[Mesa-dev] [PATCH] nv50/ir: saturate depth writes

[Ilia Mirkin]

Apparently there's no post-FS clamping logic, so we have to do this by
hand. The depth will never be outside of the 0..1 range, even on
floating point zeta buffers, so this should be safe.

Fixes dEQP-GLES3.functional.fbo.depth.*clamp.* which tests writing
invalid values on various zeta buffer formats.

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
---
 src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp
index 39cd986..d9c1f04 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp
@@ -3502,8 +3502,11 @@ Converter::exportOutputs()
          Symbol *sym = mkSymbol(FILE_SHADER_OUTPUT, 0, TYPE_F32,
                                 info->out[i].slot[c] * 4);
          Value *val = oData.load(sub.cur->values, i, c, NULL);
-         if (val)
+         if (val) {
+            if (info->out[i].sn == TGSI_SEMANTIC_POSITION)
+               mkOp1(OP_SAT, TYPE_F32, val, val);
             mkStore(OP_EXPORT, TYPE_F32, sym, NULL, val);
+         }
       }
    }
 }
-- 
2.7.3