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cosmopolitan/libc/nexgen32e/ffs.h

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Get Cosmopolitan into releasable state A new rollup tool now exists for flattening out the headers in a way that works better for our purposes than cpp. A lot of the API clutter has been removed. APIs that aren't a sure thing in terms of general recommendation are now marked internal. There's now a smoke test for the amalgamation archive and gigantic header file. So we can now guarantee you can use this project on the easiest difficulty setting without the gigantic repository. A website is being created, which is currently a work in progress: https://justine.storage.googleapis.com/cosmopolitan/index.html
2020-11-25 16:19:00 +00:00
#ifndef COSMOPOLITAN_LIBC_NEXGEN32E_FFS_H_
#define COSMOPOLITAN_LIBC_NEXGEN32E_FFS_H_
#if !(__ASSEMBLER__ + __LINKER__ + 0)
COSMOPOLITAN_C_START_
Auto-generate some documentation
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/*
* BIT SCANNING 101
* ctz(𝑥) 31^clz(𝑥) clz(𝑥)
* uint32 𝑥 bsf(𝑥) tzcnt(𝑥) ffs(𝑥) bsr(𝑥) lzcnt(𝑥)
* 0x00000000 wut 32 0 wut 32
* 0x00000001 0 0 1 0 31
* 0x80000001 0 0 1 31 0
* 0x80000000 31 31 32 31 0
* 0x00000010 4 4 5 4 27
* 0x08000010 4 4 5 27 4
* 0x08000000 27 27 28 27 4
* 0xffffffff 0 0 1 31 0
*/
Get Cosmopolitan into releasable state A new rollup tool now exists for flattening out the headers in a way that works better for our purposes than cpp. A lot of the API clutter has been removed. APIs that aren't a sure thing in terms of general recommendation are now marked internal. There's now a smoke test for the amalgamation archive and gigantic header file. So we can now guarantee you can use this project on the easiest difficulty setting without the gigantic repository. A website is being created, which is currently a work in progress: https://justine.storage.googleapis.com/cosmopolitan/index.html
2020-11-25 16:19:00 +00:00
int ffs(int) pureconst;
Auto-generate some documentation
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int ffsl(long) pureconst;
int ffsll(long long) pureconst;
#ifdef __GNUC__
#define ffs(u) __builtin_ffs(u)
#define ffsl(u) __builtin_ffsl(u)
#define ffsll(u) __builtin_ffsll(u)
#endif
Get Cosmopolitan into releasable state A new rollup tool now exists for flattening out the headers in a way that works better for our purposes than cpp. A lot of the API clutter has been removed. APIs that aren't a sure thing in terms of general recommendation are now marked internal. There's now a smoke test for the amalgamation archive and gigantic header file. So we can now guarantee you can use this project on the easiest difficulty setting without the gigantic repository. A website is being created, which is currently a work in progress: https://justine.storage.googleapis.com/cosmopolitan/index.html
2020-11-25 16:19:00 +00:00
COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#endif /* COSMOPOLITAN_LIBC_NEXGEN32E_FFS_H_ */
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