diff --git a/src/gallium/auxiliary/gallivm/lp_bld_const.c b/src/gallium/auxiliary/gallivm/lp_bld_const.c
index f94bf2f4edd..0c146a103e9 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_const.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_const.c
@@ -230,8 +230,16 @@ LLVMValueRef
 lp_build_zero(struct gallivm_state *gallivm, struct lp_type type)
 {
    if (type.length == 1) {
-      if (type.floating)
-         return lp_build_const_float(gallivm, 0.0);
+      if (type.floating) {
+         if (type.width == 16)
+            return lp_build_const_elem(gallivm, type, 0.0);
+         else if (type.width == 32)
+            return lp_build_const_float(gallivm, 0.0);
+         else {
+            assert(type.width == 64);
+            return lp_build_const_double(gallivm, 0.0);
+         }
+      }
       else
          return LLVMConstInt(LLVMIntTypeInContext(gallivm->context, type.width), 0, 0);
    } else {
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_conv.c b/src/gallium/auxiliary/gallivm/lp_bld_conv.c
index de2d9fbcbdf..86a1425ffe4 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_conv.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_conv.c
@@ -198,7 +198,8 @@ lp_build_float_to_half(struct gallivm_state *gallivm,
       if (length == 4) {
          result = lp_build_extract_range(gallivm, result, 0, 4);
       }
-      result = LLVMBuildBitCast(builder, result, lp_build_vec_type(gallivm, lp_type_float_vec(16, 16 * length)), "");
+      result = LLVMBuildBitCast(builder, result,
+                                lp_build_vec_type(gallivm, lp_type_float_vec(16, 16 * length)), "");
    }
 
    else {
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_nir_soa.c b/src/gallium/auxiliary/gallivm/lp_bld_nir_soa.c
index f06e94086e9..aa3c167dd9f 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_nir_soa.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_nir_soa.c
@@ -3241,12 +3241,37 @@ do_alu_action(struct lp_build_nir_soa_context *bld,
    case nir_op_f2f16:
    case nir_op_f2f32:
    case nir_op_f2f64:
+      /*
+       * FIXME: for f2f16 we can get here even without lp_has_fp16(), despite
+       * not announcing f16 capability. Should not happen from GL side (glsl has
+       * lowering pass for f16 pack/unpack functions if not supported) however
+       * from Vulkan side things like quantizeToF16, unpack2x16float use this.
+       * Need to fix up the llvm type in this case at least, although on some
+       * platforms this will still crash if the llvm backend doesn't handle half
+       * type on its own (but works on x86 even without f16c).
+       * Alternatively could use lp_build_half_to_float/float_to_half() but need
+       * to modify to handle rounding differently (need RNE instead of RTZ here).
+       * Ideally would be able to just use llvm half type consistently for f16,
+       * but not all backends are ready for that.
+       */
       if (src_bit_size[0] > instr->def.bit_size) {
-         result = LLVMBuildFPTrunc(builder, src[0],
-                                 dst_float_bld->vec_type, "");
+         LLVMTypeRef llvm_dst_type = dst_float_bld->vec_type;
+         if (instr->def.bit_size == 16 && !lp_has_fp16()) {
+            llvm_dst_type = LLVMHalfTypeInContext(gallivm->context);
+            if (dst_float_bld->type.length != 1)
+               llvm_dst_type = LLVMVectorType(llvm_dst_type, dst_float_bld->type.length);
+         }
+         result = LLVMBuildFPTrunc(builder, src[0], llvm_dst_type, "");
+         /* don't need a bit cast for f16, caller already has one */
       } else {
-         result = LLVMBuildFPExt(builder, src[0],
-                                 dst_float_bld->vec_type, "");
+         LLVMValueRef src0 = src[0];
+         if (src_bit_size[0] == 16 && !lp_has_fp16()) {
+            LLVMTypeRef llvm_src_type = LLVMHalfTypeInContext(gallivm->context);
+            if (dst_float_bld->type.length != 1)
+               llvm_src_type = LLVMVectorType(llvm_src_type, dst_float_bld->type.length);
+            src0 = LLVMBuildBitCast(builder, src0, llvm_src_type, "");
+         }
+         result = LLVMBuildFPExt(builder, src0, dst_float_bld->vec_type, "");
       }
       break;
    case nir_op_f2i8: