Files
openairinterface5g/openair1/PHY/TOOLS/log2_approx.c
Robert Schmidt 8107939f08 Change OAI license to CSSL v1.0 (and others)
- all RAN code, CI code, configuration files, dockerfiles, in CSSL v1.0
- all deployment code (openshift, charts, ancillary files like shell
  scripts), in MIT
- documentation in CC-BY-4.0
- exceptions might apply and are listed in NOTICE
- there is a new LICENSES folder with all licenses
- CONTRIBUTIONS.md has been updated accordingly

For automated changes based on OAI PL v1.1:

    perl -i~ -0pe 's/\/\*.*Licensed to the OpenAirInterface.*openairinterface.org\n#?/\/*\n * SPDX-License-Identifier: LicenseRef-CSSL-1.0\n/s' **/*.{c,h,cpp}
    perl -i~ -0pe 's/\/\*.*Licensed to the OpenAirInterface.*openairinterface.org\n#?/\/*\n * SPDX-License-Identifier: LicenseRef-CSSL-1.0\n/s' **/*.ts
    perl -i~ -0pe 's/<!--.*Licensed to the OpenAirInterface.*openairinterface.org\n.*-->/<!-- SPDX-License-Identifier: LicenseRef-CSSL-1.0 -->/s' **/*.xml

The rest (cmake, files with missing license, cmake) manually.
2026-03-27 16:36:37 +01:00

50 lines
779 B
C

/*
* SPDX-License-Identifier: LicenseRef-CSSL-1.0
*/
#include <simde/x86/avx512/lzcnt.h>
unsigned char log2_approx(unsigned int x)
{
const unsigned int round_val = 3037000499U; // 2^31.5
if (!x)
return 0;
int l2 = simde_x_clz32(x);
if (x > (round_val >> l2))
l2 = 32 - l2;
else
l2 = 31 - l2;
return l2;
}
unsigned char factor2(unsigned int x)
{
unsigned char l2 = 0;
int i;
for (i = 0; i < 31; i++)
if ((x & (1 << i)) != 0)
break;
l2 = i;
return l2;
}
unsigned char log2_approx64(unsigned long long int x)
{
const unsigned long long round_val = 13043817825332782212ULL; // 2^63.5
if (!x)
return 0;
int l2 = simde_x_clz64(x);
if (x > (round_val >> l2))
l2 = 64 - l2;
else
l2 = 63 - l2;
return l2;
}