radv: Don't use a divide by index_size.

Divides are pretty slow, and this is in the hot path of a draw.

Signed-off-by: Bas Nieuwenhuizen <basni@google.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>

diff --git a/src/amd/vulkan/radv_cmd_buffer.c b/src/amd/vulkan/radv_cmd_buffer.c
index c91c7b918801c41ad86dfabe2fba2de70ec5ca97..ed0aa8020cef81555d3467d98b0bbbd98684fe28 100644 (file)
--- a/src/amd/vulkan/radv_cmd_buffer.c
+++ b/src/amd/vulkan/radv_cmd_buffer.c
@@ -2643,6 +2643,12 @@ void radv_CmdDraw(
        radv_cmd_buffer_trace_emit(cmd_buffer);
 }
 
+static
+uint32_t radv_get_max_index_count(struct radv_cmd_buffer *cmd_buffer) {
+       int index_size_shift = cmd_buffer->state.index_type ? 2 : 1;
+       return (cmd_buffer->state.index_buffer->size - cmd_buffer->state.index_offset) >> index_size_shift;
+}
+
 void radv_CmdDrawIndexed(
        VkCommandBuffer                             commandBuffer,
        uint32_t                                    indexCount,
@@ -2653,7 +2659,7 @@ void radv_CmdDrawIndexed(
 {
        RADV_FROM_HANDLE(radv_cmd_buffer, cmd_buffer, commandBuffer);
        int index_size = cmd_buffer->state.index_type ? 4 : 2;
-       uint32_t index_max_size = (cmd_buffer->state.index_buffer->size - cmd_buffer->state.index_offset) / index_size;
+       uint32_t index_max_size = radv_get_max_index_count(cmd_buffer);
        uint64_t index_va;
 
        radv_cmd_buffer_flush_state(cmd_buffer, true, (instanceCount > 1), false, indexCount);
@@ -2789,8 +2795,7 @@ radv_cmd_draw_indexed_indirect_count(
        uint32_t                                    stride)
 {
        RADV_FROM_HANDLE(radv_cmd_buffer, cmd_buffer, commandBuffer);
-       int index_size = cmd_buffer->state.index_type ? 4 : 2;
-       uint32_t index_max_size = (cmd_buffer->state.index_buffer->size - cmd_buffer->state.index_offset) / index_size;
+       uint32_t index_max_size = radv_get_max_index_count(cmd_buffer);
        uint64_t index_va;
        radv_cmd_buffer_flush_state(cmd_buffer, true, false, true, 0);