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| author | Quincey Koziol <koziol@hdfgroup.org> | 2006-09-15 20:20:39 (GMT) |
|---|---|---|
| committer | Quincey Koziol <koziol@hdfgroup.org> | 2006-09-15 20:20:39 (GMT) |
| commit | b047710a9577cb381308f30b67e81f2974029333 (patch) | |
| tree | 5888c6f563bc2946d91a590ac5f7b76f5a66812b /src/H5Vprivate.h | |
| parent | 24725d64aa4e944c4be4e0dcefa0880cb8ac627c (diff) | |
| download | hdf5-b047710a9577cb381308f30b67e81f2974029333.zip hdf5-b047710a9577cb381308f30b67e81f2974029333.tar.gz hdf5-b047710a9577cb381308f30b67e81f2974029333.tar.bz2 | |
[svn-r12669] Description:
Use a slightly less efficient method of computing the log2() on SGI IRIX64,
in order to avoid a compiler bug when optimizations are turned on.
Tested on:
SGI IRIX64 6.5 (atlantia)
Diffstat (limited to 'src/H5Vprivate.h')
| -rw-r--r-- | src/H5Vprivate.h | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/src/H5Vprivate.h b/src/H5Vprivate.h index 5848a57..0554c47 100644 --- a/src/H5Vprivate.h +++ b/src/H5Vprivate.h @@ -346,19 +346,28 @@ static const char LogTable256[] = static H5_inline unsigned UNUSED H5V_log2_gen(hsize_t n) { - unsigned r = 0; /* r will be log2(n) */ + unsigned r; /* r will be log2(n) */ register unsigned int t, tt, ttt; /* temporaries */ - if((ttt = (unsigned)(n >> 32))) - if((tt = (unsigned)(n >> 48))) - r = (t = (unsigned)(n >> 56)) ? 56 + LogTable256[t] : 48 + LogTable256[tt & 0xFF]; +#ifdef H5_BAD_LOG2_CODE_GENERATED + if(n > (uint64_t)0x7fffffffffffffff) + r = 63; + else { + n &= (uint64_t)0x7fffffffffffffff; +#endif /* H5_BAD_LOG2_CODE_GENERATED */ + if((ttt = (unsigned)(n >> 32))) + if((tt = (unsigned)(n >> 48))) + r = (t = (unsigned)(n >> 56)) ? 56 + LogTable256[t] : 48 + LogTable256[tt & 0xFF]; + else + r = (t = (unsigned)(n >> 40)) ? 40 + LogTable256[t] : 32 + LogTable256[ttt & 0xFF]; else - r = (t = (unsigned)(n >> 40)) ? 40 + LogTable256[t] : 32 + LogTable256[ttt & 0xFF]; - else - if((tt = (unsigned)(n >> 16))) - r = (t = (unsigned)(n >> 24)) ? 24 + LogTable256[t] : 16 + LogTable256[tt & 0xFF]; - else - r = (t = (unsigned)(n >> 8)) ? 8 + LogTable256[t] : LogTable256[n]; + if((tt = (unsigned)(n >> 16))) + r = (t = (unsigned)(n >> 24)) ? 24 + LogTable256[t] : 16 + LogTable256[tt & 0xFF]; + else + r = (t = (unsigned)(n >> 8)) ? 8 + LogTable256[t] : LogTable256[n]; +#ifdef H5_BAD_LOG2_CODE_GENERATED + } /* end else */ +#endif /* H5_BAD_LOG2_CODE_GENERATED */ return(r); } /* H5V_log2_gen() */ |