diff --git a/autoconf/configure.ac b/autoconf/configure.ac
index bd85577..ff5804b 100644
--- a/autoconf/configure.ac
+++ b/autoconf/configure.ac
@@ -728,8 +728,8 @@
 case "$withval" in
   default)
     case "$llvm_cv_os_type" in
-    MingW) optimize_option=-O3 ;;
-    *)     optimize_option=-O2 ;;
+    MingW) optimize_option=-O2 ;;
+    *)     optimize_option=-O3 ;;
     esac ;;
   *) optimize_option="$withval" ;;
 esac
diff --git a/configure b/configure
index cb8b274..82aaccd 100755
--- a/configure
+++ b/configure
@@ -14,7 +14,7 @@
 ## M4sh Initialization.  ##
 ## --------------------- ##
 
-# Be Bourne compatible.
+# Be Bourne compatible
 if test -n "${ZSH_VERSION+set}" && (emulate sh) >/dev/null 2>&1; then
   emulate sh
   NULLCMD=:
@@ -2166,6 +2166,11 @@
     llvm_cv_no_link_all_option="-Wl,-noall_load"
     llvm_cv_os_type="Darwin"
     llvm_cv_platform_type="Unix" ;;
+  *-*-minix*)
+    llvm_cv_link_all_option="-Wl,-all_load"
+    llvm_cv_no_link_all_option="-Wl,-noall_load"
+    llvm_cv_os_type="Minix"
+    llvm_cv_platform_type="Unix" ;;
   *-*-freebsd*)
     llvm_cv_link_all_option="-Wl,--whole-archive"
     llvm_cv_no_link_all_option="-Wl,--no-whole-archive"
@@ -2260,6 +2265,8 @@
     llvm_cv_target_os_type="Cygwin" ;;
   *-*-darwin*)
     llvm_cv_target_os_type="Darwin" ;;
+  *-*-minix*)
+    llvm_cv_target_os_type="Minix" ;;
   *-*-freebsd*)
     llvm_cv_target_os_type="FreeBSD" ;;
   *-*-openbsd*)
@@ -5162,8 +5169,8 @@
 case "$withval" in
   default)
     case "$llvm_cv_os_type" in
-    MingW) optimize_option=-O3 ;;
-    *)     optimize_option=-O2 ;;
+    MingW) optimize_option=-O2 ;;
+    *)     optimize_option=-O3 ;;
     esac ;;
   *) optimize_option="$withval" ;;
 esac
@@ -11156,7 +11163,7 @@
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<EOF
-#line 11159 "configure"
+#line 11166 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H