constraint input value to [-127, +127] (#1258)

* constraint input value to [-127, +127]

* keep new line at the end

src/layer/arm/convolution_1x1_int8.h

@@ -19,7 +19,7 @@ static inline signed char float2int8(float v)
 {
     int int32 = round(v);
     if (int32 > 127) return 127;
-    if (int32 < -128) return -128;
+    if (int32 < -127) return -127;
     return (signed char)int32;
 }
 

src/layer/arm/convolutiondepthwise_3x3_int8.h

@@ -16,7 +16,7 @@ static inline signed char float2int8(float v)
 {
     int int32 = round(v);
     if (int32 > 127) return 127;
-    if (int32 < -128) return -128;
+    if (int32 < -127) return -127;
     return (signed char)int32;
 }
 

src/layer/arm/quantize_arm.cpp

@@ -25,7 +25,7 @@ static inline signed char float2int8(float v)
 {
     int int32 = round(v);
     if (int32 > 127) return 127;
-    if (int32 < -128) return -128;
+    if (int32 < -127) return -127;
     return (signed char)int32;
 }
 

src/layer/arm/requantize_arm.cpp

@@ -28,7 +28,7 @@ static inline signed char float2int8(float v)
 {
     int int32 = round(v);
     if (int32 > 127) return 127;
-    if (int32 < -128) return -128;
+    if (int32 < -127) return -127;
     return (signed char)int32;
 }
 

src/layer/quantize.cpp

@@ -37,7 +37,7 @@ static inline signed char float2int8(float v)
 {
     int int32 = round(v);
     if (int32 > 127) return 127;
-    if (int32 < -128) return -128;
+    if (int32 < -127) return -127;
     return (signed char)int32;
 }
 

src/layer/requantize.cpp

@@ -31,7 +31,7 @@ static inline signed char float2int8(float v)
 {
     int int32 = round(v);
     if (int32 > 127) return 127;
-    if (int32 < -128) return -128;
+    if (int32 < -127) return -127;
     return (signed char)int32;
 }
 

src/layer/x86/convolution_sgemm_int8.h

@@ -16,7 +16,7 @@ static inline signed char float2int8(float v)
 {
     int int32 = round(v);
     if (int32 > 127) return 127;
-    if (int32 < -128) return -128;
+    if (int32 < -127) return -127;
     return (signed char)int32;
 }
 

src/layer/x86/convolutiondepthwise_3x3_int8.h

@@ -16,7 +16,7 @@ static inline signed char float2int8(float v)
 {
     int int32 = round(v);
     if (int32 > 127) return 127;
-    if (int32 < -128) return -128;
+    if (int32 < -127) return -127;
     return (signed char)int32;
 }
 

tools/caffe/caffe2ncnn.cpp

@@ -108,8 +108,8 @@ static signed char float2int8(float value)
 
     if (tmp > 127)
         return 127;
-    if (tmp < -128)
-        return -128;
+    if (tmp < -127)
+        return -127;
 
     return tmp;
 }