boxing_nan.h

00001 /*
00002 ** mruby/boxing_nan.h - nan boxing mrb_value definition
00003 **
00004 ** See Copyright Notice in mruby.h
00005 */
00006 
00007 #ifndef MRUBY_BOXING_NAN_H
00008 #define MRUBY_BOXING_NAN_H
00009 
00010 #ifdef MRB_USE_FLOAT
00011 # error ---->> MRB_NAN_BOXING and MRB_USE_FLOAT conflict <<----
00012 #endif
00013 
00014 #ifdef MRB_INT64
00015 # error ---->> MRB_NAN_BOXING and MRB_INT64 conflict <<----
00016 #endif
00017 
00018 #define MRB_FIXNUM_SHIFT 0
00019 #define MRB_TT_HAS_BASIC MRB_TT_OBJECT
00020 
00021 #ifdef MRB_ENDIAN_BIG
00022 #define MRB_ENDIAN_LOHI(a,b) a b
00023 #else
00024 #define MRB_ENDIAN_LOHI(a,b) b a
00025 #endif
00026 
00027 /* value representation by nan-boxing:
00028  *   float : FFFFFFFFFFFFFFFF FFFFFFFFFFFFFFFF FFFFFFFFFFFFFFFF FFFFFFFFFFFFFFFF
00029  *   object: 111111111111TTTT TTPPPPPPPPPPPPPP PPPPPPPPPPPPPPPP PPPPPPPPPPPPPPPP
00030  *   int   : 1111111111110001 0000000000000000 IIIIIIIIIIIIIIII IIIIIIIIIIIIIIII
00031  *   sym   : 1111111111110001 0100000000000000 SSSSSSSSSSSSSSSS SSSSSSSSSSSSSSSS
00032  * In order to get enough bit size to save TT, all pointers are shifted 2 bits
00033  * in the right direction. Also, TTTTTT is the mrb_vtype + 1;
00034  */
00035 typedef struct mrb_value {
00036   union {
00037     mrb_float f;
00038     union {
00039       void *p;
00040       struct {
00041         MRB_ENDIAN_LOHI(
00042           uint32_t ttt;
00043           ,union {
00044             mrb_int i;
00045             mrb_sym sym;
00046           };
00047         )
00048       };
00049     } value;
00050   };
00051 } mrb_value;
00052 
00053 #define mrb_float_pool(mrb,f) mrb_float_value(mrb,f)
00054 
00055 #define mrb_tt(o)       ((enum mrb_vtype)(((o).value.ttt & 0xfc000)>>14)-1)
00056 #define mrb_type(o)     ((uint32_t)0xfff00000 < (o).value.ttt ? mrb_tt(o) : MRB_TT_FLOAT)
00057 #define mrb_ptr(o)      ((void*)((((uintptr_t)0x3fffffffffff)&((uintptr_t)((o).value.p)))<<2))
00058 #define mrb_float(o)    (o).f
00059 #define mrb_cptr(o)     mrb_ptr(o)
00060 #define mrb_fixnum(o)   (o).value.i
00061 #define mrb_symbol(o)   (o).value.sym
00062 
00063 #define BOXNAN_SET_VALUE(o, tt, attr, v) do {\
00064   (o).value.ttt = (0xfff00000|(((tt)+1)<<14));\
00065   switch (tt) {\
00066   case MRB_TT_FALSE:\
00067   case MRB_TT_TRUE:\
00068   case MRB_TT_UNDEF:\
00069   case MRB_TT_FIXNUM:\
00070   case MRB_TT_SYMBOL: (o).attr = (v); break;\
00071   default: (o).value.i = 0; (o).value.p = (void*)((uintptr_t)(o).value.p | (((uintptr_t)(v))>>2)); break;\
00072   }\
00073 } while (0)
00074 
00075 #define SET_FLOAT_VALUE(mrb,r,v) do { \
00076   if (v != v) { \
00077     (r).value.ttt = 0x7ff80000; \
00078     (r).value.i = 0; \
00079   } else { \
00080     (r).f = v; \
00081   }} while(0)
00082 
00083 #define SET_NIL_VALUE(r) BOXNAN_SET_VALUE(r, MRB_TT_FALSE, value.i, 0)
00084 #define SET_FALSE_VALUE(r) BOXNAN_SET_VALUE(r, MRB_TT_FALSE, value.i, 1)
00085 #define SET_TRUE_VALUE(r) BOXNAN_SET_VALUE(r, MRB_TT_TRUE, value.i, 1)
00086 #define SET_BOOL_VALUE(r,b) BOXNAN_SET_VALUE(r, b ? MRB_TT_TRUE : MRB_TT_FALSE, value.i, 1)
00087 #define SET_INT_VALUE(r,n) BOXNAN_SET_VALUE(r, MRB_TT_FIXNUM, value.i, (n))
00088 #define SET_SYM_VALUE(r,v) BOXNAN_SET_VALUE(r, MRB_TT_SYMBOL, value.sym, (v))
00089 #define SET_OBJ_VALUE(r,v) BOXNAN_SET_VALUE(r, (((struct RObject*)(v))->tt), value.p, (v))
00090 #define SET_PROC_VALUE(r,v) BOXNAN_SET_VALUE(r, MRB_TT_PROC, value.p, v)
00091 #define SET_CPTR_VALUE(mrb,r,v) BOXNAN_SET_VALUE(r, MRB_TT_CPTR, value.p, v)
00092 #define SET_UNDEF_VALUE(r) BOXNAN_SET_VALUE(r, MRB_TT_UNDEF, value.i, 0)
00093 
00094 #endif  /* MRUBY_BOXING_NAN_H */
00095