[Mesa-dev] [PATCH 20/45] i965/fs: Handle 32-bit to 16-bit conversions

[Alejandro Piñeiro]

These conversions to 16-bit don't need anything special at this point.
The stride should have already been adjusted before, for all 16-bit
destination ALUs.

Signed-off-by: Eduardo Lima <elima at igalia.com>
Signed-off-by: Alejandro Piñeiro <apinheiro at igalia.com>
---
 src/intel/compiler/brw_fs_nir.cpp | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/src/intel/compiler/brw_fs_nir.cpp b/src/intel/compiler/brw_fs_nir.cpp
index 15f8326..bc1bee6 100644
--- a/src/intel/compiler/brw_fs_nir.cpp
+++ b/src/intel/compiler/brw_fs_nir.cpp
@@ -715,6 +715,24 @@ fs_visitor::nir_emit_alu(const fs_builder &bld, nir_alu_instr *instr)
       inst->saturate = instr->dest.saturate;
       break;
 
+   case nir_op_f2f16:
+      /* In theory, it would be better to use BRW_OPCODE_F32TO16. Depending
+       * on the HW gen, it is a special hw opcode or just a MOV, and
+       * brw_F32TO16 (at brw_eu_emit) would do the work to chose.
+       *
+       * But if we want to use that opcode, we need to provide support on
+       * different optimizations and lowerings. As right now HF support is
+       * only for gen8+, it will be better to use directly the MOV, and use
+       * BRW_OPCODE_F32TO16 when/if we work for HF support on gen7.
+       */
+      /* fallthrough */
+
+   case nir_op_i2i16:
+   case nir_op_u2u16:
+      /* 16-bit destinations should already have stride set to 2. */
+      assert(result.stride == 2);
+      /* fallthrough */
+
    case nir_op_f2f64:
    case nir_op_i2f64:
    case nir_op_u2f64:
-- 
2.9.3