[Mesa-dev] [PATCH 23/53] intel/fs: Disable SIMD32 dispatch for fragment shaders with discard.

[Jason Ekstrand]

From: Francisco Jerez <currojerez at riseup.net>

Current discard handling requires dedicating the second flag register to
discard.  However, control-flow in SIMD32 requires both flag registers
so it's incompatible with the current discard handling.  Just don't
support SIMD32+discard for now.

Reviewed-by: Jason Ekstrand <jason at jlekstrand.net>
---
 src/intel/compiler/brw_fs_nir.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/intel/compiler/brw_fs_nir.cpp b/src/intel/compiler/brw_fs_nir.cpp
index 1168365..28f056e 100644
--- a/src/intel/compiler/brw_fs_nir.cpp
+++ b/src/intel/compiler/brw_fs_nir.cpp
@@ -3374,6 +3374,8 @@ fs_visitor::nir_emit_fs_intrinsic(const fs_builder &bld,
       if (devinfo->gen >= 6) {
          emit_discard_jump();
       }
+
+      limit_dispatch_width(16, "Fragment discard not implemented in SIMD32 mode.");
       break;
    }
 
-- 
2.5.0.400.gff86faf