diff --git a/mlir/include/mlir/Dialect/Arithmetic/IR/ArithmeticOps.td b/mlir/include/mlir/Dialect/Arithmetic/IR/ArithmeticOps.td
--- a/mlir/include/mlir/Dialect/Arithmetic/IR/ArithmeticOps.td
+++ b/mlir/include/mlir/Dialect/Arithmetic/IR/ArithmeticOps.td
@@ -860,6 +860,7 @@
   }];
 
   let hasFolder = 1;
+  let hasCanonicalizer = 1;
   let verifier = [{ return verifyTruncateOp<IntegerType>(*this); }];
 }
 
diff --git a/mlir/lib/Dialect/Arithmetic/IR/ArithmeticCanonicalization.td b/mlir/lib/Dialect/Arithmetic/IR/ArithmeticCanonicalization.td
--- a/mlir/lib/Dialect/Arithmetic/IR/ArithmeticCanonicalization.td
+++ b/mlir/lib/Dialect/Arithmetic/IR/ArithmeticCanonicalization.td
@@ -106,6 +106,16 @@
           (Arith_ConstantOp ConstantAttr<I1Attr, "1">)),
         (Arith_CmpIOp (InvertPredicate $pred), $a, $b)>;
 
+def XOrIntAttrs : NativeCodeCall<"xorIntegerAttrs($_builder, $0, $1, $2)">;
+
+// xor(xor(x, c0), c1) = xor(x, xor(c1, c2))
+def XOrXOrConstant :
+    Pat<(Arith_XOrIOp:$res
+          (Arith_XOrIOp $x, (Arith_ConstantOp APIntAttr:$c0)),
+          (Arith_ConstantOp APIntAttr:$c1)
+          ),
+        (Arith_XOrIOp $x, (Arith_ConstantOp (XOrIntAttrs $res, $c0, $c1)))>;
+
 //===----------------------------------------------------------------------===//
 // IndexCastOp
 //===----------------------------------------------------------------------===//
@@ -128,4 +138,12 @@
 def BitcastOfBitcast :
     Pat<(Arith_BitcastOp (Arith_BitcastOp $x)), (replaceWithValue $x)>;
 
+//===----------------------------------------------------------------------===//
+// TruncIOp
+//===----------------------------------------------------------------------===//
+
+// trunc(trunc(x, a), b) -> trunc(x, b)
+def DoubleTruncI :
+    Pat<(Arith_TruncIOp (Arith_TruncIOp $x)), (Arith_TruncIOp $x)>;
+
 #endif // ARITHMETIC_PATTERNS
diff --git a/mlir/lib/Dialect/Arithmetic/IR/ArithmeticOps.cpp b/mlir/lib/Dialect/Arithmetic/IR/ArithmeticOps.cpp
--- a/mlir/lib/Dialect/Arithmetic/IR/ArithmeticOps.cpp
+++ b/mlir/lib/Dialect/Arithmetic/IR/ArithmeticOps.cpp
@@ -37,6 +37,13 @@
                                     rhs.cast<IntegerAttr>().getInt());
 }
 
+static IntegerAttr xorIntegerAttrs(PatternRewriter &builder, Value res,
+                                   Attribute lhs, Attribute rhs) {
+  return builder.getIntegerAttr(res.getType(),
+                                lhs.cast<IntegerAttr>().getInt() ^
+                                    rhs.cast<IntegerAttr>().getInt());
+}
+
 /// Invert an integer comparison predicate.
 static arith::CmpIPredicate invertPredicate(arith::CmpIPredicate pred) {
   switch (pred) {
@@ -536,7 +543,7 @@
 
 void arith::XOrIOp::getCanonicalizationPatterns(
     OwningRewritePatternList &patterns, MLIRContext *context) {
-  patterns.insert<XOrINotCmpI>(context);
+  patterns.insert<XOrINotCmpI, XOrXOrConstant>(context);
 }
 
 //===----------------------------------------------------------------------===//
@@ -831,6 +838,11 @@
   return checkWidthChangeCast<std::less, IntegerType>(inputs, outputs);
 }
 
+void arith::TruncIOp::getCanonicalizationPatterns(
+    OwningRewritePatternList &patterns, MLIRContext *context) {
+  patterns.insert<DoubleTruncI>(context);
+}
+
 //===----------------------------------------------------------------------===//
 // TruncFOp
 //===----------------------------------------------------------------------===//
diff --git a/mlir/test/Dialect/Arithmetic/canonicalize.mlir b/mlir/test/Dialect/Arithmetic/canonicalize.mlir
--- a/mlir/test/Dialect/Arithmetic/canonicalize.mlir
+++ b/mlir/test/Dialect/Arithmetic/canonicalize.mlir
@@ -77,6 +77,15 @@
   return %tr : i16
 }
 
+// CHECK-LABEL: @truncTrunc
+//       CHECK:   %[[cres:.+]] = arith.trunci %arg0 : i64 to i8
+//       CHECK:   return %[[cres]]
+func @truncTrunc(%arg0: i64) -> i8 {
+  %tr1 = arith.trunci %arg0 : i64 to i32
+  %tr2 = arith.trunci %tr1 : i32 to i8
+  return %tr2 : i8
+}
+
 // CHECK-LABEL: @truncFPConstant
 //       CHECK:   %[[cres:.+]] = arith.constant 1.000000e+00 : bf16
 //       CHECK:   return %[[cres]]
@@ -316,6 +325,18 @@
 
 // -----
 
+// CHECK-LABEL: @xorxor(
+//       CHECK-NOT: xori
+//       CHECK:   return %arg0
+func @xorxor(%cmp : i1) -> i1 {
+  %true = arith.constant true
+  %ncmp = arith.xori %cmp, %true : i1
+  %nncmp = arith.xori %ncmp, %true : i1
+  return %nncmp : i1
+}
+
+// -----
+
 // CHECK-LABEL: @bitcastSameType(
 // CHECK-SAME: %[[ARG:[a-zA-Z0-9_]*]]
 func @bitcastSameType(%arg : f32) -> f32 {