summaryrefslogtreecommitdiff
path: root/test/benchmarks/bit_count2.c
diff options
context:
space:
mode:
authorVladimir Azarov <avm@intermediate-node.net>2025-08-18 03:59:02 +0200
committerVladimir Azarov <avm@intermediate-node.net>2025-08-18 03:59:02 +0200
commitdd775090878854ccfe65310f9457ce3e393c070d (patch)
treee942c0bc0e96e0eb170dfbcbe8d63a7635bba57a /test/benchmarks/bit_count2.c
parent177a172719f065dd32ea1217bfb35d6b640d0bad (diff)
Benchmark filesHEADmaster
Diffstat (limited to 'test/benchmarks/bit_count2.c')
-rwxr-xr-xtest/benchmarks/bit_count2.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/test/benchmarks/bit_count2.c b/test/benchmarks/bit_count2.c
new file mode 100755
index 0000000..a57c123
--- /dev/null
+++ b/test/benchmarks/bit_count2.c
@@ -0,0 +1,36 @@
+/* +++Date last modified: 05-Jul-1997 */
+
+int bitcount(long i)
+{
+ i = ((i & 0xAAAAAAAAL) >> 1) + (i & 0x55555555L);
+ i = ((i & 0xCCCCCCCCL) >> 2) + (i & 0x33333333L);
+ i = ((i & 0xF0F0F0F0L) >> 4) + (i & 0x0F0F0F0FL);
+ i = ((i & 0xFF00FF00L) >> 8) + (i & 0x00FF00FFL);
+ i = ((i & 0xFFFF0000L) >> 16) + (i & 0x0000FFFFL);
+ return (int)i;
+}
+
+long atol(char *);
+int printf(char *s, ...);
+
+
+int bit_count(long x)
+{
+ int n = 0;
+ if (x) do
+ n++;
+ while (0 != (x = x&(x-1))) ;
+ return(n);
+}
+
+int main(int argc, char **argv)
+{
+ long n = atol(*++argv);
+ long i;
+
+ int sum = 0;
+ for (i = 0; i < n; ++i)
+ sum += bit_count(i);
+ printf("%d\n", sum);
+ return 0;
+}