------- Comment #2 from pinskia at gcc dot gnu dot org 2005-10-17 20:56 ------- An asm instruction without any operands or clobbers (an "old style" asm) will be treated identically to a volatile asm instruction.
Or what is in the newer doc: 3933: An @code{asm} instruction without any output operands will be treated 3934: identically to a volatile @code{asm} instruction. and in PR 19341 we decided that volatile asm does not clobber memory. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24414