diff options
| author | Ian Romanick <[email protected]> | 2019-08-26 13:28:09 -0700 |
|---|---|---|
| committer | Ian Romanick <[email protected]> | 2019-08-28 11:38:51 -0700 |
| commit | d3fd1c761aab01e06665180ab86c9528c0b285b2 (patch) | |
| tree | 34eadbae076c5d8ed511434ee40f007778b9d0dd /src/intel/compiler/brw_compiler.c | |
| parent | 4662b70d23c2eed9b891e9694d956a1a2a37ab70 (diff) | |
nir/algrbraic: Don't optimize open-coded bitfield reverse when lowering is enabled
This caused a problem on Sandybridge where an open-coded
bitfieldReverse() function could be optimized to a
nir_op_bitfield_reverse that would generate an unsupported BFREV
instruction in the backend. This was encountered in some Unreal4 tech
demos in shader-db. The bug was not previously noticed because we don't
actually try to run those demos on Sandybridge.
The fixes tag is a bit a lie. The actual bug was introduced about
26,000 commits earlier in 371c4b3c48f ("nir: Recognize open-coded
bitfield_reverse."). Without the NIR lowering pass, the flag needed to
avoid the optimization does not exist. Hopefully nobody will care to
fix this on an earlier Mesa release.
Reviewed-by: Matt Turner <[email protected]>
Fixes: 7afa26d4e39 ("nir: Add lowering for nir_op_bitfield_reverse.")
Diffstat (limited to 'src/intel/compiler/brw_compiler.c')
0 files changed, 0 insertions, 0 deletions