Issue #1496032. Add -mieee to BASECFLAGS on alpha, when gcc is

the compiler.  This should(?) help to fix failures in test_math
and test_cmath on Linux/alpha.

Also add configure message reporting the result of uname -m, as
a debugging aid.

Misc/NEWS

@@ -126,6 +126,8 @@ Tests
 Build
 -----
 
+- Issue #1496032: On alpha, use -mieee when gcc is the compiler.
+
 - Issue #2544: On HP-UX systems, use 'gcc -shared' for linking when
   gcc is used as compiler.
 

configure

 #! /bin/sh
-# From configure.in Revision: 62447 .
+# From configure.in Revision: 62451 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.61 for python 2.6.
 #
@@ -2155,6 +2155,12 @@ echo "${ECHO_T}$EXTRAPLATDIR" >&6; }
 CONFIGURE_MACOSX_DEPLOYMENT_TARGET=
 EXPORT_MACOSX_DEPLOYMENT_TARGET='#'
 
+{ echo "$as_me:$LINENO: checking machine type as reported by uname -m" >&5
+echo $ECHO_N "checking machine type as reported by uname -m... $ECHO_C" >&6; }
+ac_sys_machine=`uname -m`
+{ echo "$as_me:$LINENO: result: $ac_sys_machine" >&5
+echo "${ECHO_T}$ac_sys_machine" >&6; }
+
 # checks for alternative programs
 
 # compiler flags are generated in two sets, BASECFLAGS and OPT.  OPT is just
@@ -4532,6 +4538,16 @@ echo "${ECHO_T}$ac_cv_no_strict_aliasing_ok" >&6; }
     then
       BASECFLAGS="$BASECFLAGS -fno-strict-aliasing"
     fi
+
+    # if using gcc on alpha, use -mieee to get (near) full IEEE 754
+    # support.  Without this, treatment of subnormals doesn't follow
+    # the standard.
+    case $ac_sys_machine in
+         alpha*)
+                BASECFLAGS="$BASECFLAGS -mieee"
+                ;;
+    esac
+
     case $ac_sys_system in
 	SCO_SV*)
 	    BASECFLAGS="$BASECFLAGS -m486 -DSCO5"

configure.in

@@ -333,6 +333,10 @@ AC_SUBST(EXPORT_MACOSX_DEPLOYMENT_TARGET)
 CONFIGURE_MACOSX_DEPLOYMENT_TARGET=
 EXPORT_MACOSX_DEPLOYMENT_TARGET='#'
 
+AC_MSG_CHECKING(machine type as reported by uname -m)
+ac_sys_machine=`uname -m`
+AC_MSG_RESULT($ac_sys_machine)
+
 # checks for alternative programs
 
 # compiler flags are generated in two sets, BASECFLAGS and OPT.  OPT is just
@@ -817,6 +821,16 @@ yes)
     then
       BASECFLAGS="$BASECFLAGS -fno-strict-aliasing"
     fi
+
+    # if using gcc on alpha, use -mieee to get (near) full IEEE 754
+    # support.  Without this, treatment of subnormals doesn't follow
+    # the standard.
+    case $ac_sys_machine in
+         alpha*)
+                BASECFLAGS="$BASECFLAGS -mieee"
+                ;;
+    esac
+
     case $ac_sys_system in
 	SCO_SV*)
 	    BASECFLAGS="$BASECFLAGS -m486 -DSCO5"