r600g: lower stream outputs with dst_offset < start_component

This fixes streamout breakage caused by the varying packing.

Reviewed-by: Dave Airlie <airlied@redhat.com>

diff --git a/src/gallium/drivers/r600/r600_shader.c b/src/gallium/drivers/r600/r600_shader.c
index 0ffa1fa..55b5db3 100644 (file)
--- a/src/gallium/drivers/r600/r600_shader.c
+++ b/src/gallium/drivers/r600/r600_shader.c
@@ -1530,23 +1530,63 @@ static int r600_shader_from_tgsi(struct r600_screen *rscreen,
 
        /* Add stream outputs. */
        if (ctx.type == TGSI_PROCESSOR_VERTEX && so.num_outputs) {
-               for (i = 0; i < so.num_outputs; i++) {
-                       struct r600_bytecode_output output;
+               unsigned so_gpr[PIPE_MAX_SHADER_OUTPUTS];
 
+               /* Sanity checking. */
+               if (so.num_outputs > PIPE_MAX_SHADER_OUTPUTS) {
+                       R600_ERR("Too many stream outputs: %d\n", so.num_outputs);
+                       r = -EINVAL;
+                       goto out_err;
+               }
+               for (i = 0; i < so.num_outputs; i++) {
                        if (so.output[i].output_buffer >= 4) {
-                               R600_ERR("exceeded the max number of stream output buffers, got: %d\n",
+                               R600_ERR("Exceeded the max number of stream output buffers, got: %d\n",
                                         so.output[i].output_buffer);
                                r = -EINVAL;
                                goto out_err;
                        }
+               }
+
+               /* Initialize locations where the outputs are stored. */
+               for (i = 0; i < so.num_outputs; i++) {
+                       so_gpr[i] = shader->output[so.output[i].register_index].gpr;
+
+                       /* Lower outputs with dst_offset < start_component.
+                        *
+                        * We can only output 4D vectors with a write mask, e.g. we can
+                        * only output the W component at offset 3, etc. If we want
+                        * to store Y, Z, or W at buffer offset 0, we need to use MOV
+                        * to move it to X and output X. */
                        if (so.output[i].dst_offset < so.output[i].start_component) {
-                          R600_ERR("stream_output - dst_offset cannot be less than start_component\n");
-                          r = -EINVAL;
-                          goto out_err;
+                               unsigned tmp = r600_get_temp(&ctx);
+
+                               for (j = 0; j < so.output[i].num_components; j++) {
+                                       struct r600_bytecode_alu alu;
+                                       memset(&alu, 0, sizeof(struct r600_bytecode_alu));
+                                       alu.inst = BC_INST(ctx.bc, V_SQ_ALU_WORD1_OP2_SQ_OP2_INST_MOV);
+                                       alu.src[0].sel = so_gpr[i];
+                                       alu.src[0].chan = so.output[i].start_component + j;
+
+                                       alu.dst.sel = tmp;
+                                       alu.dst.chan = j;
+                                       alu.dst.write = 1;
+                                       if (j == so.output[i].num_components - 1)
+                                               alu.last = 1;
+                                       r = r600_bytecode_add_alu(ctx.bc, &alu);
+                                       if (r)
+                                               return r;
+                               }
+                               so.output[i].start_component = 0;
+                               so_gpr[i] = tmp;
                        }
+               }
+
+               /* Write outputs to buffers. */
+               for (i = 0; i < so.num_outputs; i++) {
+                       struct r600_bytecode_output output;
 
                        memset(&output, 0, sizeof(struct r600_bytecode_output));
-                       output.gpr = shader->output[so.output[i].register_index].gpr;
+                       output.gpr = so_gpr[i];
                        output.elem_size = 0;
                        output.array_base = so.output[i].dst_offset - so.output[i].start_component;
                        output.type = V_SQ_CF_ALLOC_EXPORT_WORD0_SQ_EXPORT_WRITE;