i965/fs: Detect GRF sources in split_virtual_grfs send-from-GRF code.

It is incorrect to assume that src[0] of a SEND-from-GRF opcode is the
GRF.  For example, FS_OPCODE_UNIFORM_PULL_CONSTANT_LOAD uses src[1] for
the GRF.

To be safe, loop over all the source registers and mark any GRFs.  We
probably won't ever have more than one, but it's simpler to just check
all three rather than attempting to bail early.

Not observed to fix anything yet, but likely to.  Parallels the bug fix
in the previous commit, which actually does fix known failures.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Cc: mesa-stable@lists.freedesktop.org
(cherry picked from commit a35b32025011eeac01f2e5a476dbf3ac132a61b3)

1 files changed, 5 insertions, 1 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 3986bf5fe6e..62dccc1063e 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -1358,7 +1358,11 @@ fs_visitor::split_virtual_grfs()
        * the send is reading the whole thing.
        */
       if (inst->is_send_from_grf()) {
-         split_grf[inst->src[0].reg] = false;
+         for (int i = 0; i < 3; i++) {
+            if (inst->src[i].file == GRF) {
+               split_grf[inst->src[i].reg] = false;
+            }
+         }
       }
    }