Mesa (staging/20.1): pan/mdg: Fix perspective combination

[GitLab Mirror]

Module: Mesa
Branch: staging/20.1
Commit: acf4035456e4e9e540b085ccdb98c609b21e8892
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=acf4035456e4e9e540b085ccdb98c609b21e8892

Author: Alyssa Rosenzweig <alyssa.rosenzweig at collabora.com>
Date:   Mon Aug 31 14:20:59 2020 -0400

pan/mdg: Fix perspective combination

It's not enough to multiply by a .w reciprocal, we have to be taking the
reciprocal of the thing we're actually multiplying against.

Fixes incorrect rendering in Manhattan.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig at collabora.com>
Cc: mesa-stable
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6525>
(cherry picked from commit 41d0a81c2a3f09701e8c694b520c8d900f6ac2f1)

---

 .pick_status.json                              | 2 +-
 src/panfrost/midgard/midgard_opt_perspective.c | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/.pick_status.json b/.pick_status.json
index e721dc02d15..a3f69f7bdce 100644
--- a/.pick_status.json
+++ b/.pick_status.json
@@ -490,7 +490,7 @@
         "description": "pan/mdg: Fix perspective combination",
         "nominated": true,
         "nomination_type": 0,
-        "resolution": 0,
+        "resolution": 1,
         "master_sha": null,
         "because_sha": null
     },
diff --git a/src/panfrost/midgard/midgard_opt_perspective.c b/src/panfrost/midgard/midgard_opt_perspective.c
index 4af8c45356e..601fa259ca6 100644
--- a/src/panfrost/midgard/midgard_opt_perspective.c
+++ b/src/panfrost/midgard/midgard_opt_perspective.c
@@ -88,6 +88,7 @@ midgard_opt_combine_projection(compiler_context *ctx, midgard_block *block)
                 }
 
                 if (!frcp_found) continue;
+                if (frcp_from != ins->src[0]) continue;
                 if (frcp_component != COMPONENT_W && frcp_component != COMPONENT_Z) continue;
                 if (!mir_single_use(ctx, frcp)) continue;