zink: fix implicit feedback loop detection

the code here was all expecting the VkPipelineStageFlags bitfield expansions,
but u_foreach_bit() gives the actual bit, so implicit feedback loops were never
actually being detected

instead, convert back to the bitfield at the top of the loop so the value works
as expected

Fixes: 9ba06579035 ("zink: make implicit feedback loop application stricter")
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20863>

diff --git a/src/gallium/drivers/zink/zink_draw.cpp b/src/gallium/drivers/zink/zink_draw.cpp
index a26eb98..29b3b13 100644 (file)
--- a/src/gallium/drivers/zink/zink_draw.cpp
+++ b/src/gallium/drivers/zink/zink_draw.cpp
@@ -288,10 +288,11 @@ add_implicit_color_feedback_loop(struct zink_context *ctx, struct zink_resource
    bool is_feedback = false;
    /* avoid false positives when a texture is bound but not used */
    u_foreach_bit(vkstage, res->gfx_barrier) {
-      if (vkstage < VK_PIPELINE_STAGE_VERTEX_SHADER_BIT || vkstage > VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT)
+      VkPipelineStageFlags vkstagebit = BITFIELD_BIT(vkstage);
+      if (vkstagebit < VK_PIPELINE_STAGE_VERTEX_SHADER_BIT || vkstagebit > VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT)
          continue;
       /* in-range VkPipelineStageFlagBits can be converted to VkShaderStageFlags with a bitshift */
-      gl_shader_stage stage = vk_to_mesa_shader_stage((VkShaderStageFlagBits)(vkstage >> 3));
+      gl_shader_stage stage = vk_to_mesa_shader_stage((VkShaderStageFlagBits)(vkstagebit >> 3));
       /* check shader texture usage against resource's sampler binds */
       if ((ctx->gfx_stages[stage] && (res->sampler_binds[stage] & ctx->gfx_stages[stage]->nir->info.textures_used[0])))
          is_feedback = true;