4 files changed, 11 insertions, 0 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_context.h b/src/mesa/drivers/dri/i965/brw_context.h
index 494693c..5e66567 100644
--- a/src/mesa/drivers/dri/i965/brw_context.h
+++ b/src/mesa/drivers/dri/i965/brw_context.h
@@ -588,6 +588,8 @@ struct brw_gs_prog_data
     * Ignored if control_data_header_size is 0.
     */
    unsigned control_data_format;
+
+   bool include_primitive_id;
 };
 
 /** Number of texture sampler units */
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_gs.c b/src/mesa/drivers/dri/i965/brw_vec4_gs.c
index c526107..30989c3 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_gs.c
+++ b/src/mesa/drivers/dri/i965/brw_vec4_gs.c
@@ -45,6 +45,9 @@ do_gs_prog(struct brw_context *brw,
    c.key = *key;
    c.gp = gp;
 
+   c.prog_data.include_primitive_id =
+      (gp->program.Base.InputsRead & VARYING_BIT_PRIMITIVE_ID) != 0;
+
    /* Allocate the references to the uniforms that will end up in the
     * prog_data associated with the compiled program, and which will be freed
     * by the state cache.
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 cb7de8d..2d3a058 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_gs_visitor.cpp
@@ -102,6 +102,10 @@ vec4_gs_visitor::setup_payload()
     */
    reg++;
 
+   /* If the shader uses gl_PrimitiveIDIn, that goes in r1. */
+   if (c->prog_data.include_primitive_id)
+      attribute_map[VARYING_SLOT_PRIMITIVE_ID] = reg++;
+
    reg = setup_uniforms(reg);
 
    reg = setup_varying_inputs(reg, attribute_map);
diff --git a/src/mesa/drivers/dri/i965/gen7_gs_state.c b/src/mesa/drivers/dri/i965/gen7_gs_state.c
index 231e3c9..4f18485 100644
--- a/src/mesa/drivers/dri/i965/gen7_gs_state.c
+++ b/src/mesa/drivers/dri/i965/gen7_gs_state.c
@@ -111,6 +111,8 @@ upload_gs_state(struct brw_context *brw)
           GEN7_GS_CONTROL_DATA_HEADER_SIZE_SHIFT) |
          GEN7_GS_DISPATCH_MODE_DUAL_OBJECT |
          GEN6_GS_STATISTICS_ENABLE |
+         (brw->gs.prog_data->include_primitive_id ?
+          GEN7_GS_INCLUDE_PRIMITIVE_ID : 0) |
          GEN7_GS_ENABLE;
 
       if (brw->is_haswell) {