Profiling on S390

[Richard Henderson]

On Wed, Apr 23, 2003 at 10:23:24PM +0200, Ulrich Weigand wrote:
> However, in the case of the profiler where saving/restoring CC
> is vital for *correctness*, shouldn't the fact that CCmode copies
> are *possible* (i.e. movcc works) be enough?

Well... if movcc exists, then fine.  But if it doesn't, and
movsi doesn't support the flags register, then we're going
to generate an unreloadable insn.

OTOH, I suppose it's sufficient to abort in reload.

> If I were to introduce that capability, does the common code make
> any assumptions on just how those values are represented by integers?
> Does (subreg:SI (reg:CC ...) 0) or vice versa work?)

If a movcc pattern doesn't exist, then emit_move_insn_1 will subreg
to word_mode and try that move pattern.  But no assumptions are made
wrt the contents of the bits.


r~