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Add fast asm version of vli_mmod_fast for secp256k1

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Ken MacKay
2014-05-16 21:07:44 -07:00
parent 39583e1fc0
commit d2737ea21c
1 changed files with 344 additions and 1 deletions
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asm_avr.inc
+344 -1
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@@ -15691,7 +15691,350 @@ static void vli_mmod_fast(uint8_t *RESTRICT p_result, uint8_t *RESTRICT p_produc
}
#define asm_mmod_fast 1
#endif /* uECC_CURVE == uECC_secp160r1 */
#elif (uECC_CURVE == uECC_secp256k1)
static void vli_mmod_fast(uint8_t *RESTRICT p_result, uint8_t *RESTRICT p_product)
{
uint8_t l_carry = 0;
__asm__ volatile (
"in r30, __SP_L__ \n\t"
"in r31, __SP_H__ \n\t"
"sbiw r30, 37 \n\t"
"in r0, __SREG__ \n\t"
"cli \n\t"
"out __SP_H__, r31 \n\t"
"out __SREG__, r0 \n\t"
"out __SP_L__, r30 \n\t"
"adiw r30, 1 \n\t" /* add 1 since z initially points below the stack */
"adiw r26, 32 \n\t" /* p_product + uECC_WORDS */
"ldi r25, 0x03 \n\t"
"ldi r24, 0xD1 \n\t"
"ld r18, x+ \n\t"
"ld r19, x+ \n\t"
"ld r20, x+ \n\t"
"ld r21, x+ \n\t"
"mul r24, r18 \n\t"
"st z+, r0 \n\t"
"mov r22, r1 \n\t"
"ldi r23, 0 \n\t"
"mul r24, r19 \n\t"
"add r22, r0 \n\t"
"adc r23, r1 \n\t" /* can't overflow */
"mul r25, r18 \n\t"
"add r22, r0 \n\t"
"adc r23, r1 \n\t" /* can't overflow */
"st z+, r22 \n\t"
"ldi r22, 0 \n\t"
"mul r24, r20 \n\t"
"add r23, r0 \n\t"
"adc r22, r1 \n\t"
"mul r25, r19 \n\t"
"add r23, r0 \n\t"
"adc r22, r1 \n\t"
"st z+, r23 \n\t"
"ldi r23, 0 \n\t"
"mul r24, r21 \n\t"
"add r22, r0 \n\t"
"adc r23, r1 \n\t"
"mul r25, r20 \n\t"
"add r22, r0 \n\t"
"adc r23, r1 \n\t"
"st z+, r22 \n\t"
"ldi r22, 0 \n\t"
/* now we start adding the 2^32 part as well */
"add r23, r18 \n\t" // 28
"adc r22, r22 \n\t"
"ld r18, x+ \n\t"
"mul r24, r18 \n\t"
"add r23, r0 \n\t"
"adc r22, r1 \n\t"
"mul r25, r21 \n\t"
"add r23, r0 \n\t"
"adc r22, r1 \n\t"
"st z+, r23 \n\t"
"ldi r23, 0 \n\t"
"add r22, r19 \n\t" // 27
"adc r23, r23 \n\t"
"ld r19, x+ \n\t"
"mul r24, r19 \n\t"
"add r22, r0 \n\t"
"adc r23, r1 \n\t"
"mul r25, r18 \n\t"
"add r22, r0 \n\t"
"adc r23, r1 \n\t"
"st z+, r22 \n\t"
"ldi r22, 0 \n\t"
REPEAT(6, // 26 - 3
"add r23, r20 \n\t"
"adc r22, r22 \n\t"
"ld r20, x+ \n\t"
"mul r24, r20 \n\t"
"add r23, r0 \n\t"
"adc r22, r1 \n\t"
"mul r25, r19 \n\t"
"add r23, r0 \n\t"
"adc r22, r1 \n\t"
"st z+, r23 \n\t"
"ldi r23, 0 \n\t"
"add r22, r21 \n\t"
"adc r23, r23 \n\t"
"ld r21, x+ \n\t"
"mul r24, r21 \n\t"
"add r22, r0 \n\t"
"adc r23, r1 \n\t"
"mul r25, r20 \n\t"
"add r22, r0 \n\t"
"adc r23, r1 \n\t"
"st z+, r22 \n\t"
"ldi r22, 0 \n\t"
"add r23, r18 \n\t"
"adc r22, r22 \n\t"
"ld r18, x+ \n\t"
"mul r24, r18 \n\t"
"add r23, r0 \n\t"
"adc r22, r1 \n\t"
"mul r25, r21 \n\t"
"add r23, r0 \n\t"
"adc r22, r1 \n\t"
"st z+, r23 \n\t"
"ldi r23, 0 \n\t"
"add r22, r19 \n\t"
"adc r23, r23 \n\t"
"ld r19, x+ \n\t"
"mul r24, r19 \n\t"
"add r22, r0 \n\t"
"adc r23, r1 \n\t"
"mul r25, r18 \n\t"
"add r22, r0 \n\t"
"adc r23, r1 \n\t"
"st z+, r22 \n\t"
"ldi r22, 0 \n\t")
"add r23, r20 \n\t" // 2
"adc r22, r22 \n\t"
"ld r20, x+ \n\t"
"mul r24, r20 \n\t"
"add r23, r0 \n\t"
"adc r22, r1 \n\t"
"mul r25, r19 \n\t"
"add r23, r0 \n\t"
"adc r22, r1 \n\t"
"st z+, r23 \n\t"
"ldi r23, 0 \n\t"
"add r22, r21 \n\t" // 1
"adc r23, r23 \n\t"
"ld r21, x+ \n\t"
"mul r24, r21 \n\t"
"add r22, r0 \n\t"
"adc r23, r1 \n\t"
"mul r25, r20 \n\t"
"add r22, r0 \n\t"
"adc r23, r1 \n\t"
"st z+, r22 \n\t"
"ldi r22, 0 \n\t"
/* Now finish the carries etc */
"add r23, r18 \n\t"
"adc r22, r22 \n\t"
"mul r25, r21 \n\t"
"add r23, r0 \n\t"
"adc r22, r1 \n\t"
"st z+, r23 \n\t"
"ldi r23, 0 \n\t"
"add r22, r19 \n\t"
"adc r23, r23 \n\t"
"st z+, r22 \n\t"
"ldi r22, 0 \n\t"
"add r23, r20 \n\t"
"adc r22, r22 \n\t"
"st z+, r23 \n\t"
"ldi r23, 0 \n\t"
"add r22, r21 \n\t"
"adc r23, r23 \n\t"
"st z+, r22 \n\t"
"st z+, r23 \n\t"
"eor r1, r1 \n\t" /* make r1 be 0 again */
"sbiw r30, 37 \n\t" /* move z back to point at tmp */
"subi r26, 64 \n\t" /* move x back to point at p_product */
"sbc r27, __zero_reg__ \n\t"
/* add low bytes of tmp to p_product, storing in p_result */
"ld r18, z+ \n\t"
"ld r19, x+ \n\t"
"add r18, r19 \n\t"
"st y+, r18 \n\t"
REPEAT(31, "ld r18, z+ \n\t"
"ld r19, x+ \n\t"
"adc r18, r19 \n\t"
"st y+, r18 \n\t")
"adc %[carry], __zero_reg__ \n\t" /* Store carry bit (carry flag is cleared). */
/* at this point x is at the end of p_product, y is at the end of p_result, z is 32 bytes into tmp */
"sbiw r28, 32 \n\t" /* move y back to point at p_result */
"eor r19, r19 \n\t"
"ld r18, z+ \n\t"
"add r19, r18 \n\t"
"ld r18, z+ \n\t"
"adc r19, r18 \n\t"
"ld r18, z+ \n\t"
"adc r19, r18 \n\t"
"ld r18, z+ \n\t"
"adc r19, r18 \n\t"
"ld r18, z+ \n\t"
"adc r19, r18 \n\t"
/* now z points to the end of tmp */
"brcs mmod_remult \n\t" /* carry was set, so something was not zero (need to mult again) */
"cp r19, __zero_reg__ \n\t"
"brne mmod_remult \n\t" /* sum was not equal to zero (need to mult again) */
"rjmp mmod_after_remult \n\t"
"mmod_remult: \n\t" /* do omega_mult with the 5 relevant bytes */
/* z points to the end of tmp, x points to the end of p_product */
"sbiw r30, 5 \n\t" /* move z back to point at l_tmp + uECC_WORDS */
"sbiw r26, 32 \n\t" /* shift x back to point into the p_product buffer (we can overwrite it now) */
"ld r18, z+ \n\t"
"ld r19, z+ \n\t"
"ld r20, z+ \n\t"
"ld r21, z+ \n\t"
"mul r24, r18 \n\t"
"st x+, r0 \n\t"
"mov r22, r1 \n\t"
"ldi r23, 0 \n\t"
"mul r24, r19 \n\t"
"add r22, r0 \n\t"
"adc r23, r1 \n\t" /* can't overflow */
"mul r25, r18 \n\t"
"add r22, r0 \n\t"
"adc r23, r1 \n\t" /* can't overflow */
"st x+, r22 \n\t"
"ldi r22, 0 \n\t"
"mul r24, r20 \n\t"
"add r23, r0 \n\t"
"adc r22, r1 \n\t"
"mul r25, r19 \n\t"
"add r23, r0 \n\t"
"adc r22, r1 \n\t"
"st x+, r23 \n\t"
"ldi r23, 0 \n\t"
"mul r24, r21 \n\t"
"add r22, r0 \n\t"
"adc r23, r1 \n\t"
"mul r25, r20 \n\t"
"add r22, r0 \n\t"
"adc r23, r1 \n\t"
"st x+, r22 \n\t"
"ldi r22, 0 \n\t"
"add r23, r18 \n\t"
"adc r22, r22 \n\t"
"ld r18, z+ \n\t"
"mul r24, r18 \n\t"
"add r23, r0 \n\t"
"adc r22, r1 \n\t"
"mul r25, r21 \n\t"
"add r23, r0 \n\t"
"adc r22, r1 \n\t"
"st x+, r23 \n\t"
"ldi r23, 0 \n\t"
/* Now finish the carries etc */
"add r22, r19 \n\t"
"adc r23, r23 \n\t"
"mul r25, r18 \n\t"
"add r22, r0 \n\t"
"adc r23, r1 \n\t"
"st x+, r22 \n\t"
"ldi r22, 0 \n\t"
"add r23, r20 \n\t"
"adc r22, r22 \n\t"
"st x+, r23 \n\t"
"ldi r23, 0 \n\t"
"add r22, r21 \n\t"
"adc r23, r23 \n\t"
"st x+, r22 \n\t"
"ldi r22, 0 \n\t"
"add r23, r18 \n\t"
"adc r22, r22 \n\t"
"st x+, r23 \n\t"
"st x+, r22 \n\t"
"eor r1, r1 \n\t" /* make r1 be 0 again */
/* now z points to the end of tmp, x points to the end of p_product (y still points at p_result) */
"sbiw r26, 10 \n\t" /* move x back to point at beginning of actual data */
/* add into p_result */
"ld r18, x+ \n\t"
"ld r19, y \n\t"
"add r18, r19 \n\t"
"st y+, r18 \n\t"
REPEAT(9, "ld r18, x+ \n\t"
"ld r19, y \n\t"
"adc r18, r19 \n\t"
"st y+, r18 \n\t")
/* Done adding, now propagate carry bit */
REPEAT(22, "ld r18, y \n\t"
"adc r18, __zero_reg__ \n\t"
"st y+, r18 \n\t")
"adc %[carry], __zero_reg__ \n\t" /* Store carry bit (carry flag is cleared). */
"sbiw r28, 32 \n\t" /* move y back to point at p_result */
"mmod_after_remult: \n\t"
"sbiw r30, 1 \n\t" /* fix stack pointer */
"in r0, __SREG__ \n\t"
"cli \n\t"
"out __SP_H__, r31 \n\t"
"out __SREG__, r0 \n\t"
"out __SP_L__, r30 \n\t"
: "+x" (p_product), [carry] "+r" (l_carry)
: "y" (p_result)
: "r0", "r18", "r19", "r20", "r21", "r22", "r23", "r24", "r25", "r30", "r31", "cc", "memory"
);
if(l_carry > 0)
{
--l_carry;
vli_sub(p_result, p_result, curve_p);
}
if(l_carry > 0)
{
vli_sub(p_result, p_result, curve_p);
}
if(vli_cmp(p_result, curve_p) > 0)
{
vli_sub(p_result, p_result, curve_p);
}
}
#define asm_mmod_fast 1
#endif /* (uECC_CURVE == uECC_secp256k1) */
#endif /* (uECC_ASM == uECC_asm_fast) */