summaryrefslogtreecommitdiff
path: root/tools/lib/hweight.c
diff options
context:
space:
mode:
authorArnaldo Carvalho de Melo <acme@redhat.com>2015-07-09 16:27:25 -0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2015-07-09 16:29:56 -0300
commit0aefc3590afcc9ecbe173fc01fccbda0869d2f0a (patch)
treed4fab927d6e0ac7f50f398837317d479d3f66c37 /tools/lib/hweight.c
parentf3efe3a07e0060dc5d6c41644733e49c7bd50a5b (diff)
tools: Copy lib/hweight.c from the kernel sources
Instead of accessing it directly, as it uses EXPORT_SYMBOL, that has no meaning in tools/perf and because we removed the stubs for it, i.e. we removed the tools/include/linux/export.h file. This fixes the build for the detached tarball sources cases and removes one more source of entanglement with the kernel sources. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-oyqx541o7apa2cskjhcxi6nx@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/lib/hweight.c')
-rw-r--r--tools/lib/hweight.c62
1 files changed, 62 insertions, 0 deletions
diff --git a/tools/lib/hweight.c b/tools/lib/hweight.c
new file mode 100644
index 000000000000..0b859b884339
--- /dev/null
+++ b/tools/lib/hweight.c
@@ -0,0 +1,62 @@
+#include <linux/bitops.h>
+#include <asm/types.h>
+
+/**
+ * hweightN - returns the hamming weight of a N-bit word
+ * @x: the word to weigh
+ *
+ * The Hamming Weight of a number is the total number of bits set in it.
+ */
+
+unsigned int __sw_hweight32(unsigned int w)
+{
+#ifdef CONFIG_ARCH_HAS_FAST_MULTIPLIER
+ w -= (w >> 1) & 0x55555555;
+ w = (w & 0x33333333) + ((w >> 2) & 0x33333333);
+ w = (w + (w >> 4)) & 0x0f0f0f0f;
+ return (w * 0x01010101) >> 24;
+#else
+ unsigned int res = w - ((w >> 1) & 0x55555555);
+ res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
+ res = (res + (res >> 4)) & 0x0F0F0F0F;
+ res = res + (res >> 8);
+ return (res + (res >> 16)) & 0x000000FF;
+#endif
+}
+
+unsigned int __sw_hweight16(unsigned int w)
+{
+ unsigned int res = w - ((w >> 1) & 0x5555);
+ res = (res & 0x3333) + ((res >> 2) & 0x3333);
+ res = (res + (res >> 4)) & 0x0F0F;
+ return (res + (res >> 8)) & 0x00FF;
+}
+
+unsigned int __sw_hweight8(unsigned int w)
+{
+ unsigned int res = w - ((w >> 1) & 0x55);
+ res = (res & 0x33) + ((res >> 2) & 0x33);
+ return (res + (res >> 4)) & 0x0F;
+}
+
+unsigned long __sw_hweight64(__u64 w)
+{
+#if BITS_PER_LONG == 32
+ return __sw_hweight32((unsigned int)(w >> 32)) +
+ __sw_hweight32((unsigned int)w);
+#elif BITS_PER_LONG == 64
+#ifdef CONFIG_ARCH_HAS_FAST_MULTIPLIER
+ w -= (w >> 1) & 0x5555555555555555ul;
+ w = (w & 0x3333333333333333ul) + ((w >> 2) & 0x3333333333333333ul);
+ w = (w + (w >> 4)) & 0x0f0f0f0f0f0f0f0ful;
+ return (w * 0x0101010101010101ul) >> 56;
+#else
+ __u64 res = w - ((w >> 1) & 0x5555555555555555ul);
+ res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul);
+ res = (res + (res >> 4)) & 0x0F0F0F0F0F0F0F0Ful;
+ res = res + (res >> 8);
+ res = res + (res >> 16);
+ return (res + (res >> 32)) & 0x00000000000000FFul;
+#endif
+#endif
+}