zink: Avoid redundant cast to uint on PackHalf2x16 result

For example the previous code generates the following sequence of
SPIR-V instructions ending with a redundant cast to uint:

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

The new code generates:

  %2018 = OpExtInst %uint %1 PackHalf2x16 %2017

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 a31b0d6..374bdf5 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
@@ -1737,7 +1737,6 @@ emit_alu(struct ntv_context *ctx, nir_alu_instr *alu)
    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)