From: Dave Airlie <airlied@redhat.com>
Date: Tue, 3 Dec 2019 03:42:03 +0000 (+1000)
Subject: gallivm: fix perspective enable if usage_mask doesn't have 0 bit set
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=63b3d38a505d18e3aa1bea3ed4e8b994273b557e;p=mesa.git

gallivm: fix perspective enable if usage_mask doesn't have 0 bit set

The current code looks like a typo, and fails if the usage_mask
is for a y/z enabled input.

Fixes piglit ext_transform_feedback-immediate-reuse-index-buffer
with llvmpipe/nir

Reviewed-by: Roland Scheidegger <sroland@vmware.com>
---

diff --git a/src/gallium/drivers/llvmpipe/lp_setup_point.c b/src/gallium/drivers/llvmpipe/lp_setup_point.c
index 073ca5b1c88..092febdba92 100644
--- a/src/gallium/drivers/llvmpipe/lp_setup_point.c
+++ b/src/gallium/drivers/llvmpipe/lp_setup_point.c
@@ -224,10 +224,10 @@ setup_point_coefficients( struct lp_setup_context *setup,
       boolean perspective = !!(interp == LP_INTERP_PERSPECTIVE);
       unsigned i;
 
-      if (perspective & usage_mask) {
+      if (perspective && usage_mask) {
          fragcoord_usage_mask |= TGSI_WRITEMASK_W;
       }
-      
+
       switch (interp) {
       case LP_INTERP_POSITION:
          /*