[Mesa-dev] [PATCH] i965: Print input/output VUE maps on INTEL_DEBUG=vs, gs.

[Kenneth Graunke]

I've been carrying around a patch to do this for the last few months,
and it's been exceedingly useful for debugging GS and tessellation
problems.  I've caught lots of bugs by inspecting the interface
expectations of two adjacent stages.

It's not that much spam, so I figure we may as well just print it.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
 src/mesa/drivers/dri/i965/brw_compiler.h          |  2 ++
 src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp |  6 +++++
 src/mesa/drivers/dri/i965/brw_vs.c                |  6 ++++-
 src/mesa/drivers/dri/i965/brw_vue_map.c           | 27 +++++++++++++++++++++++
 4 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/src/mesa/drivers/dri/i965/brw_compiler.h b/src/mesa/drivers/dri/i965/brw_compiler.h
index f022f38..e3a26d6 100644
--- a/src/mesa/drivers/dri/i965/brw_compiler.h
+++ b/src/mesa/drivers/dri/i965/brw_compiler.h
@@ -458,6 +458,8 @@ struct brw_vue_map {
    int num_slots;
 };
 
+void brw_print_vue_map(FILE *fp, const struct brw_vue_map *vue_map);
+
 /**
  * Convert a VUE slot number into a byte offset within the VUE.
  */
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp
index 49c1083..1a09f76 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp
@@ -812,6 +812,12 @@ brw_compile_gs(const struct brw_compiler *compiler, void *log_data,
    /* Now that prog_data setup is done, we are ready to actually compile the
     * program.
     */
+   if (unlikely(INTEL_DEBUG & DEBUG_GS)) {
+      fprintf(stderr, "GS Input ");
+      brw_print_vue_map(stderr, &c.input_vue_map);
+      fprintf(stderr, "GS Output ");
+      brw_print_vue_map(stderr, &prog_data->base.vue_map);
+   }
 
    if (compiler->scalar_gs) {
       /* TODO: Support instanced GS.  We have basically no tests... */
diff --git a/src/mesa/drivers/dri/i965/brw_vs.c b/src/mesa/drivers/dri/i965/brw_vs.c
index 0b805b1..967448e 100644
--- a/src/mesa/drivers/dri/i965/brw_vs.c
+++ b/src/mesa/drivers/dri/i965/brw_vs.c
@@ -159,9 +159,13 @@ brw_codegen_vs_prog(struct brw_context *brw,
       start_time = get_time();
    }
 
-   if (unlikely(INTEL_DEBUG & DEBUG_VS))
+   if (unlikely(INTEL_DEBUG & DEBUG_VS)) {
       brw_dump_ir("vertex", prog, vs ? &vs->base : NULL, &vp->program.Base);
 
+      fprintf(stderr, "VS Output ");
+      brw_print_vue_map(stderr, &prog_data.base.vue_map);
+   }
+
    int st_index = -1;
    if (INTEL_DEBUG & DEBUG_SHADER_TIME)
       st_index = brw_get_shader_time_index(brw, prog, &vp->program.Base, ST_VS);
diff --git a/src/mesa/drivers/dri/i965/brw_vue_map.c b/src/mesa/drivers/dri/i965/brw_vue_map.c
index 45662bd..edb1608 100644
--- a/src/mesa/drivers/dri/i965/brw_vue_map.c
+++ b/src/mesa/drivers/dri/i965/brw_vue_map.c
@@ -178,3 +178,30 @@ brw_compute_vue_map(const struct brw_device_info *devinfo,
 
    vue_map->num_slots = separate ? slot + 1 : slot;
 }
+
+static const char *
+varying_name(brw_varying_slot slot)
+{
+   if (slot < VARYING_SLOT_MAX)
+      return gl_varying_slot_name(slot);
+
+   static const char *brw_names[] = {
+      [BRW_VARYING_SLOT_NDC - VARYING_SLOT_MAX] = "BRW_VARYING_SLOT_NDC",
+      [BRW_VARYING_SLOT_PAD - VARYING_SLOT_MAX] = "BRW_VARYING_SLOT_PAD",
+      [BRW_VARYING_SLOT_PNTC - VARYING_SLOT_MAX] = "BRW_VARYING_SLOT_PNTC",
+   };
+
+   return brw_names[slot - VARYING_SLOT_MAX];
+}
+
+void
+brw_print_vue_map(FILE *fp, const struct brw_vue_map *vue_map)
+{
+   fprintf(fp, "VUE map (%d slots, %s)\n",
+           vue_map->num_slots, vue_map->separate ? "SSO" : "non-SSO");
+   for (int i = 0; i < vue_map->num_slots; i++) {
+      fprintf(fp, "  [%d] %s\n", i,
+              varying_name(vue_map->slot_to_varying[i]));
+   }
+   fprintf(fp, "\n");
+}
-- 
2.6.2