Kai Liu
micro-ECC for mbed, ported from GCC version from Github,
Dependents: mbed_microECC Wallet_v1
Diff: asm_arm.h
- Revision:
- 0:b6fdeddc0bc9
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/asm_arm.h Thu Sep 07 12:10:11 2017 +0000
@@ -0,0 +1,820 @@
+/* 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 */
+
+ ".syntax divided \n\t"
+ : [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 */
+
+ ".syntax divided \n\t"
+ : [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_ */