diff --git a/src/activation_kernels.cu b/src/activation_kernels.cu
index b82fefad..29154824 100644
--- a/src/activation_kernels.cu
+++ b/src/activation_kernels.cu
@@ -28,26 +28,26 @@ __device__ float hardtan_activate_kernel(float x)
     return x;
 }
 __device__ float linear_activate_kernel(float x){return x;}
-__device__ float logistic_activate_kernel(float x){return 1./(1. + exp(-x));}
-__device__ float loggy_activate_kernel(float x){return 2./(1. + exp(-x)) - 1;}
+__device__ float logistic_activate_kernel(float x){return 1.f/(1.f + expf(-x));}
+__device__ float loggy_activate_kernel(float x){return 2.f/(1.f + expf(-x)) - 1;}
 __device__ float relu_activate_kernel(float x){return x*(x>0);}
-__device__ float elu_activate_kernel(float x){return (x >= 0)*x + (x < 0)*(exp(x)-1);}
+__device__ float elu_activate_kernel(float x){return (x >= 0)*x + (x < 0)*(expf(x)-1);}
 __device__ float selu_activate_kernel(float x) { return (x >= 0)*1.0507f*x + (x < 0)*1.0507f*1.6732f*(expf(x) - 1); }
-__device__ float relie_activate_kernel(float x){return (x>0) ? x : .01*x;}
-__device__ float ramp_activate_kernel(float x){return x*(x>0)+.1*x;}
-__device__ float leaky_activate_kernel(float x){return (x>0) ? x : .1*x;}
-__device__ float tanh_activate_kernel(float x){return (2/(1 + exp(-2*x)) - 1);}
+__device__ float relie_activate_kernel(float x){return (x>0) ? x : .01f*x;}
+__device__ float ramp_activate_kernel(float x){return x*(x>0)+.1f*x;}
+__device__ float leaky_activate_kernel(float x){return (x>0) ? x : .1f*x;}
+__device__ float tanh_activate_kernel(float x){return (2/(1 + expf(-2*x)) - 1);}
 __device__ float plse_activate_kernel(float x)
 {
-    if(x < -4) return .01 * (x + 4);
-    if(x > 4)  return .01 * (x - 4) + 1;
-    return .125*x + .5;
+    if(x < -4) return .01f * (x + 4);
+    if(x > 4)  return .01f * (x - 4) + 1;
+    return .125f*x + .5f;
 }
 __device__ float stair_activate_kernel(float x)
 {
-    int n = floor(x);
-    if (n%2 == 0) return floor(x/2.);
-    else return (x - n) + floor(x/2.);
+    int n = floorf(x);
+    if (n%2 == 0) return floorf(x/2.f);
+    else return (x - n) + floorf(x/2.f);
 }
 
 
@@ -60,17 +60,17 @@ __device__ float linear_gradient_kernel(float x){return 1;}
 __device__ float logistic_gradient_kernel(float x){return (1-x)*x;}
 __device__ float loggy_gradient_kernel(float x)
 {
-    float y = (x+1.)/2.;
+    float y = (x+1.F)/2.F;
     return 2*(1-y)*y;
 }
 __device__ float relu_gradient_kernel(float x){return (x>0);}
 __device__ float elu_gradient_kernel(float x){return (x >= 0) + (x < 0)*(x + 1);}
-__device__ float selu_gradient_kernel(float x) { return (x >= 0)*1.0507 + (x < 0)*(x + 1.0507*1.6732); }
-__device__ float relie_gradient_kernel(float x){return (x>0) ? 1 : .01;}
-__device__ float ramp_gradient_kernel(float x){return (x>0)+.1;}
-__device__ float leaky_gradient_kernel(float x){return (x>0) ? 1 : .1;}
+__device__ float selu_gradient_kernel(float x) { return (x >= 0)*1.0507f + (x < 0)*(x + 1.0507f*1.6732f); }
+__device__ float relie_gradient_kernel(float x){return (x>0) ? 1 : .01f;}
+__device__ float ramp_gradient_kernel(float x){return (x>0)+.1f;}
+__device__ float leaky_gradient_kernel(float x){return (x>0) ? 1 : .1f;}
 __device__ float tanh_gradient_kernel(float x){return 1-x*x;}
-__device__ float plse_gradient_kernel(float x){return (x < 0 || x > 1) ? .01 : .125;}
+__device__ float plse_gradient_kernel(float x){return (x < 0 || x > 1) ? .01f : .125f;}
 __device__ float stair_gradient_kernel(float x)
 {
     if (floor(x) == x) return 0;
diff --git a/src/activations.h b/src/activations.h
index 90930d44..442f15a2 100644
--- a/src/activations.h
+++ b/src/activations.h
@@ -22,9 +22,9 @@ void gradient_array_ongpu(float *x, int n, ACTIVATION a, float *delta);
 
 static inline float stair_activate(float x)
 {
-    int n = floor(x);
-    if (n%2 == 0) return floor(x/2.);
-    else return (x - n) + floor(x/2.);
+    int n = floorf(x);
+    if (n%2 == 0) return floorf(x/2.f);
+    else return (x - n) + floorf(x/2.f);
 }
 static inline float hardtan_activate(float x)
 {
@@ -33,32 +33,32 @@ static inline float hardtan_activate(float x)
     return x;
 }
 static inline float linear_activate(float x){return x;}
-static inline float logistic_activate(float x){return 1./(1. + exp(-x));}
-static inline float loggy_activate(float x){return 2./(1. + exp(-x)) - 1;}
+static inline float logistic_activate(float x){return 1.f/(1.f + expf(-x));}
+static inline float loggy_activate(float x){return 2.f/(1.f + expf(-x)) - 1;}
 static inline float relu_activate(float x){return x*(x>0);}
-static inline float elu_activate(float x){return (x >= 0)*x + (x < 0)*(exp(x)-1);}
-static inline float selu_activate(float x) { return (x >= 0)*1.0507*x + (x < 0)*1.0507*1.6732*(exp(x) - 1); }
-static inline float relie_activate(float x){return (x>0) ? x : .01*x;}
-static inline float ramp_activate(float x){return x*(x>0)+.1*x;}
-static inline float leaky_activate(float x){return (x>0) ? x : .1*x;}
-static inline float tanh_activate(float x){return (exp(2*x)-1)/(exp(2*x)+1);}
+static inline float elu_activate(float x){return (x >= 0)*x + (x < 0)*(expf(x)-1);}
+static inline float selu_activate(float x) { return (x >= 0)*1.0507f*x + (x < 0)*1.0507f*1.6732f*(expf(x) - 1); }
+static inline float relie_activate(float x){return (x>0) ? x : .01f*x;}
+static inline float ramp_activate(float x){return x*(x>0)+.1f*x;}
+static inline float leaky_activate(float x){return (x>0) ? x : .1f*x;}
+static inline float tanh_activate(float x){return (expf(2*x)-1)/(expf(2*x)+1);}
 static inline float plse_activate(float x)
 {
-    if(x < -4) return .01 * (x + 4);
-    if(x > 4)  return .01 * (x - 4) + 1;
-    return .125*x + .5;
+    if(x < -4) return .01f * (x + 4);
+    if(x > 4)  return .01f * (x - 4) + 1;
+    return .125f*x + .5f;
 }
 
 static inline float lhtan_activate(float x)
 {
-    if(x < 0) return .001*x;
-    if(x > 1) return .001*(x-1) + 1;
+    if(x < 0) return .001f*x;
+    if(x > 1) return .001f*(x-1) + 1;
     return x;
 }
 static inline float lhtan_gradient(float x)
 {
     if(x > 0 && x < 1) return 1;
-    return .001;
+    return .001f;
 }
 
 static inline float hardtan_gradient(float x)
@@ -70,7 +70,7 @@ static inline float linear_gradient(float x){return 1;}
 static inline float logistic_gradient(float x){return (1-x)*x;}
 static inline float loggy_gradient(float x)
 {
-    float y = (x+1.)/2.;
+    float y = (x+1.f)/2.f;
     return 2*(1-y)*y;
 }
 static inline float stair_gradient(float x)
@@ -80,12 +80,12 @@ static inline float stair_gradient(float x)
 }
 static inline float relu_gradient(float x){return (x>0);}
 static inline float elu_gradient(float x){return (x >= 0) + (x < 0)*(x + 1);}
-static inline float selu_gradient(float x) { return (x >= 0)*1.0507 + (x < 0)*(x + 1.0507*1.6732); }
-static inline float relie_gradient(float x){return (x>0) ? 1 : .01;}
-static inline float ramp_gradient(float x){return (x>0)+.1;}
-static inline float leaky_gradient(float x){return (x>0) ? 1 : .1;}
+static inline float selu_gradient(float x) { return (x >= 0)*1.0507 + (x < 0)*(x + 1.0507f*1.6732f); }
+static inline float relie_gradient(float x){return (x>0) ? 1 : .01f;}
+static inline float ramp_gradient(float x){return (x>0)+.1f;}
+static inline float leaky_gradient(float x){return (x>0) ? 1 : .1f;}
 static inline float tanh_gradient(float x){return 1-x*x;}
-static inline float plse_gradient(float x){return (x < 0 || x > 1) ? .01 : .125;}
+static inline float plse_gradient(float x){return (x < 0 || x > 1) ? .01f : .125f;}
 
 #endif
 
diff --git a/src/cuda.c b/src/cuda.c
index 77f4dd71..a8ba37fa 100644
--- a/src/cuda.c
+++ b/src/cuda.c
@@ -54,7 +54,7 @@ void check_error(cudaError_t status)
     }
 }
 
-void check_error_extended(cudaError_t status, char *file, int line, char *date_time)
+void check_error_extended(cudaError_t status, const char *file, int line, const char *date_time)
 {
     if (status != cudaSuccess)
         printf("CUDA Error: file: %s() : line: %d : build time: %s \n", file, line, date_time);
@@ -165,7 +165,7 @@ void cudnn_check_error(cudnnStatus_t status)
     }
 }
 
-void cudnn_check_error_extended(cudnnStatus_t status, char *file, int line, char *date_time)
+void cudnn_check_error_extended(cudnnStatus_t status, const char *file, int line, const char *date_time)
 {
     if (status != cudaSuccess)
         printf("\n cuDNN Error in: file: %s() : line: %d : build time: %s \n", file, line, date_time);
diff --git a/src/cuda.h b/src/cuda.h
index ecc83e40..34f68eba 100644
--- a/src/cuda.h
+++ b/src/cuda.h
@@ -44,7 +44,7 @@ extern int gpu_index;
 extern "C" {
 #endif // __cplusplus
     void check_error(cudaError_t status);
-    void check_error_extended(cudaError_t status, char *file, int line, char *date_time);
+    void check_error_extended(cudaError_t status, const char *file, int line, const char *date_time);
 #define CHECK_CUDA(X) check_error_extended(X, __FILE__ " : " __FUNCTION__, __LINE__,  __DATE__ " - " __TIME__ );
 
     cublasHandle_t blas_handle();
@@ -70,7 +70,7 @@ extern "C" {
 cudnnHandle_t cudnn_handle();
 enum {cudnn_fastest, cudnn_smallest};
 
-void cudnn_check_error_extended(cudnnStatus_t status, char *file, int line, char *date_time);
+void cudnn_check_error_extended(cudnnStatus_t status, const char *file, int line, const char *date_time);
 #define CHECK_CUDNN(X) cudnn_check_error_extended(X, __FILE__ " : " __FUNCTION__, __LINE__,  __DATE__ " - " __TIME__ );
 #endif
 
diff --git a/src/parser.c b/src/parser.c
index b2101703..671ed764 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -848,7 +848,7 @@ network parse_network_cfg_custom(char *filename, int batch, int time_steps)
     free_list(sections);
     net.outputs = get_network_output_size(net);
     net.output = get_network_output(net);
-    printf("Total BFLOPS %5.3f \n", bflops);
+    fprintf(stderr, "Total BFLOPS %5.3f \n", bflops);
 #ifdef GPU
     get_cuda_stream();
     get_cuda_memcpy_stream();
@@ -870,7 +870,7 @@ network parse_network_cfg_custom(char *filename, int batch, int time_steps)
             check_error(cudaMalloc((void **)net.output16_gpu, *net.max_output16_size * sizeof(short))); //sizeof(half)
         }
         if (workspace_size) {
-            printf(" Allocate additional workspace_size = %1.2f MB \n", (float)workspace_size/1000000);
+            fprintf(stderr, " Allocate additional workspace_size = %1.2f MB \n", (float)workspace_size/1000000);
             net.workspace = cuda_make_array(0, workspace_size / sizeof(float) + 1);
         }
         else {