Issue #1580: use short float repr where possible.

 - incorporate and adapt David Gay's dtoa and strtod
   into the Python core
 - on platforms where we can use Gay's code (almost
   all!), repr(float) is based on the shortest
   sequence of decimal digits that rounds correctly.
 - add sys.float_repr_style attribute to indicate
   whether we're using Gay's code or not
 - add autoconf magic to detect and enable SSE2
   instructions on x86/gcc
 - slight change to repr and str:  repr switches
   to exponential notation at 1e16 instead of
   1e17, str switches at 1e11 instead of 1e12

1 files changed, 20 insertions, 0 deletions

diff --git a/pyconfig.h.in b/pyconfig.h.in
index 40067f6..72f5fb3 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -15,6 +15,18 @@
 /* Define if you have the Mach cthreads package */
 #undef C_THREADS
 
+/* Define if C doubles are 64-bit IEEE 754 binary format, stored in ARM
+   mixed-endian order (byte order 45670123) */
+#undef DOUBLE_IS_ARM_MIXED_ENDIAN_IEEE754
+
+/* Define if C doubles are 64-bit IEEE 754 binary format, stored with the most
+   significant byte first */
+#undef DOUBLE_IS_BIG_ENDIAN_IEEE754
+
+/* Define if C doubles are 64-bit IEEE 754 binary format, stored with the
+   least significant byte first */
+#undef DOUBLE_IS_LITTLE_ENDIAN_IEEE754
+
 /* Define if --enable-ipv6 is specified */
 #undef ENABLE_IPV6
 
@@ -232,6 +244,10 @@
 /* Define to 1 if you have the `gai_strerror' function. */
 #undef HAVE_GAI_STRERROR
 
+/* Define if we can use gcc inline assembler to get and set x87 control word
+   */
+#undef HAVE_GCC_ASM_FOR_X87
+
 /* Define if you have the getaddrinfo function. */
 #undef HAVE_GETADDRINFO
 
@@ -970,6 +986,10 @@
 /* Define if you want to use computed gotos in ceval.c. */
 #undef USE_COMPUTED_GOTOS
 
+/* Define on x86 hardware if the x87 FPU is being used for floating-point
+   arithmetic */
+#undef USING_X87_FPU
+
 /* Define if a va_list is an array of some kind */
 #undef VA_LIST_IS_ARRAY