move float config to "mzconfig.h"; enable by default for Windows

src/configure

@@ -1339,7 +1339,7 @@ Optional Features:
   --enable-account        3m: use memory-accounting GC (enabled by default)
   --enable-compact        3m: use compact GC (no accounting)
   --enable-backtrace      3m: support GC backtrace dumps
-  --enable-float          single-precision floats support (enabled by default)
+  --enable-float          support single-precision floats (enabled by default)
   --enable-floatinstead   compile to use single-precision by default
   --enable-pthread        link with pthreads
   --enable-stackup        assume "up" if stack direction cannot be determined
@@ -2227,7 +2227,7 @@ show_explicitly_enabled "${enable_sgcdebug}" "SGC debug mode"
 show_explicitly_enabled "${enable_compact}" "Compact 3m GC"
 show_explicitly_enabled "${enable_backtrace}" "3m GC backtraces"
 
-show_explicitly_disabled "${enable_float}" "Single-precision floats"
+show_explicitly_enabled "${enable_float}" "Single-precision floats"
 show_explicitly_enabled "${enable_floatinstead}" "Single-precision default floats"
 
 show_explicitly_enabled "${enable_pthread}" "pthreads"
@@ -2331,11 +2331,19 @@ fi
 
 if test "${enable_floatinstead}" = "yes" ; then
   enable_float=yes
-  OPTIONS="${OPTIONS} -DUSE_SINGLE_FLOATS_AS_DEFAULT"
+
+cat >>confdefs.h <<\_ACEOF
+#define USE_SINGLE_FLOATS_AS_DEFAULT 1
+_ACEOF
+
 fi
 
 if test "${enable_float}" = "yes" ; then
-  OPTIONS="${OPTIONS} -DUSE_SINGLE_FLOATS"
+
+cat >>confdefs.h <<\_ACEOF
+#define USE_SINGLE_FLOATS 1
+_ACEOF
+
 fi
 
 ###### Autoconfigure #######

src/racket/configure.ac

@@ -47,7 +47,7 @@ AC_ARG_ENABLE(account, [  --enable-account        3m: use memory-accounting GC (
 AC_ARG_ENABLE(compact, [  --enable-compact        3m: use compact GC (no accounting)])
 AC_ARG_ENABLE(backtrace, [  --enable-backtrace      3m: support GC backtrace dumps])
 
-AC_ARG_ENABLE(float,   [  --enable-float          include support for single-precision floats])
+AC_ARG_ENABLE(float,   [  --enable-float          support single-precision floats (enabled by default)], , enable_float=yes)
 AC_ARG_ENABLE(floatinstead, [  --enable-floatinstead   compile to use single-precision by default])
 
 AC_ARG_ENABLE(pthread, [  --enable-pthread        link with pthreads])
@@ -390,11 +390,11 @@ fi
 
 if test "${enable_floatinstead}" = "yes" ; then
   enable_float=yes
-  OPTIONS="${OPTIONS} -DUSE_SINGLE_FLOATS_AS_DEFAULT"
+  AC_DEFINE(USE_SINGLE_FLOATS_AS_DEFAULT,1,[Single-precision floats by default])
 fi
 
 if test "${enable_float}" = "yes" ; then
-  OPTIONS="${OPTIONS} -DUSE_SINGLE_FLOATS"
+  AC_DEFINE(USE_SINGLE_FLOATS,1,[Single-precision floats])
 fi
 
 ###### Autoconfigure #######

src/racket/mzconfig.h.in

@@ -68,4 +68,8 @@ typedef unsigned long uintptr_t;
 /* Enable GC2 Places Testing. */
 #undef GC2_PLACES_TESTING
 
+/* Enable single-precision floats [as default]: */
+#undef USE_SINGLE_FLOATS
+#undef USE_SINGLE_FLOATS_AS_DEFAULT
+
 #endif

src/worksp/mzconfig.h

@@ -41,4 +41,7 @@
 /* Enable futures: */
 #define MZ_USE_FUTURES
 
+/* Enable single-precision floats: */
+#define USE_SINGLE_FLOATS
+
 #endif