Added initial code for PowerPC VSX optimisation
diff --git a/png.h b/png.h
index cad9a82..f62f445 100644
--- a/png.h
+++ b/png.h
@@ -3225,7 +3225,10 @@
# define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */
#endif
#define PNG_IGNORE_ADLER32 8
-#define PNG_OPTION_NEXT 10 /* Next option - numbers must be even */
+#ifdef PNG_POWERPC_VSX_API_SUPPORTED
+# define PNG_POWERPC_VSX 10 /* HARDWARE: PowerPC VSX SIMD instructions supported */
+#endif
+#define PNG_OPTION_NEXT 12 /* Next option - numbers must be even */
/* Return values: NOTE: there are four values and 'off' is *not* zero */
#define PNG_OPTION_UNSET 0 /* Unset - defaults to off */