lib: import ccan modules for tdb2

Imported from git://git.ozlabs.org/~ccan/ccan init-1161-g661d41f

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

6 files changed, 969 insertions, 0 deletions

diff --git a/lib/ccan/ilog/LICENSE b/lib/ccan/ilog/LICENSE
new file mode 100644
index 0000000000..5522aa5f33
--- /dev/null
+++ b/lib/ccan/ilog/LICENSE
@@ -0,0 +1,508 @@
+
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diff --git a/lib/ccan/ilog/_info b/lib/ccan/ilog/_info
new file mode 100644
index 0000000000..56de50d610
--- /dev/null
+++ b/lib/ccan/ilog/_info
@@ -0,0 +1,47 @@
+/**
+ * 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 ilog32_nz() and ilog64_nz() 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("ilog32(0x%08X)=%i\n",0,ilog32(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 ilog32_nz().
+ *      printf("ilog32(0x%08X)=%i\n",v,ilog32_nz(v));
+ *    }
+ *    return 0;
+ *  }
+ *
+ * License: LGPL (v2 or later)
+ * Author: Timothy B. Terriberry <tterribe@xiph.org>
+ */
+#include <string.h>
+#include <stdio.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/compiler\n");
+    return 0;
+  }
+  return 1;
+}
diff --git a/lib/ccan/ilog/ilog.c b/lib/ccan/ilog/ilog.c
new file mode 100644
index 0000000000..40c5a6fd50
--- /dev/null
+++ b/lib/ccan/ilog/ilog.c
@@ -0,0 +1,139 @@
+/*(C) Timothy B. Terriberry (tterribe@xiph.org) 2001-2009 LGPL (v2 or later).*/
+#include "ilog.h"
+#include <limits.h>
+
+/*The fastest fallback strategy for platforms with fast multiplication appears
+   to be based on de Bruijn sequences~\cite{LP98}.
+  Tests confirmed this to be true even on an ARM11, where it is actually faster
+   than using the native clz instruction.
+  Define ILOG_NODEBRUIJN to use a simpler fallback on platforms where
+   multiplication or table lookups are too expensive.
+
+  @UNPUBLISHED{LP98,
+    author="Charles E. Leiserson and Harald Prokop",
+    title="Using de {Bruijn} Sequences to Index a 1 in a Computer Word",
+    month=Jun,
+    year=1998,
+    note="\url{http://supertech.csail.mit.edu/papers/debruijn.pdf}"
+  }*/
+static UNNEEDED const unsigned char DEBRUIJN_IDX32[32]={
+   0, 1,28, 2,29,14,24, 3,30,22,20,15,25,17, 4, 8,
+  31,27,13,23,21,19,16, 7,26,12,18, 6,11, 5,10, 9
+};
+
+/* We always compile these in, in case someone takes address of function. */
+#undef ilog32_nz
+#undef ilog32
+#undef ilog64_nz
+#undef ilog64
+
+int ilog32(uint32_t _v){
+/*On a Pentium M, this branchless version tested as the fastest version without
+   multiplications on 1,000,000,000 random 32-bit integers, edging out a
+   similar version with branches, and a 256-entry LUT version.*/
+# if defined(ILOG_NODEBRUIJN)
+  int ret;
+  int m;
+  ret=_v>0;
+  m=(_v>0xFFFFU)<<4;
+  _v>>=m;
+  ret|=m;
+  m=(_v>0xFFU)<<3;
+  _v>>=m;
+  ret|=m;
+  m=(_v>0xFU)<<2;
+  _v>>=m;
+  ret|=m;
+  m=(_v>3)<<1;
+  _v>>=m;
+  ret|=m;
+  ret+=_v>1;
+  return ret;
+/*This de Bruijn sequence version is faster if you have a fast multiplier.*/
+# else
+  int ret;
+  ret=_v>0;
+  _v|=_v>>1;
+  _v|=_v>>2;
+  _v|=_v>>4;
+  _v|=_v>>8;
+  _v|=_v>>16;
+  _v=(_v>>1)+1;
+  ret+=DEBRUIJN_IDX32[_v*0x77CB531U>>27&0x1F];
+  return ret;
+# endif
+}
+
+int ilog32_nz(uint32_t _v)
+{
+  return ilog32(_v);
+}
+
+int ilog64(uint64_t _v){
+# if defined(ILOG_NODEBRUIJN)
+  uint32_t v;
+  int      ret;
+  int      m;
+  ret=_v>0;
+  m=(_v>0xFFFFFFFFU)<<5;
+  v=(uint32_t)(_v>>m);
+  ret|=m;
+  m=(v>0xFFFFU)<<4;
+  v>>=m;
+  ret|=m;
+  m=(v>0xFFU)<<3;
+  v>>=m;
+  ret|=m;
+  m=(v>0xFU)<<2;
+  v>>=m;
+  ret|=m;
+  m=(v>3)<<1;
+  v>>=m;
+  ret|=m;
+  ret+=v>1;
+  return ret;
+# else
+/*If we don't have a 64-bit word, split it into two 32-bit halves.*/
+#  if LONG_MAX<9223372036854775807LL
+  uint32_t v;
+  int      ret;
+  int      m;
+  ret=_v>0;
+  m=(_v>0xFFFFFFFFU)<<5;
+  v=(uint32_t)(_v>>m);
+  ret|=m;
+  v|=v>>1;
+  v|=v>>2;
+  v|=v>>4;
+  v|=v>>8;
+  v|=v>>16;
+  v=(v>>1)+1;
+  ret+=DEBRUIJN_IDX32[v*0x77CB531U>>27&0x1F];
+  return ret;
+/*Otherwise do it in one 64-bit operation.*/
+#  else
+  static const unsigned char DEBRUIJN_IDX64[64]={
+     0, 1, 2, 7, 3,13, 8,19, 4,25,14,28, 9,34,20,40,
+     5,17,26,38,15,46,29,48,10,31,35,54,21,50,41,57,
+    63, 6,12,18,24,27,33,39,16,37,45,47,30,53,49,56,
+    62,11,23,32,36,44,52,55,61,22,43,51,60,42,59,58
+  };
+  int ret;
+  ret=_v>0;
+  _v|=_v>>1;
+  _v|=_v>>2;
+  _v|=_v>>4;
+  _v|=_v>>8;
+  _v|=_v>>16;
+  _v|=_v>>32;
+  _v=(_v>>1)+1;
+  ret+=DEBRUIJN_IDX64[_v*0x218A392CD3D5DBF>>58&0x3F];
+  return ret;
+#  endif
+# endif
+}
+
+int ilog64_nz(uint64_t _v)
+{
+  return ilog64(_v);
+}
diff --git a/lib/ccan/ilog/ilog.h b/lib/ccan/ilog/ilog.h
new file mode 100644
index 0000000000..55dd009885
--- /dev/null
+++ b/lib/ccan/ilog/ilog.h
@@ -0,0 +1,150 @@
+#if !defined(_ilog_H)
+# define _ilog_H (1)
+# include "config.h"
+# include <stdint.h>
+# include <limits.h>
+# include <ccan/compiler/compiler.h>
+
+/**
+ * ilog32 - Integer binary logarithm of a 32-bit value.
+ * @_v: A 32-bit value.
+ * Returns floor(log2(_v))+1, or 0 if _v==0.
+ * This is the number of bits that would be required to represent _v in two's
+ *  complement notation with all of the leading zeros stripped.
+ * Note that many uses will resolve to the fast macro version instead.
+ *
+ * See Also:
+ *	ilog32_nz(), ilog64()
+ *
+ * Example:
+ *	// Rounds up to next power of 2 (if not a power of 2).
+ *	static uint32_t round_up32(uint32_t i)
+ *	{
+ *		assert(i != 0);
+ *		return 1U << ilog32(i-1);
+ *	}
+ */
+int ilog32(uint32_t _v) IDEMPOTENT;
+
+/**
+ * ilog32_nz - Integer binary logarithm of a non-zero 32-bit value.
+ * @_v: A 32-bit value.
+ * Returns floor(log2(_v))+1, or undefined if _v==0.
+ * This is the number of bits that would be required to represent _v in two's
+ *  complement notation with all of the leading zeros stripped.
+ * Note that many uses will resolve to the fast macro version instead.
+ * See Also:
+ *	ilog32(), ilog64_nz()
+ * Example:
+ *	// Find Last Set (ie. highest bit set, 0 to 31).
+ *	static uint32_t fls32(uint32_t i)
+ *	{
+ *		assert(i != 0);
+ *		return ilog32_nz(i) - 1;
+ *	}
+ */
+int ilog32_nz(uint32_t _v) IDEMPOTENT;
+
+/**
+ * ilog64 - Integer binary logarithm of a 64-bit value.
+ * @_v: A 64-bit value.
+ * Returns floor(log2(_v))+1, or 0 if _v==0.
+ * This is the number of bits that would be required to represent _v in two's
+ *  complement notation with all of the leading zeros stripped.
+ * Note that many uses will resolve to the fast macro version instead.
+ * See Also:
+ *	ilog64_nz(), ilog32()
+ */
+int ilog64(uint64_t _v) IDEMPOTENT;
+
+/**
+ * ilog64_nz - Integer binary logarithm of a non-zero 64-bit value.
+ * @_v: A 64-bit value.
+ * Returns floor(log2(_v))+1, or undefined if _v==0.
+ * This is the number of bits that would be required to represent _v in two's
+ *  complement notation with all of the leading zeros stripped.
+ * Note that many uses will resolve to the fast macro version instead.
+ * See Also:
+ *	ilog64(), ilog32_nz()
+ */
+int ilog64_nz(uint64_t _v) IDEMPOTENT;
+
+/**
+ * STATIC_ILOG_32 - The integer logarithm of an (unsigned, 32-bit) constant.
+ * @_v: A non-negative 32-bit constant.
+ * Returns floor(log2(_v))+1, or 0 if _v==0.
+ * This is the number of bits that would be required to represent _v in two's
+ *  complement notation with all of the leading zeros stripped.
+ * This macro should only be used when you need a compile-time constant,
+ * otherwise ilog32 or ilog32_nz are just as fast and more flexible.
+ *
+ * Example:
+ *	#define MY_PAGE_SIZE	4096
+ *	#define MY_PAGE_BITS	(STATIC_ILOG_32(PAGE_SIZE) - 1)
+ */
+#define STATIC_ILOG_32(_v) (STATIC_ILOG5((uint32_t)(_v)))
+
+/**
+ * STATIC_ILOG_64 - The integer logarithm of an (unsigned, 64-bit) constant.
+ * @_v: A non-negative 64-bit constant.
+ * Returns floor(log2(_v))+1, or 0 if _v==0.
+ * This is the number of bits that would be required to represent _v in two's
+ *  complement notation with all of the leading zeros stripped.
+ * This macro should only be used when you need a compile-time constant,
+ * otherwise ilog64 or ilog64_nz are just as fast and more flexible.
+ */
+#define STATIC_ILOG_64(_v) (STATIC_ILOG6((uint64_t)(_v)))
+
+/* Private implementation details */
+
+/*Note the casts to (int) below: this prevents "upgrading"
+   the type of an entire expression to an (unsigned) size_t.*/
+#if INT_MAX>=2147483647 && HAVE_BUILTIN_CLZ
+#define builtin_ilog32_nz(v) \
+	(((int)sizeof(unsigned)*CHAR_BIT) - __builtin_clz(v))
+#elif LONG_MAX>=2147483647L && HAVE_BUILTIN_CLZL
+#define builtin_ilog32_nz(v) \
+	(((int)sizeof(unsigned)*CHAR_BIT) - __builtin_clzl(v))
+#endif
+
+#if INT_MAX>=9223372036854775807LL && HAVE_BUILTIN_CLZ
+#define builtin_ilog64_nz(v) \
+	(((int)sizeof(unsigned)*CHAR_BIT) - __builtin_clz(v))
+#elif LONG_MAX>=9223372036854775807LL && HAVE_BUILTIN_CLZL
+#define builtin_ilog64_nz(v) \
+	(((int)sizeof(unsigned long)*CHAR_BIT) - __builtin_clzl(v))
+#elif HAVE_BUILTIN_CLZLL
+#define builtin_ilog64_nz(v) \
+	(((int)sizeof(unsigned long long)*CHAR_BIT) - __builtin_clzll(v))
+#endif
+
+#ifdef builtin_ilog32_nz
+#define ilog32(_v) (builtin_ilog32_nz(_v)&-!!(_v))
+#define ilog32_nz(_v) builtin_ilog32_nz(_v)
+#else
+#define ilog32_nz(_v) ilog32(_v)
+#define ilog32(_v) (IS_COMPILE_CONSTANT(_v) ? STATIC_ILOG_32(_v) : ilog32(_v))
+#endif /* builtin_ilog32_nz */
+
+#ifdef builtin_ilog64_nz
+#define ilog64(_v) (builtin_ilog64_nz(_v)&-!!(_v))
+#define ilog64_nz(_v) builtin_ilog64_nz(_v)
+#else
+#define ilog64_nz(_v) ilog64(_v)
+#define ilog64(_v) (IS_COMPILE_CONSTANT(_v) ? STATIC_ILOG_64(_v) : ilog64(_v))
+#endif /* builtin_ilog64_nz */
+
+/* Macros for evaluating compile-time constant ilog. */
+# define STATIC_ILOG0(_v) (!!(_v))
+# define STATIC_ILOG1(_v) (((_v)&0x2)?2:STATIC_ILOG0(_v))
+# define STATIC_ILOG2(_v) (((_v)&0xC)?2+STATIC_ILOG1((_v)>>2):STATIC_ILOG1(_v))
+# define STATIC_ILOG3(_v) \
+ (((_v)&0xF0)?4+STATIC_ILOG2((_v)>>4):STATIC_ILOG2(_v))
+# define STATIC_ILOG4(_v) \
+ (((_v)&0xFF00)?8+STATIC_ILOG3((_v)>>8):STATIC_ILOG3(_v))
+# define STATIC_ILOG5(_v) \
+ (((_v)&0xFFFF0000)?16+STATIC_ILOG4((_v)>>16):STATIC_ILOG4(_v))
+# define STATIC_ILOG6(_v) \
+ (((_v)&0xFFFFFFFF00000000ULL)?32+STATIC_ILOG5((_v)>>32):STATIC_ILOG5(_v))
+
+#endif /* _ilog_H */
diff --git a/lib/ccan/ilog/test/run-out-of-line.c b/lib/ccan/ilog/test/run-out-of-line.c
new file mode 100644
index 0000000000..48205d380e
--- /dev/null
+++ b/lib/ccan/ilog/test/run-out-of-line.c
@@ -0,0 +1,65 @@
+#include <ccan/ilog/ilog.h>
+#include <ccan/ilog/ilog.c>
+#include <stdio.h>
+#include <ccan/tap/tap.h>
+
+/*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 i;
+  int j;
+  int (*il32)(uint32_t) = ilog32;
+  int (*il64)(uint64_t) = ilog64;
+  int (*il32_nz)(uint32_t) = ilog32_nz;
+  int (*il64_nz)(uint64_t) = ilog64_nz;
+
+  /*This is how many tests you plan to run.*/
+  plan_tests(33 * NTRIALS * 3 + 65 * NTRIALS * 3);
+  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);
+      ok1(STATIC_ILOG_32(v)==l);
+      ok1(il32(v)==l);
+      ok1(il32_nz(v) == l || v == 0);
+      /*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);
+    }
+  }
+
+  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);
+      ok1(STATIC_ILOG_64(v)==l);
+      ok1(il64(v)==l);
+      ok1(il64_nz(v) == l || v == 0);
+      /*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));
+    }
+  }
+  return exit_status();
+}
diff --git a/lib/ccan/ilog/test/run.c b/lib/ccan/ilog/test/run.c
new file mode 100644
index 0000000000..bda59f920a
--- /dev/null
+++ b/lib/ccan/ilog/test/run.c
@@ -0,0 +1,60 @@
+#include <ccan/ilog/ilog.h>
+#include <ccan/ilog/ilog.c>
+#include <stdio.h>
+#include <ccan/tap/tap.h>
+
+/*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 i;
+  int j;
+  /*This is how many tests you plan to run.*/
+  plan_tests(33 * NTRIALS * 3 + 65 * NTRIALS * 3);
+  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);
+      ok1(STATIC_ILOG_32(v)==l);
+      ok1(ilog32(v)==l);
+      ok1(ilog32_nz(v) == l || v == 0);
+      /*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);
+    }
+  }
+
+  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);
+      ok1(STATIC_ILOG_64(v)==l);
+      ok1(ilog64(v)==l);
+      ok1(ilog64_nz(v) == l || v == 0);
+      /*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));
+    }
+  }
+  return exit_status();
+}