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authorSamuel Thibault <samuel.thibault@ens-lyon.org>2012-02-19 06:14:24 +0000
committerSamuel Thibault <samuel.thibault@ens-lyon.org>2012-02-19 06:14:24 +0000
commit6fafeb146e9efd59140ea58cebd7dd38ae9a6379 (patch)
tree7db89ba6a28932514b105d620bba4884ec332ec3 /libdde_linux26/contrib/include/asm-generic/bitops/fls.h
parent38c2c2458e3f4ecb329ff35621806252aac209b9 (diff)
parent8df772b3c665e663f6f9d2a70f9c691590bd3f91 (diff)
Merge branch 'dde' into upstream-merged
Diffstat (limited to 'libdde_linux26/contrib/include/asm-generic/bitops/fls.h')
-rw-r--r--libdde_linux26/contrib/include/asm-generic/bitops/fls.h41
1 files changed, 41 insertions, 0 deletions
diff --git a/libdde_linux26/contrib/include/asm-generic/bitops/fls.h b/libdde_linux26/contrib/include/asm-generic/bitops/fls.h
new file mode 100644
index 00000000..0576d1f4
--- /dev/null
+++ b/libdde_linux26/contrib/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_ */