diff --git a/src/sm3_xmss.c b/src/sm3_xmss.c
index 1a461f93..ea9b63a0 100644
--- a/src/sm3_xmss.c
+++ b/src/sm3_xmss.c
@@ -63,7 +63,7 @@ static void adrs_set_tree_index(uint8_t adrs[32], uint32_t index) {
 }
 
 static void adrs_set_key_and_mask(uint8_t adrs[32], uint8_t key_and_mask) {
-	uint32_to_bytes(key_and_mask, adrs + 4*7);
+	uint32_to_bytes((uint32_t)key_and_mask, adrs + 4*7);
 }
 
 /*
@@ -327,7 +327,7 @@ static void build_ltree(const hash256_bytes_t in_pk[67],
 	adrs_set_tree_height(adrs, tree_height++);
 
 	while (len > 1) {
-		for (i = 0; i < len/2; i++) {
+		for (i = 0; i < (uint32_t)len/2; i++) {
 			adrs_set_tree_index(adrs, i);
 			randomized_hash(pk[2 * i], pk[2 * i + 1], prf_seed_ctx, adrs, pk[i]);
 		}
@@ -382,8 +382,7 @@ void sm3_xmss_derive_root(const uint8_t xmss_secret[32], int height,
 
 	// generate all the wots pk[]
 	for (i = 0; i < (1<<height); i++) {
-		HASH256_CTX prf_ctx = prf_keygen_ctx;
-		uint8_t wots_secret[32];
+		//HASH256_CTX prf_ctx = prf_keygen_ctx;
 		hash256_bytes_t wots_sk[67];
 		hash256_bytes_t wots_pk[67];
 
@@ -612,7 +611,7 @@ int sm3_xmss_key_from_bytes(SM3_XMSS_KEY *key, const uint8_t *in, size_t inlen)
 	memcpy(key->prf_key, p, 32); p += 32;
 
 	key->index = uint32_from_bytes(p); p += 4;
-	if (key->index >= (1 << height)) {
+	if (key->index >= (uint32_t)(1 << height)) {
 		error_print();
 		return -1;
 	}
diff --git a/src/sm4_ccm.c b/src/sm4_ccm.c
index f59aee55..83e377e5 100644
--- a/src/sm4_ccm.c
+++ b/src/sm4_ccm.c
@@ -159,7 +159,7 @@ int sm4_ccm_decrypt(const SM4_KEY *sm4_key, const uint8_t *iv, size_t ivlen,
 	}
 
 	inlen_size = 15 - ivlen;
-	if (inlen_size < 8 && inlen >= (1 << (inlen_size * 8))) {
+	if (inlen_size < 8 && inlen >= (size_t)(1 << (inlen_size * 8))) {
 		error_print();
 		return -1;
 	}
@@ -181,7 +181,7 @@ int sm4_ccm_decrypt(const SM4_KEY *sm4_key, const uint8_t *iv, size_t ivlen,
 		if (aadlen < ((1<<16) - (1<<8))) {
 			length_to_bytes(aadlen, 2, block);
 			alen = 2;
-		} else if (aadlen < ((size_t)1<<32)) {
+		} else if ((uint64_t)aadlen < ((uint64_t)1<<32)) {
 			block[0] = 0xff;
 			block[1] = 0xfe;
 			length_to_bytes(aadlen, 4, block + 2);
diff --git a/src/sm9_z256.c b/src/sm9_z256.c
index e4a58472..c048eab9 100644
--- a/src/sm9_z256.c
+++ b/src/sm9_z256.c
@@ -2864,15 +2864,15 @@ void sm9_z256_fp12_line_mul(sm9_z256_fp12_t r, const sm9_z256_fp12_t a, const sm
 {
 	sm9_z256_fp4_t r0, r1, r2;
 	sm9_z256_fp2_t t;
-	
+
 	sm9_z256_fp4_t lw4;
 	sm9_z256_fp2_copy(lw4[0], lw[0]);
 	sm9_z256_fp2_copy(lw4[1], lw[2]);
-	
+
 	sm9_z256_fp4_mul(r0, a[0], lw4);
 	sm9_z256_fp4_mul(r1, a[1], lw4);
 	sm9_z256_fp4_mul(r2, a[2], lw4);
-	
+
 	sm9_z256_fp2_mul  (t, a[0][0], lw[1]);
 	sm9_z256_fp2_add  (r2[0], r2[0], t);
 	sm9_z256_fp2_mul  (t, a[0][1], lw[1]);
@@ -2885,7 +2885,7 @@ void sm9_z256_fp12_line_mul(sm9_z256_fp12_t r, const sm9_z256_fp12_t a, const sm
 	sm9_z256_fp2_add  (r1[1], r1[1], t);
 	sm9_z256_fp2_mul_u(t, a[2][1], lw[1]);
 	sm9_z256_fp2_add  (r1[0], r1[0], t);
-	
+
 	sm9_z256_fp4_copy(r[0], r0);
 	sm9_z256_fp4_copy(r[1], r1);
 	sm9_z256_fp4_copy(r[2], r2);
@@ -2898,18 +2898,18 @@ void sm9_z256_pairing(sm9_z256_fp12_t r, const SM9_Z256_TWIST_POINT *Q, const SM
 	SM9_Z256_TWIST_POINT T;
 	SM9_Z256_TWIST_POINT Q1;
 	SM9_Z256_TWIST_POINT Q2;
-	
+	SM9_Z256_AFFINE_POINT P_;
+	sm9_z256_fp2_t lw[3];
+	sm9_z256_fp2_t pre[5]; // same for Q and -Q
+	size_t i;
+
 	sm9_z256_fp2_copy(T.X, Q->X);
 	sm9_z256_fp2_copy(T.Y, Q->Y);
 	sm9_z256_fp2_copy(T.Z, Q->Z);
-	
-	SM9_Z256_AFFINE_POINT P_;
+
 	sm9_z256_point_to_affine(&P_, P);
 	sm9_z256_twist_point_neg(&Q1, Q);
-	
-	sm9_z256_fp2_t lw[3];
-	sm9_z256_fp2_t pre[5]; // same for Q and -Q
-	
+
 	sm9_z256_fp2_sqr(pre[0], Q->Y);
 	sm9_z256_fp2_mul(pre[4], Q->X, Q->Z);
 	sm9_z256_fp2_dbl(pre[4], pre[4]);
@@ -2923,7 +2923,6 @@ void sm9_z256_pairing(sm9_z256_fp12_t r, const SM9_Z256_TWIST_POINT *Q, const SM
 
 	sm9_z256_fp12_set_one(r);
 
-	int i;
 	for (i = 0; i < strlen(abits); i++) {
 		sm9_z256_fp12_sqr(r, r);
 		sm9_z256_eval_g_tangent(&T, lw, &T, &P_);
@@ -2948,7 +2947,7 @@ void sm9_z256_pairing(sm9_z256_fp12_t r, const SM9_Z256_TWIST_POINT *Q, const SM
 
 	sm9_z256_eval_g_line_no_pre(&T, lw, &T, &Q2, &P_);
 	sm9_z256_fp12_line_mul(r, r, lw);
-	
+
 	sm9_z256_final_exponent(r, r);
 }