diff options
| -rw-r--r-- | sha3.c | 66 |
1 files changed, 50 insertions, 16 deletions
@@ -34,12 +34,12 @@ #define BACKEND_HYBRID 5 // Hybrid scalar/neon backend. Slower than scalar. // if BACKEND is defined and set to 0 (the default), then unset it -// and auto-detect the appropriate backend +// and auto-detect the appropriate backend below #if defined(BACKEND) && BACKEND == BACKEND_AUTO #undef BACKEND #endif /* defined(BACKEND) && BACKEND == 0 */ -// detect backend +// auto-detect backend #ifndef BACKEND #if defined(__AVX512F__) #define BACKEND BACKEND_AVX512 @@ -74,14 +74,21 @@ static const uint64_t RCS[] = { }; #if (BACKEND == BACKEND_SCALAR) || defined(TEST_SHA3) -// If AVX-512 is supported and we are not building the test suite, -// then do not compile the scalar step functions. +// The scalar Keccak step functions in this block are only built if one +// of the following conditions is true: // -// (because they aren't used by the AVX-512 implementation). +// * we are using the scalar backend, or +// * we are building the test suite. +// +// The scalar Keccak step functions in this block are not built for +// AVX-512 and Neon backends, because those backends do not use them. /** * @brief Theta step of scalar Keccak permutation. * @param[in,out] a Keccak state (array of 25 64-bit integers). + * + * @note Only built when using the scalar backend or when building the + * test suite. */ static inline void theta(uint64_t a[static 25]) { const uint64_t c[5] = { @@ -110,6 +117,9 @@ static inline void theta(uint64_t a[static 25]) { /** * @brief Rho step of scalar Keccak permutation. * @param[in,out] a Keccak state (array of 25 64-bit integers). + * + * @note Only built when using the scalar backend or when building the + * test suite. */ static inline void rho(uint64_t a[static 25]) { a[ 1] = ROL(a[ 1], 1); // 1 % 64 = 1 @@ -145,6 +155,9 @@ static inline void rho(uint64_t a[static 25]) { /** * @brief Pi step of scalar Keccak permutation. * @param[in,out] a Keccak state (array of 25 64-bit integers). + * + * @note Only built when using the scalar backend or when building the + * test suite. */ static inline void pi(uint64_t dst[static 25], const uint64_t src[static 25]) { dst[ 0] = src[ 0]; @@ -181,6 +194,9 @@ static inline void pi(uint64_t dst[static 25], const uint64_t src[static 25]) { /** * @brief Chi step of scalar Keccak permutation. * @param[in,out] a Keccak state (array of 25 64-bit integers). + * + * @note Only built when using the scalar backend or when building the + * test suite. */ static inline void chi(uint64_t dst[static 25], const uint64_t src[static 25]) { dst[ 0] = src[ 0] ^ (~src[ 1] & src[ 2]); @@ -217,6 +233,9 @@ static inline void chi(uint64_t dst[static 25], const uint64_t src[static 25]) { /** * @brief Iota step of scalar Keccak permutation. * @param[in,out] a Keccak state (array of 25 64-bit integers). + * + * @note Only built when using the scalar backend or when building the + * test suite. */ static inline void iota(uint64_t a[static 25], const int i) { a[0] ^= RCS[i]; @@ -229,6 +248,9 @@ static inline void iota(uint64_t a[static 25], const int i) { * * @param[in,out] a Keccak state (array of 25 64-bit integers). * @param[in] num_rounds Number of rounds (12 or 24). + * + * @note Only built when using the scalar backend or when building the + * test suite. */ static inline void permute_n_scalar(uint64_t a[static 25], const size_t num_rounds) { uint64_t tmp[25] = { 0 }; @@ -469,7 +491,6 @@ static inline void permute_n_avx512(uint64_t s[static 25], const size_t num_roun #include <arm_neon.h> // rotate elements in uint64x2_t left by N bits -// vrax1q_u64() not supported on pizza #define VROLQ(A, N) vsriq_n_u64(vshlq_n_u64((A), (N)), (A), 64-(N)) // keccak row, represented as 3 128-bit vector registers @@ -478,10 +499,20 @@ static inline void permute_n_avx512(uint64_t s[static 25], const size_t num_roun // 64-bit lane per row at the expense of making many of the instructions // simpler. typedef struct { - uint64x2_t p0, p1, p2; + uint64x2_t p0, // columns 0 and 1 + p1, // columns 2 and 3 + p2; // column 4. high lane is unused } row_t; -// set contents of row +/** + * @brief Set row contents. + * + * Apply `num_rounds` of Keccak permutation. + * + * @param[in] p0 Value of columns 0 and 1. + * @param[in] p1 Value of columns 2 and 3. + * @param[in] p2 Value of columns 4 in low lane. High lane is unused. + */ static inline row_t row_set(const uint64x2_t a, const uint64x2_t b, const uint64x2_t c) { return (row_t) { a, b, c }; } @@ -489,18 +520,20 @@ static inline row_t row_set(const uint64x2_t a, const uint64x2_t b, const uint64 // get Nth pair of u64s from row #define ROW_GET(A, N) ((A).p ## N) -// load row from array +/** + * @brief Load row from memory. + * @param[in] p Pointer to 40 bytes of memory. + * @return row_t + */ static inline row_t row_load(const uint64_t p[static 5]) { return row_set(vld1q_u64(p + 0), vld1q_u64(p + 2), vdupq_n_u64(p[4])); } -// load row from array -static inline row_t row_load_unsafe(const uint64_t p[static 6]) { - const uint64x2x3_t d = vld1q_u64_x3(p); - return row_set(d.val[0], d.val[1], d.val[2]); -} - -// store row to array +/** + * @brief Store row to memory. + * @param[in] p Pointer to 40 bytes of memory. + * @param[in] a Row to store. + */ static inline void row_store(uint64_t p[static 5], const row_t a) { const uint64x2x2_t vals = { .val = { ROW_GET(a, 0), ROW_GET(a, 1) } }; vst1q_u64_x2(p + 0, vals); @@ -563,6 +596,7 @@ static inline row_t row_eor5(const row_t a, const row_t b, const row_t c, const } // rotate bits in each lane left one bit +// FIXME: want vrax1q_u64() (not supported on n2l or pi5) static inline row_t row_rol1_u64(const row_t a) { return row_set( VROLQ(ROW_GET(a, 0), 1), |