mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-02-01 20:13:31 +00:00
39bf41f4eb
- Python static hello world now 1.8mb
- Python static fully loaded now 10mb
- Python HTTPS client now uses MbedTLS
- Python REPL now completes import stmts
- Increase stack size for Python for now
- Begin synthesizing posixpath and ntpath
- Restore Python \N{UNICODE NAME} support
- Restore Python NFKD symbol normalization
- Add optimized code path for Intel SHA-NI
- Get more Python unit tests passing faster
- Get Python help() pagination working on NT
- Python hashlib now supports MbedTLS PBKDF2
- Make memcpy/memmove/memcmp/bcmp/etc. faster
- Add Mersenne Twister and Vigna to LIBC_RAND
- Provide privileged __printf() for error code
- Fix zipos opendir() so that it reports ENOTDIR
- Add basic chmod() implementation for Windows NT
- Add Cosmo's best functions to Python cosmo module
- Pin function trace indent depth to that of caller
- Show memory diagram on invalid access in MODE=dbg
- Differentiate stack overflow on crash in MODE=dbg
- Add stb_truetype and tools for analyzing font files
- Upgrade to UNICODE 13 and reduce its binary footprint
- COMPILE.COM now logs resource usage of build commands
- Start implementing basic poll() support on bare metal
- Set getauxval(AT_EXECFN) to GetModuleFileName() on NT
- Add descriptions to strerror() in non-TINY build modes
- Add COUNTBRANCH() macro to help with micro-optimizations
- Make error / backtrace / asan / memory code more unbreakable
- Add fast perfect C implementation of μ-Law and a-Law audio codecs
- Make strtol() functions consistent with other libc implementations
- Improve Linenoise implementation (see also github.com/jart/bestline)
- COMPILE.COM now suppresses stdout/stderr of successful build commands
59 lines
1.6 KiB
C
59 lines
1.6 KiB
C
#ifndef BITS_H
|
||
#define BITS_H
|
||
#include "third_party/python/Modules/_decimal/libmpdec/mpdecimal.h"
|
||
/* clang-format off */
|
||
|
||
/*
|
||
* Check if 𝑛 is a power of 2.
|
||
*/
|
||
static inline int
|
||
ispower2(mpd_size_t n)
|
||
{
|
||
return n != 0 && (n & (n-1)) == 0;
|
||
}
|
||
|
||
/*
|
||
* Returns most significant bit position of 𝑛.
|
||
* Assumptions: 𝑛 ≠ 0
|
||
*/
|
||
static inline int
|
||
mpd_bsr(mpd_size_t n)
|
||
{
|
||
#if defined(__GNUC__) && !defined(__STRICT_ANSI__)
|
||
return __builtin_clzll(n) ^ (sizeof(long long) * CHAR_BIT - 1);
|
||
#else
|
||
int pos = 0;
|
||
mpd_size_t tmp;
|
||
tmp = n >> 32; if (tmp != 0) { n = tmp; pos += 32; }
|
||
tmp = n >> 16; if (tmp != 0) { n = tmp; pos += 16; }
|
||
tmp = n >> 8; if (tmp != 0) { n = tmp; pos += 8; }
|
||
tmp = n >> 4; if (tmp != 0) { n = tmp; pos += 4; }
|
||
tmp = n >> 2; if (tmp != 0) { n = tmp; pos += 2; }
|
||
tmp = n >> 1; if (tmp != 0) { n = tmp; pos += 1; }
|
||
return pos + (int)n - 1;
|
||
#endif
|
||
}
|
||
|
||
/*
|
||
* Return the least significant bit position of n from 0 to 31 (63).
|
||
* Assumptions: n != 0.
|
||
*/
|
||
static inline int
|
||
mpd_bsf(mpd_size_t n)
|
||
{
|
||
#if defined(__GNUC__) && !defined(__STRICT_ANSI__)
|
||
return __builtin_ctzll(n);
|
||
#else
|
||
int pos;
|
||
pos = 63;
|
||
if (n & 0x00000000FFFFFFFFULL) { pos -= 32; } else { n >>= 32; }
|
||
if (n & 0x000000000000FFFFULL) { pos -= 16; } else { n >>= 16; }
|
||
if (n & 0x00000000000000FFULL) { pos -= 8; } else { n >>= 8; }
|
||
if (n & 0x000000000000000FULL) { pos -= 4; } else { n >>= 4; }
|
||
if (n & 0x0000000000000003ULL) { pos -= 2; } else { n >>= 2; }
|
||
if (n & 0x0000000000000001ULL) { pos -= 1; }
|
||
return pos;
|
||
#endif
|
||
}
|
||
|
||
#endif /* BITS_H */
|