http://d.puremagic.com/issues/show_bug.cgi?id=2648

           Summary: Unnecessary struct ABI inconsistency
           Product: D
           Version: unspecified
          Platform: PC
        OS/Version: All
            Status: NEW
          Severity: normal
          Priority: P2
         Component: DMD
        AssignedTo: bugzilla@digitalmars.com
        ReportedBy: clugdbug@yahoo.com.au


There is a horrible ABI difference between Linux and Windows which seems to be
completely unjustified. Although extern(C) needs to be different between the
systems, there's no reason for extern(D) to.

Linux and Windows should use the same return algorithm for 1,2,4, and 8-byte structs. This is the only point at which the ABI differs (except for the fact that real.sizeof is different, but that's something dictacted by the OS).

---
# For Windows, 1, 2 and 4 byte structs are returned in EAX.
# For Windows, 8 byte structs are returned in EDX,EAX, where EDX gets the most
significant half.
# For other struct sizes, the return value is stored through a hidden pointer
passed as an argument to the function.
---


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http://d.puremagic.com/issues/show_bug.cgi?id=2648


dhasenan@gmail.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |spec




------- Comment #1 from dhasenan@gmail.com  2009-04-25 15:25 -------
The ABI as implemented in DMD with regards to returning structs appears to be as the spec describes for Windows, as confirmed by mucking about with obj2asm. (Note that, to create a 3-byte struct, you need to use align(1).)

I ascertained this using dmd2.029; other versions might have different behavior.


-- 

http://d.puremagic.com/issues/show_bug.cgi?id=2648


Walter Bright <bugzilla@digitalmars.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |bugzilla@digitalmars.com
         Resolution|                            |DUPLICATE


--- Comment #2 from Walter Bright <bugzilla@digitalmars.com> 2010-11-08 01:03:29 PST ---
*** This issue has been marked as a duplicate of issue 2385 ***

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