# Re: \[PATCH 2/7\] PowerPC: add unlikely() to BUG\_ON()

- From: Andreas Schwab \<hidden\>
- Date: 2011-01-28 10:14:39 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2011/01/3670983
- Thread: https://ratatoskr.run/linuxppc-dev/2011/01/3670983/t.md

```text
"David Laight" [ref] writes:

> Also, as (I think) in some of the generated code quoted,
> use of __builtin_expect() with a boolean expression can
> force some versions of gcc to generate the integer
> value of the expression

That's more likely a side effect of the definition of likely/unlikely:
they expand to !!(x).

Andreas.

-- 
Andreas Schwab, schwab@redhat.com
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```