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| author | Michael Brown <mcb30@ipxe.org> | 2025-02-13 14:18:15 +0000 |
|---|---|---|
| committer | Michael Brown <mcb30@ipxe.org> | 2025-02-13 15:25:35 +0000 |
| commit | 5056e8ad936742ba410031cff14c0f72d87805fc (patch) | |
| tree | 843fe48d0e4eeea4d78e4c30e31c16268def5ff3 /src/arch/riscv/include/bits/bigint.h | |
| parent | bd90abf487a6b0500f457193f86ff54fd2be3143 (diff) | |
| download | ipxe-5056e8ad936742ba410031cff14c0f72d87805fc.tar.gz | |
[crypto] Expose shifted out bit from big integer shifts
Expose the bit shifted out as a result of shifting a big integer left
or right.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src/arch/riscv/include/bits/bigint.h')
| -rw-r--r-- | src/arch/riscv/include/bits/bigint.h | 36 |
1 files changed, 20 insertions, 16 deletions
diff --git a/src/arch/riscv/include/bits/bigint.h b/src/arch/riscv/include/bits/bigint.h index ab1070d88..7f87d9748 100644 --- a/src/arch/riscv/include/bits/bigint.h +++ b/src/arch/riscv/include/bits/bigint.h @@ -143,38 +143,40 @@ bigint_subtract_raw ( const unsigned long *subtrahend0, unsigned long *value0, * * @v value0 Element 0 of big integer * @v size Number of elements + * @ret out Bit shifted out */ -static inline __attribute__ (( always_inline )) void +static inline __attribute__ (( always_inline )) int bigint_shl_raw ( unsigned long *value0, unsigned int size ) { bigint_t ( size ) __attribute__ (( may_alias )) *value = ( ( void * ) value0 ); unsigned long *valueN = ( value0 + size ); unsigned long *discard_value; unsigned long discard_value_i; - unsigned long discard_carry; unsigned long discard_temp; + unsigned long carry; __asm__ __volatile__ ( "\n1:\n\t" /* Load value[i] */ LOADN " %1, (%0)\n\t" /* Shift left */ - "slli %3, %1, 1\n\t" - "or %3, %3, %2\n\t" - "srli %2, %1, %7\n\t" + "slli %2, %1, 1\n\t" + "or %2, %2, %3\n\t" + "srli %3, %1, %7\n\t" /* Store value[i] */ - STOREN " %3, (%0)\n\t" + STOREN " %2, (%0)\n\t" /* Loop */ "addi %0, %0, %6\n\t" "bne %0, %5, 1b\n\t" : "=&r" ( discard_value ), "=&r" ( discard_value_i ), - "=&r" ( discard_carry ), "=&r" ( discard_temp ), + "=&r" ( carry ), "+m" ( *value ) : "r" ( valueN ), "i" ( sizeof ( unsigned long ) ), "i" ( ( 8 * sizeof ( unsigned long ) - 1 ) ), - "0" ( value0 ), "2" ( 0 ) ); + "0" ( value0 ), "3" ( 0 ) ); + return carry; } /** @@ -182,38 +184,40 @@ bigint_shl_raw ( unsigned long *value0, unsigned int size ) { * * @v value0 Element 0 of big integer * @v size Number of elements + * @ret out Bit shifted out */ -static inline __attribute__ (( always_inline )) void +static inline __attribute__ (( always_inline )) int bigint_shr_raw ( unsigned long *value0, unsigned int size ) { bigint_t ( size ) __attribute__ (( may_alias )) *value = ( ( void * ) value0 ); unsigned long *valueN = ( value0 + size ); unsigned long *discard_value; unsigned long discard_value_i; - unsigned long discard_carry; unsigned long discard_temp; + unsigned long carry; __asm__ __volatile__ ( "\n1:\n\t" /* Load value[i] */ LOADN " %1, %6(%0)\n\t" /* Shift right */ - "srli %3, %1, 1\n\t" - "or %3, %3, %2\n\t" - "slli %2, %1, %7\n\t" + "srli %2, %1, 1\n\t" + "or %2, %2, %3\n\t" + "slli %3, %1, %7\n\t" /* Store value[i] */ - STOREN " %3, %6(%0)\n\t" + STOREN " %2, %6(%0)\n\t" /* Loop */ "addi %0, %0, %6\n\t" "bne %0, %5, 1b\n\t" : "=&r" ( discard_value ), "=&r" ( discard_value_i ), - "=&r" ( discard_carry ), "=&r" ( discard_temp ), + "=&r" ( carry ), "+m" ( *value ) : "r" ( value0 ), "i" ( -( sizeof ( unsigned long ) ) ), "i" ( ( 8 * sizeof ( unsigned long ) - 1 ) ), - "0" ( valueN ), "2" ( 0 ) ); + "0" ( valueN ), "3" ( 0 ) ); + return ( !! carry ); } /** |