[coreboot-gerrit] Change in coreboot[master]: lib and libpayload: Add popcnt functions

[Angel Pons (Code Review)]

Angel Pons has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/46421 )

Change subject: lib and libpayload: Add popcnt functions
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lib and libpayload: Add popcnt functions

Add 32-bit `popcnt` and 64-bit `popcnt64` helpers.

Change-Id: I2e6a1007e475b662a85c067d96f81326e7f02905
Signed-off-by: Angel Pons 
---
M payloads/libpayload/include/libpayload.h
M src/include/lib.h
2 files changed, 6 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/21/46421/1

diff --git a/payloads/libpayload/include/libpayload.h b/payloads/libpayload/include/libpayload.h
index 475fe0f..b761f04 100644
--- a/payloads/libpayload/include/libpayload.h
+++ b/payloads/libpayload/include/libpayload.h
@@ -445,6 +445,8 @@
 void hexdump(const void *memory, size_t length);
 void fatal(const char *msg) __attribute__((noreturn));

+/* Population Count: number of bits that are one */
+static inline int popcnt(u32 x) { return __builtin_popcount(x); }
 /* Count Leading Zeroes: clz(0) == 32, clz(0xf) == 28, clz(1 << 31) == 0 */
 static inline int clz(u32 x)
 {
@@ -455,6 +457,7 @@
 /* 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 popcnt64(u64 x) { return __builtin_popcountll(x); }
 static inline int clz64(u64 x)
 {
    return x ? __builtin_clzll(x) : sizeof(x) * 8;
diff --git a/src/include/lib.h b/src/include/lib.h
index a0003d3..5c6eef2 100644
--- a/src/include/lib.h
+++ b/src/include/lib.h
@@ -46,6 +46,8 @@
  */
 size_t hexstrtobin(const char *str, uint8_t *buf, size_t len);

+/* Population Count: number of bits that are one */
+static inline int popcnt(u32 x) { return __builtin_popcount(x); }
 /* Count Leading Zeroes: clz(0) == 32, clz(0xf) == 28, clz(1 << 31) == 0 */
 static inline int clz(u32 x) { return x ? __builtin_clz(x) : sizeof(x) * 8; }
 /* Integer binary logarithm (rounding down): log2(0) == -1, log2(5) == 2 */
@@ -56,6 +58,7 @@
 /* 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 popcnt64(u64 x) { return __builtin_popcountll(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)); }