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Revert "optimize constant_time_conditional_memxor for gcc". #2735

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Revert "optimize constant_time_conditional_memxor for gcc". #2735

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11 changes: 0 additions & 11 deletions crypto/internal.h
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Original file line number Diff line number Diff line change
Expand Up @@ -263,17 +263,6 @@ static inline void constant_time_conditional_memxor(void *dst, const void *src,
debug_assert_nonsecret(!buffers_alias(dst, n, src, n));
aliasing_uint8_t *out = dst;
const aliasing_uint8_t *in = src;
#if defined(__GNUC__) && !defined(__clang__)
// gcc 13.2.0 doesn't automatically vectorize this loop regardless of barrier
typedef aliasing_uint8_t v32u8 __attribute__((vector_size(32), aligned(1), may_alias));
size_t n_vec = n&~(size_t)31;
v32u8 masks = ((aliasing_uint8_t)mask-(v32u8){}); // broadcast
for (size_t i = 0; i < n_vec; i += 32) {
*(v32u8*)&out[i] ^= masks & *(v32u8 const*)&in[i];
}
out += n_vec;
n -= n_vec;
#endif
for (size_t i = 0; i < n; i++) {
out[i] ^= value_barrier_w(mask) & in[i];
}
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