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Remove redudent checks.

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These abs checks are implied by the subsequent line, and with the subsequent line written as it is, no underflow is possible with signed integers.
This commit is contained in:
Russell O'Connor 2023-03-07 09:10:36 -05:00
parent 8962fc95bb
commit 5d8f53e312
2 changed files with 0 additions and 4 deletions
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2
src/modinv32_impl.h
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@ -415,9 +415,7 @@ static void secp256k1_modinv32_update_de_30(secp256k1_modinv32_signed30 *d, secp
VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(d, 9, &modinfo->modulus, 1) < 0); /* d < modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(d, 9, &modinfo->modulus, 1) < 0); /* d < modulus */
VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(e, 9, &modinfo->modulus, -2) > 0); /* e > -2*modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(e, 9, &modinfo->modulus, -2) > 0); /* e > -2*modulus */
VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(e, 9, &modinfo->modulus, 1) < 0); /* e < modulus */ VERIFY_CHECK(secp256k1_modinv32_mul_cmp_30(e, 9, &modinfo->modulus, 1) < 0); /* e < modulus */
VERIFY_CHECK(labs(v) <= M30 + 1); /* |v| <= 2^30 */
VERIFY_CHECK(labs(u) <= (M30 + 1 - labs(v))); /* |u|+|v| <= 2^30 */ VERIFY_CHECK(labs(u) <= (M30 + 1 - labs(v))); /* |u|+|v| <= 2^30 */
VERIFY_CHECK(labs(r) <= M30 + 1); /* |r| <= 2^30 */
VERIFY_CHECK(labs(q) <= (M30 + 1 - labs(r))); /* |q|+|r| <= 2^30 */ VERIFY_CHECK(labs(q) <= (M30 + 1 - labs(r))); /* |q|+|r| <= 2^30 */
#endif #endif
/* [md,me] start as zero; plus [u,q] if d is negative; plus [v,r] if e is negative. */ /* [md,me] start as zero; plus [u,q] if d is negative; plus [v,r] if e is negative. */

2
src/modinv64_impl.h
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@ -419,9 +419,7 @@ static void secp256k1_modinv64_update_de_62(secp256k1_modinv64_signed62 *d, secp
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(d, 5, &modinfo->modulus, 1) < 0); /* d < modulus */ VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(d, 5, &modinfo->modulus, 1) < 0); /* d < modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(e, 5, &modinfo->modulus, -2) > 0); /* e > -2*modulus */ VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(e, 5, &modinfo->modulus, -2) > 0); /* e > -2*modulus */
VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(e, 5, &modinfo->modulus, 1) < 0); /* e < modulus */ VERIFY_CHECK(secp256k1_modinv64_mul_cmp_62(e, 5, &modinfo->modulus, 1) < 0); /* e < modulus */
VERIFY_CHECK(secp256k1_modinv64_abs(v) <= (int64_t)1 << 62); /* |v| <= 2^62 */
VERIFY_CHECK(secp256k1_modinv64_abs(u) <= (((int64_t)1 << 62) - secp256k1_modinv64_abs(v))); /* |u|+|v| <= 2^62 */ VERIFY_CHECK(secp256k1_modinv64_abs(u) <= (((int64_t)1 << 62) - secp256k1_modinv64_abs(v))); /* |u|+|v| <= 2^62 */
VERIFY_CHECK(secp256k1_modinv64_abs(r) <= (int64_t)1 << 62); /* |r| <= 2^62 */
VERIFY_CHECK(secp256k1_modinv64_abs(q) <= (((int64_t)1 << 62) - secp256k1_modinv64_abs(r))); /* |q|+|r| <= 2^62 */ VERIFY_CHECK(secp256k1_modinv64_abs(q) <= (((int64_t)1 << 62) - secp256k1_modinv64_abs(r))); /* |q|+|r| <= 2^62 */
#endif #endif
/* [md,me] start as zero; plus [u,q] if d is negative; plus [v,r] if e is negative. */ /* [md,me] start as zero; plus [u,q] if d is negative; plus [v,r] if e is negative. */