--- config.guess.orig	2013-03-29 11:15:46 +0400
+++ config.guess	2013-03-29 11:20:05 +0400
@@ -803,8 +803,45 @@
 	echo ${UNAME_MACHINE}-pc-mingw64
 	exit ;;
     *:MINGW*:*)
-	echo ${UNAME_MACHINE}-pc-mingw32
-	exit ;;
+        # This uname only tells us that MSYS is in MinGW mode.
+        # The toolchain used might be i686-pc-mingw32
+        # or x86_64-w64-mingw32 - MSYS can't know.
+        # Try cc test.
+	eval $set_cc_for_build
+	sed 's/^	//' << EOF >$dummy.c
+	#include <stdio.h>
+	__MINGW32__
+	__MINGW64__
+	__MINGW64_VERSION_MAJOR
+EOF
+	if $CC_FOR_BUILD -E $dummy.c 2>/dev/null | \
+	  grep -q __MINGW32__ >/dev/null
+	then
+	    # __MINGW32__ is not defined - this isn't MinGW at all.
+	    :
+	else
+            if $CC_FOR_BUILD -E $dummy.c 2>/dev/null | \
+		grep -q __MINGW64__ >/dev/null
+            then
+        	# 32-bit mingw
+	  	machine=i686
+            else
+        	# 64-bit mingw
+		machine=x86_64
+	    fi
+
+	    if $CC_FOR_BUILD -E $dummy.c 2>/dev/null | \
+		grep -q __MINGW64_VERSION_MAJOR >/dev/null
+	    then
+		# mingw.org toolchain
+    		echo ${machine}-pc-mingw32
+	    else
+		# mingw-w64 toolchain
+    		echo ${machine}-w64-mingw32
+	    fi
+	    exit
+	fi
+	;;
     i*:MSYS*:*)
 	echo ${UNAME_MACHINE}-pc-msys
 	exit ;;
--- Changelog.orig	2013-03-29 11:47:35 +0400
+++ Changelog	2013-03-29 11:26:59 +0400
@@ -1,3 +1,9 @@
+2013-03-29  LRN <address@hidden>
+
+	* config.guess (*:MINGW:*:*): do not use uname output to identify
+	the system, use compiler tests to detect machine architecture
+	(i686 or x86_64) and toolchain vendor (mingw.org or mingw-w64).
+
 2013-02-12  Christian Svensson  <address@hidden>
 
 	* config.guess (or1k:Linux:*:*): New.