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    SubjectRe: X32 psABI status update
    On Sun, Mar 20, 2011 at 10:08 PM, Mike Frysinger <> wrote:
    > On Thursday, March 17, 2011 01:21:16 H.J. Lu wrote:
    >> On Wed, Mar 16, 2011 at 7:57 PM, Mike Frysinger <> wrote:
    >> > in looking at the gcc files, it doesnt seem like there's any defines
    >> > setup to declare x32 directly.  instead, you'd have to do something
    >> > like: #ifdef __x86_64__
    >> > # if __SIZEOF_LONG__ == 8
    >> > /* x86_64 */
    >> > # else
    >> > /* x32 */
    >> > # endif
    >> > #endif
    >> >
    >> > any plans on adding an __x32__ (or whatever) cpp symbol to keep people
    >> > from coming up with their own special/broken crap ?  or are there some
    >> > already that i'm not seeing ?
    >> The idea is in most cases, you only need to check __x86_64__ since x32 and
    >> x86-64 are very close.  In some cases, x32 is very different from x86_64,
    >> like assembly codes on long and pointer, you can check __x86_64__ and
    >> __LP64__. In glibc, I used a different approach by using macros REG_RAX,
    >> .., MOV_LP, ADD_LP, SUB_LP and CMP_LP in assembly codes.
    > while i agree with you in general that this is how people should be doing
    > things, in practice i often see people fishing around.  education only goes so
    > far, so if there was an __x32__ define, i feel like people are more likely to
    > get it right than wrong.
    > i dont have any use cases off the top of my head, but i wouldnt be surprised
    > if the heavy inline assembly people (like the multimedia peeps e.g. libav)
    > approached it this way.  rather than google for documentation, look at the cpp
    > output between -m64 and -mx32 and see what sticks out.  "__x32__" would
    > certainly do that.

    My point is __x86_64__ version should work for both 64bit and x32. There should
    no need for a separate x32 version.

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