diff options
| author | Eric Biggers <ebiggers@kernel.org> | 2025-12-04 21:11:55 -0800 |
|---|---|---|
| committer | Eric Biggers <ebiggers@kernel.org> | 2025-12-09 15:10:21 -0800 |
| commit | 68b233b1d583f7d869fbb3afe2b0531138e001f7 (patch) | |
| tree | b9cf9cf8b244d791a7d3e1e92636d232721cd868 | |
| parent | 2e8f7b170a085f0f5522f262bffe92d6ec911abb (diff) | |
| download | tip-68b233b1d583f7d869fbb3afe2b0531138e001f7.tar.gz | |
lib/crypto: blake2s: Replace manual unrolling with unrolled_full
As we're doing in the BLAKE2b code, use unrolled_full to make the
compiler handle the loop unrolling. This simplifies the code slightly.
The generated object code is nearly the same with both gcc and clang.
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20251205051155.25274-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
| -rw-r--r-- | lib/crypto/blake2s.c | 38 |
1 files changed, 16 insertions, 22 deletions
diff --git a/lib/crypto/blake2s.c b/lib/crypto/blake2s.c index 6182c21ed943d8..71578a08474233 100644 --- a/lib/crypto/blake2s.c +++ b/lib/crypto/blake2s.c @@ -14,6 +14,7 @@ #include <linux/kernel.h> #include <linux/module.h> #include <linux/string.h> +#include <linux/unroll.h> #include <linux/types.h> static const u8 blake2s_sigma[10][16] = { @@ -71,29 +72,22 @@ blake2s_compress_generic(struct blake2s_ctx *ctx, b = ror32(b ^ c, 7); \ } while (0) -#define ROUND(r) do { \ - G(r, 0, v[0], v[ 4], v[ 8], v[12]); \ - G(r, 1, v[1], v[ 5], v[ 9], v[13]); \ - G(r, 2, v[2], v[ 6], v[10], v[14]); \ - G(r, 3, v[3], v[ 7], v[11], v[15]); \ - G(r, 4, v[0], v[ 5], v[10], v[15]); \ - G(r, 5, v[1], v[ 6], v[11], v[12]); \ - G(r, 6, v[2], v[ 7], v[ 8], v[13]); \ - G(r, 7, v[3], v[ 4], v[ 9], v[14]); \ -} while (0) - ROUND(0); - ROUND(1); - ROUND(2); - ROUND(3); - ROUND(4); - ROUND(5); - ROUND(6); - ROUND(7); - ROUND(8); - ROUND(9); - + /* + * Unroll the rounds loop to enable constant-folding of the + * blake2s_sigma values. + */ + unrolled_full + for (int r = 0; r < 10; r++) { + G(r, 0, v[0], v[4], v[8], v[12]); + G(r, 1, v[1], v[5], v[9], v[13]); + G(r, 2, v[2], v[6], v[10], v[14]); + G(r, 3, v[3], v[7], v[11], v[15]); + G(r, 4, v[0], v[5], v[10], v[15]); + G(r, 5, v[1], v[6], v[11], v[12]); + G(r, 6, v[2], v[7], v[8], v[13]); + G(r, 7, v[3], v[4], v[9], v[14]); + } #undef G -#undef ROUND for (i = 0; i < 8; ++i) ctx->h[i] ^= v[i] ^ v[i + 8]; |