Rename float configuration option names.

- `MRB_WITHOUT_FLOAT` => `MRB_NO_FLOAT`
- `MRB_USE_FLOAT` => `MRB_USE_FLOAT32`

The former is to use `USE_XXX` naming convention. The latter is to make
sure `float` is 32bit float and not floating point number in general.

51 files changed, 223 insertions, 202 deletions

diff --git a/doc/guides/mrbconf.md b/doc/guides/mrbconf.md
index d662e05bf..c95634604 100644
--- a/doc/guides/mrbconf.md
+++ b/doc/guides/mrbconf.md
@@ -46,11 +46,11 @@ You can use mrbconfs with following ways:
 
 ## Primitive type configuration.
 
-`MRB_USE_FLOAT`
+`MRB_USE_FLOAT32`
 * When defined single precision floating point type(C type `float`) is used as `mrb_float`.
-* Else double precision floating point type(C type `double`) is used as `mrb_float`.
+* Otherwise double precision floating point type(C type `double`) is used as `mrb_float`.
 
-`MRB_WITHOUT_FLOAT`
+`MRB_NO_FLOAT`
 * When defined removes floating point numbers from mruby.
 * It makes mruby easier to handle in "Microcontroller without FPU" and "Kernel Space".
 
@@ -117,7 +117,7 @@ largest value of required alignment.
 
 `MRB_NAN_BOXING`
 * If defined represent `mrb_value` in boxed `double`.
-* Conflicts with `MRB_USE_FLOAT` and `MRB_WITHOUT_FLOAT`.
+* Conflicts with `MRB_USE_FLOAT32` and `MRB_NO_FLOAT`.
 
 `MRB_WORD_BOXING`
 * If defined represent `mrb_value` as a word.
diff --git a/doc/mruby3.md b/doc/mruby3.md
index 29da25cbc..02884f51b 100644
--- a/doc/mruby3.md
+++ b/doc/mruby3.md
@@ -57,6 +57,17 @@ pull-request.
 
 Some configuration macro names are changed for consistency
 
+== `MRB_NO_FLOAT`
+
+Changed from `MRB_WITHOUT_FLOAT` to conform `USE_XXX` naming
+convention.
+
+== `MRB_USE_FLOAT32`
+
+Changed from `MRB_USE_FLOAT` to make sure `float` here means
+using single precision float, and not the opposite of
+`MRB_NO_FLOAT`.
+
 == `MRB_USE_METHOD_T_STRUCT`
 
 Changed from `MRB_METHOD_T_STRUCT`.
diff --git a/include/mrbconf.h b/include/mrbconf.h
index 734ec98e7..159aee48f 100644
--- a/include/mrbconf.h
+++ b/include/mrbconf.h
@@ -25,14 +25,24 @@
 #endif
 
 /* configuration options: */
-/* add -DMRB_USE_FLOAT to use float instead of double for floating point numbers */
-//#define MRB_USE_FLOAT
+/* add -DMRB_USE_FLOAT32 to use float instead of double for floating point numbers */
+//#define MRB_USE_FLOAT32
 
 /* exclude floating point numbers */
-//#define MRB_WITHOUT_FLOAT
+//#define MRB_NO_FLOAT
 
-#if defined(MRB_USE_FLOAT) && defined(MRB_WITHOUT_FLOAT)
-#error Cannot define MRB_USE_FLOAT and MRB_WITHOUT_FLOAT at the same time
+/* obsolete configuration */
+#if defined(MRB_USE_FLOAT)
+# define MRB_USE_FLOAT32
+#endif
+
+/* obsolete configuration */
+#if defined(MRB_WITHOUT_FLOAT)
+# define MRB_NO_FLOAT
+#endif
+
+#if defined(MRB_USE_FLOAT32) && defined(MRB_NO_FLOAT)
+#error Cannot define MRB_USE_FLOAT32 and MRB_NO_FLOAT at the same time
 #endif
 
 /* stop inlining floating point numbers in mrb_value (effective only with MRB_WORD_BOXING)*/
@@ -65,7 +75,7 @@
 # endif
 #endif
 
-/* represent mrb_value in boxed double; conflict with MRB_USE_FLOAT and MRB_WITHOUT_FLOAT */
+/* represent mrb_value in boxed double; conflict with MRB_USE_FLOAT32 and MRB_NO_FLOAT */
 //#define MRB_NAN_BOXING
 
 /* represent mrb_value as a word (natural unit of data for the processor) */
diff --git a/include/mruby.h b/include/mruby.h
index dea0a9c88..485a94d70 100644
--- a/include/mruby.h
+++ b/include/mruby.h
@@ -92,7 +92,7 @@
 #include <mruby/presym.h>
 #include <mruby/version.h>
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 #include <float.h>
 #ifndef FLT_EPSILON
 #define FLT_EPSILON (1.19209290e-07f)
@@ -104,7 +104,7 @@
 #define LDBL_EPSILON (1.08420217248550443401e-19L)
 #endif
 
-#ifdef MRB_USE_FLOAT
+#ifdef MRB_USE_FLOAT32
 #define MRB_FLOAT_EPSILON FLT_EPSILON
 #else
 #define MRB_FLOAT_EPSILON DBL_EPSILON
@@ -245,7 +245,7 @@ typedef struct mrb_state {
   struct RClass *hash_class;
   struct RClass *range_class;
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   struct RClass *float_class;
 #endif
   struct RClass *fixnum_class;
@@ -1211,7 +1211,7 @@ MRB_API mrb_bool mrb_obj_equal(mrb_state *mrb, mrb_value a, mrb_value b);
 MRB_API mrb_bool mrb_equal(mrb_state *mrb, mrb_value obj1, mrb_value obj2);
 MRB_API mrb_value mrb_convert_to_integer(mrb_state *mrb, mrb_value val, mrb_int base);
 MRB_API mrb_value mrb_Integer(mrb_state *mrb, mrb_value val);
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 MRB_API mrb_value mrb_Float(mrb_state *mrb, mrb_value val);
 #endif
 MRB_API mrb_value mrb_inspect(mrb_state *mrb, mrb_value obj);
@@ -1304,7 +1304,7 @@ MRB_API mrb_value mrb_vformat(mrb_state *mrb, const char *format, va_list ap);
 #define E_FROZEN_ERROR              (mrb_exc_get_id(mrb, MRB_SYM(FrozenError)))
 
 #define E_NOTIMP_ERROR              (mrb_exc_get_id(mrb, MRB_SYM(NotImplementedError)))
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 #define E_FLOATDOMAIN_ERROR         (mrb_exc_get_id(mrb, MRB_SYM(FloatDomainError)))
 #endif
 
diff --git a/include/mruby/boxing_nan.h b/include/mruby/boxing_nan.h
index a8655ca19..eb89ac1f9 100644
--- a/include/mruby/boxing_nan.h
+++ b/include/mruby/boxing_nan.h
@@ -7,12 +7,12 @@
 #ifndef MRUBY_BOXING_NAN_H
 #define MRUBY_BOXING_NAN_H
 
-#ifdef MRB_USE_FLOAT
-# error ---->> MRB_NAN_BOXING and MRB_USE_FLOAT conflict <<----
+#ifdef MRB_USE_FLOAT32
+# error ---->> MRB_NAN_BOXING and MRB_USE_FLOAT32 conflict <<----
 #endif
 
-#ifdef MRB_WITHOUT_FLOAT
-# error ---->> MRB_NAN_BOXING and MRB_WITHOUT_FLOAT conflict <<----
+#ifdef MRB_NO_FLOAT
+# error ---->> MRB_NAN_BOXING and MRB_NO_FLOAT conflict <<----
 #endif
 
 #ifdef MRB_INT64
diff --git a/include/mruby/boxing_no.h b/include/mruby/boxing_no.h
index 23b48c6f8..345f6b35b 100644
--- a/include/mruby/boxing_no.h
+++ b/include/mruby/boxing_no.h
@@ -11,7 +11,7 @@
 #define MRB_SYMBOL_SHIFT 0
 
 union mrb_value_union {
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   mrb_float f;
 #endif
   void *p;
@@ -26,7 +26,7 @@ typedef struct mrb_value {
 
 #define mrb_ptr(o)      (o).value.p
 #define mrb_cptr(o)     mrb_ptr(o)
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 #define mrb_float(o)    (o).value.f
 #endif
 #define mrb_fixnum(o)   (o).value.i
@@ -43,7 +43,7 @@ typedef struct mrb_value {
 #define SET_TRUE_VALUE(r) BOXNIX_SET_VALUE(r, MRB_TT_TRUE, value.i, 1)
 #define SET_BOOL_VALUE(r,b) BOXNIX_SET_VALUE(r, b ? MRB_TT_TRUE : MRB_TT_FALSE, value.i, 1)
 #define SET_INT_VALUE(r,n) BOXNIX_SET_VALUE(r, MRB_TT_FIXNUM, value.i, (n))
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 #define SET_FLOAT_VALUE(mrb,r,v) BOXNIX_SET_VALUE(r, MRB_TT_FLOAT, value.f, (v))
 #endif
 #define SET_SYM_VALUE(r,v) BOXNIX_SET_VALUE(r, MRB_TT_SYMBOL, value.sym, (v))
diff --git a/include/mruby/boxing_word.h b/include/mruby/boxing_word.h
index a91d10421..b9b6a3fe9 100644
--- a/include/mruby/boxing_word.h
+++ b/include/mruby/boxing_word.h
@@ -11,7 +11,7 @@
 #error MRB_INT64 cannot be used with MRB_WORD_BOXING in 32-bit mode.
 #endif
 
-#if !defined(MRB_WITHOUT_FLOAT) || defined(MRB_NO_FLOAT_INLINE)
+#if !defined(MRB_NO_FLOAT) || defined(MRB_NO_FLOAT_INLINE)
 struct RFloat {
   MRB_OBJECT_HEADER;
   mrb_float f;
@@ -80,7 +80,7 @@ union mrb_value_ {
   };
 #endif
   struct RBasic *bp;
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   struct RFloat *fp;
 #endif
   struct RCptr *vp;
@@ -96,13 +96,13 @@ mrb_val_union(mrb_value v)
 }
 
 MRB_API mrb_value mrb_word_boxing_cptr_value(struct mrb_state*, void*);
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 MRB_API mrb_value mrb_word_boxing_float_value(struct mrb_state*, mrb_float);
 #endif
 
 #define mrb_ptr(o)     mrb_val_union(o).p
 #define mrb_cptr(o)    mrb_val_union(o).vp->p
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 #define mrb_float(o)   mrb_val_union(o).fp->f
 #endif
 #define mrb_fixnum(o)  BOXWORD_SHIFT_VALUE(o, FIXNUM, mrb_int)
@@ -124,7 +124,7 @@ MRB_API mrb_value mrb_word_boxing_float_value(struct mrb_state*, mrb_float);
 #define mrb_nil_p(o)  ((o) == MRB_Qnil)
 #define mrb_false_p(o) ((o) == MRB_Qfalse)
 #define mrb_true_p(o)  ((o) == MRB_Qtrue)
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 #define mrb_float_p(o) BOXWORD_OBJ_TYPE_P(o, FLOAT)
 #endif
 #define mrb_array_p(o) BOXWORD_OBJ_TYPE_P(o, ARRAY)
@@ -146,7 +146,7 @@ MRB_API mrb_value mrb_word_boxing_float_value(struct mrb_state*, mrb_float);
 #define mrb_istruct_p(o) BOXWORD_OBJ_TYPE_P(o, ISTRUCT)
 #define mrb_break_p(o) BOXWORD_OBJ_TYPE_P(o, BREAK)
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 #define SET_FLOAT_VALUE(mrb,r,v) ((r) = mrb_word_boxing_float_value(mrb, v))
 #endif
 #define SET_CPTR_VALUE(mrb,r,v) ((r) = mrb_word_boxing_cptr_value(mrb, v))
diff --git a/include/mruby/class.h b/include/mruby/class.h
index 88e5915e5..a02c4ef17 100644
--- a/include/mruby/class.h
+++ b/include/mruby/class.h
@@ -37,7 +37,7 @@ mrb_class(mrb_state *mrb, mrb_value v)
     return mrb->symbol_class;
   case MRB_TT_FIXNUM:
     return mrb->fixnum_class;
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   case MRB_TT_FLOAT:
     return mrb->float_class;
 #endif
diff --git a/include/mruby/error.h b/include/mruby/error.h
index 67a0a539e..b607dd957 100644
--- a/include/mruby/error.h
+++ b/include/mruby/error.h
@@ -32,7 +32,7 @@ MRB_API mrb_noreturn void mrb_no_method_error(mrb_state *mrb, mrb_sym id, mrb_va
 /* declaration for `fail` method */
 MRB_API mrb_value mrb_f_raise(mrb_state*, mrb_value);
 
-#if defined(MRB_64BIT) || defined(MRB_USE_FLOAT) || defined(MRB_NAN_BOXING) || defined(MRB_WORD_BOXING)
+#if defined(MRB_64BIT) || defined(MRB_USE_FLOAT32) || defined(MRB_NAN_BOXING) || defined(MRB_WORD_BOXING)
 struct RBreak {
   MRB_OBJECT_HEADER;
   const struct RProc *proc;
@@ -62,7 +62,7 @@ mrb_break_value_set(struct RBreak *brk, mrb_value val)
   brk->flags &= ~RBREAK_VALUE_TT_MASK;
   brk->flags |= val.tt;
 }
-#endif  /* MRB_64BIT || MRB_USE_FLOAT || MRB_NAN_BOXING || MRB_WORD_BOXING */
+#endif  /* MRB_64BIT || MRB_USE_FLOAT32 || MRB_NAN_BOXING || MRB_WORD_BOXING */
 #define mrb_break_proc_get(brk) ((brk)->proc)
 #define mrb_break_proc_set(brk, p) ((brk)->proc = p)
 
diff --git a/include/mruby/numeric.h b/include/mruby/numeric.h
index 06a33cc6f..10b242688 100644
--- a/include/mruby/numeric.h
+++ b/include/mruby/numeric.h
@@ -22,7 +22,7 @@ MRB_BEGIN_DECL
 #define POSFIXABLE(f) TYPED_POSFIXABLE(f,mrb_int)
 #define NEGFIXABLE(f) TYPED_NEGFIXABLE(f,mrb_int)
 #define FIXABLE(f) TYPED_FIXABLE(f,mrb_int)
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 #ifdef MRB_INT64
 #define FIXABLE_FLOAT(f) ((f)>=-9223372036854775808.0 && (f)<9223372036854775808.0)
 #else
@@ -30,12 +30,12 @@ MRB_BEGIN_DECL
 #endif
 #endif
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 MRB_API mrb_value mrb_flo_to_fixnum(mrb_state *mrb, mrb_value val);
 #endif
 MRB_API mrb_value mrb_fixnum_to_str(mrb_state *mrb, mrb_value x, mrb_int base);
 /* ArgumentError if format string doesn't match /%(\.[0-9]+)?[aAeEfFgG]/ */
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 MRB_API mrb_value mrb_float_to_str(mrb_state *mrb, mrb_value x, const char *fmt);
 MRB_API int mrb_float_to_cstr(mrb_state *mrb, char *buf, size_t len, const char *fmt, mrb_float f);
 MRB_API mrb_float mrb_to_flo(mrb_state *mrb, mrb_value x);
@@ -161,13 +161,13 @@ mrb_int_mul_overflow(mrb_int multiplier, mrb_int multiplicand, mrb_int *product)
 
 #endif
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 # include <stdint.h>
 # include <float.h>
 
 # define MRB_FLT_RADIX          FLT_RADIX
 
-# ifdef MRB_USE_FLOAT
+# ifdef MRB_USE_FLOAT32
 #  define MRB_FLT_MANT_DIG      FLT_MANT_DIG
 #  define MRB_FLT_EPSILON       FLT_EPSILON
 #  define MRB_FLT_DIG           FLT_DIG
@@ -178,7 +178,7 @@ mrb_int_mul_overflow(mrb_int multiplier, mrb_int multiplicand, mrb_int *product)
 #  define MRB_FLT_MAX           FLT_MAX
 #  define MRB_FLT_MAX_10_EXP    FLT_MAX_10_EXP
 
-# else /* not MRB_USE_FLOAT */
+# else /* not MRB_USE_FLOAT32 */
 #  define MRB_FLT_MANT_DIG      DBL_MANT_DIG
 #  define MRB_FLT_EPSILON       DBL_EPSILON
 #  define MRB_FLT_DIG           DBL_DIG
@@ -188,8 +188,8 @@ mrb_int_mul_overflow(mrb_int multiplier, mrb_int multiplicand, mrb_int *product)
 #  define MRB_FLT_MAX_EXP       DBL_MAX_EXP
 #  define MRB_FLT_MAX           DBL_MAX
 #  define MRB_FLT_MAX_10_EXP    DBL_MAX_10_EXP
-# endif /* MRB_USE_FLOAT */
-#endif /* MRB_WITHOUT_FLOAT */
+# endif /* MRB_USE_FLOAT32 */
+#endif /* MRB_NO_FLOAT */
 
 MRB_END_DECL
 
diff --git a/include/mruby/value.h b/include/mruby/value.h
index 473774b00..88c8d4dba 100644
--- a/include/mruby/value.h
+++ b/include/mruby/value.h
@@ -75,9 +75,9 @@ struct mrb_state;
 # define MRB_ENDIAN_LOHI(a,b) b a
 #endif
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 MRB_API double mrb_float_read(const char*, char**);
-#ifdef MRB_USE_FLOAT
+#ifdef MRB_USE_FLOAT32
   typedef float mrb_float;
 #else
   typedef double mrb_float;
@@ -90,7 +90,7 @@ MRB_API int mrb_msvc_vsnprintf(char *s, size_t n, const char *format, va_list ar
 MRB_API int mrb_msvc_snprintf(char *s, size_t n, const char *format, ...);
 # define vsnprintf(s, n, format, arg) mrb_msvc_vsnprintf(s, n, format, arg)
 # define snprintf(s, n, format, ...) mrb_msvc_snprintf(s, n, format, __VA_ARGS__)
-# if _MSC_VER < 1800 && !defined MRB_WITHOUT_FLOAT
+# if _MSC_VER < 1800 && !defined MRB_NO_FLOAT
 #  include <float.h>
 #  define isfinite(n) _finite(n)
 #  define isnan _isnan
@@ -195,7 +195,7 @@ struct RCptr {
 #ifndef mrb_true_p
 #define mrb_true_p(o)  (mrb_type(o) == MRB_TT_TRUE)
 #endif
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 #ifndef mrb_float_p
 #define mrb_float_p(o) (mrb_type(o) == MRB_TT_FLOAT)
 #endif
@@ -264,7 +264,7 @@ struct RCptr {
  *
  * Takes a float and boxes it into an mrb_value
  */
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 MRB_INLINE mrb_value mrb_float_value(struct mrb_state *mrb, mrb_float f)
 {
   mrb_value v;
diff --git a/mrbgems/mruby-compiler/core/codegen.c b/mrbgems/mruby-compiler/core/codegen.c
index f60f1f077..372a2c5f7 100644
--- a/mrbgems/mruby-compiler/core/codegen.c
+++ b/mrbgems/mruby-compiler/core/codegen.c
@@ -530,7 +530,7 @@ new_lit(codegen_scope *s, mrb_value val)
         return i;
     }
     break;
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   case MRB_TT_FLOAT:
     for (i=0; i<s->irep->plen; i++) {
       mrb_float f1, f2;
@@ -588,7 +588,7 @@ new_lit(codegen_scope *s, mrb_value val)
     }
     break;
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   case MRB_TT_FLOAT:
     pv->tt = IREP_TT_FLOAT;
     pv->u.f = mrb_float(val);
@@ -1330,7 +1330,7 @@ raise_error(codegen_scope *s, const char *msg)
   genop_1(s, OP_ERR, idx);
 }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 static double
 readint_float(codegen_scope *s, const char *p, int base)
 {
@@ -2442,7 +2442,7 @@ codegen(codegen_scope *s, node *tree, int val)
       mrb_bool overflow;
 
       i = readint_mrb_int(s, p, base, FALSE, &overflow);
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
       if (overflow) {
         double f = readint_float(s, p, base);
         int off = new_lit(s, mrb_float_value(s->mrb, f));
@@ -2473,7 +2473,7 @@ codegen(codegen_scope *s, node *tree, int val)
     }
     break;
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   case NODE_FLOAT:
     if (val) {
       char *p = (char*)tree;
@@ -2490,7 +2490,7 @@ codegen(codegen_scope *s, node *tree, int val)
     {
       nt = nint(tree->car);
       switch (nt) {
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
       case NODE_FLOAT:
         if (val) {
           char *p = (char*)tree->cdr;
@@ -2511,7 +2511,7 @@ codegen(codegen_scope *s, node *tree, int val)
           mrb_bool overflow;
 
           i = readint_mrb_int(s, p, base, TRUE, &overflow);
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
           if (overflow) {
             double f = readint_float(s, p, base);
             int off = new_lit(s, mrb_float_value(s->mrb, -f));
@@ -2531,7 +2531,7 @@ codegen(codegen_scope *s, node *tree, int val)
               int off = new_lit(s, mrb_fixnum_value(i));
               genop_2(s, OP_LOADL, cursp(), off);
             }
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
           }
 #endif
           push();
diff --git a/mrbgems/mruby-compiler/core/parse.y b/mrbgems/mruby-compiler/core/parse.y
index c67c694fe..8e3087a2a 100644
--- a/mrbgems/mruby-compiler/core/parse.y
+++ b/mrbgems/mruby-compiler/core/parse.y
@@ -981,7 +981,7 @@ new_int(parser_state *p, const char *s, int base, int suffix)
   return result;
 }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 /* (:float . i) */
 static node*
 new_float(parser_state *p, const char *s, int suffix)
@@ -5661,7 +5661,7 @@ parser_yylex(parser_state *p)
     }
     tokfix(p);
     if (is_float) {
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
       yywarning_s(p, "floating point numbers are not supported", tok(p));
       pylval.nd = new_int(p, "0", 10, 0);
       return tINTEGER;
diff --git a/mrbgems/mruby-compiler/core/y.tab.c b/mrbgems/mruby-compiler/core/y.tab.c
index 096543349..48173933f 100644
--- a/mrbgems/mruby-compiler/core/y.tab.c
+++ b/mrbgems/mruby-compiler/core/y.tab.c
@@ -1044,7 +1044,7 @@ new_int(parser_state *p, const char *s, int base, int suffix)
   return result;
 }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 /* (:float . i) */
 static node*
 new_float(parser_state *p, const char *s, int suffix)
@@ -11553,7 +11553,7 @@ parser_yylex(parser_state *p)
     }
     tokfix(p);
     if (is_float) {
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
       yywarning_s(p, "floating point numbers are not supported", tok(p));
       pylval.nd = new_int(p, "0", 10, 0);
       return tINTEGER;
diff --git a/mrbgems/mruby-complex/src/complex.c b/mrbgems/mruby-complex/src/complex.c
index 24dad4235..85735b704 100644
--- a/mrbgems/mruby-complex/src/complex.c
+++ b/mrbgems/mruby-complex/src/complex.c
@@ -3,8 +3,8 @@
 #include <mruby/numeric.h>
 #include <math.h>
 
-#ifdef MRB_WITHOUT_FLOAT
-# error Complex conflicts 'MRB_WITHOUT_FLOAT' configuration in your 'build_config.rb'
+#ifdef MRB_NO_FLOAT
+# error Complex conflicts with 'MRB_NO_FLOAT' configuration
 #endif
 
 struct mrb_complex {
@@ -12,13 +12,13 @@ struct mrb_complex {
   mrb_float imaginary;
 };
 
-#ifdef MRB_USE_FLOAT
+#ifdef MRB_USE_FLOAT32
 #define F(x) x##f
 #else
 #define F(x) x
 #endif
 
-#if defined(MRB_64BIT) || defined(MRB_USE_FLOAT)
+#if defined(MRB_64BIT) || defined(MRB_USE_FLOAT32)
 
 #define COMPLEX_USE_ISTRUCT
 /* use TT_ISTRUCT */
diff --git a/mrbgems/mruby-complex/test/complex.rb b/mrbgems/mruby-complex/test/complex.rb
index d996e8277..14711ad73 100644
--- a/mrbgems/mruby-complex/test/complex.rb
+++ b/mrbgems/mruby-complex/test/complex.rb
@@ -60,7 +60,7 @@ assert 'Complex#/' do
   assert_complex Complex(9, 8)  / 4             , ((9 / 4)            + 2i)
   assert_complex Complex(20, 9) / 9.8           , (2.0408163265306123 + 0.9183673469387754i)
   if 1e39.infinite? then
-    # MRB_USE_FLOAT in effect
+    # MRB_USE_FLOAT32 in effect
     ten = 1e21
     one = 1e20
   else
@@ -80,7 +80,7 @@ assert 'Complex#abs' do
   assert_float Complex(-1).abs,        1
   assert_float Complex(3.0, -4.0).abs, 5.0
   if 1e39.infinite? then
-    # MRB_USE_FLOAT in effect
+    # MRB_USE_FLOAT32 in effect
     exp = 125
   else
     exp = 1021
diff --git a/mrbgems/mruby-inline-struct/test/inline.c b/mrbgems/mruby-inline-struct/test/inline.c
index 5d307dcab..b4d9b1f1e 100644
--- a/mrbgems/mruby-inline-struct/test/inline.c
+++ b/mrbgems/mruby-inline-struct/test/inline.c
@@ -13,7 +13,7 @@ istruct_test_initialize(mrb_state *mrb, mrb_value self)
   if (mrb_fixnum_p(object)) {
     strncpy(string, "fixnum", size-1);
   }
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   else if (mrb_float_p(object)) {
     strncpy(string, "float", size-1);
   }
diff --git a/mrbgems/mruby-io/src/file.c b/mrbgems/mruby-io/src/file.c
index 04dece910..a28360d81 100644
--- a/mrbgems/mruby-io/src/file.c
+++ b/mrbgems/mruby-io/src/file.c
@@ -448,8 +448,8 @@ mrb_file_size(mrb_state *mrb, mrb_value self)
   }
 
   if (st.st_size > MRB_INT_MAX) {
-#ifdef MRB_WITHOUT_FLOAT
-    mrb_raise(mrb, E_RUNTIME_ERROR, "File#size too large for MRB_WITHOUT_FLOAT");
+#ifdef MRB_NO_FLOAT
+    mrb_raise(mrb, E_RUNTIME_ERROR, "File#size too large for MRB_NO_FLOAT");
 #else
     return mrb_float_value(mrb, (mrb_float)st.st_size);
 #endif
diff --git a/mrbgems/mruby-io/src/io.c b/mrbgems/mruby-io/src/io.c
index 988d19b02..587e195d9 100644
--- a/mrbgems/mruby-io/src/io.c
+++ b/mrbgems/mruby-io/src/io.c
@@ -973,10 +973,10 @@ mrb_io_sysseek(mrb_state *mrb, mrb_value io)
     mrb_sys_fail(mrb, "sysseek");
   }
   if (pos > MRB_INT_MAX) {
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
     return mrb_float_value(mrb, (mrb_float)pos);
 #else
-    mrb_raise(mrb, E_IO_ERROR, "sysseek reached too far for MRB_WITHOUT_FLOAT");
+    mrb_raise(mrb, E_IO_ERROR, "sysseek reached too far for MRB_NO_FLOAT");
 #endif
   } else {
     return mrb_fixnum_value(pos);
@@ -1081,7 +1081,7 @@ time2timeval(mrb_state *mrb, mrb_value time)
       t.tv_usec = 0;
       break;
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
     case MRB_TT_FLOAT:
       t.tv_sec = (ftime_t)mrb_float(time);
       t.tv_usec = (fsuseconds_t)((mrb_float(time) - t.tv_sec) * 1000000.0);
diff --git a/mrbgems/mruby-kernel-ext/src/kernel.c b/mrbgems/mruby-kernel-ext/src/kernel.c
index 70991c704..eaf8c6eb0 100644
--- a/mrbgems/mruby-kernel-ext/src/kernel.c
+++ b/mrbgems/mruby-kernel-ext/src/kernel.c
@@ -112,7 +112,7 @@ mrb_f_integer(mrb_state *mrb, mrb_value self)
   return mrb_convert_to_integer(mrb, arg, base);
 }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 /*
  *  call-seq:
  *     Float(arg)    -> float
@@ -212,7 +212,7 @@ mrb_mruby_kernel_ext_gem_init(mrb_state *mrb)
   mrb_define_module_function(mrb, krn, "caller", mrb_f_caller, MRB_ARGS_OPT(2));
   mrb_define_method(mrb, krn, "__method__", mrb_f_method, MRB_ARGS_NONE());
   mrb_define_module_function(mrb, krn, "Integer", mrb_f_integer, MRB_ARGS_ARG(1,1));
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   mrb_define_module_function(mrb, krn, "Float", mrb_f_float, MRB_ARGS_REQ(1));
 #endif
   mrb_define_module_function(mrb, krn, "String", mrb_f_string, MRB_ARGS_REQ(1));
diff --git a/mrbgems/mruby-math/src/math.c b/mrbgems/mruby-math/src/math.c
index ff1e84684..fcde7e700 100644
--- a/mrbgems/mruby-math/src/math.c
+++ b/mrbgems/mruby-math/src/math.c
@@ -4,8 +4,8 @@
 ** See Copyright Notice in mruby.h
 */
 
-#ifdef MRB_WITHOUT_FLOAT
-# error Math conflicts 'MRB_WITHOUT_FLOAT' configuration in your 'build_config.rb'
+#ifdef MRB_NO_FLOAT
+# error Math conflicts with 'MRB_NO_FLOAT' configuration
 #endif
 
 #include <mruby.h>
diff --git a/mrbgems/mruby-numeric-ext/src/numeric_ext.c b/mrbgems/mruby-numeric-ext/src/numeric_ext.c
index fd7072ccd..d00be4b5d 100644
--- a/mrbgems/mruby-numeric-ext/src/numeric_ext.c
+++ b/mrbgems/mruby-numeric-ext/src/numeric_ext.c
@@ -59,7 +59,7 @@ mrb_mruby_numeric_ext_gem_init(mrb_state* mrb)
   mrb_define_method(mrb, i, "anybits?", mrb_int_anybits, MRB_ARGS_REQ(1));
   mrb_define_method(mrb, i, "nobits?", mrb_int_nobits, MRB_ARGS_REQ(1));
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   mrb_define_const_id(mrb, mrb->float_class, MRB_SYM(RADIX),        mrb_fixnum_value(MRB_FLT_RADIX));
   mrb_define_const_id(mrb, mrb->float_class, MRB_SYM(MANT_DIG),     mrb_fixnum_value(MRB_FLT_MANT_DIG));
   mrb_define_const_id(mrb, mrb->float_class, MRB_SYM(EPSILON),      mrb_float_value(mrb, MRB_FLT_EPSILON));
@@ -70,7 +70,7 @@ mrb_mruby_numeric_ext_gem_init(mrb_state* mrb)
   mrb_define_const_id(mrb, mrb->float_class, MRB_SYM(MAX_EXP),      mrb_fixnum_value(MRB_FLT_MAX_EXP));
   mrb_define_const_id(mrb, mrb->float_class, MRB_SYM(MAX),          mrb_float_value(mrb, MRB_FLT_MAX));
   mrb_define_const_id(mrb, mrb->float_class, MRB_SYM(MAX_10_EXP),   mrb_fixnum_value(MRB_FLT_MAX_10_EXP));
-#endif /* MRB_WITHOUT_FLOAT */
+#endif /* MRB_NO_FLOAT */
 }
 
 void
diff --git a/mrbgems/mruby-object-ext/src/object.c b/mrbgems/mruby-object-ext/src/object.c
index 57361e8e2..2d99ce8c2 100644
--- a/mrbgems/mruby-object-ext/src/object.c
+++ b/mrbgems/mruby-object-ext/src/object.c
@@ -17,7 +17,7 @@ nil_to_a(mrb_state *mrb, mrb_value obj)
   return mrb_ary_new(mrb);
 }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 /*
  *  call-seq:
  *     nil.to_f    -> 0.0
@@ -115,7 +115,7 @@ mrb_mruby_object_ext_gem_init(mrb_state* mrb)
   struct RClass * n = mrb->nil_class;
 
   mrb_define_method(mrb, n, "to_a", nil_to_a,       MRB_ARGS_NONE());
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   mrb_define_method(mrb, n, "to_f", nil_to_f,       MRB_ARGS_NONE());
 #endif
   mrb_define_method(mrb, n, "to_h", nil_to_h,       MRB_ARGS_NONE());
diff --git a/mrbgems/mruby-os-memsize/src/memsize.c b/mrbgems/mruby-os-memsize/src/memsize.c
index 7030299f4..78ef1e4df 100644
--- a/mrbgems/mruby-os-memsize/src/memsize.c
+++ b/mrbgems/mruby-os-memsize/src/memsize.c
@@ -111,7 +111,7 @@ os_memsize_of_object(mrb_state* mrb, mrb_value obj)
     case MRB_TT_DATA:
       size += mrb_objspace_page_slot_size();
       break;
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
     case MRB_TT_FLOAT:
 #ifdef MRB_WORD_BOXING
       size += mrb_objspace_page_slot_size() +
diff --git a/mrbgems/mruby-pack/src/pack.c b/mrbgems/mruby-pack/src/pack.c
index e222cd946..45427afa0 100644
--- a/mrbgems/mruby-pack/src/pack.c
+++ b/mrbgems/mruby-pack/src/pack.c
@@ -425,7 +425,7 @@ unpack_q(mrb_state *mrb, const unsigned char *src, int srclen, mrb_value ary, un
   return 8;
 }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 static int
 pack_double(mrb_state *mrb, mrb_value o, mrb_value str, mrb_int sidx, unsigned int flags)
 {
@@ -1248,7 +1248,7 @@ mrb_pack_pack(mrb_state *mrb, mrb_value ary)
       if (type == PACK_TYPE_INTEGER) {
         o = mrb_to_int(mrb, o);
       }
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
       else if (type == PACK_TYPE_FLOAT) {
         if (!mrb_float_p(o)) {
           mrb_float f = mrb_to_flo(mrb, o);
@@ -1284,7 +1284,7 @@ mrb_pack_pack(mrb_state *mrb, mrb_value ary)
       case PACK_DIR_STR:
         ridx += pack_a(mrb, o, result, ridx, count, flags);
         break;
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
       case PACK_DIR_DOUBLE:
         ridx += pack_double(mrb, o, result, ridx, flags);
         break;
@@ -1381,7 +1381,7 @@ pack_unpack(mrb_state *mrb, mrb_value str, int single)
       case PACK_DIR_QUAD:
         srcidx += unpack_q(mrb, sptr, srclen - srcidx, result, flags);
         break;
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
       case PACK_DIR_FLOAT:
         srcidx += unpack_float(mrb, sptr, srclen - srcidx, result, flags);
         break;
diff --git a/mrbgems/mruby-random/src/random.c b/mrbgems/mruby-random/src/random.c
index fdb28e012..3010b3db7 100644
--- a/mrbgems/mruby-random/src/random.c
+++ b/mrbgems/mruby-random/src/random.c
@@ -85,7 +85,7 @@ rand_uint32(rand_state *state)
 }
 #endif  /* XORSHIFT96 */
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 static double
 rand_real(rand_state *t)
 {
@@ -100,7 +100,7 @@ random_rand(mrb_state *mrb, rand_state *t, mrb_value max)
   mrb_value value;
 
   if (mrb_fixnum(max) == 0) {
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
     value = mrb_float_value(mrb, rand_real(t));
 #else
     mrb_raise(mrb, E_ARGUMENT_ERROR, "Float not supported");
diff --git a/mrbgems/mruby-range-ext/src/range.c b/mrbgems/mruby-range-ext/src/range.c
index 633894070..421e7d33a 100644
--- a/mrbgems/mruby-range-ext/src/range.c
+++ b/mrbgems/mruby-range-ext/src/range.c
@@ -96,7 +96,7 @@ range_last(mrb_state *mrb, mrb_value range)
  *    ('a'..'z').size  #=> nil
  */
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 static mrb_value
 range_size(mrb_state *mrb, mrb_value range)
 {
@@ -170,7 +170,7 @@ range_size(mrb_state *mrb, mrb_value range)
   }
   return mrb_nil_value();
 }
-#endif /* MRB_WITHOUT_FLOAT */
+#endif /* MRB_NO_FLOAT */
 
 void
 mrb_mruby_range_ext_gem_init(mrb_state* mrb)
diff --git a/mrbgems/mruby-rational/src/rational.c b/mrbgems/mruby-rational/src/rational.c
index 4a72a42f2..f9470de86 100644
--- a/mrbgems/mruby-rational/src/rational.c
+++ b/mrbgems/mruby-rational/src/rational.c
@@ -87,7 +87,7 @@ rational_s_new(mrb_state *mrb, mrb_value self)
 {
   mrb_int numerator, denominator;
 
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
   mrb_get_args(mrb, "ii", &numerator, &denominator);
 #else
 
@@ -136,7 +136,7 @@ rational_s_new(mrb_state *mrb, mrb_value self)
   return rational_new(mrb, numerator, denominator);
 }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 static mrb_value
 rational_to_f(mrb_state *mrb, mrb_value self)
 {
@@ -194,7 +194,7 @@ void mrb_mruby_rational_gem_init(mrb_state *mrb)
   mrb_define_class_method(mrb, rat, "_new", rational_s_new, MRB_ARGS_REQ(2));
   mrb_define_method(mrb, rat, "numerator", rational_numerator, MRB_ARGS_NONE());
   mrb_define_method(mrb, rat, "denominator", rational_denominator, MRB_ARGS_NONE());
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   mrb_define_method(mrb, rat, "to_f", rational_to_f, MRB_ARGS_NONE());
 #endif
   mrb_define_method(mrb, rat, "to_i", rational_to_i, MRB_ARGS_NONE());
diff --git a/mrbgems/mruby-sleep/src/mrb_sleep.c b/mrbgems/mruby-sleep/src/mrb_sleep.c
index a653242d1..7771db56b 100644
--- a/mrbgems/mruby-sleep/src/mrb_sleep.c
+++ b/mrbgems/mruby-sleep/src/mrb_sleep.c
@@ -44,7 +44,7 @@ mrb_f_sleep(mrb_state *mrb, mrb_value self)
 {
     time_t beg = time(0);
     time_t end;
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
     mrb_float sec;
 
     mrb_get_args(mrb, "f", &sec);
diff --git a/mrbgems/mruby-sprintf/src/sprintf.c b/mrbgems/mruby-sprintf/src/sprintf.c
index 0cf462ef7..7f36616ec 100644
--- a/mrbgems/mruby-sprintf/src/sprintf.c
+++ b/mrbgems/mruby-sprintf/src/sprintf.c
@@ -10,7 +10,7 @@
 #include <mruby/string.h>
 #include <mruby/hash.h>
 #include <mruby/numeric.h>
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 #include <math.h>
 #endif
 #include <ctype.h>
@@ -20,7 +20,7 @@
 #define EXTENDSIGN(n, l) (((~0U << (n)) >> (((n)*(l)) % BITSPERDIG)) & ~(~0U << (n)))
 
 mrb_value mrb_str_format(mrb_state *, mrb_int, const mrb_value *, mrb_value);
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 static void fmt_setup(char*,size_t,int,int,mrb_int,mrb_int);
 #endif
 
@@ -863,7 +863,7 @@ retry:
 
   bin_retry:
         switch (mrb_type(val)) {
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
           case MRB_TT_FLOAT:
             val = mrb_flo_to_fixnum(mrb, val);
             if (mrb_fixnum_p(val)) goto bin_retry;
@@ -1030,7 +1030,7 @@ retry:
       }
       break;
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
       case 'f':
       case 'g':
       case 'G':
@@ -1131,7 +1131,7 @@ retry:
   return result;
 }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 static void
 fmt_setup(char *buf, size_t size, int c, int flags, mrb_int width, mrb_int prec)
 {
diff --git a/mrbgems/mruby-string-ext/src/string.c b/mrbgems/mruby-string-ext/src/string.c
index ded34a89e..71fb5bb65 100644
--- a/mrbgems/mruby-string-ext/src/string.c
+++ b/mrbgems/mruby-string-ext/src/string.c
@@ -12,7 +12,7 @@
 #define ENC_COMP_P(enc, enc_lit) \
   str_casecmp_p(RSTRING_PTR(enc), RSTRING_LEN(enc), enc_lit, sizeof(enc_lit"")-1)
 
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
 # define mrb_float_p(o) FALSE
 #endif
 
diff --git a/mrbgems/mruby-test/driver.c b/mrbgems/mruby-test/driver.c
index fe1a475d5..4b82a9abc 100644
--- a/mrbgems/mruby-test/driver.c
+++ b/mrbgems/mruby-test/driver.c
@@ -224,8 +224,8 @@ mrb_init_test_driver(mrb_state *mrb, mrb_bool verbose)
   mrb_define_const(mrb, mrbtest, "FIXNUM_MIN", mrb_fixnum_value(MRB_INT_MIN));
   mrb_define_const(mrb, mrbtest, "FIXNUM_BIT", mrb_fixnum_value(MRB_INT_BIT));
 
-#ifndef MRB_WITHOUT_FLOAT
-#ifdef MRB_USE_FLOAT
+#ifndef MRB_NO_FLOAT
+#ifdef MRB_USE_FLOAT32
   mrb_define_const(mrb, mrbtest, "FLOAT_TOLERANCE", mrb_float_value(mrb, 1e-6));
 #else
   mrb_define_const(mrb, mrbtest, "FLOAT_TOLERANCE", mrb_float_value(mrb, 1e-12));
diff --git a/mrbgems/mruby-test/vformat.c b/mrbgems/mruby-test/vformat.c
index e7ada02da..d73e52311 100644
--- a/mrbgems/mruby-test/vformat.c
+++ b/mrbgems/mruby-test/vformat.c
@@ -48,7 +48,7 @@ vf_s_format_d(mrb_state *mrb, mrb_value klass)
   return mrb_format(mrb, fmt, d);
 }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 /* f float */
 static mrb_value
 vf_s_format_f(mrb_state *mrb, mrb_value klass)
@@ -167,7 +167,7 @@ mrb_init_test_vformat(mrb_state *mrb)
   
   VF_DEFINE_FORMAT_METHOD(c);
   VF_DEFINE_FORMAT_METHOD(d);
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   VF_DEFINE_FORMAT_METHOD(f);
 #endif
   VF_DEFINE_FORMAT_METHOD(i);
diff --git a/mrbgems/mruby-time/src/time.c b/mrbgems/mruby-time/src/time.c
index 3655695cf..3d5cdca2e 100644
--- a/mrbgems/mruby-time/src/time.c
+++ b/mrbgems/mruby-time/src/time.c
@@ -4,7 +4,7 @@
 ** See Copyright Notice in mruby.h
 */
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 #include <math.h>
 #endif
 
@@ -30,7 +30,7 @@ double round(double x) {
 }
 #endif
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 # if !defined(__MINGW64__) && defined(_WIN32)
 #  define llround(x) round(x)
 # endif
@@ -199,7 +199,7 @@ struct mrb_time {
 
 static const struct mrb_data_type mrb_time_type = { "Time", mrb_free };
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 void mrb_check_num_exact(mrb_state *mrb, mrb_float num);
 typedef mrb_float mrb_sec;
 #define mrb_sec_value(mrb, sec) mrb_float_value(mrb, sec)
@@ -231,7 +231,7 @@ mrb_to_time_t(mrb_state *mrb, mrb_value obj, time_t *usec)
   time_t t;
 
   switch (mrb_type(obj)) {
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
     case MRB_TT_FLOAT:
       {
         mrb_float f = mrb_float(obj);
@@ -250,7 +250,7 @@ mrb_to_time_t(mrb_state *mrb, mrb_value obj, time_t *usec)
         }
       }
       break;
-#endif /* MRB_WITHOUT_FLOAT */
+#endif /* MRB_NO_FLOAT */
     default:
     case MRB_TT_FIXNUM:
       {
@@ -572,7 +572,7 @@ mrb_time_minus(mrb_state *mrb, mrb_value self)
   tm = time_get_ptr(mrb, self);
   tm2 = DATA_CHECK_GET_PTR(mrb, other, &mrb_time_type, struct mrb_time);
   if (tm2) {
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
     mrb_float f;
     f = (mrb_sec)(tm->sec - tm2->sec)
       + (mrb_sec)(tm->usec - tm2->usec) / 1.0e6;
@@ -843,7 +843,7 @@ mrb_time_sec(mrb_state *mrb, mrb_value self)
   return mrb_fixnum_value(tm->datetime.tm_sec);
 }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 /* 15.2.19.7.24 */
 /* Returns a Float with the time since the epoch in seconds. */
 static mrb_value
@@ -864,7 +864,7 @@ mrb_time_to_i(mrb_state *mrb, mrb_value self)
   struct mrb_time *tm;
 
   tm = time_get_ptr(mrb, self);
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   if (!fixable_time_t_p(tm->sec)) {
     return mrb_float_value(mrb, (mrb_float)tm->sec);
   }
@@ -880,7 +880,7 @@ mrb_time_usec(mrb_state *mrb, mrb_value self)
   struct mrb_time *tm;
 
   tm = time_get_ptr(mrb, self);
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   if (!fixable_time_t_p(tm->usec)) {
     return mrb_float_value(mrb, (mrb_float)tm->usec);
   }
@@ -995,7 +995,7 @@ mrb_mruby_time_gem_init(mrb_state* mrb)
 
   mrb_define_method(mrb, tc, "sec" , mrb_time_sec, MRB_ARGS_NONE());        /* 15.2.19.7.23 */
   mrb_define_method(mrb, tc, "to_i", mrb_time_to_i, MRB_ARGS_NONE());       /* 15.2.19.7.25 */
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   mrb_define_method(mrb, tc, "to_f", mrb_time_to_f, MRB_ARGS_NONE());       /* 15.2.19.7.24 */
 #endif
   mrb_define_method(mrb, tc, "usec", mrb_time_usec, MRB_ARGS_NONE());       /* 15.2.19.7.26 */
diff --git a/src/array.c b/src/array.c
index 285600969..432599bf7 100644
--- a/src/array.c
+++ b/src/array.c
@@ -825,7 +825,7 @@ aget_index(mrb_state *mrb, mrb_value index)
   if (mrb_fixnum_p(index)) {
     return mrb_fixnum(index);
   }
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   else if (mrb_float_p(index)) {
     return (mrb_int)mrb_float(index);
   }
diff --git a/src/class.c b/src/class.c
index 455a1b4e1..845246e97 100644
--- a/src/class.c
+++ b/src/class.c
@@ -899,7 +899,7 @@ mrb_get_args(mrb_state *mrb, const char *format, ...)
         }
       }
       break;
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
     case 'f':
       {
         mrb_float *p;
@@ -1343,7 +1343,7 @@ mrb_singleton_class_ptr(mrb_state *mrb, mrb_value v)
     return mrb->object_class;
   case MRB_TT_SYMBOL:
   case MRB_TT_FIXNUM:
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   case MRB_TT_FLOAT:
 #endif
     return NULL;
diff --git a/src/dump.c b/src/dump.c
index 3bc95f629..489e70f8a 100644
--- a/src/dump.c
+++ b/src/dump.c
@@ -13,8 +13,8 @@
 #include <mruby/numeric.h>
 #include <mruby/debug.h>
 
-#ifndef MRB_WITHOUT_FLOAT
-#ifdef MRB_USE_FLOAT
+#ifndef MRB_NO_FLOAT
+#ifdef MRB_USE_FLOAT32
 #define MRB_FLOAT_FMT "%.9g"
 #else
 #define MRB_FLOAT_FMT "%.17g"
@@ -88,7 +88,7 @@ write_iseq_block(mrb_state *mrb, const mrb_irep *irep, uint8_t *buf, uint8_t fla
   return cur - buf;
 }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 static mrb_value
 float_to_str(mrb_state *mrb, mrb_float f)
 {
@@ -131,7 +131,7 @@ get_pool_block_size(mrb_state *mrb, const mrb_irep *irep)
       break;
 
     case IREP_TT_FLOAT:
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
       {
         mrb_value str = float_to_str(mrb, irep->pool[pool_no].u.f);
         mrb_int len = RSTRING_LEN(str);
@@ -192,7 +192,7 @@ write_pool_block(mrb_state *mrb, const mrb_irep *irep, uint8_t *buf)
 
     case IREP_TT_FLOAT:
       cur += uint8_to_bin(IREP_TT_FLOAT, cur); /* data type */
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
       {
         mrb_value str = float_to_str(mrb, irep->pool[pool_no].u.f);
         ptr = RSTRING_PTR(str);
diff --git a/src/error.c b/src/error.c
index 742049ace..b6a82f867 100644
--- a/src/error.c
+++ b/src/error.c
@@ -288,7 +288,7 @@ mrb_vformat(mrb_state *mrb, const char *format, va_list ap)
 #endif
           obj = mrb_fixnum_value(i);
           goto L_cat_obj;
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
         case 'f':
           obj = mrb_float_value(mrb, (mrb_float)va_arg(ap, double));
           goto L_cat_obj;
diff --git a/src/etc.c b/src/etc.c
index a1e384717..b0019e6de 100644
--- a/src/etc.c
+++ b/src/etc.c
@@ -70,7 +70,7 @@ mrb_obj_to_sym(mrb_state *mrb, mrb_value name)
 }
 
 MRB_API mrb_int
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
 mrb_fixnum_id(mrb_int f)
 #else
 mrb_float_id(mrb_float f)
@@ -80,7 +80,7 @@ mrb_float_id(mrb_float f)
   int len = sizeof(f);
   uint32_t id = 0;
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   /* normalize -0.0 to 0.0 */
   if (f == 0) f = 0.0;
 #endif
@@ -115,7 +115,7 @@ mrb_obj_id(mrb_value obj)
   case MRB_TT_SYMBOL:
     return MakeID(mrb_symbol(obj));
   case MRB_TT_FIXNUM:
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
     return MakeID(mrb_fixnum_id(mrb_fixnum(obj)));
 #else
     return MakeID2(mrb_float_id((mrb_float)mrb_fixnum(obj)), MRB_TT_FLOAT);
@@ -147,7 +147,7 @@ mrb_obj_id(mrb_value obj)
 #ifdef MRB_WORD_BOXING
 #define mrb_xxx_boxing_cptr_value mrb_word_boxing_cptr_value
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 MRB_API mrb_value
 mrb_word_boxing_float_value(mrb_state *mrb, mrb_float f)
 {
@@ -158,7 +158,7 @@ mrb_word_boxing_float_value(mrb_state *mrb, mrb_float f)
   MRB_SET_FROZEN_FLAG(v.bp);
   return v.w;
 }
-#endif  /* MRB_WITHOUT_FLOAT */
+#endif  /* MRB_NO_FLOAT */
 #endif  /* MRB_WORD_BOXING */
 
 #if defined(MRB_WORD_BOXING) || (defined(MRB_NAN_BOXING) && defined(MRB_64BIT))
diff --git a/src/fmt_fp.c b/src/fmt_fp.c
index 81ace6ec8..2c1e13c36 100644
--- a/src/fmt_fp.c
+++ b/src/fmt_fp.c
@@ -1,4 +1,4 @@
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 #if defined(MRB_DISABLE_STDIO) || defined(_WIN32) || defined(_WIN64)
 /*
 
diff --git a/src/gc.c b/src/gc.c
index 17f7e81e4..50269f95c 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -122,7 +122,7 @@ typedef struct {
     struct RException exc;
     struct RBreak brk;
 #ifdef MRB_WORD_BOXING
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
     struct RFloat floatv;
 #endif
     struct RCptr cptr;
@@ -784,7 +784,7 @@ obj_free(mrb_state *mrb, struct RBasic *obj, int end)
     /* cannot happen */
     return;
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   case MRB_TT_FLOAT:
 #ifdef MRB_WORD_BOXING
     break;
@@ -929,7 +929,7 @@ root_scan_phase(mrb_state *mrb, mrb_gc *gc)
   mrb_gc_mark(mrb, (struct RBasic*)mrb->hash_class);
   mrb_gc_mark(mrb, (struct RBasic*)mrb->range_class);
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   mrb_gc_mark(mrb, (struct RBasic*)mrb->float_class);
 #endif
   mrb_gc_mark(mrb, (struct RBasic*)mrb->fixnum_class);
diff --git a/src/hash.c b/src/hash.c
index 72ed3c731..2eef4afaf 100644
--- a/src/hash.c
+++ b/src/hash.c
@@ -11,7 +11,7 @@
 #include <mruby/string.h>
 #include <mruby/variable.h>
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 /* a function to get hash value of a float number */
 mrb_int mrb_float_id(mrb_float f);
 #endif
@@ -65,7 +65,7 @@ ht_hash_func(mrb_state *mrb, htable *t, mrb_value key)
   case MRB_TT_FALSE:
   case MRB_TT_SYMBOL:
   case MRB_TT_FIXNUM:
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   case MRB_TT_FLOAT:
 #endif
     h = (size_t)mrb_obj_id(key);
@@ -99,7 +99,7 @@ ht_hash_equal(mrb_state *mrb, htable *t, mrb_value a, mrb_value b)
     switch (mrb_type(b)) {
     case MRB_TT_FIXNUM:
       return mrb_fixnum(a) == mrb_fixnum(b);
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
     case MRB_TT_FLOAT:
       return (mrb_float)mrb_fixnum(a) == mrb_float(b);
 #endif
@@ -107,7 +107,7 @@ ht_hash_equal(mrb_state *mrb, htable *t, mrb_value a, mrb_value b)
       return FALSE;
     }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   case MRB_TT_FLOAT:
     switch (mrb_type(b)) {
     case MRB_TT_FIXNUM:
diff --git a/src/load.c b/src/load.c
index 67217b128..b06b9ff37 100644
--- a/src/load.c
+++ b/src/load.c
@@ -39,7 +39,7 @@ offset_crc_body(void)
   return ((uint8_t *)header.binary_crc - (uint8_t *)&header) + sizeof(header.binary_crc);
 }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 double mrb_str_len_to_dbl(mrb_state *mrb, const char *s, size_t len, mrb_bool badcheck);
 
 static double
@@ -165,7 +165,7 @@ read_irep_record_1(mrb_state *mrb, const uint8_t *bin, size_t *len, uint8_t flag
 #endif
 
       case IREP_TT_FLOAT:
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
         pool[i].tt = tt;
         pool_data_len = bin_to_uint16(src); /* pool data length */
         src += sizeof(uint16_t);
@@ -173,7 +173,7 @@ read_irep_record_1(mrb_state *mrb, const uint8_t *bin, size_t *len, uint8_t flag
         src += pool_data_len;
         break;
 #else
-        return NULL;            /* MRB_WITHOUT_FLOAT */
+        return NULL;            /* MRB_NO_FLOAT */
 #endif
 
       case IREP_TT_STR:
diff --git a/src/numeric.c b/src/numeric.c
index 195bd40cf..f4ad116a4 100644
--- a/src/numeric.c
+++ b/src/numeric.c
@@ -4,7 +4,7 @@
 ** See Copyright Notice in mruby.h
 */
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 #include <float.h>
 #include <math.h>
 #endif
@@ -18,8 +18,8 @@
 #include <mruby/string.h>
 #include <mruby/class.h>
 
-#ifndef MRB_WITHOUT_FLOAT
-#ifdef MRB_USE_FLOAT
+#ifndef MRB_NO_FLOAT
+#ifdef MRB_USE_FLOAT32
 #define trunc(f) truncf(f)
 #define floor(f) floorf(f)
 #define ceil(f) ceilf(f)
@@ -30,7 +30,7 @@
 #endif
 #endif
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 MRB_API mrb_float
 mrb_to_flo(mrb_state *mrb, mrb_value val)
 {
@@ -68,7 +68,7 @@ static mrb_value
 integral_pow(mrb_state *mrb, mrb_value x)
 {
   mrb_value y = mrb_get_arg1(mrb);
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   mrb_float d;
 #endif
 
@@ -79,7 +79,7 @@ integral_pow(mrb_state *mrb, mrb_value x)
     mrb_int result = 1;
 
     if (exp < 0)
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
       return mrb_fixnum_value(0);
 #else
       goto float_pow;
@@ -87,7 +87,7 @@ integral_pow(mrb_state *mrb, mrb_value x)
     for (;;) {
       if (exp & 1) {
         if (mrb_int_mul_overflow(result, base, &result)) {
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
           goto float_pow;
 #endif
         }
@@ -95,14 +95,14 @@ integral_pow(mrb_state *mrb, mrb_value x)
       exp >>= 1;
       if (exp == 0) break;
       if (mrb_int_mul_overflow(base, base, &base)) {
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
         goto float_pow;
 #endif
       }
     }
     return mrb_fixnum_value(result);
   }
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
   mrb_raise(mrb, E_TYPE_ERROR, "non fixnum value");
 #else
  float_pow:
@@ -114,7 +114,7 @@ integral_pow(mrb_state *mrb, mrb_value x)
 static mrb_value
 integral_idiv(mrb_state *mrb, mrb_value x)
 {
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
   mrb_value y = mrb_get_arg1(mrb);
 
   if (!mrb_fixnum_p(y)) {
@@ -151,7 +151,7 @@ integral_idiv(mrb_state *mrb, mrb_value x)
 static mrb_value
 integral_div(mrb_state *mrb, mrb_value xv)
 {
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
   mrb_int y;
 
   mrb_get_args(mrb, "i", &y);
@@ -184,7 +184,7 @@ integral_coerce_step_counter(mrb_state *mrb, mrb_value self)
 
   mrb_get_args(mrb, "oo", &num, &step);
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   if (mrb_float_p(self) || mrb_float_p(num) || mrb_float_p(step)) {
     return mrb_Float(mrb, self);
   }
@@ -193,7 +193,7 @@ integral_coerce_step_counter(mrb_state *mrb, mrb_value self)
   return self;
 }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 /********************************************************************
  *
  * Document-class: Float
@@ -386,7 +386,7 @@ fix_eql(mrb_state *mrb, mrb_value x)
   return mrb_bool_value(mrb_fixnum(x) == mrb_fixnum(y));
 }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 static mrb_value
 flo_eql(mrb_state *mrb, mrb_value x)
 {
@@ -803,13 +803,13 @@ fixnum_mul(mrb_state *mrb, mrb_value x, mrb_value y)
     if (a == 0) return x;
     b = mrb_fixnum(y);
     if (mrb_int_mul_overflow(a, b, &c)) {
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
       return mrb_float_value(mrb, (mrb_float)a * (mrb_float)b);
 #endif
     }
     return mrb_fixnum_value(c);
   }
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
   mrb_raise(mrb, E_TYPE_ERROR, "non fixnum value");
 #else
   return mrb_float_value(mrb, (mrb_float)a * mrb_to_flo(mrb, y));
@@ -822,7 +822,7 @@ mrb_num_mul(mrb_state *mrb, mrb_value x, mrb_value y)
   if (mrb_fixnum_p(x)) {
     return fixnum_mul(mrb, x, y);
   }
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   if (mrb_float_p(x)) {
     return mrb_float_value(mrb, mrb_float(x) * mrb_to_flo(mrb, y));
   }
@@ -898,7 +898,7 @@ fix_mod(mrb_state *mrb, mrb_value x)
     mrb_int mod;
 
     if (b == 0) {
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
       /* ZeroDivisionError */
       return mrb_fixnum_value(0);
 #else
@@ -910,7 +910,7 @@ fix_mod(mrb_state *mrb, mrb_value x)
     fixdivmod(mrb, a, b, NULL, &mod);
     return mrb_fixnum_value(mod);
   }
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
   mrb_raise(mrb, E_TYPE_ERROR, "non fixnum value");
 #else
   else {
@@ -937,7 +937,7 @@ fix_divmod(mrb_state *mrb, mrb_value x)
     mrb_int div, mod;
 
     if (mrb_fixnum(y) == 0) {
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
       return mrb_assoc_new(mrb, mrb_fixnum_value(0), mrb_fixnum_value(0));
 #else
       return mrb_assoc_new(mrb, ((mrb_fixnum(x) == 0) ?
@@ -949,7 +949,7 @@ fix_divmod(mrb_state *mrb, mrb_value x)
     fixdivmod(mrb, mrb_fixnum(x), mrb_fixnum(y), &div, &mod);
     return mrb_assoc_new(mrb, mrb_fixnum_value(div), mrb_fixnum_value(mod));
   }
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
   mrb_raise(mrb, E_TYPE_ERROR, "non fixnum value");
 #else
   else {
@@ -964,7 +964,7 @@ fix_divmod(mrb_state *mrb, mrb_value x)
 #endif
 }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 static mrb_value
 flo_divmod(mrb_state *mrb, mrb_value x)
 {
@@ -999,7 +999,7 @@ fix_equal(mrb_state *mrb, mrb_value x)
   switch (mrb_type(y)) {
   case MRB_TT_FIXNUM:
     return mrb_bool_value(mrb_fixnum(x) == mrb_fixnum(y));
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   case MRB_TT_FLOAT:
     return mrb_bool_value((mrb_float)mrb_fixnum(x) == mrb_float(y));
 #endif
@@ -1027,7 +1027,7 @@ fix_rev(mrb_state *mrb, mrb_value num)
   return mrb_fixnum_value(~val);
 }
 
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
 #define bit_op(x,y,op1,op2) do {\
   return mrb_fixnum_value(mrb_fixnum(x) op2 mrb_fixnum(y));\
 } while(0)
@@ -1095,7 +1095,7 @@ static mrb_value
 lshift(mrb_state *mrb, mrb_int val, mrb_int width)
 {
   if (width < 0) {              /* mrb_int overflow */
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
     return mrb_fixnum_value(0);
 #else
     return mrb_float_value(mrb, INFINITY);
@@ -1104,7 +1104,7 @@ lshift(mrb_state *mrb, mrb_int val, mrb_int width)
   if (val > 0) {
     if ((width > NUMERIC_SHIFT_WIDTH_MAX) ||
         (val   > (MRB_INT_MAX >> width))) {
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
       return mrb_fixnum_value(-1);
 #else
       goto bit_overflow;
@@ -1115,7 +1115,7 @@ lshift(mrb_state *mrb, mrb_int val, mrb_int width)
   else {
     if ((width > NUMERIC_SHIFT_WIDTH_MAX) ||
         (val   <= (MRB_INT_MIN >> width))) {
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
       return mrb_fixnum_value(0);
 #else
       goto bit_overflow;
@@ -1124,7 +1124,7 @@ lshift(mrb_state *mrb, mrb_int val, mrb_int width)
     return mrb_fixnum_value(val * ((mrb_int)1 << width));
   }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 bit_overflow:
   {
     mrb_float f = (mrb_float)val;
@@ -1210,7 +1210,7 @@ fix_rshift(mrb_state *mrb, mrb_value x)
  *
  */
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 static mrb_value
 fix_to_f(mrb_state *mrb, mrb_value num)
 {
@@ -1267,13 +1267,13 @@ fixnum_plus(mrb_state *mrb, mrb_value x, mrb_value y)
     if (a == 0) return y;
     b = mrb_fixnum(y);
     if (mrb_int_add_overflow(a, b, &c)) {
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
       return mrb_float_value(mrb, (mrb_float)a + (mrb_float)b);
 #endif
     }
     return mrb_fixnum_value(c);
   }
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
   mrb_raise(mrb, E_TYPE_ERROR, "non fixnum value");
 #else
   return mrb_float_value(mrb, (mrb_float)a + mrb_to_flo(mrb, y));
@@ -1286,7 +1286,7 @@ mrb_num_plus(mrb_state *mrb, mrb_value x, mrb_value y)
   if (mrb_fixnum_p(x)) {
     return fixnum_plus(mrb, x, y);
   }
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   if (mrb_float_p(x)) {
     return mrb_float_value(mrb, mrb_float(x) + mrb_to_flo(mrb, y));
   }
@@ -1323,13 +1323,13 @@ fixnum_minus(mrb_state *mrb, mrb_value x, mrb_value y)
 
     b = mrb_fixnum(y);
     if (mrb_int_sub_overflow(a, b, &c)) {
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
       return mrb_float_value(mrb, (mrb_float)a - (mrb_float)b);
 #endif
     }
     return mrb_fixnum_value(c);
   }
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
   mrb_raise(mrb, E_TYPE_ERROR, "non fixnum value");
 #else
   return mrb_float_value(mrb, (mrb_float)a - mrb_to_flo(mrb, y));
@@ -1342,7 +1342,7 @@ mrb_num_minus(mrb_state *mrb, mrb_value x, mrb_value y)
   if (mrb_fixnum_p(x)) {
     return fixnum_minus(mrb, x, y);
   }
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   if (mrb_float_p(x)) {
     return mrb_float_value(mrb, mrb_float(x) - mrb_to_flo(mrb, y));
   }
@@ -1431,26 +1431,26 @@ fix_to_s(mrb_state *mrb, mrb_value self)
 static mrb_int
 cmpnum(mrb_state *mrb, mrb_value v1, mrb_value v2)
 {
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
   mrb_int x, y;
 #else
   mrb_float x, y;
 #endif
 
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
   x = mrb_fixnum(v1);
 #else
   x = mrb_to_flo(mrb, v1);
 #endif
   switch (mrb_type(v2)) {
   case MRB_TT_FIXNUM:
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
     y = mrb_fixnum(v2);
 #else
     y = (mrb_float)mrb_fixnum(v2);
 #endif
     break;
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   case MRB_TT_FLOAT:
     y = mrb_float(v2);
     break;
@@ -1585,7 +1585,7 @@ num_infinite_p(mrb_state *mrb, mrb_value self)
  * Returns a new float which is the sum of <code>float</code>
  * and <code>other</code>.
  */
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 static mrb_value
 flo_plus(mrb_state *mrb, mrb_value x)
 {
@@ -1600,7 +1600,7 @@ void
 mrb_init_numeric(mrb_state *mrb)
 {
   struct RClass *numeric, *integer, *fixnum, *integral;
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   struct RClass *fl;
 #endif
 
@@ -1627,7 +1627,7 @@ mrb_init_numeric(mrb_state *mrb)
   mrb_undef_class_method(mrb, integer, "new");
   mrb_define_method(mrb, integer, "to_i",     int_to_i,        MRB_ARGS_NONE()); /* 15.2.8.3.24 */
   mrb_define_method(mrb, integer, "to_int",   int_to_i,        MRB_ARGS_NONE());
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   mrb_define_method(mrb, integer, "ceil",     int_to_i,        MRB_ARGS_NONE()); /* 15.2.8.3.8 (x) */
   mrb_define_method(mrb, integer, "floor",    int_to_i,        MRB_ARGS_NONE()); /* 15.2.8.3.10 (x) */
   mrb_define_method(mrb, integer, "round",    int_to_i,        MRB_ARGS_NONE()); /* 15.2.8.3.12 (x) */
@@ -1648,14 +1648,14 @@ mrb_init_numeric(mrb_state *mrb)
   mrb_define_method(mrb, fixnum,  "<<",       fix_lshift,      MRB_ARGS_REQ(1)); /* 15.2.8.3.12 */
   mrb_define_method(mrb, fixnum,  ">>",       fix_rshift,      MRB_ARGS_REQ(1)); /* 15.2.8.3.13 */
   mrb_define_method(mrb, fixnum,  "eql?",     fix_eql,         MRB_ARGS_REQ(1)); /* 15.2.8.3.16 */
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   mrb_define_method(mrb, fixnum,  "to_f",     fix_to_f,        MRB_ARGS_NONE()); /* 15.2.8.3.23 */
 #endif
   mrb_define_method(mrb, fixnum,  "to_s",     fix_to_s,        MRB_ARGS_OPT(1)); /* 15.2.8.3.25 */
   mrb_define_method(mrb, fixnum,  "inspect",  fix_to_s,        MRB_ARGS_OPT(1));
   mrb_define_method(mrb, fixnum,  "divmod",   fix_divmod,      MRB_ARGS_REQ(1)); /* 15.2.8.3.30 (x) */
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   /* Float Class */
   mrb->float_class = fl = mrb_define_class(mrb, "Float", numeric);                 /* 15.2.9 */
   MRB_SET_INSTANCE_TT(fl, MRB_TT_FLOAT);
diff --git a/src/object.c b/src/object.c
index fd1f9e215..634f70830 100644
--- a/src/object.c
+++ b/src/object.c
@@ -24,7 +24,7 @@ mrb_obj_eq(mrb_state *mrb, mrb_value v1, mrb_value v2)
   case MRB_TT_SYMBOL:
     return (mrb_symbol(v1) == mrb_symbol(v2));
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   case MRB_TT_FLOAT:
     return (mrb_float(v1) == mrb_float(v2));
 #endif
@@ -47,7 +47,7 @@ mrb_equal(mrb_state *mrb, mrb_value obj1, mrb_value obj2)
   mrb_value result;
 
   if (mrb_obj_eq(mrb, obj1, obj2)) return TRUE;
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   /* value mixing with integer and float */
   if (mrb_fixnum_p(obj1)) {
     if (mrb_float_p(obj2) && (mrb_float)mrb_fixnum(obj1) == mrb_float(obj2))
@@ -330,7 +330,7 @@ static const struct types {
   {MRB_TT_ICLASS, "iClass"},  /* internal use: mixed-in module holder */
   {MRB_TT_SCLASS, "SClass"},
   {MRB_TT_PROC,   "Proc"},
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   {MRB_TT_FLOAT,  "Float"},
 #endif
   {MRB_TT_ARRAY,  "Array"},
@@ -510,7 +510,7 @@ mrb_to_int(mrb_state *mrb, mrb_value val)
 {
 
   if (!mrb_fixnum_p(val)) {
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
     if (mrb_float_p(val)) {
       return mrb_flo_to_fixnum(mrb, val);
     }
@@ -530,7 +530,7 @@ mrb_convert_to_integer(mrb_state *mrb, mrb_value val, mrb_int base)
     mrb_raise(mrb, E_TYPE_ERROR, "can't convert nil into Integer");
   }
   switch (mrb_type(val)) {
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
     case MRB_TT_FLOAT:
       if (base != 0) goto arg_error;
       return mrb_flo_to_fixnum(mrb, val);
@@ -566,7 +566,7 @@ mrb_Integer(mrb_state *mrb, mrb_value val)
   return mrb_convert_to_integer(mrb, val, 0);
 }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 MRB_API mrb_value
 mrb_Float(mrb_state *mrb, mrb_value val)
 {
diff --git a/src/range.c b/src/range.c
index 868d3d397..8f09eda24 100644
--- a/src/range.c
+++ b/src/range.c
@@ -23,7 +23,7 @@ r_check(mrb_state *mrb, mrb_value a, mrb_value b)
 
   ta = mrb_type(a);
   tb = mrb_type(b);
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
   if (ta == MRB_TT_FIXNUM && tb == MRB_TT_FIXNUM ) {
 #else
   if ((ta == MRB_TT_FIXNUM || ta == MRB_TT_FLOAT) &&
diff --git a/src/string.c b/src/string.c
index 73e514f41..f15770403 100644
--- a/src/string.c
+++ b/src/string.c
@@ -8,7 +8,7 @@
 # define _CRT_NONSTDC_NO_DEPRECATE
 #endif
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 #include <float.h>
 #include <math.h>
 #endif
@@ -2365,7 +2365,7 @@ mrb_str_len_to_inum(mrb_state *mrb, const char *str, size_t len, mrb_int base, i
     n *= base;
     n += c;
     if (n > (uint64_t)MRB_INT_MAX + (sign ? 0 : 1)) {
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
       if (base == 10) {
         return mrb_float_value(mrb, mrb_str_to_dbl(mrb, mrb_str_new(mrb, str, len), badcheck));
       }
@@ -2476,7 +2476,7 @@ mrb_str_to_i(mrb_state *mrb, mrb_value self)
   return mrb_str_to_inum(mrb, self, base, FALSE);
 }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 double
 mrb_str_len_to_dbl(mrb_state *mrb, const char *s, size_t len, mrb_bool badcheck)
 {
@@ -2937,7 +2937,7 @@ mrb_init_string(mrb_state *mrb)
   mrb_define_method(mrb, s, "slice",           mrb_str_aref_m,          MRB_ARGS_ANY());  /* 15.2.10.5.34 */
   mrb_define_method(mrb, s, "split",           mrb_str_split_m,         MRB_ARGS_ANY());  /* 15.2.10.5.35 */
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
   mrb_define_method(mrb, s, "to_f",            mrb_str_to_f,            MRB_ARGS_NONE()); /* 15.2.10.5.38 */
 #endif
   mrb_define_method(mrb, s, "to_i",            mrb_str_to_i,            MRB_ARGS_ANY());  /* 15.2.10.5.39 */
@@ -2954,7 +2954,7 @@ mrb_init_string(mrb_state *mrb)
   mrb_define_method(mrb, s, "byteslice",       mrb_str_byteslice,       MRB_ARGS_ARG(1,1));
 }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 /*
  * Source code for the "strtod" library procedure.
  *
diff --git a/src/vm.c b/src/vm.c
index 87606c1b4..48dea94fb 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -6,7 +6,7 @@
 
 #include <stddef.h>
 #include <stdarg.h>
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
 #include <math.h>
 #endif
 #include <mruby.h>
@@ -1101,7 +1101,7 @@ RETRY_TRY_BLOCK:
         }
         goto L_RAISE;
 #endif
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
       case IREP_TT_FLOAT:
         regs[a] = mrb_float_value(mrb, pool[b].u.f);
         break;
@@ -2265,7 +2265,7 @@ RETRY_TRY_BLOCK:
         SET_INT_VALUE(regs[a], z);                                          \
     }                                                                       \
     break
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
 #define OP_MATH_CASE_FLOAT(op_name, t1, t2) (void)0
 #define OP_MATH_OVERFLOW_INT(op_name, x, y, z) SET_INT_VALUE(regs[a], z)
 #else
@@ -2305,14 +2305,14 @@ RETRY_TRY_BLOCK:
     }
 
     CASE(OP_DIV, B) {
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
       double x, y, f;
 #endif
 
       /* need to check if op is overridden */
       switch (TYPES2(mrb_type(regs[a]),mrb_type(regs[a+1]))) {
       case TYPES2(MRB_TT_FIXNUM,MRB_TT_FIXNUM):
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
         {
           mrb_int x = mrb_fixnum(regs[a]);
           mrb_int y = mrb_fixnum(regs[a+1]);
@@ -2342,7 +2342,7 @@ RETRY_TRY_BLOCK:
         goto L_SEND_SYM;
       }
 
-#ifndef MRB_WITHOUT_FLOAT
+#ifndef MRB_NO_FLOAT
       if (y == 0) {
         if (x > 0) f = INFINITY;
         else if (x < 0) f = -INFINITY;
@@ -2378,7 +2378,7 @@ RETRY_TRY_BLOCK:
         SET_INT_VALUE(regs[a], z);                                          \
     }                                                                       \
     break
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
 #define OP_MATHI_CASE_FLOAT(op_name) (void)0
 #else
 #define OP_MATHI_CASE_FLOAT(op_name)                                        \
@@ -2400,7 +2400,7 @@ RETRY_TRY_BLOCK:
 
 #define OP_CMP_BODY(op,v1,v2) (v1(regs[a]) op v2(regs[a+1]))
 
-#ifdef MRB_WITHOUT_FLOAT
+#ifdef MRB_NO_FLOAT
 #define OP_CMP(op,sym) do {\
   int result;\
   /* need to check if - is overridden */\
diff --git a/target/RX630.rb b/target/RX630.rb
index 8b1bbb42f..1b1f425c1 100644
--- a/target/RX630.rb
+++ b/target/RX630.rb
@@ -30,7 +30,7 @@ MRuby::CrossBuild.new("RX630") do |conf|
     cc.compile_options = %Q[%{flags} -o "%{outfile}" -c "%{infile}"]
 
     #configuration for low memory environment
-    cc.defines << %w(MRB_USE_FLOAT)
+    cc.defines << %w(MRB_USE_FLOAT32)
     cc.defines << %w(MRB_HEAP_PAGE_SIZE=64)
     cc.defines << %w(KHASH_DEFAULT_SIZE=8)
     cc.defines << %w(MRB_STR_BUF_MIN_SIZE=20)
diff --git a/tasks/gitlab.rake b/tasks/gitlab.rake
index 377b1cc9d..5c7b3d8c5 100644
--- a/tasks/gitlab.rake
+++ b/tasks/gitlab.rake
@@ -62,10 +62,10 @@ task :gitlab_config do
 
   configs = []
   [true, false].each do |mode_32|
-    ['', 'MRB_USE_FLOAT'].each do |float_conf|
+    ['', 'MRB_USE_FLOAT32'].each do |float_conf|
       ['', 'MRB_NAN_BOXING', 'MRB_WORD_BOXING'].each do |boxing_conf|
         ['', 'MRB_UTF8_STRING'].each do |utf8_conf|
-          next if (float_conf == 'MRB_USE_FLOAT') && (boxing_conf == 'MRB_NAN_BOXING')
+          next if (float_conf == 'MRB_USE_FLOAT32') && (boxing_conf == 'MRB_NAN_BOXING')
           next if (int_conf == 'MRB_INT64') && (boxing_conf == 'MRB_NAN_BOXING')
           next if (int_conf == 'MRB_INT64') && (boxing_conf == 'MRB_WORD_BOXING') && mode_32
           env = [float_conf, int_conf, boxing_conf, utf8_conf].map do |conf|
diff --git a/test/t/float.rb b/test/t/float.rb
index dc989636f..1cbc90532 100644
--- a/test/t/float.rb
+++ b/test/t/float.rb
@@ -207,7 +207,7 @@ assert('Float#>>') do
 end
 
 assert('Float#to_s') do
-  uses_float = 4e38.infinite?  # enable MRB_USE_FLOAT?
+  uses_float = 4e38.infinite?  # enable MRB_USE_FLOAT32?
 
   assert_equal("Infinity", Float::INFINITY.to_s)
   assert_equal("-Infinity", (-Float::INFINITY).to_s)