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Re: [PATCH] Improved trailing bit counting operation
- From: Richard Earnshaw <rearnsha at arm dot com>
- To: Daniel Gutson <dgutson at codesourcery dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Fri, 21 Aug 2009 10:14:33 +0100
- Subject: Re: [PATCH] Improved trailing bit counting operation
- References: <4A557D1B.20502@codesourcery.com> <4A7B5A34.1010402@codesourcery.com> <4A8AD74C.1010608@codesourcery.com>
On Tue, 2009-08-18 at 13:31 -0300, Daniel Gutson wrote:
> Hi,
> friendly reminder: any update on this?
>
OK
R.
> Thanks!
> Daniel.
>
>
> Daniel Gutson wrote:
> > Hi,
> > any update on this?
> >
> > Thanks!
> > Daniel.
> >
> > Daniel Gutson wrote:
> >> The attached patch improves the __builtin_ctz built-in function, which
> >> returns the number of trailing zero bits in a value, by using shorter
> >> instruction sequence for ARMv6T2 and later.
> >>
> >> Please let me know any comment, or commit it for me since I don't have
> >> write access.
> >>
> >> Thanks,
> >> Daniel.
> >>
> >> ---
> >> 07-09-2009 Daniel Gutson <dgutson@codesourcery.com>
> >>
> >> gcc/
> >> * config/arm/arm.md (UNSPEC_RBIT): New constant.
> >> (rbitsi2): New insn.
> >> (ctzsi2): New expand.
> >>
> >> gcc/testsuite/
> >> * gcc.target/arm/ctz.c: New test case.
> >>
> >>
> >
>