Samuel Iglesias Gonsálvez <sigles...@igalia.com> writes:
> From: "Juan A. Suarez Romero" <jasua...@igalia.com>
>
> When converting a DF to F, we set dst stride to 2, to fulfil alignment
> restrictions.
>
> But in IVB/BYT, this is not necessary, as each DF conversion already
> writes 2 F, the first one the real value, and the second one a 0. That
> is, IVB/BYT already set stride = 2 implicitly, so we must set it to 1
> explicitly to avoid ending up with stride = 4.
>
> v2:
> - Fix typo (Matt)
> ---
> src/mesa/drivers/dri/i965/brw_fs_generator.cpp | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
> b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
> index 45881e3ec95..487f2e90224 100644
> --- a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
> +++ b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
> @@ -1629,6 +1629,16 @@ fs_generator::generate_code(const cfg_t *cfg, int
> dispatch_width)
> inst->src[i].type != BRW_REGISTER_TYPE_UD ||
> !inst->src[i].negate);
> }
> + /* When converting from DF->F, we set destination's stride as 2 as an
> + * alignment requirement. But in IVB/BYT, each DF implicitly writes 2
> F,
> + * being the first one the converted value. So we don't need to
> + * explicitly set stride 2, but 1.
> + */
> + if (devinfo->gen == 7 && !devinfo->is_haswell &&
> + type_sz(inst->src[0].type) > type_sz(inst->dst.type)) {This should be exec_type_size(inst) rather than type_sz(inst->src[0].type). > + assert(inst->dst.stride == 2 || inst->dst.stride == 1); > + inst->dst.stride = 1; > + } This is modifying the IR, please don't. Also I don't think the above has the same semantics as a destination region with stride 2... AFAIUI IVB will just write garbage into the odd channels when the destination type is narrower than a DF which is really not what a strided move is supposed to do. If that's the case it would probably be safer to add a new F64TO32 virtual opcode for type conversions and assert(inst->dst.stride == 1) here... > dst = brw_reg_from_fs_reg(compiler->devinfo, inst, > &inst->dst, compressed); > > -- > 2.11.0 > > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/mesa-dev
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