Tim's ilog module.

[ccan] / ccan / ilog / test / run.c

diff --git a/ccan/ilog/test/run.c b/ccan/ilog/test/run.c
new file mode 100644 (file)
index 0000000..8193584
--- /dev/null
+++ b/ccan/ilog/test/run.c
@@ -0,0 +1,90 @@
+#include <stdio.h>
+#include "ilog/ilog.h"
+#include "tap/tap.h"
+#if defined(__GNUC_PREREQ)
+# if __GNUC_PREREQ(4,2)
+#  pragma GCC diagnostic ignored "-Wparentheses"
+# endif
+#endif
+
+/*Dead simple (but slow) versions to compare against.*/
+
+static int test_ilog32(uint32_t _v){
+  int ret;
+  for(ret=0;_v;ret++)_v>>=1;
+  return ret;
+}
+
+static int test_ilog64(uint64_t _v){
+  int ret;
+  for(ret=0;_v;ret++)_v>>=1;
+  return ret;
+}
+
+#define NTRIALS (64)
+
+int main(int _argc,const char *_argv[]){
+  int nmatches;
+  int i;
+  int j;
+  /*This is how many tests you plan to run.*/
+  plan_tests(2);
+  nmatches=0;
+  for(i=0;i<=32;i++){
+    uint32_t v;
+    /*Test each bit in turn (and 0).*/
+    v=i?(uint32_t)1U<<i-1:0;
+    for(j=0;j<NTRIALS;j++){
+      int l;
+      l=test_ilog32(v);
+      if(ILOG_32(v)!=l){
+        fprintf(stderr,"ILOG_32(0x%08lX): %i != %i\n",(long)v,ILOG_32(v),l);
+      }
+      else nmatches++;
+      if(ilog32(v)!=l){
+        fprintf(stderr,"ilog32(0x%08lX): %i != %i\n",(long)v,ilog32(v),l);
+      }
+      else nmatches++;
+      if(STATIC_ILOG_32(v)!=l){
+        fprintf(stderr,"STATIC_ILOG_32(0x%08lX): %i != %i\n",
+         (long)v,STATIC_ILOG_32(v),l);
+      }
+      else nmatches++;
+      /*Also try a few more pseudo-random values with at most the same number
+         of bits.*/
+      v=1103515245U*v+12345U&0xFFFFFFFFU>>(33-i>>1)>>(32-i>>1);
+    }
+  }
+  ok1(nmatches==3*(32+1)*NTRIALS);
+  nmatches=0;
+  for(i=0;i<=64;i++){
+    uint64_t v;
+    /*Test each bit in turn (and 0).*/
+    v=i?(uint64_t)1U<<i-1:0;
+    for(j=0;j<NTRIALS;j++){
+      int l;
+      l=test_ilog64(v);
+      if(ILOG_64(v)!=l){
+        fprintf(stderr,"ILOG_64(0x%016llX): %i != %i\n",
+         (long long)v,ILOG_64(v),l);
+      }
+      else nmatches++;
+      if(ilog64(v)!=l){
+        fprintf(stderr,"ilog64(0x%016llX): %i != %i\n",
+         (long long)v,ilog64(v),l);
+      }
+      else nmatches++;
+      if(STATIC_ILOG_64(v)!=l){
+        fprintf(stderr,"STATIC_ILOG_64(0x%016llX): %i != %i\n",
+         (long long)v,STATIC_ILOG_64(v),l);
+      }
+      else nmatches++;
+      /*Also try a few more pseudo-random values with at most the same number
+         of bits.*/
+      v=(uint64_t)(2862933555777941757ULL*v+3037000493ULL
+       &0xFFFFFFFFFFFFFFFFULL>>(65-i>>1)>>(64-i>>1));
+    }
+  }
+  ok1(nmatches==3*(64+1)*NTRIALS);
+  return exit_status();
+}