The GCC version we use internally to build 4.6 treats unused variable warnings as errors. This was causing bootstraps to fail. Tested on x86_64. Committed to gcc-4_6-branch. * tree-vect-stmts.c (vect_transform_stmt): Remove unused local variable ORIG_SCALAR_STMT. Index: tree-vect-stmts.c =================================================================== --- tree-vect-stmts.c (revision 178875) +++ tree-vect-stmts.c (working copy) @@ -4814,7 +4814,7 @@ vect_transform_stmt (gimple stmt, gimple bool is_store = false; gimple vec_stmt = NULL; stmt_vec_info stmt_info = vinfo_for_stmt (stmt); - gimple orig_stmt_in_pattern, orig_scalar_stmt = stmt; + gimple orig_stmt_in_pattern; bool done; switch (STMT_VINFO_TYPE (stmt_info)) -- This patch is available for review at http://codereview.appspot.com/5013044