Re: [PATCH vkd3d 5/6] vkd3d-shader/hlsl: Fold constant not-equal expressions.

[Francisco Casas]

Hello,

March 23, 2022 11:28 AM, "Giovanni Mascellani"  wrote:
> Signed-off-by: Giovanni Mascellani
>
> libs/vkd3d-shader/hlsl_constant_ops.c | 41 +++++++++++++++++++++++++++
> 1 file changed, 41 insertions(+)
>
> diff --git a/libs/vkd3d-shader/hlsl_constant_ops.c b/libs/vkd3d-shader/hlsl_constant_ops.c
> index 6c852ba1..2f090863 100644
> --- a/libs/vkd3d-shader/hlsl_constant_ops.c
> +++ b/libs/vkd3d-shader/hlsl_constant_ops.c
> @@ -224,6 +224,43 @@ static bool fold_mul(struct hlsl_ctx *ctx, struct hlsl_ir_constant *dst,
> return true;
> }
>
> +static bool fold_nequal(struct hlsl_ctx *ctx, struct hlsl_ir_constant *dst,
> - struct hlsl_ir_constant *src1, struct hlsl_ir_constant *src2)
>
> +{
> - enum hlsl_base_type type = dst->node.data_type->base_type;
> -
> - assert(type == HLSL_TYPE_BOOL);
> - assert(src1->node.data_type->base_type == src2->node.data_type->base_type);
> -
> - for (int k = 0; k < 4; ++k)
> - {
> - switch (src1->node.data_type->base_type)
> - {
> - case HLSL_TYPE_FLOAT:
> - case HLSL_TYPE_HALF:
> - dst->value[k].b = src1->value[k].f != src2->value[k].f;
> - break;
> -
> - case HLSL_TYPE_DOUBLE:
> - dst->value[k].b = src1->value[k].d != src2->value[k].d;
> - break;
> -
> - case HLSL_TYPE_INT:
> - case HLSL_TYPE_UINT:
> - case HLSL_TYPE_BOOL:
> - dst->value[k].b = src1->value[k].u != src2->value[k].u;

I am not so sure we can compare bools using .u, since sizeof(bool) is 1.
The next 3 bytes may not be initialized.
(more probably now that we have hlsl_new_constant()).
> - break;
> -
> - default:
> - FIXME("Fold not-equal for type %s.\n", debug_hlsl_type(ctx, dst->node.data_type));
> - return false;
> - }
> -
> - dst->value[k].b *= ~0u;
> - }
> - return true;
>
> +}
> -
>
> bool hlsl_fold_constants(struct hlsl_ctx *ctx, struct hlsl_ir_node *instr, void *context)
> {
> struct hlsl_ir_constant *arg1, *arg2 = NULL, *res;
> @@ -266,6 +303,10 @@ bool hlsl_fold_constants(struct hlsl_ctx *ctx, struct hlsl_ir_node *instr,
> void
> success = fold_mul(ctx, res, arg1, arg2);
> break;
> - case HLSL_OP2_NEQUAL:
> - success = fold_nequal(ctx, res, arg1, arg2);
> - break;
> -
>
> default:
> FIXME("Fold "%s" expression.\n", debug_hlsl_expr_op(expr->op));
> success = false;
> -- 
> 2.35.1

Best regards,
Francisco.