blob: e3c8cb15e705c06da5c1a6e9af3eeacdf15f8eb0 [file] [log] [blame]
/* Copyright 2015, Kenneth MacKay. Licensed under the BSD 2-clause license. */
#ifndef _UECC_ASM_ARM_H_
#define _UECC_ASM_ARM_H_
#if (uECC_SUPPORTS_secp256r1 || uECC_SUPPORTS_secp256k1)
#define uECC_MIN_WORDS 8
#endif
#if uECC_SUPPORTS_secp224r1
#undef uECC_MIN_WORDS
#define uECC_MIN_WORDS 7
#endif
#if uECC_SUPPORTS_secp192r1
#undef uECC_MIN_WORDS
#define uECC_MIN_WORDS 6
#endif
#if uECC_SUPPORTS_secp160r1
#undef uECC_MIN_WORDS
#define uECC_MIN_WORDS 5
#endif
#if (uECC_PLATFORM == uECC_arm_thumb)
#define REG_RW "+l"
#define REG_WRITE "=l"
#else
#define REG_RW "+r"
#define REG_WRITE "=r"
#endif
#if (uECC_PLATFORM == uECC_arm_thumb || uECC_PLATFORM == uECC_arm_thumb2)
#define REG_RW_LO "+l"
#define REG_WRITE_LO "=l"
#else
#define REG_RW_LO "+r"
#define REG_WRITE_LO "=r"
#endif
#if (uECC_PLATFORM == uECC_arm_thumb2)
#define RESUME_SYNTAX
#else
#define RESUME_SYNTAX ".syntax divided \n\t"
#endif
#if (uECC_OPTIMIZATION_LEVEL >= 2)
uECC_VLI_API uECC_word_t uECC_vli_add(uECC_word_t *result,
const uECC_word_t *left,
const uECC_word_t *right,
wordcount_t num_words) {
#if (uECC_MAX_WORDS != uECC_MIN_WORDS)
#if (uECC_PLATFORM == uECC_arm_thumb) || (uECC_PLATFORM == uECC_arm_thumb2)
uint32_t jump = (uECC_MAX_WORDS - num_words) * 4 * 2 + 1;
#else /* ARM */
uint32_t jump = (uECC_MAX_WORDS - num_words) * 4 * 4;
#endif
#endif
uint32_t carry;
uint32_t left_word;
uint32_t right_word;
__asm__ volatile (
".syntax unified \n\t"
"movs %[carry], #0 \n\t"
#if (uECC_MAX_WORDS != uECC_MIN_WORDS)
"adr %[left], 1f \n\t"
".align 4 \n\t"
"adds %[jump], %[left] \n\t"
#endif
"ldmia %[lptr]!, {%[left]} \n\t"
"ldmia %[rptr]!, {%[right]} \n\t"
"adds %[left], %[right] \n\t"
"stmia %[dptr]!, {%[left]} \n\t"
#if (uECC_MAX_WORDS != uECC_MIN_WORDS)
"bx %[jump] \n\t"
#endif
"1: \n\t"
REPEAT(DEC(uECC_MAX_WORDS),
"ldmia %[lptr]!, {%[left]} \n\t"
"ldmia %[rptr]!, {%[right]} \n\t"
"adcs %[left], %[right] \n\t"
"stmia %[dptr]!, {%[left]} \n\t")
"adcs %[carry], %[carry] \n\t"
RESUME_SYNTAX
: [dptr] REG_RW_LO (result), [lptr] REG_RW_LO (left), [rptr] REG_RW_LO (right),
#if (uECC_MAX_WORDS != uECC_MIN_WORDS)
[jump] REG_RW_LO (jump),
#endif
[carry] REG_WRITE_LO (carry), [left] REG_WRITE_LO (left_word),
[right] REG_WRITE_LO (right_word)
:
: "cc", "memory"
);
return carry;
}
#define asm_add 1
uECC_VLI_API uECC_word_t uECC_vli_sub(uECC_word_t *result,
const uECC_word_t *left,
const uECC_word_t *right,
wordcount_t num_words) {
#if (uECC_MAX_WORDS != uECC_MIN_WORDS)
#if (uECC_PLATFORM == uECC_arm_thumb) || (uECC_PLATFORM == uECC_arm_thumb2)
uint32_t jump = (uECC_MAX_WORDS - num_words) * 4 * 2 + 1;
#else /* ARM */
uint32_t jump = (uECC_MAX_WORDS - num_words) * 4 * 4;
#endif
#endif
uint32_t carry;
uint32_t left_word;
uint32_t right_word;
__asm__ volatile (
".syntax unified \n\t"
"movs %[carry], #0 \n\t"
#if (uECC_MAX_WORDS != uECC_MIN_WORDS)
"adr %[left], 1f \n\t"
".align 4 \n\t"
"adds %[jump], %[left] \n\t"
#endif
"ldmia %[lptr]!, {%[left]} \n\t"
"ldmia %[rptr]!, {%[right]} \n\t"
"subs %[left], %[right] \n\t"
"stmia %[dptr]!, {%[left]} \n\t"
#if (uECC_MAX_WORDS != uECC_MIN_WORDS)
"bx %[jump] \n\t"
#endif
"1: \n\t"
REPEAT(DEC(uECC_MAX_WORDS),
"ldmia %[lptr]!, {%[left]} \n\t"
"ldmia %[rptr]!, {%[right]} \n\t"
"sbcs %[left], %[right] \n\t"
"stmia %[dptr]!, {%[left]} \n\t")
"adcs %[carry], %[carry] \n\t"
RESUME_SYNTAX
: [dptr] REG_RW_LO (result), [lptr] REG_RW_LO (left), [rptr] REG_RW_LO (right),
#if (uECC_MAX_WORDS != uECC_MIN_WORDS)
[jump] REG_RW_LO (jump),
#endif
[carry] REG_WRITE_LO (carry), [left] REG_WRITE_LO (left_word),
[right] REG_WRITE_LO (right_word)
:
: "cc", "memory"
);
return !carry; /* Note that on ARM, carry flag set means "no borrow" when subtracting
(for some reason...) */
}
#define asm_sub 1
#endif /* (uECC_OPTIMIZATION_LEVEL >= 2) */
#if (uECC_OPTIMIZATION_LEVEL >= 3)
#if (uECC_PLATFORM != uECC_arm_thumb)
#if uECC_ARM_USE_UMAAL
#include "asm_arm_mult_square_umaal.inc"
#else
#include "asm_arm_mult_square.inc"
#endif
#if (uECC_OPTIMIZATION_LEVEL == 3)
uECC_VLI_API void uECC_vli_mult(uint32_t *result,
const uint32_t *left,
const uint32_t *right,
wordcount_t num_words) {
register uint32_t *r0 __asm__("r0") = result;
register const uint32_t *r1 __asm__("r1") = left;
register const uint32_t *r2 __asm__("r2") = right;
register uint32_t r3 __asm__("r3") = num_words;
__asm__ volatile (
".syntax unified \n\t"
#if (uECC_MIN_WORDS == 5)
FAST_MULT_ASM_5
#if (uECC_MAX_WORDS > 5)
FAST_MULT_ASM_5_TO_6
#endif
#if (uECC_MAX_WORDS > 6)
FAST_MULT_ASM_6_TO_7
#endif
#if (uECC_MAX_WORDS > 7)
FAST_MULT_ASM_7_TO_8
#endif
#elif (uECC_MIN_WORDS == 6)
FAST_MULT_ASM_6
#if (uECC_MAX_WORDS > 6)
FAST_MULT_ASM_6_TO_7
#endif
#if (uECC_MAX_WORDS > 7)
FAST_MULT_ASM_7_TO_8
#endif
#elif (uECC_MIN_WORDS == 7)
FAST_MULT_ASM_7
#if (uECC_MAX_WORDS > 7)
FAST_MULT_ASM_7_TO_8
#endif
#elif (uECC_MIN_WORDS == 8)
FAST_MULT_ASM_8
#endif
"1: \n\t"
RESUME_SYNTAX
: "+r" (r0), "+r" (r1), "+r" (r2)
: "r" (r3)
: "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory"
);
}
#define asm_mult 1
#if uECC_SQUARE_FUNC
uECC_VLI_API void uECC_vli_square(uECC_word_t *result,
const uECC_word_t *left,
wordcount_t num_words) {
register uint32_t *r0 __asm__("r0") = result;
register const uint32_t *r1 __asm__("r1") = left;
register uint32_t r2 __asm__("r2") = num_words;
__asm__ volatile (
".syntax unified \n\t"
#if (uECC_MIN_WORDS == 5)
FAST_SQUARE_ASM_5
#if (uECC_MAX_WORDS > 5)
FAST_SQUARE_ASM_5_TO_6
#endif
#if (uECC_MAX_WORDS > 6)
FAST_SQUARE_ASM_6_TO_7
#endif
#if (uECC_MAX_WORDS > 7)
FAST_SQUARE_ASM_7_TO_8
#endif
#elif (uECC_MIN_WORDS == 6)
FAST_SQUARE_ASM_6
#if (uECC_MAX_WORDS > 6)
FAST_SQUARE_ASM_6_TO_7
#endif
#if (uECC_MAX_WORDS > 7)
FAST_SQUARE_ASM_7_TO_8
#endif
#elif (uECC_MIN_WORDS == 7)
FAST_SQUARE_ASM_7
#if (uECC_MAX_WORDS > 7)
FAST_SQUARE_ASM_7_TO_8
#endif
#elif (uECC_MIN_WORDS == 8)
FAST_SQUARE_ASM_8
#endif
"1: \n\t"
RESUME_SYNTAX
: "+r" (r0), "+r" (r1)
: "r" (r2)
: "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory"
);
}
#define asm_square 1
#endif /* uECC_SQUARE_FUNC */
#else /* (uECC_OPTIMIZATION_LEVEL > 3) */
uECC_VLI_API void uECC_vli_mult(uint32_t *result,
const uint32_t *left,
const uint32_t *right,
wordcount_t num_words) {
register uint32_t *r0 __asm__("r0") = result;
register const uint32_t *r1 __asm__("r1") = left;
register const uint32_t *r2 __asm__("r2") = right;
register uint32_t r3 __asm__("r3") = num_words;
#if uECC_SUPPORTS_secp160r1
if (num_words == 5) {
__asm__ volatile (
".syntax unified \n\t"
FAST_MULT_ASM_5
RESUME_SYNTAX
: "+r" (r0), "+r" (r1), "+r" (r2)
: "r" (r3)
: "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory"
);
return;
}
#endif
#if uECC_SUPPORTS_secp192r1
if (num_words == 6) {
__asm__ volatile (
".syntax unified \n\t"
FAST_MULT_ASM_6
RESUME_SYNTAX
: "+r" (r0), "+r" (r1), "+r" (r2)
: "r" (r3)
: "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory"
);
return;
}
#endif
#if uECC_SUPPORTS_secp224r1
if (num_words == 7) {
__asm__ volatile (
".syntax unified \n\t"
FAST_MULT_ASM_7
RESUME_SYNTAX
: "+r" (r0), "+r" (r1), "+r" (r2)
: "r" (r3)
: "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory"
);
return;
}
#endif
#if (uECC_SUPPORTS_secp256r1 || uECC_SUPPORTS_secp256k1)
if (num_words == 8) {
__asm__ volatile (
".syntax unified \n\t"
FAST_MULT_ASM_8
RESUME_SYNTAX
: "+r" (r0), "+r" (r1), "+r" (r2)
: "r" (r3)
: "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory"
);
return;
}
#endif
}
#define asm_mult 1
#if uECC_SQUARE_FUNC
uECC_VLI_API void uECC_vli_square(uECC_word_t *result,
const uECC_word_t *left,
wordcount_t num_words) {
register uint32_t *r0 __asm__("r0") = result;
register const uint32_t *r1 __asm__("r1") = left;
register uint32_t r2 __asm__("r2") = num_words;
#if uECC_SUPPORTS_secp160r1
if (num_words == 5) {
__asm__ volatile (
".syntax unified \n\t"
FAST_SQUARE_ASM_5
RESUME_SYNTAX
: "+r" (r0), "+r" (r1)
: "r" (r2)
: "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory"
);
return;
}
#endif
#if uECC_SUPPORTS_secp192r1
if (num_words == 6) {
__asm__ volatile (
".syntax unified \n\t"
FAST_SQUARE_ASM_6
RESUME_SYNTAX
: "+r" (r0), "+r" (r1)
: "r" (r2)
: "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory"
);
return;
}
#endif
#if uECC_SUPPORTS_secp224r1
if (num_words == 7) {
__asm__ volatile (
".syntax unified \n\t"
FAST_SQUARE_ASM_7
RESUME_SYNTAX
: "+r" (r0), "+r" (r1)
: "r" (r2)
: "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory"
);
return;
}
#endif
#if (uECC_SUPPORTS_secp256r1 || uECC_SUPPORTS_secp256k1)
if (num_words == 8) {
__asm__ volatile (
".syntax unified \n\t"
FAST_SQUARE_ASM_8
RESUME_SYNTAX
: "+r" (r0), "+r" (r1)
: "r" (r2)
: "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory"
);
return;
}
#endif
}
#define asm_square 1
#endif /* uECC_SQUARE_FUNC */
#endif /* (uECC_OPTIMIZATION_LEVEL > 3) */
#endif /* uECC_PLATFORM != uECC_arm_thumb */
#endif /* (uECC_OPTIMIZATION_LEVEL >= 3) */
/* ---- "Small" implementations ---- */
#if !asm_add
uECC_VLI_API uECC_word_t uECC_vli_add(uECC_word_t *result,
const uECC_word_t *left,
const uECC_word_t *right,
wordcount_t num_words) {
uint32_t carry = 0;
uint32_t left_word;
uint32_t right_word;
__asm__ volatile (
".syntax unified \n\t"
"1: \n\t"
"ldmia %[lptr]!, {%[left]} \n\t" /* Load left word. */
"ldmia %[rptr]!, {%[right]} \n\t" /* Load right word. */
"lsrs %[carry], #1 \n\t" /* Set up carry flag (carry = 0 after this). */
"adcs %[left], %[left], %[right] \n\t" /* Add with carry. */
"adcs %[carry], %[carry], %[carry] \n\t" /* Store carry bit. */
"stmia %[dptr]!, {%[left]} \n\t" /* Store result word. */
"subs %[ctr], #1 \n\t" /* Decrement counter. */
"bne 1b \n\t" /* Loop until counter == 0. */
RESUME_SYNTAX
: [dptr] REG_RW (result), [lptr] REG_RW (left), [rptr] REG_RW (right),
[ctr] REG_RW (num_words), [carry] REG_RW (carry),
[left] REG_WRITE (left_word), [right] REG_WRITE (right_word)
:
: "cc", "memory"
);
return carry;
}
#define asm_add 1
#endif
#if !asm_sub
uECC_VLI_API uECC_word_t uECC_vli_sub(uECC_word_t *result,
const uECC_word_t *left,
const uECC_word_t *right,
wordcount_t num_words) {
uint32_t carry = 1; /* carry = 1 initially (means don't borrow) */
uint32_t left_word;
uint32_t right_word;
__asm__ volatile (
".syntax unified \n\t"
"1: \n\t"
"ldmia %[lptr]!, {%[left]} \n\t" /* Load left word. */
"ldmia %[rptr]!, {%[right]} \n\t" /* Load right word. */
"lsrs %[carry], #1 \n\t" /* Set up carry flag (carry = 0 after this). */
"sbcs %[left], %[left], %[right] \n\t" /* Subtract with borrow. */
"adcs %[carry], %[carry], %[carry] \n\t" /* Store carry bit. */
"stmia %[dptr]!, {%[left]} \n\t" /* Store result word. */
"subs %[ctr], #1 \n\t" /* Decrement counter. */
"bne 1b \n\t" /* Loop until counter == 0. */
RESUME_SYNTAX
: [dptr] REG_RW (result), [lptr] REG_RW (left), [rptr] REG_RW (right),
[ctr] REG_RW (num_words), [carry] REG_RW (carry),
[left] REG_WRITE (left_word), [right] REG_WRITE (right_word)
:
: "cc", "memory"
);
return !carry;
}
#define asm_sub 1
#endif
#if !asm_mult
uECC_VLI_API void uECC_vli_mult(uECC_word_t *result,
const uECC_word_t *left,
const uECC_word_t *right,
wordcount_t num_words) {
#if (uECC_PLATFORM != uECC_arm_thumb)
uint32_t c0 = 0;
uint32_t c1 = 0;
uint32_t c2 = 0;
uint32_t k = 0;
uint32_t i;
uint32_t t0, t1;
__asm__ volatile (
".syntax unified \n\t"
"1: \n\t" /* outer loop (k < num_words) */
"movs %[i], #0 \n\t" /* i = 0 */
"b 3f \n\t"
"2: \n\t" /* outer loop (k >= num_words) */
"movs %[i], %[k] \n\t" /* i = k */
"subs %[i], %[last_word] \n\t" /* i = k - (num_words - 1) (times 4) */
"3: \n\t" /* inner loop */
"subs %[t0], %[k], %[i] \n\t" /* t0 = k-i */
"ldr %[t1], [%[right], %[t0]] \n\t" /* t1 = right[k - i] */
"ldr %[t0], [%[left], %[i]] \n\t" /* t0 = left[i] */
"umull %[t0], %[t1], %[t0], %[t1] \n\t" /* (t0, t1) = left[i] * right[k - i] */
"adds %[c0], %[c0], %[t0] \n\t" /* add low word to c0 */
"adcs %[c1], %[c1], %[t1] \n\t" /* add high word to c1, including carry */
"adcs %[c2], %[c2], #0 \n\t" /* add carry to c2 */
"adds %[i], #4 \n\t" /* i += 4 */
"cmp %[i], %[last_word] \n\t" /* i > (num_words - 1) (times 4)? */
"bgt 4f \n\t" /* if so, exit the loop */
"cmp %[i], %[k] \n\t" /* i <= k? */
"ble 3b \n\t" /* if so, continue looping */
"4: \n\t" /* end inner loop */
"str %[c0], [%[result], %[k]] \n\t" /* result[k] = c0 */
"mov %[c0], %[c1] \n\t" /* c0 = c1 */
"mov %[c1], %[c2] \n\t" /* c1 = c2 */
"movs %[c2], #0 \n\t" /* c2 = 0 */
"adds %[k], #4 \n\t" /* k += 4 */
"cmp %[k], %[last_word] \n\t" /* k <= (num_words - 1) (times 4) ? */
"ble 1b \n\t" /* if so, loop back, start with i = 0 */
"cmp %[k], %[last_word], lsl #1 \n\t" /* k <= (num_words * 2 - 2) (times 4) ? */
"ble 2b \n\t" /* if so, loop back, start with i = (k + 1) - num_words */
/* end outer loop */
"str %[c0], [%[result], %[k]] \n\t" /* result[num_words * 2 - 1] = c0 */
RESUME_SYNTAX
: [c0] "+r" (c0), [c1] "+r" (c1), [c2] "+r" (c2),
[k] "+r" (k), [i] "=&r" (i), [t0] "=&r" (t0), [t1] "=&r" (t1)
: [result] "r" (result), [left] "r" (left), [right] "r" (right),
[last_word] "r" ((num_words - 1) * 4)
: "cc", "memory"
);
#else /* Thumb-1 */
uint32_t r4, r5, r6, r7;
__asm__ volatile (
".syntax unified \n\t"
"subs %[r3], #1 \n\t" /* r3 = num_words - 1 */
"lsls %[r3], #2 \n\t" /* r3 = (num_words - 1) * 4 */
"mov r8, %[r3] \n\t" /* r8 = (num_words - 1) * 4 */
"lsls %[r3], #1 \n\t" /* r3 = (num_words - 1) * 8 */
"mov r9, %[r3] \n\t" /* r9 = (num_words - 1) * 8 */
"movs %[r3], #0 \n\t" /* c0 = 0 */
"movs %[r4], #0 \n\t" /* c1 = 0 */
"movs %[r5], #0 \n\t" /* c2 = 0 */
"movs %[r6], #0 \n\t" /* k = 0 */
"push {%[r0]} \n\t" /* keep result on the stack */
"1: \n\t" /* outer loop (k < num_words) */
"movs %[r7], #0 \n\t" /* r7 = i = 0 */
"b 3f \n\t"
"2: \n\t" /* outer loop (k >= num_words) */
"movs %[r7], %[r6] \n\t" /* r7 = k */
"mov %[r0], r8 \n\t" /* r0 = (num_words - 1) * 4 */
"subs %[r7], %[r0] \n\t" /* r7 = i = k - (num_words - 1) (times 4) */
"3: \n\t" /* inner loop */
"mov r10, %[r3] \n\t"
"mov r11, %[r4] \n\t"
"mov r12, %[r5] \n\t"
"mov r14, %[r6] \n\t"
"subs %[r0], %[r6], %[r7] \n\t" /* r0 = k - i */
"ldr %[r4], [%[r2], %[r0]] \n\t" /* r4 = right[k - i] */
"ldr %[r0], [%[r1], %[r7]] \n\t" /* r0 = left[i] */
"lsrs %[r3], %[r0], #16 \n\t" /* r3 = a1 */
"uxth %[r0], %[r0] \n\t" /* r0 = a0 */
"lsrs %[r5], %[r4], #16 \n\t" /* r5 = b1 */
"uxth %[r4], %[r4] \n\t" /* r4 = b0 */
"movs %[r6], %[r3] \n\t" /* r6 = a1 */
"muls %[r6], %[r5], %[r6] \n\t" /* r6 = a1 * b1 */
"muls %[r3], %[r4], %[r3] \n\t" /* r3 = b0 * a1 */
"muls %[r5], %[r0], %[r5] \n\t" /* r5 = a0 * b1 */
"muls %[r0], %[r4], %[r0] \n\t" /* r0 = a0 * b0 */
/* Add middle terms */
"lsls %[r4], %[r3], #16 \n\t"
"lsrs %[r3], %[r3], #16 \n\t"
"adds %[r0], %[r4] \n\t"
"adcs %[r6], %[r3] \n\t"
"lsls %[r4], %[r5], #16 \n\t"
"lsrs %[r5], %[r5], #16 \n\t"
"adds %[r0], %[r4] \n\t"
"adcs %[r6], %[r5] \n\t"
"mov %[r3], r10\n\t"
"mov %[r4], r11\n\t"
"mov %[r5], r12\n\t"
"adds %[r3], %[r0] \n\t" /* add low word to c0 */
"adcs %[r4], %[r6] \n\t" /* add high word to c1, including carry */
"movs %[r0], #0 \n\t" /* r0 = 0 (does not affect carry bit) */
"adcs %[r5], %[r0] \n\t" /* add carry to c2 */
"mov %[r6], r14\n\t" /* r6 = k */
"adds %[r7], #4 \n\t" /* i += 4 */
"cmp %[r7], r8 \n\t" /* i > (num_words - 1) (times 4)? */
"bgt 4f \n\t" /* if so, exit the loop */
"cmp %[r7], %[r6] \n\t" /* i <= k? */
"ble 3b \n\t" /* if so, continue looping */
"4: \n\t" /* end inner loop */
"ldr %[r0], [sp, #0] \n\t" /* r0 = result */
"str %[r3], [%[r0], %[r6]] \n\t" /* result[k] = c0 */
"mov %[r3], %[r4] \n\t" /* c0 = c1 */
"mov %[r4], %[r5] \n\t" /* c1 = c2 */
"movs %[r5], #0 \n\t" /* c2 = 0 */
"adds %[r6], #4 \n\t" /* k += 4 */
"cmp %[r6], r8 \n\t" /* k <= (num_words - 1) (times 4) ? */
"ble 1b \n\t" /* if so, loop back, start with i = 0 */
"cmp %[r6], r9 \n\t" /* k <= (num_words * 2 - 2) (times 4) ? */
"ble 2b \n\t" /* if so, loop back, with i = (k + 1) - num_words */
/* end outer loop */
"str %[r3], [%[r0], %[r6]] \n\t" /* result[num_words * 2 - 1] = c0 */
"pop {%[r0]} \n\t" /* pop result off the stack */
RESUME_SYNTAX
: [r3] "+l" (num_words), [r4] "=&l" (r4),
[r5] "=&l" (r5), [r6] "=&l" (r6), [r7] "=&l" (r7)
: [r0] "l" (result), [r1] "l" (left), [r2] "l" (right)
: "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory"
);
#endif
}
#define asm_mult 1
#endif
#if uECC_SQUARE_FUNC
#if !asm_square
uECC_VLI_API void uECC_vli_square(uECC_word_t *result,
const uECC_word_t *left,
wordcount_t num_words) {
#if (uECC_PLATFORM != uECC_arm_thumb)
uint32_t c0 = 0;
uint32_t c1 = 0;
uint32_t c2 = 0;
uint32_t k = 0;
uint32_t i, tt;
uint32_t t0, t1;
__asm__ volatile (
".syntax unified \n\t"
"1: \n\t" /* outer loop (k < num_words) */
"movs %[i], #0 \n\t" /* i = 0 */
"b 3f \n\t"
"2: \n\t" /* outer loop (k >= num_words) */
"movs %[i], %[k] \n\t" /* i = k */
"subs %[i], %[last_word] \n\t" /* i = k - (num_words - 1) (times 4) */
"3: \n\t" /* inner loop */
"subs %[tt], %[k], %[i] \n\t" /* tt = k-i */
"ldr %[t1], [%[left], %[tt]] \n\t" /* t1 = left[k - i] */
"ldr %[t0], [%[left], %[i]] \n\t" /* t0 = left[i] */
"umull %[t0], %[t1], %[t0], %[t1] \n\t" /* (t0, t1) = left[i] * right[k - i] */
"cmp %[i], %[tt] \n\t" /* (i < k - i) ? */
"bge 4f \n\t" /* if i >= k - i, skip */
"adds %[c0], %[c0], %[t0] \n\t" /* add low word to c0 */
"adcs %[c1], %[c1], %[t1] \n\t" /* add high word to c1, including carry */
"adcs %[c2], %[c2], #0 \n\t" /* add carry to c2 */
"4: \n\t"
"adds %[c0], %[c0], %[t0] \n\t" /* add low word to c0 */
"adcs %[c1], %[c1], %[t1] \n\t" /* add high word to c1, including carry */
"adcs %[c2], %[c2], #0 \n\t" /* add carry to c2 */
"adds %[i], #4 \n\t" /* i += 4 */
"cmp %[i], %[k] \n\t" /* i >= k? */
"bge 5f \n\t" /* if so, exit the loop */
"subs %[tt], %[k], %[i] \n\t" /* tt = k - i */
"cmp %[i], %[tt] \n\t" /* i <= k - i? */
"ble 3b \n\t" /* if so, continue looping */
"5: \n\t" /* end inner loop */
"str %[c0], [%[result], %[k]] \n\t" /* result[k] = c0 */
"mov %[c0], %[c1] \n\t" /* c0 = c1 */
"mov %[c1], %[c2] \n\t" /* c1 = c2 */
"movs %[c2], #0 \n\t" /* c2 = 0 */
"adds %[k], #4 \n\t" /* k += 4 */
"cmp %[k], %[last_word] \n\t" /* k <= (num_words - 1) (times 4) ? */
"ble 1b \n\t" /* if so, loop back, start with i = 0 */
"cmp %[k], %[last_word], lsl #1 \n\t" /* k <= (num_words * 2 - 2) (times 4) ? */
"ble 2b \n\t" /* if so, loop back, start with i = (k + 1) - num_words */
/* end outer loop */
"str %[c0], [%[result], %[k]] \n\t" /* result[num_words * 2 - 1] = c0 */
RESUME_SYNTAX
: [c0] "+r" (c0), [c1] "+r" (c1), [c2] "+r" (c2),
[k] "+r" (k), [i] "=&r" (i), [tt] "=&r" (tt), [t0] "=&r" (t0), [t1] "=&r" (t1)
: [result] "r" (result), [left] "r" (left), [last_word] "r" ((num_words - 1) * 4)
: "cc", "memory"
);
#else
uint32_t r3, r4, r5, r6, r7;
__asm__ volatile (
".syntax unified \n\t"
"subs %[r2], #1 \n\t" /* r2 = num_words - 1 */
"lsls %[r2], #2 \n\t" /* r2 = (num_words - 1) * 4 */
"mov r8, %[r2] \n\t" /* r8 = (num_words - 1) * 4 */
"lsls %[r2], #1 \n\t" /* r2 = (num_words - 1) * 8 */
"mov r9, %[r2] \n\t" /* r9 = (num_words - 1) * 8 */
"movs %[r2], #0 \n\t" /* c0 = 0 */
"movs %[r3], #0 \n\t" /* c1 = 0 */
"movs %[r4], #0 \n\t" /* c2 = 0 */
"movs %[r5], #0 \n\t" /* k = 0 */
"push {%[r0]} \n\t" /* keep result on the stack */
"1: \n\t" /* outer loop (k < num_words) */
"movs %[r6], #0 \n\t" /* r6 = i = 0 */
"b 3f \n\t"
"2: \n\t" /* outer loop (k >= num_words) */
"movs %[r6], %[r5] \n\t" /* r6 = k */
"mov %[r0], r8 \n\t" /* r0 = (num_words - 1) * 4 */
"subs %[r6], %[r0] \n\t" /* r6 = i = k - (num_words - 1) (times 4) */
"3: \n\t" /* inner loop */
"mov r10, %[r2] \n\t"
"mov r11, %[r3] \n\t"
"mov r12, %[r4] \n\t"
"mov r14, %[r5] \n\t"
"subs %[r7], %[r5], %[r6] \n\t" /* r7 = k - i */
"ldr %[r3], [%[r1], %[r7]] \n\t" /* r3 = left[k - i] */
"ldr %[r0], [%[r1], %[r6]] \n\t" /* r0 = left[i] */
"lsrs %[r2], %[r0], #16 \n\t" /* r2 = a1 */
"uxth %[r0], %[r0] \n\t" /* r0 = a0 */
"lsrs %[r4], %[r3], #16 \n\t" /* r4 = b1 */
"uxth %[r3], %[r3] \n\t" /* r3 = b0 */
"movs %[r5], %[r2] \n\t" /* r5 = a1 */
"muls %[r5], %[r4], %[r5] \n\t" /* r5 = a1 * b1 */
"muls %[r2], %[r3], %[r2] \n\t" /* r2 = b0 * a1 */
"muls %[r4], %[r0], %[r4] \n\t" /* r4 = a0 * b1 */
"muls %[r0], %[r3], %[r0] \n\t" /* r0 = a0 * b0 */
/* Add middle terms */
"lsls %[r3], %[r2], #16 \n\t"
"lsrs %[r2], %[r2], #16 \n\t"
"adds %[r0], %[r3] \n\t"
"adcs %[r5], %[r2] \n\t"
"lsls %[r3], %[r4], #16 \n\t"
"lsrs %[r4], %[r4], #16 \n\t"
"adds %[r0], %[r3] \n\t"
"adcs %[r5], %[r4] \n\t"
/* Add to acc, doubling if necessary */
"mov %[r2], r10\n\t"
"mov %[r3], r11\n\t"
"mov %[r4], r12\n\t"
"cmp %[r6], %[r7] \n\t" /* (i < k - i) ? */
"bge 4f \n\t" /* if i >= k - i, skip */
"movs %[r7], #0 \n\t" /* r7 = 0 */
"adds %[r2], %[r0] \n\t" /* add low word to c0 */
"adcs %[r3], %[r5] \n\t" /* add high word to c1, including carry */
"adcs %[r4], %[r7] \n\t" /* add carry to c2 */
"4: \n\t"
"movs %[r7], #0 \n\t" /* r7 = 0 */
"adds %[r2], %[r0] \n\t" /* add low word to c0 */
"adcs %[r3], %[r5] \n\t" /* add high word to c1, including carry */
"adcs %[r4], %[r7] \n\t" /* add carry to c2 */
"mov %[r5], r14\n\t" /* r5 = k */
"adds %[r6], #4 \n\t" /* i += 4 */
"cmp %[r6], %[r5] \n\t" /* i >= k? */
"bge 5f \n\t" /* if so, exit the loop */
"subs %[r7], %[r5], %[r6] \n\t" /* r7 = k - i */
"cmp %[r6], %[r7] \n\t" /* i <= k - i? */
"ble 3b \n\t" /* if so, continue looping */
"5: \n\t" /* end inner loop */
"ldr %[r0], [sp, #0] \n\t" /* r0 = result */
"str %[r2], [%[r0], %[r5]] \n\t" /* result[k] = c0 */
"mov %[r2], %[r3] \n\t" /* c0 = c1 */
"mov %[r3], %[r4] \n\t" /* c1 = c2 */
"movs %[r4], #0 \n\t" /* c2 = 0 */
"adds %[r5], #4 \n\t" /* k += 4 */
"cmp %[r5], r8 \n\t" /* k <= (num_words - 1) (times 4) ? */
"ble 1b \n\t" /* if so, loop back, start with i = 0 */
"cmp %[r5], r9 \n\t" /* k <= (num_words * 2 - 2) (times 4) ? */
"ble 2b \n\t" /* if so, loop back, with i = (k + 1) - num_words */
/* end outer loop */
"str %[r2], [%[r0], %[r5]] \n\t" /* result[num_words * 2 - 1] = c0 */
"pop {%[r0]} \n\t" /* pop result off the stack */
RESUME_SYNTAX
: [r2] "+l" (num_words), [r3] "=&l" (r3), [r4] "=&l" (r4),
[r5] "=&l" (r5), [r6] "=&l" (r6), [r7] "=&l" (r7)
: [r0] "l" (result), [r1] "l" (left)
: "r8", "r9", "r10", "r11", "r12", "r14", "cc", "memory"
);
#endif
}
#define asm_square 1
#endif
#endif /* uECC_SQUARE_FUNC */
#endif /* _UECC_ASM_ARM_H_ */