random: help compiler out with fast_mix() by using simpler arguments

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commit 791332b3cb upstream.

Now that fast_mix() has more than one caller, gcc no longer inlines it.
That's fine. But it also doesn't handle the compound literal argument we
pass it very efficiently, nor does it handle the loop as well as it
could. So just expand the code to spell out this function so that it
generates the same code as it did before. Performance-wise, this now
behaves as it did before the last commit. The difference in actual code
size on x86 is 45 bytes, which is less than a cache line.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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Jason A. Donenfeld 2022-05-06 23:19:43 +02:00 • committed by Greg Kroah-Hartman

parent 4649394c47

commit 82caef8409

1 changed files with 23 additions and 21 deletions

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drivers/char/random.c

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