zink: Output PackHalf2x16 to uint not float

Fixes InconsistentSpirv validation errors reporting that PackHalf2x16
outputs uint rather than float.

For example the previous code generates the following SPIR-V with
PackHalf2x16 output as a float:

  %2018 = OpExtInst %float %1 PackHalf2x16 %2017
  %2019 = OpBitcast %uint %2018

The new code generates:

  %2018 = OpExtInst %uint %1 PackHalf2x16 %2017
  %2019 = OpBitcast %uint %2018

cc: mesa-stable

Reviewed-By: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14568>

diff --git a/src/gallium/drivers/zink/nir_to_spirv/nir_to_spirv.c b/src/gallium/drivers/zink/nir_to_spirv/nir_to_spirv.c
index 47f69f9..a31b0d6 100644 (file)
--- a/src/gallium/drivers/zink/nir_to_spirv/nir_to_spirv.c
+++ b/src/gallium/drivers/zink/nir_to_spirv/nir_to_spirv.c
@@ -1733,7 +1733,13 @@ emit_alu(struct ntv_context *ctx, nir_alu_instr *alu)
    BUILTIN_UNOP(nir_op_ufind_msb, GLSLstd450FindUMsb)
    BUILTIN_UNOP(nir_op_find_lsb, GLSLstd450FindILsb)
    BUILTIN_UNOP(nir_op_ifind_msb, GLSLstd450FindSMsb)
-   BUILTIN_UNOPF(nir_op_pack_half_2x16, GLSLstd450PackHalf2x16)
+
+   case nir_op_pack_half_2x16:
+      assert(nir_op_infos[alu->op].num_inputs == 1);
+      result = emit_builtin_unop(ctx, GLSLstd450PackHalf2x16, get_dest_type(ctx, &alu->dest.dest, nir_type_uint), src[0]);
+      force_float = true;
+      break;
+
    BUILTIN_UNOPF(nir_op_unpack_half_2x16, GLSLstd450UnpackHalf2x16)
    BUILTIN_UNOPF(nir_op_pack_64_2x32, GLSLstd450PackDouble2x32)
 #undef BUILTIN_UNOP