From 54a26c673ec382dbaa9d8d28e0993e232f7df21b Mon Sep 17 00:00:00 2001
From: Jian Li <jianlijianli@google.com>
Date: Tue, 3 Sep 2019 07:50:11 -0700
Subject: [PATCH] Bound quantized clipping properly.

PiperOrigin-RevId: 266927331
---
 tensorflow/lite/kernels/lstm.cc | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/tensorflow/lite/kernels/lstm.cc b/tensorflow/lite/kernels/lstm.cc
index 55fcf4124d2..7ace5333991 100644
--- a/tensorflow/lite/kernels/lstm.cc
+++ b/tensorflow/lite/kernels/lstm.cc
@@ -137,14 +137,15 @@ TfLiteStatus PopulateQuantizedLstmParams(
   auto* proj_params = reinterpret_cast<TfLiteAffineQuantization*>(
       output_tensor->quantization.params);
   if (cell_clip > 0.0) {
-    quantized_lstm_param->quantized_cell_clip =
-        static_cast<int16_t>(cell_clip / cell_params->scale->data[0]);
+    quantized_lstm_param->quantized_cell_clip = static_cast<int32_t>(
+        std::min(std::max(cell_clip / cell_params->scale->data[0], -32768.0f),
+                 32767.0f));
   } else {
     quantized_lstm_param->quantized_cell_clip = 0;
   }
   if (proj_clip > 0.0) {
-    quantized_lstm_param->quantized_proj_clip =
-        static_cast<int8_t>(proj_clip / proj_params->scale->data[0]);
+    quantized_lstm_param->quantized_proj_clip = static_cast<int32_t>(std::min(
+        std::max(proj_clip / proj_params->scale->data[0], -128.0f), 127.0f));
   } else {
     quantized_lstm_param->quantized_proj_clip = 0;
   }