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Switching to using a union instead of type-cast to get at the bits

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of a flonum for eqv? comparison.
Fixes issue #164.
This commit is contained in:
Alex Shinn 2012-12-22 03:28:58 +00:00
parent 11cdc6930d
commit cdd337f3aa
1 changed files with 4 additions and 2 deletions
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6
include/chibi/sexp.h
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@ -301,6 +301,7 @@ struct sexp_struct {
union {
/* basic types */
double flonum;
char flonum_bits[sizeof(double)]; /* for eqv? comparison on flonums */
struct sexp_type_struct type;
struct {
sexp car, cdr;
@ -609,6 +610,7 @@ union sexp_flonum_conv {
SEXP_API sexp sexp_flonum_predicate (sexp ctx, sexp x);
#if SEXP_64_BIT
SEXP_API float sexp_flonum_value (sexp x);
#define sexp_flonum_bits(f) ((char*)&f)
SEXP_API sexp sexp_make_flonum(sexp ctx, float f);
#else
#define sexp_make_flonum(ctx, x) ((sexp) ((((union sexp_flonum_conv)((float)(x))).bits & ~SEXP_IMMEDIATE_MASK) + SEXP_IFLONUM_TAG))
@ -617,6 +619,7 @@ SEXP_API sexp sexp_make_flonum(sexp ctx, float f);
#else
#define sexp_flonump(x) (sexp_check_tag(x, SEXP_FLONUM))
#define sexp_flonum_value(f) ((f)->value.flonum)
#define sexp_flonum_bits(f) ((f)->value.flonum_bits)
sexp sexp_make_flonum(sexp ctx, double f);
#endif
@ -821,8 +824,7 @@ SEXP_API sexp sexp_make_unsigned_integer(sexp ctx, sexp_luint_t x);
#define sexp_nanp(x) (sexp_flonump(x) && isnan(sexp_flonum_value(x)))
#if SEXP_USE_IEEE_EQV
#define sexp_flonum_bits(x) (*(long*)(&(sexp_flonum_value(x))))
#define sexp_flonum_eqv(x, y) (sexp_flonum_bits(x) == sexp_flonum_bits(y))
#define sexp_flonum_eqv(x, y) (memcmp(sexp_flonum_bits(x), sexp_flonum_bits(y), sizeof(double)) == 0)
#else
#define sexp_flonum_eqv(x, y) (sexp_flonum_value(x) == sexp_flonum_value(y))
#endif