- size_t j;
- FILE *fp = fopen ("conftest.out", "w");
- if (fp == NULL)
- return 1;
- for (j = 0; j < NWORDS; j++)
- anded_words[j] = ~ (unsigned int) 0;
- add_to_ored_words (0.25L);
- add_to_ored_words (0.5L);
- add_to_ored_words (1.0L);
- add_to_ored_words (2.0L);
- add_to_ored_words (4.0L);
- /* Remove bits that are common (e.g. if representation of the first mantissa
- bit is explicit). */
- for (j = 0; j < NWORDS; j++)
- ored_words[j] &= ~anded_words[j];
- /* Now find the nonzero word. */
- for (j = 0; j < NWORDS; j++)
- if (ored_words[j] != 0)
- break;
- if (j < NWORDS)
- {
- size_t i;
- for (i = j + 1; i < NWORDS; i++)
- if (ored_words[i] != 0)
- {
- fprintf (fp, "unknown");
- return (fclose (fp) != 0);
- }
- for (i = 0; ; i++)
- if ((ored_words[j] >> i) & 1)
- {
- fprintf (fp, "word %d bit %d", (int) j, (int) i);
- return (fclose (fp) != 0);
- }
- }
- fprintf (fp, "unknown");
- return (fclose (fp) != 0);
-}
- ],
- [gl_cv_cc_long_double_expbit0=`cat conftest.out`],
- [gl_cv_cc_long_double_expbit0="unknown"],
- [
- dnl When cross-compiling, we don't know. It depends on the
- dnl ABI and compiler version. There are too many cases.
- gl_cv_cc_long_double_expbit0="unknown"
+ int result = 0;
+
+ if (!isnanl (NaNl ()))
+ result |= 1;
+
+ {
+ memory_long_double m;
+ unsigned int i;
+
+ /* The isnanl function should be immune against changes in the sign bit and
+ in the mantissa bits. The xor operation twiddles a bit that can only be
+ a sign bit or a mantissa bit (since the exponent never extends to
+ bit 31). */
+ m.value = NaNl ();
+ m.word[NWORDS / 2] ^= (unsigned int) 1 << (sizeof (unsigned int) * CHAR_BIT - 1);
+ for (i = 0; i < NWORDS; i++)
+ m.word[i] |= 1;
+ if (!isnanl (m.value))
+ result |= 1;
+ }
+
+#if ((defined __ia64 && LDBL_MANT_DIG == 64) || (defined __x86_64__ || defined __amd64__) || (defined __i386 || defined __i386__ || defined _I386 || defined _M_IX86 || defined _X86_))
+/* Representation of an 80-bit 'long double' as an initializer for a sequence
+ of 'unsigned int' words. */
+# ifdef WORDS_BIGENDIAN
+# define LDBL80_WORDS(exponent,manthi,mantlo) \
+ { ((unsigned int) (exponent) << 16) | ((unsigned int) (manthi) >> 16), \
+ ((unsigned int) (manthi) << 16) | (unsigned int) (mantlo) >> 16), \
+ (unsigned int) (mantlo) << 16 \
+ }
+# else
+# define LDBL80_WORDS(exponent,manthi,mantlo) \
+ { mantlo, manthi, exponent }
+# endif
+ { /* Quiet NaN. */
+ static memory_long_double x =
+ { LDBL80_WORDS (0xFFFF, 0xC3333333, 0x00000000) };
+ if (!isnanl (x.value))
+ result |= 2;
+ }
+ {
+ /* Signalling NaN. */
+ static memory_long_double x =
+ { LDBL80_WORDS (0xFFFF, 0x83333333, 0x00000000) };
+ if (!isnanl (x.value))
+ result |= 2;
+ }
+ /* The isnanl function should recognize Pseudo-NaNs, Pseudo-Infinities,
+ Pseudo-Zeroes, Unnormalized Numbers, and Pseudo-Denormals, as defined in
+ Intel IA-64 Architecture Software Developer's Manual, Volume 1:
+ Application Architecture.
+ Table 5-2 "Floating-Point Register Encodings"
+ Figure 5-6 "Memory to Floating-Point Register Data Translation"
+ */
+ { /* Pseudo-NaN. */
+ static memory_long_double x =
+ { LDBL80_WORDS (0xFFFF, 0x40000001, 0x00000000) };
+ if (!isnanl (x.value))
+ result |= 4;
+ }
+ { /* Pseudo-Infinity. */
+ static memory_long_double x =
+ { LDBL80_WORDS (0xFFFF, 0x00000000, 0x00000000) };
+ if (!isnanl (x.value))
+ result |= 8;
+ }
+ { /* Pseudo-Zero. */
+ static memory_long_double x =
+ { LDBL80_WORDS (0x4004, 0x00000000, 0x00000000) };
+ if (!isnanl (x.value))
+ result |= 16;
+ }
+ { /* Unnormalized number. */
+ static memory_long_double x =
+ { LDBL80_WORDS (0x4000, 0x63333333, 0x00000000) };
+ if (!isnanl (x.value))
+ result |= 32;
+ }
+ { /* Pseudo-Denormal. */
+ static memory_long_double x =
+ { LDBL80_WORDS (0x0000, 0x83333333, 0x00000000) };
+ if (!isnanl (x.value))
+ result |= 64;
+ }
+#endif
+
+ return result;
+}]])],
+ [gl_cv_func_isnanl_works=yes],
+ [gl_cv_func_isnanl_works=no],
+ [case "$host_cpu" in
+ # Guess no on ia64, x86_64, i386.
+ ia64 | x86_64 | i*86) gl_cv_func_isnanl_works="guessing no";;
+ *)
+ case "$host_os" in
+ netbsd*) gl_cv_func_isnanl_works="guessing no";;
+ *) gl_cv_func_isnanl_works="guessing yes";;
+ esac
+ ;;
+ esac