radeonsi/gfx10: separate code for determining the number of vertices for NGG

Reviewed-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>

diff --git a/src/gallium/drivers/radeonsi/gfx10_shader_ngg.c b/src/gallium/drivers/radeonsi/gfx10_shader_ngg.c
index 0eb422a..afb9ad3 100644 (file)
--- a/src/gallium/drivers/radeonsi/gfx10_shader_ngg.c
+++ b/src/gallium/drivers/radeonsi/gfx10_shader_ngg.c
@@ -83,6 +83,46 @@ static LLVMValueRef ngg_get_initial_edgeflag(struct si_shader_context *ctx, unsi
        return ctx->i1false;
 }
 
+/**
+ * Return the number of vertices as a constant in \p num_vertices,
+ * and return a more precise value as LLVMValueRef from the function.
+ */
+static LLVMValueRef ngg_get_vertices_per_prim(struct si_shader_context *ctx,
+                                             unsigned *num_vertices)
+{
+       const struct si_shader_info *info = &ctx->shader->selector->info;
+
+       if (ctx->type == PIPE_SHADER_VERTEX) {
+               if (info->properties[TGSI_PROPERTY_VS_BLIT_SGPRS_AMD]) {
+                       /* Blits always use axis-aligned rectangles with 3 vertices. */
+                       *num_vertices = 3;
+                       return LLVMConstInt(ctx->i32, 3, 0);
+               } else {
+                       /* We always build up all three indices for the prim export
+                        * independent of the primitive type. The additional garbage
+                        * data shouldn't hurt. This number doesn't matter with
+                        * NGG passthrough.
+                        */
+                       *num_vertices = 3;
+
+                       /* Extract OUTPRIM field. */
+                       LLVMValueRef num = si_unpack_param(ctx, ctx->vs_state_bits, 2, 2);
+                       return LLVMBuildAdd(ctx->ac.builder, num, ctx->i32_1, "");
+               }
+       } else {
+               assert(ctx->type == PIPE_SHADER_TESS_EVAL);
+
+               if (info->properties[TGSI_PROPERTY_TES_POINT_MODE])
+                       *num_vertices = 1;
+               else if (info->properties[TGSI_PROPERTY_TES_PRIM_MODE] == PIPE_PRIM_LINES)
+                       *num_vertices = 2;
+               else
+                       *num_vertices = 3;
+
+               return LLVMConstInt(ctx->i32, *num_vertices, false);
+       }
+}
+
 static void build_streamout_vertex(struct si_shader_context *ctx,
                                   LLVMValueRef *so_buffer, LLVMValueRef *wg_offset_dw,
                                   unsigned stream, LLVMValueRef offset_vtx,
@@ -532,31 +572,7 @@ void gfx10_emit_ngg_epilogue(struct ac_shader_abi *abi,
 
        /* Determine the number of vertices per primitive. */
        unsigned num_vertices;
-       LLVMValueRef num_vertices_val;
-
-       if (ctx->type == PIPE_SHADER_VERTEX) {
-               if (info->properties[TGSI_PROPERTY_VS_BLIT_SGPRS_AMD]) {
-                       /* Blits always use axis-aligned rectangles with 3 vertices. */
-                       num_vertices = 3;
-                       num_vertices_val = LLVMConstInt(ctx->i32, 3, 0);
-               } else {
-                       /* Extract OUTPRIM field. */
-                       tmp = si_unpack_param(ctx, ctx->vs_state_bits, 2, 2);
-                       num_vertices_val = LLVMBuildAdd(builder, tmp, ctx->i32_1, "");
-                       num_vertices = 3; /* TODO: optimize for points & lines */
-               }
-       } else {
-               assert(ctx->type == PIPE_SHADER_TESS_EVAL);
-
-               if (info->properties[TGSI_PROPERTY_TES_POINT_MODE])
-                       num_vertices = 1;
-               else if (info->properties[TGSI_PROPERTY_TES_PRIM_MODE] == PIPE_PRIM_LINES)
-                       num_vertices = 2;
-               else
-                       num_vertices = 3;
-
-               num_vertices_val = LLVMConstInt(ctx->i32, num_vertices, false);
-       }
+       LLVMValueRef num_vertices_val = ngg_get_vertices_per_prim(ctx, &num_vertices);
 
        /* Streamout */
        LLVMValueRef emitted_prims = NULL;