Re: [PATCH v2 1/3] d3dcompiler: Store derefs as an offset to a variable.

[Matteo Bruni]

On Wed, May 20, 2020 at 3:18 AM Zebediah Figura  wrote:
> @@ -633,17 +660,21 @@ static struct hlsl_ir_deref *new_array_deref(struct hlsl_ir_node *array,
>          return NULL;
>      }
> - if (!(array = get_var_deref(array)))
> -
>    return NULL;
> - if (data_type->reg_size > 1)
> - {

Doesn't this need to happen even for reg_size == 1 now that we're
using a scalar offset?
> -
>    struct hlsl_ir_constant *c;
> -
>    struct hlsl_ir_node *mul;
>
> - if (!(deref = d3dcompiler_alloc(sizeof(*deref))))
> -
>    return NULL;
> -
>    if (!(c = new_uint_constant(data_type->reg_size * 4, loc)))
> -
>        return NULL;
> -
>    list_add_after(&index->entry, &c->node.entry);
> -
>    if (!(mul = new_binary_expr(HLSL_IR_BINOP_MUL, index, &c->node, loc)))
> -
>        return NULL;
> -
>    list_add_after(&c->node.entry, &mul->entry);
> -
>    index = mul;
> - }
> - init_node(&deref->node, HLSL_IR_DEREF, data_type, loc);
> - deref->src.type = HLSL_IR_DEREF_ARRAY;
> - deref->src.v.array.array = array;
> - deref->src.v.array.index = index;
> - return deref;
> - return new_deref(array, index, data_type, loc);
>
> }
>
> static void struct_var_initializer(struct list *list, struct hlsl_ir_var *var,
> @@ -1513,12 +1490,6 @@ struct hlsl_ir_node *make_assignment(struct hlsl_ir_node *lhs, enum parse_assign
>          lhs = lhs_inner;
>      }
> - if (!validate_lhs_deref(lhs))
> - {
> -
>    d3dcompiler_free(assign);
> -
>    return NULL;
> - }
> - TRACE("Creating proper assignment expression.\n");
>    if (writemask == BWRITERSP_WRITEMASK_ALL)
>        type = lhs->data_type;
>
> @@ -1562,26 +1533,12 @@ struct hlsl_ir_node *make_assignment(struct hlsl_ir_node *lhs, enum parse_assign
>          enum hlsl_ir_expr_op op = op_from_assignment(assign_op);
>          struct hlsl_ir_node *expr;
> -
>    if (assign->lhs.type != HLSL_IR_DEREF_VAR)
> -
>    {
> -
>        FIXME("LHS expression not supported in compound assignments yet.\n");
> -
>        assign->rhs = rhs;
> -
>    }
> -
>    else
> -
>    {
> -
>        TRACE("Adding an expression for the compound assignment.\n");
> -
>        expr = new_binary_expr(op, lhs, rhs, lhs->loc);
> -
>        list_add_after(&rhs->entry, &expr->entry);
> -
>        assign->rhs = expr;
> -
>    }
> - }
> - else
> - {
> -
>    list_remove(&lhs->entry);
> -
>    /* Don't recursively free the deref; we just copied its members. */
> -
>    d3dcompiler_free(lhs);
> -
>    assign->rhs = rhs;
> -
>    TRACE("Adding an expression for the compound assignment.\n");
> -
>    expr = new_binary_expr(op, lhs, rhs, lhs->loc);
> -
>    list_add_after(&rhs->entry, &expr->entry);
> -
>    rhs = expr;
> }
> - assign->rhs = rhs;

I guess this is one of the cases where using a struct hlsl_deref for
both lvalues and rvalues comes in handy (to some degree).