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Re: Honnor ix86_accumulate_outgoing_args again

> and because LRA still misses some reload functionality for
> elimination.  I am a bit embarrassed: I have this thing to do for 4
> months and I still did not start to work on it yet.  There are too
> much things on my plate.
> As we are going to use outgoing arg accumulation, this problem is
> becoming higher priority one.

Thank you,
we currently use outgoing arg accumulation always on x86_64, I plan to
re-disable arg accumulation on CPUs that handle push/pop well (i.e. have stack
engine).  This brings nice code size savings.

I wonder how much this actually comes from not omitting frame pointer in
non-leaf functions with IRA. EBP based addressing is more compact than ESP
and thus -fomit-frame-pointer is disabled with -Os.

Perhaps frame elimination can be actually decided on by register allocation?

On similar note I just benchmarked -mfpmath=sse for 32bit code and it is quite
big performance win and again causes about 5% code size regression.  I want to
propose defaulting to -mfpmath=sse for 32bit for -ffast-math and -Ofast.  (in a
way I would like to see -mfpmath=sse by default for 32bit on CPUs supporting
SSE2, but that has been voted down long time ago becuase it loses the 80bit
precision for temporaries in double/float computations).

I wonder if we can eventually make -mfpmath=sse,387 working well (I did not
bechmark it yet, but statically it still produces more spiling than -mfpmath=sse)
and/or if we can possibly decide on fpmath based on hotness of function
(at least with profile around).

Thanks for all the hard work on IRA!

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