lib and libpayload: add 64-bit versions of clz, __ffs and log2
Add 64-bit versions of clz, __ffs & log2: `__ffs64`, `__clz64`,
and `log2_64`.
Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Change-Id: Iefc6e6c51f5b20607c88e38660a499a4f77ce0d0
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45938
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/src/include/lib.h b/src/include/lib.h
index 46d8b02..a0003d3 100644
--- a/src/include/lib.h
+++ b/src/include/lib.h
@@ -56,4 +56,8 @@
/* Integer binary logarithm (rounding up): log2_ceil(0) == -1, log2(5) == 3 */
static inline int log2_ceil(u32 x) { return (x == 0) ? -1 : log2(x * 2 - 1); }
+static inline int clz64(u64 x) { return x ? __builtin_clzll(x) : sizeof(x) * 8; }
+static inline int log2_64(u64 x) { return sizeof(x) * 8 - clz64(x) - 1; }
+static inline int __ffs64(u64 x) { return log2_64(x & (u64)(-(s64)x)); }
+
#endif /* __LIB_H__ */