From 5d8f53e31293c582fb3fe02157bc67d2eeccea77 Mon Sep 17 00:00:00 2001 From: Russell O'Connor Date: Tue, 7 Mar 2023 09:10:36 -0500 Subject: [PATCH] Remove redudent checks. 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. --- src/modinv32_impl.h | 2 -- src/modinv64_impl.h | 2 -- 2 files changed, 4 deletions(-) diff --git a/src/modinv32_impl.h b/src/modinv32_impl.h index 72065b45f..643750560 100644 --- a/src/modinv32_impl.h +++ b/src/modinv32_impl.h @@ -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(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(labs(v) <= M30 + 1); /* |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 */ #endif /* [md,me] start as zero; plus [u,q] if d is negative; plus [v,r] if e is negative. */ diff --git a/src/modinv64_impl.h b/src/modinv64_impl.h index ae596cf0d..e33727d38 100644 --- a/src/modinv64_impl.h +++ b/src/modinv64_impl.h @@ -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(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_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(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 */ #endif /* [md,me] start as zero; plus [u,q] if d is negative; plus [v,r] if e is negative. */