+/*
+ * for evergreen we need to scan the shader to find the number of GPRs we need to
+ * reserve for interpolation.
+ *
+ * we need to know if we are going to emit
+ * any centroid inputs
+ * if perspective and linear are required
+*/
+static int evergreen_gpr_count(struct r600_shader_ctx *ctx)
+{
+ int i;
+ int num_baryc;
+
+ ctx->input_linear = FALSE;
+ ctx->input_perspective = FALSE;
+ ctx->input_centroid = FALSE;
+ ctx->num_interp_gpr = 1;
+
+ /* any centroid inputs */
+ for (i = 0; i < ctx->info.num_inputs; i++) {
+ /* skip position/face */
+ if (ctx->info.input_semantic_name[i] == TGSI_SEMANTIC_POSITION ||
+ ctx->info.input_semantic_name[i] == TGSI_SEMANTIC_FACE)
+ continue;
+ if (ctx->info.input_interpolate[i] == TGSI_INTERPOLATE_LINEAR)
+ ctx->input_linear = TRUE;
+ if (ctx->info.input_interpolate[i] == TGSI_INTERPOLATE_PERSPECTIVE)
+ ctx->input_perspective = TRUE;
+ if (ctx->info.input_centroid[i])
+ ctx->input_centroid = TRUE;
+ }
+
+ num_baryc = 0;
+ /* ignoring sample for now */
+ if (ctx->input_perspective)
+ num_baryc++;
+ if (ctx->input_linear)
+ num_baryc++;
+ if (ctx->input_centroid)
+ num_baryc *= 2;
+
+ ctx->num_interp_gpr += (num_baryc + 1) >> 1;
+
+ /* TODO PULL MODEL and LINE STIPPLE, FIXED PT POS */
+ return ctx->num_interp_gpr;
+}
+