[PATCH 2/5] d3dcompiler: Fold addition and multiplication of uint constants.

[Matteo Bruni]

On Tue, Jun 30, 2020 at 1:56 AM Zebediah Figura <z.figura12 at gmail.com> wrote:
>
> Signed-off-by: Zebediah Figura <zfigura at codeweavers.com>
> ---
>  dlls/d3dcompiler_43/hlsl.y | 101 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 101 insertions(+)
>
> diff --git a/dlls/d3dcompiler_43/hlsl.y b/dlls/d3dcompiler_43/hlsl.y
> index 475fd414fd7..15bd0d007b9 100644
> --- a/dlls/d3dcompiler_43/hlsl.y
> +++ b/dlls/d3dcompiler_43/hlsl.y
> @@ -2838,6 +2838,105 @@ static void dump_function(struct wine_rb_entry *entry, void *context)
>      wine_rb_for_each_entry(&func->overloads, dump_function_decl, NULL);
>  }
>
> +static BOOL transform_ir(BOOL (*func)(struct hlsl_ir_node *), struct list *instrs)

Since this is going to be a pretty generic helper: we might want to
pass some "void *context" to func.

> +{
> +    struct hlsl_ir_node *instr, *next;
> +    BOOL progress = 0;
> +
> +    LIST_FOR_EACH_ENTRY_SAFE(instr, next, instrs, struct hlsl_ir_node, entry)
> +    {
> +        if (instr->type == HLSL_IR_IF)
> +        {
> +            struct hlsl_ir_if *iff = if_from_node(instr);
> +            progress |= transform_ir(func, iff->then_instrs);
> +            if (iff->else_instrs)
> +                progress |= transform_ir(func, iff->else_instrs);
> +        }

I like to have a blank line between declarations and other statements.

> +        else if (instr->type == HLSL_IR_LOOP)
> +            progress |= transform_ir(func, loop_from_node(instr)->body);

Unrelated to the patch: maybe we should always initialize else_instrs?
I think that would get rid of a bunch of checks with no drawback.

> +
> +        progress |= func(instr);
> +    }
> +
> +    return progress;
> +}
> +
> +static void replace_node(struct hlsl_ir_node *old, struct hlsl_ir_node *new)
> +{
> +    struct hlsl_src *src, *next;
> +
> +    LIST_FOR_EACH_ENTRY_SAFE(src, next, &old->uses, struct hlsl_src, entry)
> +    {
> +        hlsl_src_remove(src);
> +        hlsl_src_from_node(src, new);
> +    }
> +    list_add_before(&old->entry, &new->entry);
> +    list_remove(&old->entry);
> +    free_instr(old);
> +}
> +
> +static BOOL fold_constants(struct hlsl_ir_node *instr)
> +{
> +    struct hlsl_ir_constant *arg1, *arg2 = NULL, *res;
> +    struct hlsl_ir_expr *expr;
> +    unsigned int i;
> +
> +    if (instr->type != HLSL_IR_EXPR)
> +        return FALSE;
> +    expr = expr_from_node(instr);
> +
> +    for (i = 0; i < ARRAY_SIZE(expr->operands); ++i)
> +    {
> +        if (expr->operands[i].node && expr->operands[i].node->type != HLSL_IR_CONSTANT)
> +            return FALSE;
> +    }
> +    arg1 = constant_from_node(expr->operands[0].node);
> +    if (expr->operands[1].node)
> +        arg2 = constant_from_node(expr->operands[1].node);
> +
> +    if (!(res = d3dcompiler_alloc(sizeof(*res))))
> +    {
> +        hlsl_ctx.status = PARSE_ERR;
> +        return FALSE;
> +    }
> +    init_node(&res->node, HLSL_IR_CONSTANT, instr->data_type, instr->loc);
> +
> +    switch (instr->data_type->base_type)
> +    {
> +        case HLSL_TYPE_UINT:
> +        {
> +            unsigned int i;
> +
> +            switch (expr->op)
> +            {
> +                case HLSL_IR_BINOP_ADD:
> +                    for (i = 0; i < 16; ++i)
> +                        res->value.u[i] = arg1->value.u[i] + arg2->value.u[i];
> +                    break;
> +
> +                case HLSL_IR_BINOP_MUL:
> +                    for (i = 0; i < 16; ++i)
> +                        res->value.u[i] = arg1->value.u[i] * arg2->value.u[i];
> +                    break;

I'd prefer if this only operated on the valid components: maybe it's
not going to be any faster but I feel it would be less confusing and
it also happens to be "partial constants ready" (whether we go ahead
with that or not).

> +
> +                default:
> +                    FIXME("Fold uint expr %#x.\n", expr->op);
> +                    d3dcompiler_free(res);
> +                    return FALSE;
> +            }
> +            break;
> +        }
> +
> +        default:
> +            FIXME("Fold %s expr %#x.\n", debug_base_type(instr->data_type), expr->op);
> +            d3dcompiler_free(res);
> +            return FALSE;
> +    }
> +
> +    replace_node(&expr->node, &res->node);
> +    return TRUE;
> +}
> +
>  /* Allocate a unique, ordered index to each instruction, which will be used for
>   * computing liveness ranges. */
>  static unsigned int index_instructions(struct list *instrs, unsigned int index)
> @@ -3009,6 +3108,8 @@ HRESULT parse_hlsl(enum shader_type type, DWORD major, DWORD minor,
>
>      list_move_head(entry_func->body, &hlsl_ctx.static_initializers);
>
> +    while (transform_ir(fold_constants, entry_func->body));
> +
>      /* Index 0 means unused; index 1 means function entry, so start at 2. */
>      index_instructions(entry_func->body, 2);

As we discussed elsewhere, we probably want to move transform_ir() and
its calls out of hlsl.y.