> An example of an unspec_volatile instruction pattern in > config/i386/i386.md > is "cld". I ran across that, your hints should give me some information to chew on for the next hours. Currently I am compiling with this code to see what happens:
(define_insn "movnop" [(unspec_volatile [(const_int 0)] UNSPECV_MOVNOP)] "" "movl.r\t%edi,%edi" [(set_attr "length" "2") (set_attr "length_immediate" "0") (set_attr "modrm" "0")]) and then a gen_movnop(/* better name anyone? */) to use it. Lets see what happens > But since you have to have a new gas anyway, wouldn't it be simpler to > have > a new option for gas to instruct it to choose the opcodes that are > expected > by the win32 applications? This was my first idea, but Alexandre Julliard(the Wine maintainer) disliked it and prefered a function attribute to turn it on per-function. However, from looking at the gcc code it seems that this is the best option to generate Win32-friendly code everywhere. I'll look at your other suggestions and talk to Alexandre again.
