diff --git a/configure.ac b/configure.ac
index 77eaa724e..788b69a81 100644
--- a/configure.ac
+++ b/configure.ac
@@ -7354,7 +7354,7 @@ then
                 AM_CFLAGS="$AM_CFLAGS $OPTIMIZE_HUGE_CFLAGS"
             fi
         else
-            if test "$ENABLED_SP" = "yes" && test "$ENABLED_SP_SMALL" = "no"
+            if (test "$ENABLED_SP" = "yes" || test "$ENABLED_SP_MATH_ALL" = "yes") && test "$ENABLED_SP_SMALL" = "no"
             then
                 AM_CFLAGS="$AM_CFLAGS $OPTIMIZE_FAST_CFLAGS"
                 if test "$ENABLED_FASTHUGEMATH" = "yes"
diff --git a/wolfcrypt/src/blake2b.c b/wolfcrypt/src/blake2b.c
index 26466aebf..9ed1fe70e 100644
--- a/wolfcrypt/src/blake2b.c
+++ b/wolfcrypt/src/blake2b.c
@@ -120,10 +120,13 @@ int blake2b_init_param( blake2b_state *S, const blake2b_param *P )
 }
 
 
-
 int blake2b_init( blake2b_state *S, const byte outlen )
 {
+#ifdef WOLFSSL_BLAKE2B_INIT_EACH_FIELD
   blake2b_param P[1];
+#else
+  volatile blake2b_param P[1];
+#endif
 
   if ( ( !outlen ) || ( outlen > BLAKE2B_OUTBYTES ) ) return BAD_FUNC_ARG;
 
@@ -140,12 +143,12 @@ int blake2b_init( blake2b_state *S, const byte outlen )
   XMEMSET( P->salt,     0, sizeof( P->salt ) );
   XMEMSET( P->personal, 0, sizeof( P->personal ) );
 #else
-  XMEMSET( P, 0, sizeof( *P ) );
+  XMEMSET( (blake2b_param *)P, 0, sizeof( *P ) );
   P->digest_length = outlen;
   P->fanout        = 1;
   P->depth         = 1;
 #endif
-  return blake2b_init_param( S, P );
+  return blake2b_init_param( S, (blake2b_param *)P );
 }
 
 
@@ -153,7 +156,11 @@ int blake2b_init_key( blake2b_state *S, const byte outlen, const void *key,
                       const byte keylen )
 {
   int ret = 0;
+#ifdef WOLFSSL_BLAKE2B_INIT_EACH_FIELD
   blake2b_param P[1];
+#else
+  volatile blake2b_param P[1];
+#endif
 
   if ( ( !outlen ) || ( outlen > BLAKE2B_OUTBYTES ) ) return BAD_FUNC_ARG;
 
@@ -172,14 +179,14 @@ int blake2b_init_key( blake2b_state *S, const byte outlen, const void *key,
   XMEMSET( P->salt,     0, sizeof( P->salt ) );
   XMEMSET( P->personal, 0, sizeof( P->personal ) );
 #else
-  XMEMSET( P, 0, sizeof( *P ) );
+  XMEMSET( (blake2b_param *)P, 0, sizeof( *P ) );
   P->digest_length = outlen;
   P->key_length    = keylen;
   P->fanout        = 1;
   P->depth         = 1;
 #endif
 
-  ret = blake2b_init_param( S, P );
+  ret = blake2b_init_param( S, (blake2b_param *)P );
   if ( ret < 0 ) return ret;
 
   {
diff --git a/wolfcrypt/src/blake2s.c b/wolfcrypt/src/blake2s.c
index f73fe2ab1..f6478dd0e 100644
--- a/wolfcrypt/src/blake2s.c
+++ b/wolfcrypt/src/blake2s.c
@@ -119,7 +119,11 @@ int blake2s_init_param( blake2s_state *S, const blake2s_param *P )
 
 int blake2s_init( blake2s_state *S, const byte outlen )
 {
+#ifdef WOLFSSL_BLAKE2S_INIT_EACH_FIELD
   blake2s_param P[1];
+#else
+  volatile blake2s_param P[1];
+#endif
 
   if ( ( !outlen ) || ( outlen > BLAKE2S_OUTBYTES ) ) return BAD_FUNC_ARG;
 
@@ -132,16 +136,15 @@ int blake2s_init( blake2s_state *S, const byte outlen )
   store32( &P->node_offset, 0 );
   P->node_depth    = 0;
   P->inner_length  = 0;
-  XMEMSET( P->reserved, 0, sizeof( P->reserved ) );
   XMEMSET( P->salt,     0, sizeof( P->salt ) );
   XMEMSET( P->personal, 0, sizeof( P->personal ) );
 #else
-  XMEMSET( P, 0, sizeof( *P ) );
+  XMEMSET( (blake2s_param *)P, 0, sizeof( *P ) );
   P->digest_length = outlen;
   P->fanout        = 1;
   P->depth         = 1;
 #endif
-  return blake2s_init_param( S, P );
+  return blake2s_init_param( S, (blake2s_param *)P );
 }
 
 
@@ -149,7 +152,11 @@ int blake2s_init_key( blake2s_state *S, const byte outlen, const void *key,
                       const byte keylen )
 {
   int ret = 0;
+#ifdef WOLFSSL_BLAKE2S_INIT_EACH_FIELD
   blake2s_param P[1];
+#else
+  volatile blake2s_param P[1];
+#endif
 
   if ( ( !outlen ) || ( outlen > BLAKE2S_OUTBYTES ) ) return BAD_FUNC_ARG;
 
@@ -164,18 +171,17 @@ int blake2s_init_key( blake2s_state *S, const byte outlen, const void *key,
   store64( &P->node_offset, 0 );
   P->node_depth    = 0;
   P->inner_length  = 0;
-  XMEMSET( P->reserved, 0, sizeof( P->reserved ) );
   XMEMSET( P->salt,     0, sizeof( P->salt ) );
   XMEMSET( P->personal, 0, sizeof( P->personal ) );
 #else
-  XMEMSET( P, 0, sizeof( *P ) );
+  XMEMSET( (blake2s_param *)P, 0, sizeof( *P ) );
   P->digest_length = outlen;
   P->key_length    = keylen;
   P->fanout        = 1;
   P->depth         = 1;
 #endif
 
-  ret = blake2s_init_param( S, P );
+  ret = blake2s_init_param( S, (blake2s_param *)P );
   if (ret < 0)
       return ret;
 
diff --git a/wolfcrypt/src/sp_int.c b/wolfcrypt/src/sp_int.c
index 0effb7f7d..7eed698ae 100644
--- a/wolfcrypt/src/sp_int.c
+++ b/wolfcrypt/src/sp_int.c
@@ -93,6 +93,12 @@ This library provides single precision (SP) integer math functions.
  * WOLFSSL_SP_FAST_MODEXP       Allow fast mod_exp with small C code
  */
 
+/* WOLFSSL_SP_SMALL is incompatibile with clang-12+ -Os. */
+#if defined(__clang__) && defined(__clang_major__) && \
+    (__clang_major__ >= 12) && defined(WOLFSSL_SP_SMALL)
+    #undef WOLFSSL_SP_SMALL
+#endif
+
 #include <wolfssl/wolfcrypt/sp_int.h>
 
 /* DECL_SP_INT: Declare one variable of type 'sp_int'. */
diff --git a/wolfssl/wolfcrypt/blake2-int.h b/wolfssl/wolfcrypt/blake2-int.h
index e1c73fc85..de44a3524 100644
--- a/wolfssl/wolfcrypt/blake2-int.h
+++ b/wolfssl/wolfcrypt/blake2-int.h
@@ -73,7 +73,7 @@
     byte  node_depth;    /* 15 */
     byte  inner_length;  /* 16 */
     /* byte  reserved[0]; */
-    byte  salt[BLAKE2B_SALTBYTES]; /* 24 */
+    byte  salt[BLAKE2S_SALTBYTES]; /* 24 */
     byte  personal[BLAKE2S_PERSONALBYTES];  /* 32 */
   } blake2s_param;