SDL_blit_N.c: Correct vec_perm() application on little-endian 64-bit PowerPC

The LE transformation for vec_perm has an implicit assumption that the
permutation is being used to reorder vector elements (in this case 4-byte
integer word elements), not to reorder bytes within those elements.  Although
this is legal behavior, it is not anticipated by the transformation performed
by the compilers.

This causes pygame-1.9.1 test failure on PPC64LE because blitted pixmaps are
corrupted there due to how SDL uses vec_perm().

From RedHat / Fedora:
Original patch was provided by: Menanteau Guy <>
1 file changed