etnaviv: Extend compiler for MRTs

We will see multiple fragment outputs when MRTs are used. Keep
track of the registers for the outputs.

Signed-off-by: Christian Gmeiner <cgmeiner@igalia.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/26565>

src/gallium/drivers/etnaviv/etnaviv_compiler.h

@@ -120,7 +120,7 @@ struct etna_shader_variant {
    uint32_t vs_load_balancing;
 
    /* special outputs (ps only) */
-   int ps_color_out_reg; /* color output register */
+   int ps_color_out_reg[PIPE_MAX_COLOR_BUFS]; /* color output register */
    int ps_depth_out_reg; /* depth output register */
 
    /* unknown input property (XX_INPUT_COUNT, field UNK8) */

src/gallium/drivers/etnaviv/etnaviv_compiler_nir.c

@@ -105,7 +105,14 @@ etna_emit_output(struct etna_compile *c, nir_variable *var, struct etna_inst_src
    if (is_fs(c)) {
       switch (var->data.location) {
       case FRAG_RESULT_DATA0:
-         c->variant->ps_color_out_reg = src.reg;
+      case FRAG_RESULT_DATA1:
+      case FRAG_RESULT_DATA2:
+      case FRAG_RESULT_DATA3:
+      case FRAG_RESULT_DATA4:
+      case FRAG_RESULT_DATA5:
+      case FRAG_RESULT_DATA6:
+      case FRAG_RESULT_DATA7:
+         c->variant->ps_color_out_reg[var->data.location - FRAG_RESULT_DATA0] = src.reg;
          break;
       case FRAG_RESULT_DEPTH:
          c->variant->ps_depth_out_reg = src.reg;
@@ -1141,7 +1148,6 @@ etna_compile_shader(struct etna_shader_variant *v)
    v->vs_id_in_reg = -1;
    v->vs_pos_out_reg = -1;
    v->vs_pointsize_out_reg = -1;
-   v->ps_color_out_reg = 0; /* 0 for shader that doesn't write fragcolor.. */
    v->ps_depth_out_reg = -1;
 
    if (s->info.stage == MESA_SHADER_FRAGMENT)

src/gallium/drivers/etnaviv/etnaviv_shader.c

@@ -100,7 +100,9 @@ etna_dump_shader(const struct etna_shader_variant *shader)
       printf("  vs_pointsize_out_reg=%i\n", shader->vs_pointsize_out_reg);
       printf("  vs_load_balancing=0x%08x\n", shader->vs_load_balancing);
    } else {
-      printf("  ps_color_out_reg=%i\n", shader->ps_color_out_reg);
+      for (int idx = 0; idx < ARRAY_SIZE(shader->ps_color_out_reg); idx++)
+         printf("  ps_color_out_reg[%u]=%i\n", idx, shader->ps_color_out_reg[idx]);
+
       printf("  ps_depth_out_reg=%i\n", shader->ps_depth_out_reg);
    }
    printf("  input_count_unk8=0x%08x\n", shader->input_count_unk8);
@@ -188,7 +190,19 @@ etna_link_shaders(struct etna_context *ctx, struct compiled_shader_state *cs,
    cs->VS_START_PC = 0;
 
    cs->PS_END_PC = fs->code_size / 4;
-   cs->PS_OUTPUT_REG[0] = fs->ps_color_out_reg;
+
+   cs->PS_OUTPUT_REG[0] =
+      VIVS_PS_OUTPUT_REG_0(fs->ps_color_out_reg[0]) |
+      VIVS_PS_OUTPUT_REG_1(fs->ps_color_out_reg[1]) |
+      VIVS_PS_OUTPUT_REG_2(fs->ps_color_out_reg[2]) |
+      VIVS_PS_OUTPUT_REG_3(fs->ps_color_out_reg[3]);
+
+   cs->PS_OUTPUT_REG[1] =
+      VIVS_PS_OUTPUT_REG2_4(fs->ps_color_out_reg[4]) |
+      VIVS_PS_OUTPUT_REG2_5(fs->ps_color_out_reg[5]) |
+      VIVS_PS_OUTPUT_REG2_6(fs->ps_color_out_reg[6]) |
+      VIVS_PS_OUTPUT_REG2_7(fs->ps_color_out_reg[7]);
+
    cs->PS_INPUT_COUNT =
       VIVS_PS_INPUT_COUNT_COUNT(link.num_varyings + 1) | /* Number of inputs plus position */
       VIVS_PS_INPUT_COUNT_UNK8(fs->input_count_unk8);