Re: [PATCH vkd3d 07/12] vkd3d-shader/hlsl: Support matrix indexing.

[Zebediah Figura]

On 4/18/22 01:34, Giovanni Mascellani wrote:
> Signed-off-by: Giovanni Mascellani
>
> libs/vkd3d-shader/hlsl.y               | 87 +++++++++++++++++++++++++-
>   tests/hlsl-matrix-indexing.shader_test |  8 +--
>   2 files changed, 88 insertions(+), 7 deletions(-)
>
> diff --git a/libs/vkd3d-shader/hlsl.y b/libs/vkd3d-shader/hlsl.y
> index 291f8392..b6a8e496 100644
> --- a/libs/vkd3d-shader/hlsl.y
> +++ b/libs/vkd3d-shader/hlsl.y
> @@ -581,6 +581,89 @@ static bool add_record_load(struct hlsl_ctx *ctx, struct list *instrs, struct hl
>       return !!add_load(ctx, instrs, record, &c->node, field->type, loc);
>   }
>
> +static struct hlsl_ir_expr *add_binary_arithmetic_expr(struct hlsl_ctx *ctx, struct list *instrs,
> -
>    enum hlsl_ir_expr_op op, struct hlsl_ir_node *arg1, struct hlsl_ir_node *arg2,
> -
>    const struct vkd3d_shader_location *loc);
> -
>
> +static struct hlsl_ir_node *compute_matrix_offset(struct hlsl_ctx *ctx, struct list *instrs,
> -
>    struct hlsl_type *type, struct hlsl_ir_node *x, struct hlsl_ir_node *y,
> -
>    const struct vkd3d_shader_location *loc)
>
> +{
> - struct hlsl_ir_node *major, *minor;
> - struct hlsl_ir_expr *mul, *add;
> - struct hlsl_ir_constant *four;
> -
> - if (type->modifiers & HLSL_MODIFIER_ROW_MAJOR)
> - {
> -
>    minor = x;
> -
>    major = y;
> - }
> - else
> - {
> -
>    minor = y;
> -
>    major = x;
> - }
> -
> - if (!(four = hlsl_new_uint_constant(ctx, 4, loc)))
> -
>    return NULL;
> - list_add_tail(instrs, &four->node.entry);
> -
> - if (!(mul = add_binary_arithmetic_expr(ctx, instrs, HLSL_OP2_MUL, &four->node, major, loc)))
> -
>    return NULL;
> -
> - if (!(add = add_binary_arithmetic_expr(ctx, instrs, HLSL_OP2_ADD, &mul->node, minor, loc)))
> -
>    return NULL;

Why do we need this, and not just hlsl_new_binary_expr()? We already 
cast the index to a scalar uint.

In general I think we want to avoid using add_*() helpers if possible, 
where not triggered directly by user code.
> -
> - return &add->node;
>
> +}
> -
>
> +static bool add_matrix_load(struct hlsl_ctx *ctx, struct list *instrs,
> -
>    struct hlsl_ir_node *matrix, struct hlsl_ir_node *index, const struct vkd3d_shader_location *loc)

How about add_matrix_index() instead?
> +{
> - struct hlsl_type *mat_type = matrix->data_type, *ret_type, *scal_type;
> - static unsigned int counter = 0;
> - struct hlsl_ir_load *load;
> - struct hlsl_ir_var *var;
> - unsigned int i;
> - char name[32];
> -
> - ret_type = hlsl_get_vector_type(ctx, mat_type->base_type, mat_type->dimx);
> - scal_type = hlsl_get_scalar_type(ctx, mat_type->base_type);
> -
> - sprintf(name, "<index-%x>", counter++);

Please always use # for hexadecimal formats (or, in this case, %u may be 
better). I see the constructor path doesn't, but we should change that.
> - var = hlsl_new_synthetic_var(ctx, name, ret_type, *loc);
> - if (!var)
> -
>    return false;
> -
> - for (i = 0; i < mat_type->dimx; ++i)
> - {
> -
>    struct hlsl_ir_node *offset;
> -
>    struct hlsl_ir_store *store;
> -
>    struct hlsl_ir_load *value;
> -
>    struct hlsl_ir_constant *c;
> -
> -
>    if (!(c = hlsl_new_uint_constant(ctx, i, loc)))
> -
>        return false;
> -
>    list_add_tail(instrs, &c->node.entry);
> -
> -
>    if (!(offset = compute_matrix_offset(ctx, instrs, mat_type, &c->node, index, loc)))
> -
>        return false;

The signature of this function feels awkward to me. Could we fold the 
subsequent add_load() call into it, and call it something like 
add_matrix_scalar_load() instead? Note also that it'd be useful for 
matrix swizzles in that case, since I think we want to stop generating 
HLSL_IR_SWIZZLE instructions for those.
> -
> -
>    if (!(value = add_load(ctx, instrs, matrix, offset, scal_type, *loc)))
> -
>        return false;
> -
> -
>    if (!(store = hlsl_new_store(ctx, var, &c->node, &value->node, 0, *loc)))
> -
>        return false;
> -
>    list_add_tail(instrs, &store->node.entry);
> - }
> -
> - if (!(load = hlsl_new_load(ctx, var, NULL, ret_type, *loc)))

hlsl_new_var_load(ctx, var, *loc)
> -
>    return false;
> - list_add_tail(instrs, &load->node.entry);
> -
> - return true;
>
> +}
> - static bool add_array_load(struct hlsl_ctx *ctx, struct list *instrs, struct hlsl_ir_node *array,
>         struct hlsl_ir_node *index, const struct vkd3d_shader_location loc)
> {