gallivm/nir: add some f16 support

GLSL lowers packhalf2x16 itself, but for SPIRV we don't have that
option.

For packing when NIR lowers it uses f2f16
and for unpack it needs the casting and f2f32

Fixes:
dEQP-VK.glsl.builtin.function.pack_unpack.packhalf2x16*
dEQP-VK.glsl.builtin.function.pack_unpack.unpackhalf2x16*

Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6381>

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_nir.c b/src/gallium/auxiliary/gallivm/lp_bld_nir.c
index 9a60452479b4b88abc0162236b918272f49fb1f2..c008e22c67dead5e75f2ae8c8c871d5ee61e595b 100644 (file)
--- a/src/gallium/auxiliary/gallivm/lp_bld_nir.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_nir.c
@@ -46,6 +46,8 @@ static LLVMValueRef cast_type(struct lp_build_nir_context *bld_base, LLVMValueRe
    switch (alu_type) {
    case nir_type_float:
       switch (bit_size) {
+      case 16:
+         return LLVMBuildBitCast(builder, val, LLVMVectorType(LLVMHalfTypeInContext(bld_base->base.gallivm->context), bld_base->base.type.length), "");
       case 32:
          return LLVMBuildBitCast(builder, val, bld_base->base.vec_type, "");
       case 64:
@@ -489,9 +491,17 @@ static LLVMValueRef do_alu_action(struct lp_build_nir_context *bld_base,
    case nir_op_f2b32:
       result = flt_to_bool32(bld_base, src_bit_size[0], src[0]);
       break;
-   case nir_op_f2f32:
+   case nir_op_f2f16:
       result = LLVMBuildFPTrunc(builder, src[0],
-                                bld_base->base.vec_type, "");
+                                LLVMVectorType(LLVMHalfTypeInContext(gallivm->context), bld_base->base.type.length), "");
+      break;
+   case nir_op_f2f32:
+      if (src_bit_size[0] < 32)
+         result = LLVMBuildFPExt(builder, src[0],
+                                 bld_base->base.vec_type, "");
+      else
+         result = LLVMBuildFPTrunc(builder, src[0],
+                                   bld_base->base.vec_type, "");
       break;
    case nir_op_f2f64:
       result = LLVMBuildFPExt(builder, src[0],