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| author | Karl Williamson <khw@cpan.org> | 2021-07-20 11:57:39 -0600 |
|---|---|---|
| committer | Karl Williamson <khw@cpan.org> | 2021-07-30 05:41:28 -0600 |
| commit | 330cd0ce7cbde4175b21369c749c6a3186d2ac77 (patch) | |
| tree | 499d612a443c881e4504fd595b05a3b6ff4a1cfa /embed.fnc | |
| parent | b5288edf08d3f057f4cb70d49137c0a10da649a4 (diff) | |
| download | perl-330cd0ce7cbde4175b21369c749c6a3186d2ac77.tar.gz | |
Create and use 32 and 64 bit msbit_pos() fcns
The existing code to determine the position of the most significant 1
bit in a word is extracted from variant_byte_number(), and generalized
to use the deBruijn method previously added that works on any bit in the
word, rather than the existing method which looks just at the msb of
each byte. The code is moved to a new function in preparation for being
called from other places.
A U32 version is created, and on 64 bit platforms, a second, parallel,
version taking a U64 argument is also created. This is because future
commits may care about the word size differences.
Diffstat (limited to 'embed.fnc')
| -rw-r--r-- | embed.fnc | 2 |
1 files changed, 2 insertions, 0 deletions
@@ -1143,9 +1143,11 @@ ATidRp |bool |is_utf8_invariant_string_loc|NN const U8* const s \ |NULLOK const U8 ** ep CTiRp |unsigned|single_1bit_pos32|U32 word CTiRp |unsigned|lsbit_pos32|U32 word +CTiRp |unsigned|msbit_pos32|U32 word #ifdef U64TYPE /* HAS_QUAD undefined outside of core */ CTiRp |unsigned|single_1bit_pos64|U64 word CTiRp |unsigned|lsbit_pos64|U64 word +CTiRp |unsigned|msbit_pos64|U64 word #endif #ifndef EBCDIC CTiRp |unsigned int|variant_byte_number|PERL_UINTMAX_T word |