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src/arch/arm32/include/bits/bigint.h
264 строки
7 KB
Michael Brown
[crypto] Use inline assembly for bigint_grow() and bigint_shrink()
16 июн 2026, 18:07
16 июн 2026, 18:07
cd873a2
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#ifndef _BITS_BIGINT_H #define _BITS_BIGINT_H /** @file * * Big integer support */ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); #include <stdint.h> #include <string.h> /** Element of a big integer */ typedef uint32_t bigint_element_t; /** * Add big integers * * @v addend0 Element 0 of big integer to add * @v value0 Element 0 of big integer to be added to * @v size Number of elements * @ret carry Carry out */ static inline __attribute__ (( always_inline )) int bigint_add_raw ( const uint32_t *addend0, uint32_t *value0, unsigned int size ) { bigint_t ( size ) __attribute__ (( may_alias )) *value = ( ( void * ) value0 ); uint32_t *discard_addend; uint32_t *discard_value; uint32_t *discard_end; uint32_t discard_addend_i; uint32_t discard_value_i; int carry; __asm__ __volatile__ ( "adds %2, %0, %9, lsl #2\n\t" /* clear CF */ "\n1:\n\t" "ldmia %0!, {%3}\n\t" "ldr %4, [%1]\n\t" "adcs %4, %3\n\t" "stmia %1!, {%4}\n\t" "teq %0, %2\n\t" "bne 1b\n\t" : "=l" ( discard_addend ), "=l" ( discard_value ), "=l" ( discard_end ), "=l" ( discard_addend_i ), "=l" ( discard_value_i ), "=@cccs" ( carry ), "+m" ( *value ) : "0" ( addend0 ), "1" ( value0 ), "l" ( size ) ); return carry; } /** * Subtract big integers * * @v subtrahend0 Element 0 of big integer to subtract * @v value0 Element 0 of big integer to be subtracted from * @v size Number of elements * @ret borrow Borrow out */ static inline __attribute__ (( always_inline )) int bigint_subtract_raw ( const uint32_t *subtrahend0, uint32_t *value0, unsigned int size ) { bigint_t ( size ) __attribute__ (( may_alias )) *value = ( ( void * ) value0 ); uint32_t *discard_subtrahend; uint32_t *discard_value; uint32_t *discard_end; uint32_t discard_subtrahend_i; uint32_t discard_value_i; int borrow; __asm__ __volatile__ ( "add %2, %0, %9, lsl #2\n\t" "cmp %2, %0\n\t" /* set CF */ "\n1:\n\t" "ldmia %0!, {%3}\n\t" "ldr %4, [%1]\n\t" "sbcs %4, %3\n\t" "stmia %1!, {%4}\n\t" "teq %0, %2\n\t" "bne 1b\n\t" : "=l" ( discard_subtrahend ), "=l" ( discard_value ), "=l" ( discard_end ), "=l" ( discard_subtrahend_i ), "=l" ( discard_value_i ), "=@cccc" ( borrow ), "+m" ( *value ) : "0" ( subtrahend0 ), "1" ( value0 ), "l" ( size ) ); return borrow; } /** * Shift big integer left * * @v value0 Element 0 of big integer * @v size Number of elements * @ret out Bit shifted out */ static inline __attribute__ (( always_inline )) int bigint_shl_raw ( uint32_t *value0, unsigned int size ) { bigint_t ( size ) __attribute__ (( may_alias )) *value = ( ( void * ) value0 ); uint32_t *discard_value; uint32_t *discard_end; uint32_t discard_value_i; int carry; __asm__ __volatile__ ( "adds %1, %0, %1, lsl #2\n\t" /* clear CF */ "\n1:\n\t" "ldr %2, [%0]\n\t" "adcs %2, %2\n\t" "stmia %0!, {%2}\n\t" "teq %0, %1\n\t" "bne 1b\n\t" : "=l" ( discard_value ), "=l" ( discard_end ), "=l" ( discard_value_i ), "=@cccs" ( carry ), "+m" ( *value ) : "0" ( value0 ), "1" ( size ) ); return carry; } /** * Shift big integer right * * @v value0 Element 0 of big integer * @v size Number of elements * @ret out Bit shifted out */ static inline __attribute__ (( always_inline )) int bigint_shr_raw ( uint32_t *value0, unsigned int size ) { bigint_t ( size ) __attribute__ (( may_alias )) *value = ( ( void * ) value0 ); uint32_t *discard_value; uint32_t *discard_end; uint32_t discard_value_i; int carry; __asm__ __volatile__ ( "adds %1, %0, %1, lsl #2\n\t" /* clear CF */ "\n1:\n\t" "ldmdb %1!, {%2}\n\t" "rrxs %2, %2\n\t" "str %2, [%1]\n\t" "teq %0, %1\n\t" "bne 1b\n\t" : "=l" ( discard_value ), "=l" ( discard_end ), "=l" ( discard_value_i ), "=@cccs" ( carry ), "+m" ( *value ) : "0" ( value0 ), "1" ( size ) ); return carry; } /** * Grow big integer * * @v source0 Element 0 of source big integer * @v source_size Number of elements in source big integer * @v dest0 Element 0 of destination big integer * @v dest_size Number of elements in destination big integer */ static inline __attribute__ (( always_inline )) void bigint_grow_raw ( const uint32_t *source0, unsigned int source_size, uint32_t *dest0, unsigned int dest_size ) { bigint_t ( dest_size ) __attribute__ (( may_alias )) *dest = ( ( void * ) dest0 ); const uint32_t *source_end = ( source0 + source_size ); uint32_t *dest_end = ( dest0 + dest_size ); uint32_t *discard_source; uint32_t *discard_dest; uint32_t discard_source_i; __asm__ __volatile__ ( "\n1:\n\t" "ldmia %0!, {%2}\n\t" "stmia %1!, {%2}\n\t" "teq %0, %4\n\t" "bne 1b\n\t" "eor %2, %2\n\t" "b 3f\n\t" "\n2:\n\t" "stmia %1!, {%2}\n\t" "\n3:\n\t" "teq %1, %5\n\t" "bne 2b\n\t" : "=&l" ( discard_source ), "=&l" ( discard_dest ), "=&l" ( discard_source_i ), "=m" ( *dest ) : "l" ( source_end ), "l" ( dest_end ), "0" ( source0 ), "1" ( dest0 ) ); } /** * Shrink big integer * * @v source0 Element 0 of source big integer * @v source_size Number of elements in source big integer * @v dest0 Element 0 of destination big integer * @v dest_size Number of elements in destination big integer */ static inline __attribute__ (( always_inline )) void bigint_shrink_raw ( const uint32_t *source0, unsigned int source_size __unused, uint32_t *dest0, unsigned int dest_size ) { bigint_t ( dest_size ) __attribute__ (( may_alias )) *dest = ( ( void * ) dest0 ); uint32_t *dest_end = ( dest0 + dest_size ); uint32_t *discard_source; uint32_t *discard_dest; uint32_t discard_source_i; __asm__ __volatile__ ( "\n1:\n\t" "ldmia %0!, {%2}\n\t" "stmia %1!, {%2}\n\t" "teq %1, %4\n\t" "bne 1b\n\t" : "=&l" ( discard_source ), "=&l" ( discard_dest ), "=&l" ( discard_source_i ), "=m" ( *dest ) : "l" ( dest_end ), "0" ( source0 ), "1" ( dest0 ) ); } /** * Multiply big integer elements * * @v multiplicand Multiplicand element * @v multiplier Multiplier element * @v result Result element * @v carry Carry element */ static inline __attribute__ (( always_inline )) void bigint_multiply_one ( const uint32_t multiplicand, const uint32_t multiplier, uint32_t *result, uint32_t *carry ) { uint32_t discard_low; uint32_t discard_high; __asm__ __volatile__ ( /* Perform multiplication */ "umull %0, %1, %4, %5\n\t" /* Accumulate result */ "adds %2, %0\n\t" "adc %1, #0\n\t" /* Accumulate carry (cannot overflow) */ "adds %2, %3\n\t" "adc %3, %1, #0\n\t" : "=r" ( discard_low ), "=r" ( discard_high ), "+r" ( *result ), "+r" ( *carry ) : "r" ( multiplicand ), "r" ( multiplier ) : "cc" ); } #endif /* _BITS_BIGINT_H */