--- orig/configure	Tue May  5 16:02:59 2009
+++ patched/configure	Wed May  6 12:45:35 2009
@@ -1,4 +1,4 @@
-#! /bin/sh
+#! /bin/bash
 #
 # Original version (C) 2000 Pontscho/fresh!mindworkz
 #                      pontscho@makacs.poliod.hu
@@ -1327,7 +1327,7 @@
 # Determine our OS name and CPU architecture
 if test -z "$_target" ; then
   # OS name
-  system_name=$(uname -s 2>&1)
+  system_name=`uname -s 2>&1`
   case "$system_name" in
   Linux|FreeBSD|NetBSD|OpenBSD|DragonFly|BSD/OS|Darwin|SunOS|QNX|GNU|BeOS|MorphOS|AIX|AmigaOS)
     ;;
@@ -1356,7 +1356,7 @@
 
 
   # host's CPU/instruction set
-   host_arch=$(uname -p 2>&1)
+   host_arch=$`uname -p 2>&1`
    case "$host_arch" in
    i386|sparc|ppc|alpha|arm|mips|vax)
      ;;
@@ -1370,7 +1370,7 @@
       # recognize.
 
       # x86/x86pc is used by QNX
-      case "$(uname -m 2>&1)" in
+      case "`uname -m 2>&1`" in
       i[3-9]86*|x86|x86pc|k5|k6|k6_2|k6_3|k6-2|k6-3|pentium*|athlon*|i586_i686|i586-i686|BePC) host_arch=i386 ;;
       ia64) host_arch=ia64 ;;
       x86_64|amd64)
@@ -1390,7 +1390,7 @@
       sh3|sh4|sh4a) host_arch=sh ;;
       s390) host_arch=s390 ;;
       s390x) host_arch=s390x ;;
-      mips*) host_arch=mips ;;
+      mips*|IP*) host_arch=mips ;; # SGI machines are IP*
       vax) host_arch=vax ;;
       xtensa*) host_arch=xtensa ;;
       *) host_arch=UNKNOWN ;;
@@ -1555,6 +1555,17 @@
     echores "$cc_version"
     break
     fi
+    if test "$cc_name_tmp" = "MIPSpro"; then
+    mipspro="true"
+    cc_name=$cc_name_tmp
+    cc_vendor=SGI
+    cc_version=`$_cc -v 2>&1 | tail -n 1 | cut -d ' ' -f 4`
+    _cc_major=$(echo $cc_version | cut -d '.' -f 1)
+    _cc_minor=$(echo $cc_version | cut -d '.' -f 2)
+    _cc_mini=$(echo $cc_version | cut -d '.' -f 3)
+    echores "$cc_version"
+    break
+    fi
   done
 fi # icc
 test "$cc_fail" = yes && die "unsupported compiler version"
@@ -2240,9 +2251,9 @@
     _target_arch='ARCH_SGI_MIPS = yes'
     iproc='sgi-mips'
 
-    if irix ; then
+    if irix && !($mipspro = "true") ; then  # GCC on IRIX? Why? 
 	echocheck "CPU type"
-	proc=$(hinv -c processor | grep CPU | cut -d " " -f3)
+	proc=`hinv -c processor | grep CPU | cut -d " " -f3`
 	case "$(echo $proc)" in
 	    R3000) _march='-mips1' _mcpu='-mtune=r2000' ;;
 	    R4000) _march='-mips3' _mcpu='-mtune=r4000' ;;
@@ -2256,6 +2267,8 @@
 	    _mcpu=''
 	fi
         echores "$proc"
+    else
+        echo "MIPSpro C compiler detected, optimization flags left undefined."
     fi
 
     ;;
@@ -4838,15 +4851,11 @@
 
 fi #if darwin
 
-
+# IRIX builtin libpng is not GNU, but that was in the long long ago.
+# Modern IRIX systems should have the Nekoware libpng available.
 echocheck "PNG support"
 if test "$_png" = auto ; then
-  _png=no
-  if irix ; then
-    # Don't check for -lpng on irix since it has its own libpng
-    # incompatible with the GNU libpng
-    _res_comment="disabled on irix (not GNU libpng)"
-  else
+_png=no
 cat > $TMPC << EOF
 #include <png.h>
 #include <string.h>
@@ -4864,7 +4873,7 @@
       fi
     fi
   fi
-fi
+
 echores "$_png"
 if test "$_png" = yes ; then
   def_png='#define CONFIG_PNG 1'