Some issues compiling on Irix:

+ the code in writemovie.c no longer compiles (since the renderer
refactor). I have #if 0-ed it.

+ OpenGL on Irix doesn't have GL_ARB_vertex_program

+ mmap on Irix doesn't like MAP_ANON.

+ If using the MipsPro 7.3 compiler, the variable MIPS73_ISOHEADERS
can be set to point to the directory with those weird C++ headers
that don't have .h in the name

intern/guardedalloc/intern/mallocn.c

@@ -259,8 +259,13 @@ void *MEM_mapallocN(unsigned int len, const char *str)
 	
 	len = (len + 3 ) & ~3; 	/* allocate in units of 4 */
 	
+#if defined(__sgi)
+	memh= mmap(0, len+sizeof(MemHead)+sizeof(MemTail), 
+			   PROT_READ|PROT_WRITE, MAP_SHARED, -1, 0);
+#else
 	memh= mmap(0, len+sizeof(MemHead)+sizeof(MemTail), 
 			   PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANON, -1, 0);
+#endif
 	
 	if(memh!=(MemHead *)-1) {
 		make_memhead_header(memh, len, str);

source/blender/src/writemovie.c

@@ -30,7 +30,8 @@
  * ***** END GPL/BL DUAL LICENSE BLOCK *****
  */
 
-#ifdef __sgi
+//#ifdef __sgi
+#if 0
 
 #include <unistd.h>
 #include <movie.h>

source/gameengine/Rasterizer/RAS_OpenGLRasterizer/RAS_GLExtensionManager.h

@@ -52,6 +52,10 @@
 #  undef __glext_h_
 #endif
 
+#ifdef __sgi
+#  undef GL_ARB_vertex_program
+#endif
+
 #include "glext.h"
 
 #include "EXT_separate_specular_color.h"

source/nan_compile.mk

@@ -117,7 +117,11 @@ ifeq ($(OS),irix)
     CCC	= CC
     CFLAGS	+= -n32 -mips3 -Xcpluscomm
     CCFLAGS	+= -n32 -mips3 -Xcpluscomm -LANG:std
+ifdef MIPS73_ISOHEADERS
     CCFLAGS	+= -LANG:libc_in_namespace_std=off -I$(MIPS73_ISOHEADERS)
+else
+    CCFLAGS	+= -LANG:libc_in_namespace_std=off
+endif
     REL_CFLAGS	+= -n32 -mips3 -O2 -OPT:Olimit=0
     REL_CCFLAGS += -n32 -mips3 -O2 -OPT:Olimit=0
     OPENGL_HEADERS = /usr/include