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Re: [PATCH] Add inline bsearch expansion

On 01/05/2013 04:26 PM, OndÅej BÃlka wrote:
On Sat, Jan 05, 2013 at 02:19:37PM +0100, Jakub Jelinek wrote:
On Sat, Jan 05, 2013 at 01:51:30PM +0100, OndÅej BÃlka wrote:
I looked into qsort/bsearch functions. Here I
added inline version of bsearch.

It saves multiplications instructions as size is
most of time known in advance.
When compiled with gcc-4.7.1 and icc 12.1.4 with -O2
it can inline ccmp functions from example below.
gcc-4.5.3 does not inline ccmp.

I don't comment on whether it is a good idea or not etc., just nits that you should guard it with #ifdef __USE_EXTERN_INLINES and use __extern_inline instead of extern inline.


I also added gcc-4.7 requirement as element size can be probably better handled separately. When I profiled my system bsearch was mostly used by firefox. There element sizes were from 90% 8,16,32 and 10% 40,56.

  stdlib/stdlib.h |   33 +++++++++++++++++++++++++++++++++
  1 files changed, 33 insertions(+), 0 deletions(-)

diff --git a/stdlib/stdlib.h b/stdlib/stdlib.h
index fc83f4e..bcb504e 100644
--- a/stdlib/stdlib.h
+++ b/stdlib/stdlib.h
@@ -755,6 +755,39 @@ extern void *bsearch (const void *__key, const void *__base,
  		      size_t __nmemb, size_t __size, __compar_fn_t __compar)
       __nonnull ((1, 2, 5)) __wur;

+/* From gcc-4.7 we can inline __compar function.  */
+#if __GNUC_PREREQ (4, 7)

What exactly is the dependency on GCC 4.7? Just that 4.7 inlines this and previous versions not?

What about other compilers that inline it?

I guess we can drop the dependency on 4.7, can't we?

 Andreas Jaeger aj@{,} Twitter/Identica: jaegerandi
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