gh-104263: Rely on Py_NAN and introduce Py_INFINITY (GH-104202)

This PR removes `_Py_dg_stdnan` and `_Py_dg_infinity` in favour of
using the standard `NAN` and `INFINITY` macros provided by C99.
This change has the side-effect of fixing a bug on MIPS where the
hard-coded value used by `_Py_dg_stdnan` gave a signalling NaN
rather than a quiet NaN.
---------

Co-authored-by: Mark Dickinson <dickinsm@gmail.com>

1 files changed, 1 insertions, 40 deletions

diff --git a/Python/pystrtod.c b/Python/pystrtod.c
index d77b846..9bb060e 100644
--- a/Python/pystrtod.c
+++ b/Python/pystrtod.c
@@ -23,44 +23,6 @@ case_insensitive_match(const char *s, const char *t)
    return the NaN or Infinity as a double and set *endptr to point just beyond
    the successfully parsed portion of the string.  On failure, return -1.0 and
    set *endptr to point to the start of the string. */
-
-#if _PY_SHORT_FLOAT_REPR == 1
-
-double
-_Py_parse_inf_or_nan(const char *p, char **endptr)
-{
-    double retval;
-    const char *s;
-    int negate = 0;
-
-    s = p;
-    if (*s == '-') {
-        negate = 1;
-        s++;
-    }
-    else if (*s == '+') {
-        s++;
-    }
-    if (case_insensitive_match(s, "inf")) {
-        s += 3;
-        if (case_insensitive_match(s, "inity"))
-            s += 5;
-        retval = _Py_dg_infinity(negate);
-    }
-    else if (case_insensitive_match(s, "nan")) {
-        s += 3;
-        retval = _Py_dg_stdnan(negate);
-    }
-    else {
-        s = p;
-        retval = -1.0;
-    }
-    *endptr = (char *)s;
-    return retval;
-}
-
-#else
-
 double
 _Py_parse_inf_or_nan(const char *p, char **endptr)
 {
@@ -84,7 +46,7 @@ _Py_parse_inf_or_nan(const char *p, char **endptr)
     }
     else if (case_insensitive_match(s, "nan")) {
         s += 3;
-        retval = negate ? -Py_NAN : Py_NAN;
+        retval = negate ? -fabs(Py_NAN) : fabs(Py_NAN);
     }
     else {
         s = p;
@@ -94,7 +56,6 @@ _Py_parse_inf_or_nan(const char *p, char **endptr)
     return retval;
 }
 
-#endif
 
 /**
  * _PyOS_ascii_strtod: