diff -up vxl-git4e07960/core/vil/vil_round.h.secondary vxl-git4e07960/core/vil/vil_round.h
--- vxl-git4e07960/core/vil/vil_round.h.secondary	2012-12-05 08:23:37.072384920 -0500
+++ vxl-git4e07960/core/vil/vil_round.h	2012-12-05 08:24:06.682385737 -0500
@@ -25,9 +25,8 @@
 # endif
 #endif
 
-// Turn on fast impl when using GCC on Intel-based machines with the following exception:
-//   PPC with Mac OS X
-#if defined(__GNUC__) && (!defined(__APPLE__)  || !defined(__ppc__) )
+// Turn on fast impl when using GCC on Intel-based machines
+#if defined(__GNUC__) && (defined(__i386__)  || defined(__x86_64__) )
 # define GCC_USE_FAST_IMPL 1
 #else
 # define GCC_USE_FAST_IMPL 0
diff -up vxl-git4e07960/core/vnl/vnl_math.h.secondary vxl-git4e07960/core/vnl/vnl_math.h
--- vxl-git4e07960/core/vnl/vnl_math.h.secondary	2012-12-05 08:12:25.282386747 -0500
+++ vxl-git4e07960/core/vnl/vnl_math.h	2012-12-05 08:13:05.142387632 -0500
@@ -53,9 +53,8 @@
 #   include <emmintrin.h> // sse 2 intrinsics
 # endif
 #endif
-// Turn on fast impl when using GCC on Intel-based machines with the following exception:
-//   PPC with Mac OS X
-#if defined(__GNUC__) && (!defined(__APPLE__)  || !defined(__ppc__) )
+// Turn on fast impl when using GCC on Intel-based machines
+#if defined(__GNUC__) && (defined(__i386__)  || defined(__x86_64__))
 # define GCC_USE_FAST_IMPL 1
 #else
 # define GCC_USE_FAST_IMPL 0