diff options
| author | Michael Brown | 2024-10-08 12:52:07 +0200 |
|---|---|---|
| committer | Michael Brown | 2024-10-10 16:35:16 +0200 |
| commit | f78c5a763cc7bb2e2b7b437e7cc74a3efb876960 (patch) | |
| tree | c0e9186ed0dfad5c3201f87ec5cde3ac4967ae9c /src/include | |
| parent | [crypto] Rename bigint_rol()/bigint_ror() to bigint_shl()/bigint_shr() (diff) | |
| download | ipxe-f78c5a763cc7bb2e2b7b437e7cc74a3efb876960.tar.gz ipxe-f78c5a763cc7bb2e2b7b437e7cc74a3efb876960.tar.xz ipxe-f78c5a763cc7bb2e2b7b437e7cc74a3efb876960.zip | |
[crypto] Use architecture-independent bigint_is_set()
Every architecture uses the same implementation for bigint_is_set(),
and there is no reason to suspect that a future CPU architecture will
provide a more efficient way to implement this operation.
Simplify the code by providing a single architecture-independent
implementation of bigint_is_set().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src/include')
| -rw-r--r-- | src/include/ipxe/bigint.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/src/include/ipxe/bigint.h b/src/include/ipxe/bigint.h index 19cd4e3dd..c556afbc1 100644 --- a/src/include/ipxe/bigint.h +++ b/src/include/ipxe/bigint.h @@ -285,6 +285,25 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); #include <bits/bigint.h> +/** + * Test if bit is set in big integer + * + * @v value0 Element 0 of big integer + * @v size Number of elements + * @v bit Bit to test + * @ret is_set Bit is set + */ +static inline __attribute__ (( always_inline )) int +bigint_bit_is_set_raw ( const bigint_element_t *value0, unsigned int size, + unsigned int bit ) { + const bigint_t ( size ) __attribute__ (( may_alias )) *value = + ( ( const void * ) value0 ); + unsigned int index = ( bit / ( 8 * sizeof ( value->element[0] ) ) ); + unsigned int subindex = ( bit % ( 8 * sizeof ( value->element[0] ) ) ); + + return ( !! ( value->element[index] & ( 1UL << subindex ) ) ); +} + void bigint_init_raw ( bigint_element_t *value0, unsigned int size, const void *data, size_t len ); void bigint_done_raw ( const bigint_element_t *value0, unsigned int size, |