[Mesa-dev] [PATCH] nir/algebraic: Don't emit empty initializers for MSVC

[Brian Paul]

On 05/02/2019 02:34 PM, Connor Abbott wrote:
> Just don't emit the transform array at all if there are no transforms
> for a state, and avoid trying to walk over it.
> ---
> Brian, does this build on Windows? I tested it on my shader-db
> on radeonsi.

Yes, it compiles.  Thanks!

Tested-by: Brian Paul <brianp at vmware.com>

Though it looks like Dylan had some suggestions.

-Brian

> 
> ---
>   src/compiler/nir/nir_algebraic.py | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/src/compiler/nir/nir_algebraic.py b/src/compiler/nir/nir_algebraic.py
> index 6db749e9248..7af80a4f92e 100644
> --- a/src/compiler/nir/nir_algebraic.py
> +++ b/src/compiler/nir/nir_algebraic.py
> @@ -993,11 +993,13 @@ static const uint16_t CONST_STATE = 1;
>   % endfor
>   
>   % for state_id, state_xforms in enumerate(automaton.state_patterns):
> +% if len(state_xforms) > 0: # avoid emitting a 0-length array for MSVC
>   static const struct transform ${pass_name}_state${state_id}_xforms[] = {
>   % for i in state_xforms:
>     { ${xforms[i].search.c_ptr(cache)}, ${xforms[i].replace.c_value_ptr(cache)}, ${xforms[i].condition_index} },
>   % endfor
>   };
> +% endif
>   % endfor
>   
>   static const struct per_op_table ${pass_name}_table[nir_num_search_ops] = {
> @@ -1080,7 +1082,8 @@ ${pass_name}_block(nir_builder *build, nir_block *block,
>         switch (states[alu->dest.dest.ssa.index]) {
>   % for i in range(len(automaton.state_patterns)):
>         case ${i}:
> -         for (unsigned i = 0; i < ARRAY_SIZE(${pass_name}_state${i}_xforms); i++) {
> +         % if len(automaton.state_patterns[i]) > 0:
> +         for (unsigned i = 0; i < ${len(automaton.state_patterns[i])}; i++) {
>               const struct transform *xform = &${pass_name}_state${i}_xforms[i];
>               if (condition_flags[xform->condition_offset] &&
>                   nir_replace_instr(build, alu, xform->search, xform->replace)) {
> @@ -1088,6 +1091,7 @@ ${pass_name}_block(nir_builder *build, nir_block *block,
>                  break;
>               }
>            }
> +         % endif
>            break;
>   % endfor
>         default: assert(0);
>