Add Tensor equality API.

Summary: #8366

Reviewed By: mergennachin

Differential Revision: D71910685

Author: shoumikhin

extension/apple/ExecuTorch/Exported/ExecuTorchTensor.h

@@ -200,6 +200,14 @@ __attribute__((deprecated("This API is experimental.")))
                 error:(NSError **)error
     NS_SWIFT_NAME(resize(to:));
 
+/**
+ * Determines whether the current tensor is equal to another tensor.
+ *
+ * @param other Another ExecuTorchTensor instance to compare against.
+ * @return YES if the tensors have the same type, shape, strides, and data; otherwise, NO.
+ */
+- (BOOL)isEqualToTensor:(nullable ExecuTorchTensor *)other;
+
 + (instancetype)new NS_UNAVAILABLE;
 - (instancetype)init NS_UNAVAILABLE;
 

extension/apple/ExecuTorch/Exported/ExecuTorchTensor.mm

@@ -128,6 +128,32 @@ - (BOOL)resizeToShape:(NSArray<NSNumber *> *)shape
   return YES;
 }
 
+- (BOOL)isEqualToTensor:(nullable ExecuTorchTensor *)other {
+  if (!other) {
+    return NO;
+  }
+  const auto *data = _tensor->unsafeGetTensorImpl()->data();
+  const auto *otherData = other->_tensor->unsafeGetTensorImpl()->data();
+  const auto size = self.count * ExecuTorchSizeOfDataType(self.dataType);
+  return self.dataType == other.dataType &&
+         self.count == other.count &&
+         [self.shape isEqual:other.shape] &&
+         [self.dimensionOrder isEqual:other.dimensionOrder] &&
+         [self.strides isEqual:other.strides] &&
+         self.shapeDynamism == other.shapeDynamism &&
+         (data && otherData ? std::memcmp(data, otherData, size) == 0 : data == otherData);
+}
+
+- (BOOL)isEqual:(nullable id)other {
+  if (self == other) {
+    return YES;
+  }
+  if (![other isKindOfClass:[ExecuTorchTensor class]]) {
+    return NO;
+  }
+  return [self isEqualToTensor:(ExecuTorchTensor *)other];
+}
+
 @end
 
 @implementation ExecuTorchTensor (BytesNoCopy)

extension/apple/ExecuTorch/__tests__/TensorTest.swift

@@ -190,4 +190,27 @@ class TensorTest: XCTestCase {
     }
     XCTAssertThrowsError(try tensor.resize(to: [2, 3]))
   }
+
+  func testIsEqual() {
+    var data: [Float] = [1.0, 2.0, 3.0, 4.0]
+    let tensor1 = data.withUnsafeMutableBytes {
+      Tensor(bytesNoCopy: $0.baseAddress!, shape: [2, 2], dataType: .float)
+    }
+    let tensor2 = Tensor(tensor1)
+    XCTAssertTrue(tensor1.isEqual(tensor2))
+    XCTAssertTrue(tensor2.isEqual(tensor1))
+
+    var dataModified: [Float] = [1.0, 2.0, 3.0, 5.0]
+    let tensor3 = dataModified.withUnsafeMutableBytes {
+      Tensor(bytesNoCopy: $0.baseAddress!, shape: [2, 2], dataType: .float)
+    }
+    XCTAssertFalse(tensor1.isEqual(tensor3))
+    let tensor4 = data.withUnsafeMutableBytes {
+      Tensor(bytesNoCopy: $0.baseAddress!, shape: [4, 1], dataType: .float)
+    }
+    XCTAssertFalse(tensor1.isEqual(tensor4))
+    XCTAssertTrue(tensor1.isEqual(tensor1))
+    XCTAssertFalse(tensor1.isEqual(NSString(string: "Not a tensor")))
+    XCTAssertFalse(tensor4.isEqual(tensor2.copy()))
+  }
 }