i965/sbe: fix number of inputs for active components

In 16631ca30ea6 we fixed gen9 active components to account for padded
inputs in the URB, which we can have with SSO programs. To do that,
instead of going through the bitfield of inputs (which doesn't include
padding information), we compute the number of inputs from the size
of the URB entry.

Unfortunately, there are some special inputs that are not stored in
the URB and that we also need to account for. These special inputs
are identified and handled during calculate_attr_overrides().

Instead of keeping track of the exact number of inputs, we just
program active components for all possible inputs like we do in
anvil.

This fixes a regression in a WebGL program that uses Point Sprite
functionality (specifically, VARYING_SLOT_PNTC).

v2:
 - Add 'Fixes' tag (Mark Janes)
 - make no_vue_inputs int instead of uint32_t, and add const qualifier
   to num_inputs variable (Ian)

v3:
 - Do not try to count inputs correctly, just program all input
   slots like we do in anvil (Ken)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105224
Fixes: 16631ca30ea6 (i965/sbe: fix active components for SSO programs with over 16 inputs)
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
(cherry picked from commit bc73016703f8f2815e000f1c100532cf6e13cd3c)

1 files changed, 2 insertions, 4 deletions

diff --git a/src/mesa/drivers/dri/i965/genX_state_upload.c b/src/mesa/drivers/dri/i965/genX_state_upload.c
index 28bb4af2ab8..05b2d5def39 100644
--- a/src/mesa/drivers/dri/i965/genX_state_upload.c
+++ b/src/mesa/drivers/dri/i965/genX_state_upload.c
@@ -3473,10 +3473,8 @@ genX(upload_sbe)(struct brw_context *brw)
 
 #if GEN_GEN >= 9
       /* prepare the active component dwords */
-      const int num_inputs = urb_entry_read_length * 2;
-      for (int input_index = 0; input_index < num_inputs; input_index++) {
-         sbe.AttributeActiveComponentFormat[input_index] = ACTIVE_COMPONENT_XYZW;
-      }
+      for (int i = 0; i < 32; i++)
+         sbe.AttributeActiveComponentFormat[i] = ACTIVE_COMPONENT_XYZW;
 #endif
    }