diff options
Diffstat (limited to 'src/include')
| -rw-r--r-- | src/include/vm.H | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/src/include/vm.H b/src/include/vm.H index d386e4c3..0ef6f973 100644 --- a/src/include/vm.H +++ b/src/include/vm.H @@ -166,25 +166,28 @@ namespace OpenAxiom { // VM integers are divided into classes: small numbers, // and large numbers. A small number fits entirely in a register. // A large number is allocated and represented by its address. - using Fixnum = intptr_t; + using FixnumBits = intptr_t; + enum class Fixnum : FixnumBits { + minimum = FixnumBits(~(~ValueBits() >> 2)), + zero = FixnumBits(0), + one = FixnumBits(1), + maximum = FixnumBits(~ValueBits() >> 2), + }; constexpr ValueBits fix_tag = 0x1; constexpr bool is_fixnum(Value v) { - return (v & 0x1) == fix_tag; + return (ValueBits(v) & 0x1) == fix_tag; } constexpr Fixnum to_fixnum(Value v) { - return Fixnum(v >> 1); + return Fixnum(FixnumBits(v) >> 1); } constexpr Value from_fixnum(Fixnum i) { - return (Fixnum(i) << 1 ) | fix_tag; + return (ValueBits(i) << 1 ) | fix_tag; } - constexpr Fixnum fixnum_maximum = to_fixnum(~Value{ }); - constexpr Fixnum fixnum_minimum = -fixnum_maximum - 1; - // ------------ // -- String -- // ------------ @@ -262,7 +265,7 @@ namespace OpenAxiom { inline Fixnum count_nodes(Value v) { if (auto p = to_pair_if_can(v)) return count_nodes(p); - return 0; + return Fixnum::zero; } // --------------- |