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Re: [ft-devel] assembler or builtin?
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From: |
Behdad Esfahbod |
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Subject: |
Re: [ft-devel] assembler or builtin? |
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Date: |
Mon, 07 Jul 2014 16:24:20 -0400 |
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User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 |
On 14-07-07 03:01 PM, Alexei Podtelezhnikov wrote:
> Hi all,
>
> Many architectures have special instructions for the most significant
> bit: BSR on x86, CLZ on ARM. Some compilers have builtin functions for
> that too: __builtin_clz in gcc, _BitScanReverse in VC2005 and up. What
> would be a preferred way of using this functionality in freetype
> for FT_MSB?
>
> Here is a relevant piece:
> http://en.wikipedia.org/wiki/Find_first_set
I suggest using the builtins and letting the compiler designers write the
assembler.
--
behdad
http://behdad.org/