Re: [Qemu-devel] [RFC] TCG new op: setcond

[Laurent Desnogues]

Hello,

Here is an updated patch for setcond.

Changes since the previous patch:

  - support TCG i386 for 32 and 64 bit variants
  - support TCG x86_64 support for 32 and 64 bit variants
  - fix for x86_64 prefix output
  - fix for input/output overlap
  - use setcond for Alpha cmp instructions
  - add setcondi

Digging into x86 is certainly not a pleasant experience for me,
especially as I have no experience on it.  So this patch may
contain bugs and overlooks;  note however my changes were
tested on x86_64 and i386 platforms with test programs for
Alpha and ARM.

What remains to be done:

  - document setcond in tcg/README
  - implement it in all backends (ARM, PPC, PPC64, SPARC)
  - use it at least once in every frontend (cris, i386, m68k, MIPS,
    PPC, sh4, SPARC)
  - provide tests.

Also there's a choice to be done between return 1 if the test
succeeds or -1.

I am concerned by 64 bit setcond on the register-started i386.
Isn't there a high risk the register allocator will run out of
registers?  If it's so, I guess it should be rewritten with a helper.

Thanks to Paul and Avi for their comments and uncovering silly
bugs and overlooks.

Comments and criticisms welcome as usual :-)


Laurent

Signed-off-by: Laurent Desnogues <address@hidden>

setcond-2.patch.bz2
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