v_pk_add/mul/fma/fmac/min/max_f16 threw in f16 denormal modes 0-2. On
RDNA2 (gfx1031) bit 6 clear flushes each denormal input lane to a zero
of its sign, and bit 7 clear flushes an add result below 2^-14 and a
mul or fma result whose exact value rounded to 11 significant bits
with an unbounded exponent is below 2^-14, as the scalar forms do;
min/max flush only their inputs. Packed f16 still throws for f16
rounding other than nearest even.
Co-Authored-By: Claude Opus 5.5 <[email protected]>