mbed-mruby

Diff: include/mruby/numeric.h

Revision:

0:158c61bb030f

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/include/mruby/numeric.h	Wed Mar 25 17:36:16 2015 +0000
@@ -0,0 +1,67 @@
+/*
+** mruby/numeric.h - Numeric, Integer, Float, Fixnum class
+**
+** See Copyright Notice in mruby.h
+*/
+
+#ifndef MRUBY_NUMERIC_H
+#define MRUBY_NUMERIC_H
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+#define POSFIXABLE(f) ((f) <= MRB_INT_MAX)
+#define NEGFIXABLE(f) ((f) >= MRB_INT_MIN)
+#define FIXABLE(f) (POSFIXABLE(f) && NEGFIXABLE(f))
+
+MRB_API mrb_value mrb_flo_to_fixnum(mrb_state *mrb, mrb_value val);
+MRB_API mrb_value mrb_fixnum_to_str(mrb_state *mrb, mrb_value x, int base);
+MRB_API mrb_float mrb_to_flo(mrb_state *mrb, mrb_value x);
+
+mrb_value mrb_fixnum_plus(mrb_state *mrb, mrb_value x, mrb_value y);
+mrb_value mrb_fixnum_minus(mrb_state *mrb, mrb_value x, mrb_value y);
+mrb_value mrb_fixnum_mul(mrb_state *mrb, mrb_value x, mrb_value y);
+mrb_value mrb_num_div(mrb_state *mrb, mrb_value x, mrb_value y);
+
+#define MRB_UINT_MAKE2(n) uint ## n ## _t
+#define MRB_UINT_MAKE(n) MRB_UINT_MAKE2(n)
+#define mrb_uint MRB_UINT_MAKE(MRB_INT_BIT)
+
+#ifdef MRB_WORD_BOXING
+# define MRB_INT_OVERFLOW_MASK ((mrb_uint)1 << (MRB_INT_BIT - 1 - MRB_FIXNUM_SHIFT))
+#else
+# define MRB_INT_OVERFLOW_MASK ((mrb_uint)1 << (MRB_INT_BIT - 1))
+#endif
+
+static inline mrb_bool
+mrb_int_add_overflow(mrb_int augend, mrb_int addend, mrb_int *sum)
+{
+  mrb_uint x = (mrb_uint)augend;
+  mrb_uint y = (mrb_uint)addend;
+  mrb_uint z = (mrb_uint)(x + y);
+  *sum = (mrb_int)z;
+  return !!(((x ^ z) & (y ^ z)) & MRB_INT_OVERFLOW_MASK);
+}
+
+static inline mrb_bool
+mrb_int_sub_overflow(mrb_int minuend, mrb_int subtrahend, mrb_int *difference)
+{
+  mrb_uint x = (mrb_uint)minuend;
+  mrb_uint y = (mrb_uint)subtrahend;
+  mrb_uint z = (mrb_uint)(x - y);
+  *difference = (mrb_int)z;
+  return !!(((x ^ z) & (~y ^ z)) & MRB_INT_OVERFLOW_MASK);
+}
+
+#undef MRB_INT_OVERFLOW_MASK
+#undef mrb_uint
+#undef MRB_UINT_MAKE
+#undef MRB_UINT_MAKE2
+
+#if defined(__cplusplus)
+}  /* extern "C" { */
+#endif
+
+#endif  /* MRUBY_NUMERIC_H */
+