yalloc.h

/* yalloc.h - common definitions

   This file is part of yalloc, yet another memory allocator providing affordable safety in a compact package.

   SPDX-FileCopyrightText: © 2024 Joris van der Geer
   SPDX-License-Identifier: GPL-3.0-or-later
*/

static const char yal_version[] = "0.8.4-alpha.0";

#if Isgcc || Isclang // enable extensions conditionally
 #define Mallike __attribute__ ((malloc))
 #define Align(a) __attribute__ ((aligned (a)))
 #define likely(a) __builtin_expect( (a),1)
 #define unlikely(a) __builtin_expect( (a),0)

 #define Hot __attribute__ ((hot))

 #if defined (__x86_64__) || defined (__i386__)
  #define Pause __builtin_ia32_pause();
 #elif defined (__arm__)
  #define Pause __yield();
 #else
  #define Pause
 #endif

 #define sat_mul(a,b,res) __builtin_umull_overflow((a),(b),(res))

 #ifdef __has_builtin
  #if __has_builtin(__builtin_clz)
    #define clz(x) (unsigned int)__builtin_clz((x))
    #define clzl(x) (unsigned int)__builtin_clzl((x))
  #endif
  #if __has_builtin(__builtin_ctz)
    #define ctz(x) (unsigned int)__builtin_ctz((x))
    #define ctzl(x) (unsigned int)__builtin_ctzl((x))
  #endif
 #endif

#else
 #define Mallike
 #define Align(a)
 #define likely(a) (a)
 #define unlikely(a) (a)
 #define Cold
 #define Hot
 #define Pause

 static bool sat_mul(unsigned long a,unsigned long b,unsigned long *res)
 {
   unsigned long c = a * b;
   *res = c;
   return c < a || c < b; // heuristic
 }

#endif // gcc or clang

#if __musl_libc__ // support integration into musl libc
  #define malloc __libc_malloc_impl
  #define calloc __libc_calloc
  #define realloc __libc_realloc
  #define free __libc_free

  #define mmap __mmap
  #define mremap __mremap

  void __malloc_donate(char Unused * start, char Unused * end) {}

#elif  __haiku_libroot__  // and Haiku libroot
 #define Inc_os
 #define Miniprint_inc
#endif

#ifndef clz
  static Const int clz(unsigned int x)
  {
    int n = nn = 31;
    if (x == 0) return 0;
    while ( (x & (1u << n)) == 0) n--;
    return nn - n;
  }
  static Const int clzl(unsigned long x)
  {
    int n = nn = sizeof(long) * 8 - 1;
    if (x == 0) return 0;
    while ( (x & (1ul << n)) == 0) n--;
    return nn - n;
  }
#endif

#ifndef ctz
  static Const int ctz(unsigned int x)
  {
    int n = 0;
    while ( (x & (1u << n)) == 0) n++;
    return n;
  }

  static Const int ctzl(unsigned long x)
  {
    int n = 0;
    while ( (x & (1u << n)) == 0) n++;
    return n;
  }
#endif

static inline ub4 Const doalign4(ub4 n,ub4 a) { return (n + a - 1) & ~(a - 1); }

static inline size_t Const doalign8(size_t n,size_t a) { return (n + a - 1) & ~(a - 1); }

#if Yal_enable_check > 1
static bool chkalign(void *p,size_t len,ub4 std) {
  static const ub2 as[] = { 1,1,2,4,4,8,8,8 };
  ub4 a;
  size_t ap,ip = (size_t)p;

  if (len < 8) a = as[len];
  else a = std;
  ap = doalign8(ip,a);
  return ap != ip;
}
#endif

// derived config shared with configure
#define Max2class (Mmap_max_threshold + 3)
#define Clascnt (Max2class * 4)
static const ub4 class_grain = 3;
static const ub4 class_grain1 = class_grain + 1;

#define Hi20 0xfffffu
#define Hi24 0xffffffU
#define Hi30 0x3fffffffu
#define Hi31 0x7fffffffu
#define Hi64 0xfffffffffffffffful

#define Bit31 0x80000000ul