diff -r bfc1c1131e8f libgo/Makefile.am
--- a/libgo/Makefile.am	Wed Feb 02 18:08:21 2011 +0100
+++ b/libgo/Makefile.am	Thu Feb 03 15:57:15 2011 +0100
@@ -660,6 +660,9 @@
 if LIBGO_IS_LINUX
 go_os_sys_file = go/os/sys_linux.go
 else
+if LIBGO_IS_IRIX
+go_os_sys_file = go/os/sys_uname.go
+else
 if LIBGO_IS_SOLARIS
 go_os_sys_file = go/os/sys_uname.go
 else
@@ -670,6 +673,7 @@
 endif
 endif
 endif
+endif
 
 go_os_files = \
 	go/os/dir.go \
diff -r bfc1c1131e8f libgo/configure.ac
--- a/libgo/configure.ac	Wed Feb 02 18:08:21 2011 +0100
+++ b/libgo/configure.ac	Thu Feb 03 15:57:15 2011 +0100
@@ -114,6 +114,7 @@
 
 is_darwin=no
 is_freebsd=no
+is_irix=no
 is_linux=no
 is_rtems=no
 is_solaris=no
@@ -121,12 +122,14 @@
 case ${host} in
   *-*-darwin*)   is_darwin=yes;  GOOS=darwin ;;
   *-*-freebsd*)  is_freebsd=yes; GOOS=freebsd ;;
+  *-*-irix6*)    is_irix=yes;    GOOS=irix ;;
   *-*-linux*)    is_linux=yes;   GOOS=linux ;;
   *-*-rtems*)    is_rtems=yes;   GOOS=rtems ;;
   *-*-solaris2*) is_solaris=yes; GOOS=solaris ;;
 esac
 AM_CONDITIONAL(LIBGO_IS_DARWIN, test $is_darwin = yes)
 AM_CONDITIONAL(LIBGO_IS_FREEBSD, test $is_freebsd = yes)
+AM_CONDITIONAL(LIBGO_IS_IRIX, test $is_irix = yes)
 AM_CONDITIONAL(LIBGO_IS_LINUX, test $is_linux = yes)
 AM_CONDITIONAL(LIBGO_IS_RTEMS, test $is_rtems = yes)
 AM_CONDITIONAL(LIBGO_IS_SOLARIS, test $is_solaris = yes)
diff -r bfc1c1131e8f libgo/go/debug/proc/proc_irix.go
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libgo/go/debug/proc/proc_irix.go	Thu Feb 03 15:57:15 2011 +0100
@@ -0,0 +1,17 @@
+// Copyright 2011 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package proc
+
+import "os"
+
+// Process tracing is not supported on IRIX yet.
+
+func Attach(pid int) (Process, os.Error) {
+	return nil, os.NewError("debug/proc not implemented on IRIX")
+}
+
+func ForkExec(argv0 string, argv []string, envv []string, dir string, fd []*os.File) (Process, os.Error) {
+	return Attach(0)
+}
diff -r bfc1c1131e8f libgo/mksysinfo.sh
--- a/libgo/mksysinfo.sh	Wed Feb 02 18:08:21 2011 +0100
+++ b/libgo/mksysinfo.sh	Thu Feb 03 15:57:15 2011 +0100
@@ -26,6 +26,11 @@
 #include "config.h"
 
 #define _GNU_SOURCE
+#if defined(__sgi__)
+/* IRIX 6 needs _XOPEN_SOURCE=500 for the XPG5 version of struct msghdr in
+   <sys/socket.h>.  */
+#define _XOPEN_SOURCE 500
+#endif
 #if defined(__sun__) && defined(__svr4__)
 /* Needed by Solaris header files.  */
 #define _XOPEN_SOURCE 600
@@ -37,6 +42,12 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <netinet/in.h>
+/* <netinet/tcp.h> needs u_char/u_short, but <sys/bsd_types> is only
+   included by <netinet/in.h> if _SGIAPI (i.e. _SGI_SOURCE
+   && !_XOPEN_SOURCE.  */
+#ifdef __sgi__
+#include <sys/bsd_types.h>
+#endif
 #include <netinet/tcp.h>
 #include <signal.h>
 #if defined(HAVE_SYSCALL_H)
@@ -76,12 +87,13 @@
   grep -v '^func' | \
   grep -v '^type _timeval ' | \
   grep -v '^type _timespec ' | \
+  grep -v '^type _timespec\(_t\)\? ' | \
   grep -v '^type _timestruc_t ' | \
   grep -v '^type _epoll_' | \
   grep -v 'in6_addr' | \
   grep -v 'sockaddr_in6' | \
   sed -e 's/\([^a-zA-Z0-9_]\)_timeval\([^a-zA-Z0-9_]\)/\1Timeval\2/g' \
-      -e 's/\([^a-zA-Z0-9_]\)_timespec\([^a-zA-Z0-9_]\)/\1Timespec\2/g' \
+      -e 's/\([^a-zA-Z0-9_]\)_timespec\(_t\)\?\([^a-zA-Z0-9_]\)/\1Timespec\3/g' \
       -e 's/\([^a-zA-Z0-9_]\)_timestruc_t\([^a-zA-Z0-9_]\)/\1Timestruc\2/g' \
     >> ${OUT}
 
@@ -283,13 +295,17 @@
   sed -e 's/type _timeval /type Timeval /' \
       -e 's/tv_sec *[a-zA-Z0-9_]*/Sec Timeval_sec_t/' \
       -e 's/tv_usec *[a-zA-Z0-9_]*/Usec Timeval_usec_t/' >> ${OUT}
-timespec=`grep '^type _timespec ' gen-sysinfo.go`
+timespec=`grep '^type _timespec ' gen-sysinfo.go || true`
+if test "$timespec" = ""; then
+  # IRIX 6.5 has __timespec instead.
+  timespec=`grep '^type ___timespec ' gen-sysinfo.go || true`
+fi
 timespec_sec=`echo $timespec | sed -n -e 's/^.*tv_sec \([^ ]*\);.*$/\1/p'`
 timespec_nsec=`echo $timespec | sed -n -e 's/^.*tv_nsec \([^ ]*\);.*$/\1/p'`
 echo "type Timespec_sec_t $timespec_sec" >> ${OUT}
 echo "type Timespec_nsec_t $timespec_nsec" >> ${OUT}
 echo $timespec | \
-  sed -e 's/^type _timespec /type Timespec /' \
+  sed -e 's/^type \(__\)\?_timespec /type Timespec /' \
       -e 's/tv_sec *[a-zA-Z0-9_]*/Sec Timespec_sec_t/' \
       -e 's/tv_nsec *[a-zA-Z0-9_]*/Nsec Timespec_nsec_t/' >> ${OUT}
 
@@ -322,7 +338,7 @@
       -e 's/st_mtim/Mtime/' \
       -e 's/st_ctim/Ctime/' \
       -e 's/\([^a-zA-Z0-9_]\)_timeval\([^a-zA-Z0-9_]\)/\1Timeval\2/g' \
-      -e 's/\([^a-zA-Z0-9_]\)_timespec\([^a-zA-Z0-9_]\)/\1Timespec\2/g' \
+      -e 's/\([^a-zA-Z0-9_]\)_timespec\(_t\)\?\([^a-zA-Z0-9_]\)/\1Timespec\3/g' \
       -e 's/\([^a-zA-Z0-9_]\)_timestruc_t\([^a-zA-Z0-9_]\)/\1Timestruc\2/g' \
     >> ${OUT}
 
diff -r bfc1c1131e8f libgo/syscalls/syscall_irix.go
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libgo/syscalls/syscall_irix.go	Thu Feb 03 15:57:15 2011 +0100
@@ -0,0 +1,17 @@
+// syscall_irix.go -- IRIX 6 specific syscall interface.
+
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package syscall
+
+import "unsafe"
+
+// FIXME: ptrace(3C) has this, but exec.go expects the next.
+//func libc_ptrace(request int, pid Pid_t, addr int, data int) int __asm__ ("ptrace")
+
+func libc_ptrace(request int, pid Pid_t, addr uintptr, data *byte) int __asm__ ("ptrace")
+
+var dummy *byte
+const sizeofPtr uintptr = uintptr(unsafe.Sizeof(dummy))
