panfrost/midgard: Set int outmod for ops writing integers
By default, the "normal" output modifier is set on ALU ops. This is the
correct default for float outputs -- for floats, it preserves the semantic
value. Unfortunately, when used with integers, it does not preserve the
bitstream encoding, causing misbehaviour. (It's an open question what
happens when `normal` is used with integers -- does it apply some other
transformation? or does it do floating point normalization/etc on the
ints as if they were floats?).
Instead, we default to the "clamp to integer" output modifier for
ops writing integers. Semantically, this makes sense (clamping an
integer to the nearest integer is the identity function). In the
hardware with an integer opcode, this is the actual "normal".
This fixes numerous sporadic and sometimes bizarre bugs relating to
integers, especially integer moves. With this in place, we no longer
care about the types involved; it's just bits on the wire again.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
2 files changed