Add an asm barrier

jedisct1 · jedisct1 · commit e6fc57b4dd92 · 2025-12-30T01:29:20.000+01:00
diff --git a/src/ipcrypt2.c b/src/ipcrypt2.c
@@ -981,8 +981,11 @@ ipcrypt_pfx_set_bit(uint8_t ip16[16], const unsigned int bit_index, const uint8_
 {
     const size_t  byte_index = 15 - bit_index / 8;
     const uint8_t bit_mask   = (uint8_t) (1 << (bit_index % 8));
-    const uint8_t mask       = (uint8_t) -((bit_value & 1));
+    uint8_t       mask       = (uint8_t) -((bit_value & 1));
 
+#if defined(__GNUC__) || defined(__clang__)
+    __asm__ __volatile__("" : "+r"(mask) ::);
+#endif
     ip16[byte_index] = (ip16[byte_index] & ~bit_mask) | (bit_mask & mask);
 }
 

Original file line number	Diff line number	Diff line change
`@@ -981,8 +981,11 @@ ipcrypt_pfx_set_bit(uint8_t ip16[16], const unsigned int bit_index, const uint8_`
`981`	`981`	`{`
`982`	`982`	`const size_t byte_index = 15 - bit_index / 8;`
`983`	`983`	`const uint8_t bit_mask = (uint8_t) (1 << (bit_index % 8));`
`984`		`- const uint8_t mask = (uint8_t) -((bit_value & 1));`
	`984`	`+ uint8_t mask = (uint8_t) -((bit_value & 1));`
`985`	`985`
	`986`	`+#if defined(__GNUC__) \|\| defined(__clang__)`
	`987`	`+ __asm__ __volatile__("" : "+r"(mask) ::);`
	`988`	`+#endif`
`986`	`989`	`ip16[byte_index] = (ip16[byte_index] & ~bit_mask) \| (bit_mask & mask);`
`987`	`990`	`}`
`988`	`991`