[coreboot-gerrit] Change in coreboot[master]: lib and libpayload: add 64-bit versions of clz, __ffs and log2

[Angel Pons (Code Review)]

Angel Pons has submitted this change. ( https://review.coreboot.org/c/coreboot/+/45938 )

Change subject: lib and libpayload: add 64-bit versions of clz, __ffs and log2
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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 
Change-Id: Iefc6e6c51f5b20607c88e38660a499a4f77ce0d0
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45938
Tested-by: build bot (Jenkins) 
Reviewed-by: Julius Werner 
Reviewed-by: Angel Pons 
---
M payloads/libpayload/include/libpayload.h
M src/include/lib.h
2 files changed, 12 insertions(+), 0 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Julius Werner: Looks good to me, approved
  Angel Pons: Looks good to me, approved

diff --git a/payloads/libpayload/include/libpayload.h b/payloads/libpayload/include/libpayload.h
index 01d71b8..475fe0f 100644
--- a/payloads/libpayload/include/libpayload.h
+++ b/payloads/libpayload/include/libpayload.h
@@ -454,6 +454,14 @@
 static inline int log2(u32 x) { return (int)sizeof(x) * 8 - clz(x) - 1; }
 /* Find First Set: __ffs(0xf) == 0, __ffs(0) == -1, __ffs(1 << 31) == 31 */
 static inline int __ffs(u32 x) { return log2(x & (u32)(-(s32)x)); }
+
+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)); }
 /** @} */

/**
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__ */