new configuration macro 'l_mathlim' (simplifies some dependencies

on float type)

lstrlib.c

@@ -1,5 +1,5 @@
 /*
-** $Id: lstrlib.c,v 1.227 2015/03/28 19:14:47 roberto Exp roberto $
+** $Id: lstrlib.c,v 1.228 2015/04/03 18:41:57 roberto Exp roberto $
 ** Standard library for string operations and pattern-matching
 ** See Copyright Notice in lua.h
 */
@@ -11,6 +11,7 @@
 
 
 #include <ctype.h>
+#include <float.h>
 #include <limits.h>
 #include <stddef.h>
 #include <stdio.h>
@@ -812,12 +813,10 @@ static int str_gsub (lua_State *L) {
 /*
 ** Number of bits that goes into the first digit. It can be any value
 ** between 1 and 4; the following definition tries to align the number
-** to nibble boundaries. The default is 1 bit, that aligns double
-** (1+52-bit mantissa) and quad precision (1+112-bit mantissa). For
-** float (24-bit mantissa) and 80-bit long double (64-bit mantissa), 4
-** does the alignment.
+** to nibble boundaries by making what is left after that first digit a
+** multiple of 4.
 */
-#define L_NBFD	((sizeof(lua_Number) == 4 || sizeof(lua_Number) == 12) ? 4 : 1)
+#define L_NBFD		((l_mathlim(MANT_DIG) - 1)%4 + 1)
 
 
 /*
@@ -881,11 +880,9 @@ static int lua_number2strx (lua_State *L, char *buff, const char *fmt,
 /*
 ** Maximum size of each formatted item. This maximum size is produced
 ** by format('%.99f', minfloat), and is equal to 99 + 2 ('-' and '.') +
-** number of decimal digits to represent minfloat (which is ~308 for
-** a double and ~4932 for long double).
+** number of decimal digits to represent minfloat.
 */
-#define MAX_ITEM  \
-  (sizeof(lua_Number) <= 4 ? 150 : sizeof(lua_Number) <= 8 ? 450 : 5050)
+#define MAX_ITEM	(120 + l_mathlim(MAX_10_EXP))
 
 
 /* valid flags in a format specification */

luaconf.h

@@ -1,5 +1,5 @@
 /*
-** $Id: luaconf.h,v 1.249 2015/03/31 12:00:07 roberto Exp roberto $
+** $Id: luaconf.h,v 1.250 2015/04/03 18:41:57 roberto Exp roberto $
 ** Configuration file for Lua
 ** See Copyright Notice in lua.h
 */
@@ -404,16 +404,14 @@
 
 /*
 @@ LUA_NUMBER is the floating-point type used by Lua.
-**
 @@ LUAI_UACNUMBER is the result of an 'usual argument conversion'
 @@ over a floating number.
-**
+@@ l_mathlim(x) corrects limit name 'x' to the proper float type
+** by prefixing it with one of FLT/DBL/LDBL.
 @@ LUA_NUMBER_FRMLEN is the length modifier for writing floats.
 @@ LUA_NUMBER_FMT is the format for writing floats.
 @@ lua_number2str converts a float to a string.
-**
 @@ l_mathop allows the addition of an 'l' or 'f' to all math operations.
-**
 @@ lua_str2number converts a decimal numeric string to a number.
 */
 
@@ -421,6 +419,8 @@
 
 #define LUA_NUMBER	float
 
+#define l_mathlim(n)		(FLT_##n)
+
 #define LUAI_UACNUMBER	double
 
 #define LUA_NUMBER_FRMLEN	""
@@ -435,6 +435,8 @@
 
 #define LUA_NUMBER	long double
 
+#define l_mathlim(n)		(LDBL_##n)
+
 #define LUAI_UACNUMBER	long double
 
 #define LUA_NUMBER_FRMLEN	"L"
@@ -448,6 +450,8 @@
 
 #define LUA_NUMBER	double
 
+#define l_mathlim(n)		(DBL_##n)
+
 #define LUAI_UACNUMBER	double
 
 #define LUA_NUMBER_FRMLEN	""
@@ -620,7 +624,7 @@
 #if !defined(LUA_USE_C89) && defined(__STDC_VERSION__) && \
     __STDC_VERSION__ >= 199901L
 #include <stdint.h>
-#if defined (INTPTR_MAX)  /* even in C99 this type is optional */
+#if defined(INTPTR_MAX)  /* even in C99 this type is optional */
 #undef LUA_KCONTEXT
 #define LUA_KCONTEXT	intptr_t
 #endif