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authorSrikant Patnaik2015-01-13 15:08:24 +0530
committerSrikant Patnaik2015-01-13 15:08:24 +0530
commit97327692361306d1e6259021bc425e32832fdb50 (patch)
treefe9088f3248ec61e24f404f21b9793cb644b7f01 /include/asm-generic/bitops/fls.h
parent2d05a8f663478a44e088d122e0d62109bbc801d0 (diff)
parenta3a8b90b61e21be3dde9101c4e86c881e0f06210 (diff)
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dirty fix to merging
Diffstat (limited to 'include/asm-generic/bitops/fls.h')
-rw-r--r--include/asm-generic/bitops/fls.h41
1 files changed, 41 insertions, 0 deletions
diff --git a/include/asm-generic/bitops/fls.h b/include/asm-generic/bitops/fls.h
new file mode 100644
index 00000000..0576d1f4
--- /dev/null
+++ b/include/asm-generic/bitops/fls.h
@@ -0,0 +1,41 @@
+#ifndef _ASM_GENERIC_BITOPS_FLS_H_
+#define _ASM_GENERIC_BITOPS_FLS_H_
+
+/**
+ * fls - find last (most-significant) bit set
+ * @x: the word to search
+ *
+ * This is defined the same way as ffs.
+ * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
+ */
+
+static __always_inline int fls(int x)
+{
+ int r = 32;
+
+ if (!x)
+ return 0;
+ if (!(x & 0xffff0000u)) {
+ x <<= 16;
+ r -= 16;
+ }
+ if (!(x & 0xff000000u)) {
+ x <<= 8;
+ r -= 8;
+ }
+ if (!(x & 0xf0000000u)) {
+ x <<= 4;
+ r -= 4;
+ }
+ if (!(x & 0xc0000000u)) {
+ x <<= 2;
+ r -= 2;
+ }
+ if (!(x & 0x80000000u)) {
+ x <<= 1;
+ r -= 1;
+ }
+ return r;
+}
+
+#endif /* _ASM_GENERIC_BITOPS_FLS_H_ */