Duncan Sands 00fee65fd2 In TargetLowering::LowerCallTo, don't assert that
the return value is zero-extended if it isn't
sign-extended.  It may also be any-extended.
Also, if a floating point value was returned
in a larger floating point type, pass 1 as the
second operand to FP_ROUND, which tells it
that all the precision is in the original type.
I think this is right but I could be wrong.
Finally, when doing libcalls, set isZExt on
a parameter if it is "unsigned".  Currently
isSExt is set when signed, and nothing is
set otherwise.  This should be right for all
calls to standard library routines.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47122 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-14 17:28:50 +00:00
..
2008-02-11 23:47:56 +00:00

TODO:
  - Un-bitrot ISel
  - Hook up If-Conversion a la ARM target
  - Hook up all branch analysis functions
  - Instruction scheduling
  - Bundling
  - Dynamic Optimization
  - Testing and bugfixing
  - stop passing FP args in both FP *and* integer regs when not required
  - allocate low (nonstacked) registers more aggressively
  - clean up and thoroughly test the isel patterns.
  - fix stacked register allocation order: (for readability) we don't want
    the out? registers being the first ones used
  - fix up floating point
    (nb http://gcc.gnu.org/wiki?pagename=ia64%20floating%20point )
  - bundling!
    (we will avoid the mess that is:
     http://gcc.gnu.org/ml/gcc/2003-12/msg00832.html )
  - instruction scheduling (hmmmm! ;)
  - counted loop support
  - make integer + FP mul/div more clever (we have fixed pseudocode atm)
  - track and use comparison complements

INFO:
  - we are strictly LP64 here, no support for ILP32 on HP-UX. Linux users
    don't need to worry about this.
  - i have instruction scheduling/bundling pseudocode, that really works
    (has been tested, albeit at the perl-script level).
    so, before you go write your own, send me an email!

KNOWN DEFECTS AT THE CURRENT TIME:
  - C++ vtables contain naked function pointers, not function descriptors,
  which is bad. see http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=406
  - varargs are broken
  - alloca doesn't work (indeed, stack frame layout is bogus)
  - no support for big-endian environments
  - (not really the backend, but...) the CFE has some issues on IA64.
    these will probably be fixed soon.
  
ACKNOWLEDGEMENTS:
  - Chris Lattner (x100)
  - Other LLVM developers ("hey, that looks familiar")

CONTACT:
  - You can email me at duraid@octopus.com.au. If you find a small bug,
    just email me. If you find a big bug, please file a bug report
    in bugzilla! http://llvm.cs.uiuc.edu is your one stop shop for all
    things LLVM.