[Mesa-dev] [PATCH] nir/search: Save/restore the variables_seen bitmask when matching

[Connor Abbott]

On Fri, May 8, 2015 at 2:53 PM, Jason Ekstrand <jason at jlekstrand.net> wrote:
> total instructions in shared programs: 7152330 -> 7137006 (-0.21%)
> instructions in affected programs:     1330548 -> 1315224 (-1.15%)
> helped:                                5797
> HURT:                                  76
> GAINED:                                0
> LOST:                                  8
> ---
>  src/glsl/nir/nir_search.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/src/glsl/nir/nir_search.c b/src/glsl/nir/nir_search.c
> index d86655b..4c83349 100644
> --- a/src/glsl/nir/nir_search.c
> +++ b/src/glsl/nir/nir_search.c
> @@ -199,6 +199,10 @@ match_expression(const nir_search_expression *expr, nir_alu_instr *instr,
>        }
>     }
>
> +   /* Stash off the current variables_seen bitmask.  This way we can
> +    * restore it prior to matching in the commutative case below. */

Puth the */ on the next line, and this is

Reviewed-by: Connor Abbott <cwabbott0 at gmail.com>

> +   unsigned variables_seen_stash = state->variables_seen;
> +
>     bool matched = true;
>     for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) {
>        /* If the source is an explicitly sized source, then we need to reset
> @@ -221,6 +225,13 @@ match_expression(const nir_search_expression *expr, nir_alu_instr *instr,
>
>     if (nir_op_infos[instr->op].algebraic_properties & NIR_OP_IS_COMMUTATIVE) {
>        assert(nir_op_infos[instr->op].num_inputs == 2);
> +
> +      /* Restore the variables_seen bitmask.  If we don't do this, then we
> +       * could end up with an erroneous failure due to variables found in the
> +       * first match attempt above not matching those in the second.
> +       */
> +      state->variables_seen = variables_seen_stash;
> +
>        if (!match_value(expr->srcs[0], instr, 1, num_components,
>                         swizzle, state))
>           return false;
> --
> 2.4.0
>
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/mesa-dev