add flag (#7934)

FEATURE

Author: Linchenn

tfjs-backend-webgl/src/flags_webgl.ts

@@ -89,6 +89,9 @@ ENV.registerFlag('WEBGL_LAZILY_UNPACK', () => ENV.getBool('WEBGL_PACK'));
 /** Whether we will use the im2col algorithm to speed up convolutions. */
 ENV.registerFlag('WEBGL_CONV_IM2COL', () => ENV.getBool('WEBGL_PACK'));
 
+/** Whether we will pack conv2dTranspose op. */
+ENV.registerFlag('WEBGL_PACK_CONV2DTRANSPOSE', () => ENV.getBool('WEBGL_PACK'));
+
 /** The maximum texture dimension. */
 ENV.registerFlag(
     'WEBGL_MAX_TEXTURE_SIZE',

tfjs-backend-webgl/src/kernels/Conv2DBackpropInput.ts

@@ -35,7 +35,8 @@ export function conv2DBackpropInput(args: {
       inputShape, filter.shape as [number, number, number, number], strides,
       1 /* dilations */, pad, dimRoundingMode, false, $dataFormat);
 
-  if (env().getBool('WEBGL_PACK') && $dataFormat === 'channelsLast') {
+  if (env().getBool('WEBGL_PACK_CONV2DTRANSPOSE') &&
+      $dataFormat === 'channelsLast') {
     const customValues = [
       [convInfo.strideHeight, convInfo.strideWidth],
     ];