Mesa (staging/20.2): llvmpipe: only read 0 for channels being read

[GitLab Mirror]

Module: Mesa
Branch: staging/20.2
Commit: 43b0e51f43455cf01b336879fced33f4b079e122
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=43b0e51f43455cf01b336879fced33f4b079e122

Author: Dave Airlie <airlied at redhat.com>
Date:   Wed Aug 12 15:48:42 2020 +1000

llvmpipe: only read 0 for channels being read

KHR-GL45.robust_buffer_access_behavior.vertex_buffer_objects
on the CTS 4.6.0 branch and this fixes it.

Roland identified that if the vertex format doesn't contain channels
then we shouldn't be overriding them to 0, so RGB fetch out of bounds
should return 0 for RGB, but the A channel should still be getting back
1.

Cc: <mesa-stable at lists.freedesktop.org>
Reviewed-by: Roland Scheidegger <sroland at vmware.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6287>
(cherry picked from commit 430e3310e2aed924dc4e0729644e629007d73ef7)

---

 .pick_status.json                      | 2 +-
 src/gallium/auxiliary/draw/draw_llvm.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/.pick_status.json b/.pick_status.json
index 8f2c628b5b2..0402a9a371c 100644
--- a/.pick_status.json
+++ b/.pick_status.json
@@ -1228,7 +1228,7 @@
         "description": "llvmpipe: only read 0 for channels being read",
         "nominated": true,
         "nomination_type": 0,
-        "resolution": 0,
+        "resolution": 1,
         "master_sha": null,
         "because_sha": null
     },
diff --git a/src/gallium/auxiliary/draw/draw_llvm.c b/src/gallium/auxiliary/draw/draw_llvm.c
index 845ed6242b1..22644aa5eab 100644
--- a/src/gallium/auxiliary/draw/draw_llvm.c
+++ b/src/gallium/auxiliary/draw/draw_llvm.c
@@ -1128,7 +1128,7 @@ fetch_vector(struct gallivm_state *gallivm,
    }
 
    /* out-of-bound fetches return all zeros */
-   for (i = 0; i < TGSI_NUM_CHANNELS; i++) {
+   for (i = 0; i < format_desc->nr_channels; i++) {
       inputs[i] = LLVMBuildBitCast(builder, inputs[i], blduivec.vec_type, "");
       inputs[i] = LLVMBuildAnd(builder, inputs[i], valid_mask, "");
       inputs[i] = LLVMBuildBitCast(builder, inputs[i],