random: eliminate redundant new_rotate variable
- eliminate new_rotate - move input_rotate masking - simplify input_rotate update - move input_rotate update to end of inner loop for readability Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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@ -455,7 +455,7 @@ static void __add_entropy_words(struct entropy_store *r, const __u32 *in,
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0x00000000, 0x3b6e20c8, 0x76dc4190, 0x4db26158,
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0xedb88320, 0xd6d6a3e8, 0x9b64c2b0, 0xa00ae278 };
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unsigned long i, add_ptr, tap1, tap2, tap3, tap4, tap5;
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int new_rotate, input_rotate;
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int input_rotate;
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int wordmask = r->poolinfo->poolwords - 1;
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__u32 w, next_w;
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unsigned long flags;
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@ -474,20 +474,10 @@ static void __add_entropy_words(struct entropy_store *r, const __u32 *in,
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add_ptr = r->add_ptr;
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while (nwords--) {
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w = rol32(next_w, input_rotate);
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w = rol32(next_w, input_rotate & 31);
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if (nwords > 0)
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next_w = *in++;
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i = add_ptr = (add_ptr - 1) & wordmask;
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/*
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* Normally, we add 7 bits of rotation to the pool.
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* At the beginning of the pool, add an extra 7 bits
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* rotation, so that successive passes spread the
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* input bits across the pool evenly.
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*/
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new_rotate = input_rotate + 14;
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if (i)
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new_rotate = input_rotate + 7;
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input_rotate = new_rotate & 31;
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/* XOR in the various taps */
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w ^= r->pool[(i + tap1) & wordmask];
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@ -497,6 +487,14 @@ static void __add_entropy_words(struct entropy_store *r, const __u32 *in,
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w ^= r->pool[(i + tap5) & wordmask];
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w ^= r->pool[i];
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r->pool[i] = (w >> 3) ^ twist_table[w & 7];
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/*
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* Normally, we add 7 bits of rotation to the pool.
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* At the beginning of the pool, add an extra 7 bits
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* rotation, so that successive passes spread the
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* input bits across the pool evenly.
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*/
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input_rotate += i ? 7 : 14;
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}
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r->input_rotate = input_rotate;
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