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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /include/asm-generic/bitops/ffs.h
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'include/asm-generic/bitops/ffs.h')
-rw-r--r--include/asm-generic/bitops/ffs.h42
1 files changed, 42 insertions, 0 deletions
diff --git a/include/asm-generic/bitops/ffs.h b/include/asm-generic/bitops/ffs.h
new file mode 100644
index 000000000..323fd5d6a
--- /dev/null
+++ b/include/asm-generic/bitops/ffs.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_BITOPS_FFS_H_
+#define _ASM_GENERIC_BITOPS_FFS_H_
+
+/**
+ * ffs - find first bit set
+ * @x: the word to search
+ *
+ * This is defined the same way as
+ * the libc and compiler builtin ffs routines, therefore
+ * differs in spirit from ffz (man ffs).
+ */
+static inline int ffs(int x)
+{
+ int r = 1;
+
+ if (!x)
+ return 0;
+ if (!(x & 0xffff)) {
+ x >>= 16;
+ r += 16;
+ }
+ if (!(x & 0xff)) {
+ x >>= 8;
+ r += 8;
+ }
+ if (!(x & 0xf)) {
+ x >>= 4;
+ r += 4;
+ }
+ if (!(x & 3)) {
+ x >>= 2;
+ r += 2;
+ }
+ if (!(x & 1)) {
+ x >>= 1;
+ r += 1;
+ }
+ return r;
+}
+
+#endif /* _ASM_GENERIC_BITOPS_FFS_H_ */