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Avoid undefined shift behaviour

master
Pieter Wuille 8 years ago
parent
commit
9048def7c7
  1. 2
      src/scalar_4x64_impl.h
  2. 2
      src/scalar_8x32_impl.h

2
src/scalar_4x64_impl.h

@ -95,7 +95,7 @@ static void secp256k1_scalar_add(secp256k1_scalar_t *r, const secp256k1_scalar_t @@ -95,7 +95,7 @@ static void secp256k1_scalar_add(secp256k1_scalar_t *r, const secp256k1_scalar_t
static void secp256k1_scalar_add_bit(secp256k1_scalar_t *r, unsigned int bit) {
VERIFY_CHECK(bit < 256);
uint128_t t = (uint128_t)r->d[0] + (((uint64_t)((bit >> 6) == 0)) << bit);
uint128_t t = (uint128_t)r->d[0] + (((uint64_t)((bit >> 6) == 0)) << (bit & 0x3F));
r->d[0] = t & 0xFFFFFFFFFFFFFFFFULL; t >>= 64;
t += (uint128_t)r->d[1] + (((uint64_t)((bit >> 6) == 1)) << (bit & 0x3F));
r->d[1] = t & 0xFFFFFFFFFFFFFFFFULL; t >>= 64;

2
src/scalar_8x32_impl.h

@ -133,7 +133,7 @@ static void secp256k1_scalar_add(secp256k1_scalar_t *r, const secp256k1_scalar_t @@ -133,7 +133,7 @@ static void secp256k1_scalar_add(secp256k1_scalar_t *r, const secp256k1_scalar_t
static void secp256k1_scalar_add_bit(secp256k1_scalar_t *r, unsigned int bit) {
VERIFY_CHECK(bit < 256);
uint64_t t = (uint64_t)r->d[0] + (((uint32_t)((bit >> 5) == 0)) << bit);
uint64_t t = (uint64_t)r->d[0] + (((uint32_t)((bit >> 5) == 0)) << (bit & 0x1F));
r->d[0] = t & 0xFFFFFFFFULL; t >>= 32;
t += (uint64_t)r->d[1] + (((uint32_t)((bit >> 5) == 1)) << (bit & 0x1F));
r->d[1] = t & 0xFFFFFFFFULL; t >>= 32;

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