Detect support for unaligned memory access

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
This commit is contained in:
Dave Rodgman 2022-11-22 18:55:17 +00:00
parent 8c18baf8c1
commit fdd967ebdc

View file

@ -69,6 +69,18 @@ extern void (*mbedtls_test_hook_test_fail)( const char * test, int line, const c
*/
#define MBEDTLS_ALLOW_PRIVATE_ACCESS
/** Detect architectures where unaligned memory accesses are safe and performant.
*
* This list is incomplete.
*/
#if defined(__i386__) || defined(__amd64__) || defined( __x86_64__) \
|| defined(__ARM_FEATURE_UNALIGNED) \
|| defined(__aarch64__) \
|| defined(__ARM_ARCH_8__) || defined(__ARM_ARCH_8A__) || defined(__ARM_ARCH_8M__) \
|| defined(__ARM_ARCH_7A__)
#define MBEDTLS_ALLOW_UNALIGNED_ACCESS
#endif
/** Byte Reading Macros
*
* Given a multi-byte integer \p x, MBEDTLS_BYTE_n retrieves the n-th
@ -404,6 +416,7 @@ extern void (*mbedtls_test_hook_test_fail)( const char * test, int line, const c
*/
static inline void mbedtls_xor( unsigned char* r, unsigned char const *a, unsigned char const *b, size_t n )
{
#if defined(MBEDTLS_ALLOW_UNALIGNED_ACCESS)
uint32_t *a32 = (uint32_t*)a;
uint32_t *b32 = (uint32_t*)b;
uint32_t *r32 = (uint32_t*)r;
@ -415,6 +428,12 @@ static inline void mbedtls_xor( unsigned char* r, unsigned char const *a, unsign
{
r[i] = a[i] ^ b[i];
}
#else
for ( size_t i = 0; i < n; i++ )
{
r[i] = a[i] ^ b[i];
}
#endif
}
/* Fix MSVC C99 compatible issue