--- /dev/null
+/**
+ * ilog - Integer logarithm.
+ *
+ * ILOG_32() and ILOG_64() compute the minimum number of bits required to store
+ * an unsigned 32-bit or 64-bit value without any leading zero bits.
+ * This can also be thought of as the location of the highest set bit, with
+ * counting starting from one (so that 0 returns 0, 1 returns 1, and 2**31
+ * returns 32).
+ * When the value is known to be non-zero ILOGNZ_32() and ILOGNZ_64() can
+ * compile into as few as two instructions, one of which may get optimized out
+ * later.
+ * STATIC_ILOG_32 and STATIC_ILOG_64 allow computation on compile-time
+ * constants, so other compile-time constants can be derived from them.
+ *
+ * Example:
+ * #include <stdio.h>
+ * #include <limits.h>
+ * #include <ccan/ilog/ilog.h>
+ *
+ * int main(void){
+ * int i;
+ * printf("ILOG_32(0x%08X)=%i\n",0,ILOG_32(0));
+ * for(i=1;i<=STATIC_ILOG_32(USHRT_MAX);i++){
+ * uint32_t v;
+ * v=(uint32_t)1U<<i-1;
+ * //Here we know v is non-zero, so we can use ILOGNZ_32().
+ * printf("ILOG_32(0x%08X)=%i\n",v,ILOGNZ_32(v));
+ * }
+ * return 0;
+ * }
+ *
+ * License: LGPL (v2 or later)
+ */
+#include <string.h>
+#include "config.h"
+
+int main(int _argc,const char *_argv[]){
+ /*Expect exactly one argument.*/
+ if(_argc!=2)return 1;
+ if(strcmp(_argv[1],"depends")==0){
+ /*PRINTF-CCAN-PACKAGES-YOU-NEED-ONE-PER-LINE-IF-ANY*/
+ return 0;
+ }
+ return 1;
+}