#include #include #include /* * This implements the binary GCD algorithm. (Often attributed to Stein, * but as Knuth has noted, appears in a first-century Chinese math text.) * * This is faster than the division-based algorithm even on x86, which * has decent hardware division. */ #if !defined(CONFIG_CPU_NO_EFFICIENT_FFS) && !defined(CPU_NO_EFFICIENT_FFS) /* If __ffs is available, the even/odd algorithm benchmarks slower. */ unsigned long gcd(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; b >>= __ffs(b); if (b == 1) return r & -r; for (;;) { a >>= __ffs(a); if (a == 1) return r & -r; if (a == b) return a << __ffs(r); if (a < b) swap(a, b); a -= b; } } #else /* If normalization is done by loops, the even/odd algorithm is a win. */ unsigned long gcd(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; /* Isolate lsbit of r */ r &= -r; while (!(b & r)) b >>= 1; if (b == r) return r; for (;;) { while (!(a & r)) a >>= 1; if (a == r) return r; if (a == b) return a; if (a < b) swap(a, b); a -= b; a >>= 1; if (a & r) a += b; a >>= 1; } } #endif EXPORT_SYMBOL_GPL(gcd); cted'>nds-private-remove net-next plumbingsTobias Klauser
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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-02-03 22:19:15 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-02-03 22:19:15 +0100
commit424414947da3dd5cb0d60e4f299f7c51e472ae77 (patch)
treea4067480c4256c80ae8f8438a3e4bb88e32050bc /include/net/irda/iriap.h
parenta3683e0c1410c5c8136a7a93b0336ce88d3b893a (diff)
parentd07830db1bdb254e4b50d366010b219286b8c937 (diff)
Merge tag 'usb-serial-4.10-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial into usb-linus
Johan writes: USB-serial fixes for v4.10-rc7 One more device ID for pl2303. Signed-off-by: Johan Hovold <johan@kernel.org>
Diffstat (limited to 'include/net/irda/iriap.h')