Mercurial > hg > octave-lyh > gnulib-hg
changeset 9121:2b6b38e4a82e
(popcount32): Reduce size of constants, to allow better code
generation, and add U to large constants to avoid warnings, in non-GCC
case.
Suggested by Bruno Haible.
| author | Ben Pfaff <blp@gnu.org> |
|---|---|
| date | Tue, 24 Jul 2007 02:35:09 +0000 |
| parents | af87f682cfec |
| children | f547a45baada |
| files | ChangeLog lib/popcount.h |
| diffstat | 2 files changed, 12 insertions(+), 5 deletions(-) [+] |
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--- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2007-07-23 Ben Pfaff <blp@gnu.org> + + * lib/popcount.h (popcount32): Reduce size of constants, to allow + better code generation, and add U to large constants to avoid + warnings, in non-GCC case. + Suggested by Bruno Haible. + 2007-07-23 Ben Pfaff <blp@gnu.org> * lib/popcount.h: Use verify_true instead of if...abort.
--- a/lib/popcount.h +++ b/lib/popcount.h @@ -41,11 +41,11 @@ static inline int popcount32 (unsigned int x) { - x = ((x & 0xaaaaaaaa) >> 1) + (x & 0x55555555); - x = ((x & 0xcccccccc) >> 2) + (x & 0x33333333); - x = ((x & 0xf0f0f0f0) >> 4) + (x & 0x0f0f0f0f); - x = ((x & 0xff00ff00) >> 8) + (x & 0x00ff00ff); - return (x >> 16) + (x & 0xff); + x = ((x & 0xaaaaaaaaU) >> 1) + (x & 0x55555555U); + x = ((x & 0xccccccccU) >> 2) + (x & 0x33333333U); + x = (x >> 16) + (x & 0xffff); + x = ((x & 0xf0f0) >> 4) + (x & 0x0f0f); + return (x >> 8) + (x & 0x00ff); } #endif