[PATCH v2 18/18] bitops: Add parity() macro for automatic type-based selection
Kuan-Wei Chiu <[email protected]>
| Newsgroups | dev.linux.lists.brcm80211,org.freedesktop.lists.dri-devel,org.infradead.lists.linux-mtd,org.kernel.vger.bpf,org.kernel.vger.linux-input,org.kernel.vger.linux-kernel,org.kernel.vger.linux-media,org.kernel.vger.linux-serial,org.kernel.vger.linux-wireless,org.kernel.vger.netdev |
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| Message-ID | <[email protected]> |
Introduce the parity() macro, which selects the appropriate parity function (parity8(), parity16(), parity32(), or parity64()) based on the size of the input type. This improves usability by allowing a generic parity calculation without requiring explicit function selection. If the input type does not match the supported sizes, BUILD_BUG() is triggered to catch invalid usage at compile time. Co-developed-by: Yu-Chun Lin <[email protected]> Signed-off-by: Yu-Chun Lin <[email protected]> Signed-off-by: Kuan-Wei Chiu <[email protected]> --- Place this patch last in the series to avoid compilation errors. include/linux/bitops.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/include/linux/bitops.h b/include/linux/bitops.h index 41e9e7fb894b..fa4e45741dff 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -339,6 +339,28 @@ static inline __attribute_const__ int parity64(u64 val) return __builtin_constant_p(val) ? _parity_const(val) : _parity64(val); } +#define parity(val) \ +({ \ + int __ret; \ + switch (BITS_PER_TYPE(val)) { \ + case 64: \ + __ret = parity64(val); \ + break; \ + case 32: \ + __ret = parity32(val); \ + break; \ + case 16: \ + __ret = parity16(val); \ + break; \ + case 8: \ + __ret = parity8(val); \ + break; \ + default: \ + BUILD_BUG(); \ + } \ + __ret; \ +}) + /** * __ffs64 - find first set bit in a 64 bit word * @word: The 64 bit word -- 2.34.1