Hi,

The attached patch adds a new switch -fftz-math which makes certain
optimizations
assume that "flush to zero" behavior of denormal inputs and outputs is
not an optimization
hint, but required behavior for semantical correctness.

The need for this was initiated by HSAIL (BRIG). With HSAIL, flush to
zero handling is required,
(not only "allowed") in case an HSAIL instruction is marked with the
'ftz' modifier (all HSA Base
profile instructions are).

The patch is not complete and likely misses many optimizations.
However, it is a starting point
that fixes a few cases brought out by the HSAIL conformance suite. We
plan to extend this
as new cases come up.

OK for trunk?

BR,
Pekka