diff options
Diffstat (limited to 'src/llimits.h')
| -rw-r--r-- | src/llimits.h | 113 |
1 files changed, 15 insertions, 98 deletions
diff --git a/src/llimits.h b/src/llimits.h index 1b8c79bd..c4416f89 100644 --- a/src/llimits.h +++ b/src/llimits.h @@ -1,5 +1,5 @@ /* -** $Id: llimits.h,v 1.103 2013/02/20 14:08:56 roberto Exp $ +** $Id: llimits.h,v 1.108 2013/06/19 14:27:00 roberto Exp $ ** Limits, basic types, and some other `installation-dependent' definitions ** See Copyright Notice in lua.h */ @@ -27,8 +27,14 @@ typedef LUAI_MEM l_mem; typedef unsigned char lu_byte; +/* maximum value for size_t */ #define MAX_SIZET ((size_t)(~(size_t)0)-2) +/* maximum size visible for Lua (must be representable in a lua_Integer */ +#define MAX_SIZE (sizeof(size_t) <= sizeof(lua_Integer) ? MAX_SIZET \ + : (size_t)(~(lua_Unsigned)0)-2) + + #define MAX_LUMEM ((lu_mem)(~(lu_mem)0)-2) #define MAX_LMEM ((l_mem) ((MAX_LUMEM >> 1) - 2)) @@ -36,6 +42,12 @@ typedef unsigned char lu_byte; #define MAX_INT (INT_MAX-2) /* maximum value of an int (-2 for safety) */ + +/* minimum and maximum values for lua_Integer */ +#define MAX_INTEGER ((lua_Integer)(~(lua_Unsigned)0 >> 1)) +#define MIN_INTEGER (~MAX_INTEGER) + + /* ** conversion of pointer to integer ** this is for hashing only; there is no problem if the integer @@ -96,6 +108,8 @@ typedef LUAI_UACNUMBER l_uacNumber; #define cast_num(i) cast(lua_Number, (i)) #define cast_int(i) cast(int, (i)) #define cast_uchar(i) cast(unsigned char, (i)) +#define cast_integer(i) cast(lua_Integer, (i)) +#define cast_unsigned(i) cast(lua_Unsigned, (i)) /* @@ -190,103 +204,6 @@ typedef lu_int32 Instruction; #define luai_userstateyield(L,n) ((void)L) #endif -/* -** lua_number2int is a macro to convert lua_Number to int. -** lua_number2integer is a macro to convert lua_Number to lua_Integer. -** lua_number2unsigned is a macro to convert a lua_Number to a lua_Unsigned. -** lua_unsigned2number is a macro to convert a lua_Unsigned to a lua_Number. -** luai_hashnum is a macro to hash a lua_Number value into an integer. -** The hash must be deterministic and give reasonable values for -** both small and large values (outside the range of integers). -*/ - -#if defined(MS_ASMTRICK) || defined(LUA_MSASMTRICK) /* { */ -/* trick with Microsoft assembler for X86 */ - -#define lua_number2int(i,n) __asm {__asm fld n __asm fistp i} -#define lua_number2integer(i,n) lua_number2int(i, n) -#define lua_number2unsigned(i,n) \ - {__int64 l; __asm {__asm fld n __asm fistp l} i = (unsigned int)l;} - - -#elif defined(LUA_IEEE754TRICK) /* }{ */ -/* the next trick should work on any machine using IEEE754 with - a 32-bit int type */ - -union luai_Cast { double l_d; LUA_INT32 l_p[2]; }; - -#if !defined(LUA_IEEEENDIAN) /* { */ -#define LUAI_EXTRAIEEE \ - static const union luai_Cast ieeeendian = {-(33.0 + 6755399441055744.0)}; -#define LUA_IEEEENDIANLOC (ieeeendian.l_p[1] == 33) -#else -#define LUA_IEEEENDIANLOC LUA_IEEEENDIAN -#define LUAI_EXTRAIEEE /* empty */ -#endif /* } */ - -#define lua_number2int32(i,n,t) \ - { LUAI_EXTRAIEEE \ - volatile union luai_Cast u; u.l_d = (n) + 6755399441055744.0; \ - (i) = (t)u.l_p[LUA_IEEEENDIANLOC]; } - -#define luai_hashnum(i,n) \ - { volatile union luai_Cast u; u.l_d = (n) + 1.0; /* avoid -0 */ \ - (i) = u.l_p[0]; (i) += u.l_p[1]; } /* add double bits for his hash */ - -#define lua_number2int(i,n) lua_number2int32(i, n, int) -#define lua_number2unsigned(i,n) lua_number2int32(i, n, lua_Unsigned) - -/* the trick can be expanded to lua_Integer when it is a 32-bit value */ -#if defined(LUA_IEEELL) -#define lua_number2integer(i,n) lua_number2int32(i, n, lua_Integer) -#endif - -#endif /* } */ - - -/* the following definitions always work, but may be slow */ - -#if !defined(lua_number2int) -#define lua_number2int(i,n) ((i)=(int)(n)) -#endif - -#if !defined(lua_number2integer) -#define lua_number2integer(i,n) ((i)=(lua_Integer)(n)) -#endif - -#if !defined(lua_number2unsigned) /* { */ -/* the following definition assures proper modulo behavior */ -#if defined(LUA_NUMBER_DOUBLE) || defined(LUA_NUMBER_FLOAT) -#include <math.h> -#define SUPUNSIGNED ((lua_Number)(~(lua_Unsigned)0) + 1) -#define lua_number2unsigned(i,n) \ - ((i)=(lua_Unsigned)((n) - floor((n)/SUPUNSIGNED)*SUPUNSIGNED)) -#else -#define lua_number2unsigned(i,n) ((i)=(lua_Unsigned)(n)) -#endif -#endif /* } */ - - -#if !defined(lua_unsigned2number) -/* on several machines, coercion from unsigned to double is slow, - so it may be worth to avoid */ -#define lua_unsigned2number(u) \ - (((u) <= (lua_Unsigned)INT_MAX) ? (lua_Number)(int)(u) : (lua_Number)(u)) -#endif - - - -#if defined(ltable_c) && !defined(luai_hashnum) - -#include <float.h> -#include <math.h> - -#define luai_hashnum(i,n) { int e; \ - n = l_mathop(frexp)(n, &e) * (lua_Number)(INT_MAX - DBL_MAX_EXP); \ - lua_number2int(i, n); i += e; } - -#endif - /* |