[PATCH vkd3d 3/5] vkd3d-shader: Implement multiplication and division.

[Matteo Bruni]

On Mon, Jan 18, 2021 at 10:34 PM Zebediah Figura
<zfigura at codeweavers.com> wrote:
>
> Signed-off-by: Zebediah Figura <zfigura at codeweavers.com>
> ---
>  libs/vkd3d-shader/preproc.l |  2 +-
>  libs/vkd3d-shader/preproc.y | 24 ++++++++++++++++++++++--
>  2 files changed, 23 insertions(+), 3 deletions(-)
>
> diff --git a/libs/vkd3d-shader/preproc.l b/libs/vkd3d-shader/preproc.l
> index 011f8dbb..a522b7c8 100644
> --- a/libs/vkd3d-shader/preproc.l
> +++ b/libs/vkd3d-shader/preproc.l
> @@ -157,7 +157,7 @@ IDENTIFIER      [A-Za-z_][A-Za-z0-9_]*
>      }
>
>  <INITIAL>{WS}+                      {}
> -<INITIAL>[-()\[\]{},+!]             {return yytext[0];}
> +<INITIAL>[-()\[\]{},+!*/]           {return yytext[0];}
>  <INITIAL>.                          {return T_TEXT;}
>
>  %%
> diff --git a/libs/vkd3d-shader/preproc.y b/libs/vkd3d-shader/preproc.y
> index 51df5d40..1060e9d7 100644
> --- a/libs/vkd3d-shader/preproc.y
> +++ b/libs/vkd3d-shader/preproc.y
> @@ -335,6 +335,7 @@ static void free_parse_arg_names(struct parse_arg_names *args)
>
>  %type <integer> primary_expr
>  %type <integer> unary_expr
> +%type <integer> mul_expr
>  %type <string> body_token
>  %type <const_string> body_token_const
>  %type <string_buffer> body_text
> @@ -439,6 +440,14 @@ body_token_const
>          {
>              $$ = "!";
>          }
> +    | '*'
> +        {
> +            $$ = "*";
> +        }
> +    | '/'
> +        {
> +            $$ = "/";
> +        }
>      | T_CONCAT
>          {
>              $$ = "##";
> @@ -480,7 +489,7 @@ directive
>              }
>              vkd3d_free($2);
>          }
> -    | T_IF unary_expr T_NEWLINE
> +    | T_IF mul_expr T_NEWLINE
>          {
>              if (!preproc_push_if(ctx, !!$2))
>                  YYABORT;
> @@ -495,7 +504,7 @@ directive
>              preproc_push_if(ctx, !preproc_find_macro(ctx, $2));
>              vkd3d_free($2);
>          }
> -    | T_ELIF unary_expr T_NEWLINE
> +    | T_ELIF mul_expr T_NEWLINE
>          {
>              const struct preproc_file *file = preproc_get_top_file(ctx);
>
> @@ -631,3 +640,14 @@ unary_expr
>          {
>              $$ = !$2;
>          }
> +
> +mul_expr
> +    : unary_expr
> +    | mul_expr '*' unary_expr
> +        {
> +            $$ = $1 * $3;
> +        }
> +    | mul_expr '/' unary_expr
> +        {
> +            $$ = $1 / $3;
> +        }

I don't know that we care but notice that e.g. "#if 1 / 0" causes a
floating point exception.