diff --git a/include/gmssl/sm4_cl.h b/include/gmssl/sm4_cl.h
index c3a5fe64..ac73f971 100644
--- a/include/gmssl/sm4_cl.h
+++ b/include/gmssl/sm4_cl.h
@@ -1,5 +1,5 @@
 /*
- *  Copyright 2014-2022 The GmSSL Project. All Rights Reserved.
+ *  Copyright 2014-2024 The GmSSL Project. All Rights Reserved.
  *
  *  Licensed under the Apache License, Version 2.0 (the License); you may
  *  not use this file except in compliance with the License.
@@ -40,7 +40,7 @@ typedef struct {
 
 int sm4_cl_set_encrypt_key(SM4_CL_CTX *ctx, const uint8_t key[16]);
 int sm4_cl_set_decrypt_key(SM4_CL_CTX *ctx, const uint8_t key[16]);
-int sm4_cl_ctr32_encrypt(SM4_CL_CTX *ctx, uint8_t iv[16], const uint8_t *in, size_t nblocks, uint8_t *out);
+int sm4_cl_ctr32_encrypt_blocks(SM4_CL_CTX *ctx, uint8_t iv[16], const uint8_t *in, size_t nblocks, uint8_t *out);
 void sm4_cl_cleanup(SM4_CL_CTX *ctx);
 
 
diff --git a/src/sm4_cl.c b/src/sm4_cl.c
index 52ad3b52..05ade0fb 100644
--- a/src/sm4_cl.c
+++ b/src/sm4_cl.c
@@ -198,7 +198,7 @@ static int sm4_cl_set_key(SM4_CL_CTX *ctx, const uint8_t key[16], int enc)
 		free(log);
 		goto end;
 	}
-	if (!(ctx->kernel = clCreateKernel(ctx->program, "sm4_ctr32_encrypt", &err))) {
+	if (!(ctx->kernel = clCreateKernel(ctx->program, "sm4_ctr32_encrypt_blocks", &err))) {
 		cl_error_print(err);
 		goto end;
 	}
@@ -243,7 +243,7 @@ int sm4_cl_set_decrypt_key(SM4_CL_CTX *ctx, const uint8_t key[16])
 	return sm4_cl_set_key(ctx, key, 0);
 }
 
-int sm4_cl_ctr32_encrypt(SM4_CL_CTX *ctx, uint8_t iv[16], const uint8_t *in, size_t nblocks, uint8_t *out)
+int sm4_cl_ctr32_encrypt_blocks(SM4_CL_CTX *ctx, uint8_t iv[16], const uint8_t *in, size_t nblocks, uint8_t *out)
 {
 	int ret = -1;
 	cl_int err;
@@ -330,7 +330,7 @@ __constant unsigned char SBOX[256] = {
 	0x18, 0xf0, 0x7d, 0xec, 0x3a, 0xdc, 0x4d, 0x20, 0x79, 0xee, 0x5f, 0x3e, 0xd7, 0xcb, 0x39, 0x48,
 };
 
-__kernel void sm4_ctr32_encrypt(__global const unsigned int *rkey, __global const unsigned int *ctr, __global unsigned char *data)
+__kernel void sm4_ctr32_encrypt_blocks(__global const unsigned int *rkey, __global const unsigned int *ctr, __global unsigned char *data)
 {
 	unsigned int x0, x1, x2, x3, x4, i, t;
 	uint global_id = get_global_id(0);
diff --git a/tests/sm4_cltest.c b/tests/sm4_cltest.c
index af861325..2999c342 100644
--- a/tests/sm4_cltest.c
+++ b/tests/sm4_cltest.c
@@ -18,7 +18,7 @@
 #include <gmssl/error.h>
 
 
-static int test_sm4_cl_ctr32_encrypt(void)
+static int test_sm4_cl_ctr32_encrypt_blocks(void)
 {
 	const char *key_hex = "0123456789abcdeffedcba9876543210";
 	const char *iv_hex =  "0123456789abcdeffedcba9876543210";
@@ -56,7 +56,7 @@ static int test_sm4_cl_ctr32_encrypt(void)
 	}
 
 	memcpy(ctr, iv, sizeof(iv));
-	if (sm4_cl_ctr32_encrypt(&ctx, ctr, buf, nblocks, buf) != 1) {
+	if (sm4_cl_ctr32_encrypt_blocks(&ctx, ctr, buf, nblocks, buf) != 1) {
 		error_print();
 		goto end;
 	}
@@ -75,7 +75,7 @@ end:
 	return ret;
 }
 
-static int test_sm4_cl_ctr32_encrypt_speed(void)
+static int speed_sm4_cl_ctr32_encrypt_blocks(void)
 {
 	const uint8_t key[16] = {
 		0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef,
@@ -96,7 +96,7 @@ static int test_sm4_cl_ctr32_encrypt_speed(void)
 	uint8_t ctr[16];
 	size_t nblocks = 1024*1024;
 	uint8_t *buf = NULL;
-	clock_t start, end;
+	clock_t begin, end;
 	double seconds;
 	size_t i;
 
@@ -113,15 +113,15 @@ static int test_sm4_cl_ctr32_encrypt_speed(void)
 		goto end;
 	}
 
-	start = clock();
-	if (sm4_cl_ctr32_encrypt(&ctx, ctr, buf, nblocks, buf) != 1) {
+	begin = clock();
+	if (sm4_cl_ctr32_encrypt_blocks(&ctx, ctr, buf, nblocks, buf) != 1) {
 		error_print();
 		goto end;
 	}
 	end = clock();
 
-	seconds = (double)(end - start)/CLOCKS_PER_SEC;
-	fprintf(stderr, "sm4_cl_encrypt: %f-MiB per seconds\n", 16/seconds);
+	seconds = (double)(end - begin)/CLOCKS_PER_SEC;
+	fprintf(stderr, "%s: %f-MiB per seconds\n", __FUNCTION__, 16/seconds);
 
 	ret = 1;
 end:
@@ -132,8 +132,10 @@ end:
 
 int main(void)
 {
-	if (test_sm4_cl_ctr32_encrypt() != 1) goto err;
-	if (test_sm4_cl_ctr32_encrypt_speed() != 1) goto err;
+	if (test_sm4_cl_ctr32_encrypt_blocks() != 1) goto err;
+#if ENABLE_TEST_SPEED
+	if (speed_sm4_cl_ctr32_encrypt_blocks() != 1) goto err;
+#endif
 	printf("%s all tests passed\n", __FILE__);
 	return 0;
 err: