8faa0dc4253e05ea45bc62 Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Tue, 15 Dec 2009 00:52:11 +0000
Subject: Fold (zext (and x, cst)) -> (and (zext x), cst).

llvm-svn: 91380
---
 llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 13 +++++++++++++
 1 file changed, 13 insertions(+)

(limited to 'llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp')

diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 52b7ed5f158..bec5241ea92 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -3202,6 +3202,19 @@ SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) {
                        X, DAG.getConstant(Mask, VT));
   }
 
+  // Fold (zext (and x, cst)) -> (and (zext x), cst)
+  if (N0.getOpcode() == ISD::AND &&
+      N0.getOperand(1).getOpcode() == ISD::Constant &&
+      N0.getOperand(0).getOpcode() != ISD::TRUNCATE &&
+      N0.getOperand(0).hasOneUse()) {
+    APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
+    Mask.zext(VT.getSizeInBits());
+    return DAG.getNode(ISD::AND, N->getDebugLoc(), VT,
+                       DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT,
+                                   N0.getOperand(0)),
+                       DAG.getConstant(Mask, VT));
+  }
+
   // fold (zext (load x)) -> (zext (truncate (zextload x)))
   if (ISD::isNON_EXTLoad(N0.getNode()) &&
       ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
-- 
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