diff --git a/source/m3_exec.c b/source/m3_exec.c
index 6579520..2b1c341 100644
--- a/source/m3_exec.c
+++ b/source/m3_exec.c
@@ -104,7 +104,7 @@ d_m3OpDef  (CallIndirect)
         {
             if (type == function->funcType)
             {
-                if (not function->compiled)
+                if (UNLIKELY(not function->compiled))
                     r = Compile_Function (function);
 
                 if (not r)
@@ -194,7 +194,7 @@ d_m3OpDef  (Compile)
 
     m3ret_t result = m3Err_none;
 
-    if (not function->compiled) // check to see if function was compiled since this operation was emitted.
+    if (UNLIKELY(not function->compiled)) // check to see if function was compiled since this operation was emitted.
         result = Compile_Function (function);
 
     if (not result)
diff --git a/source/m3_exec.h b/source/m3_exec.h
index ff66996..7dfe5eb 100644
--- a/source/m3_exec.h
+++ b/source/m3_exec.h
@@ -238,8 +238,8 @@ d_m3UnaryOp_i (i64, EqualToZero, OP_EQZ)
 
 // clz(0), ctz(0) results are undefined for rest platforms, fix it
 #if (defined(__i386__) || defined(__x86_64__)) && !(defined(__AVX2__) || (defined(__ABM__) && defined(__BMI__)))
-    #define OP_CLZ_32(x) (OP_EQZ(x) ? 32 : __builtin_clz(x))
-    #define OP_CTZ_32(x) (OP_EQZ(x) ? 32 : __builtin_ctz(x))
+    #define OP_CLZ_32(x) (UNLIKELY((x) == 0) ? 32 : __builtin_clz(x))
+    #define OP_CTZ_32(x) (UNLIKELY((x) == 0) ? 32 : __builtin_ctz(x))
     // for 64-bit instructions branchless approach more preferable
     #define OP_CLZ_64(x) (__builtin_clzll((x) | (1LL <<  0)) + OP_EQZ(x))
     #define OP_CTZ_64(x) (__builtin_ctzll((x) | (1LL << 63)) + OP_EQZ(x))
@@ -251,10 +251,10 @@ d_m3UnaryOp_i (i64, EqualToZero, OP_EQZ)
     #define OP_CLZ_64(x) __builtin_clzll(x)
     #define OP_CTZ_64(x) __builtin_ctzll(x)
 #else
-    #define OP_CLZ_32(x) (OP_EQZ(x) ? 32 : __builtin_clz(x))
-    #define OP_CTZ_32(x) (OP_EQZ(x) ? 32 : __builtin_ctz(x))
-    #define OP_CLZ_64(x) (OP_EQZ(x) ? 64 : __builtin_clzll(x))
-    #define OP_CTZ_64(x) (OP_EQZ(x) ? 64 : __builtin_ctzll(x))
+    #define OP_CLZ_32(x) (UNLIKELY((x) == 0) ? 32 : __builtin_clz(x))
+    #define OP_CTZ_32(x) (UNLIKELY((x) == 0) ? 32 : __builtin_ctz(x))
+    #define OP_CLZ_64(x) (UNLIKELY((x) == 0) ? 64 : __builtin_clzll(x))
+    #define OP_CTZ_64(x) (UNLIKELY((x) == 0) ? 64 : __builtin_ctzll(x))
 #endif
 
 d_m3UnaryOp_i (u32, Clz, OP_CLZ_32)