diff --git a/src/compiler/nir/nir_lower_subgroups.c b/src/compiler/nir/nir_lower_subgroups.c
index eca441fcf39..1e2e3f0eebf 100644
--- a/src/compiler/nir/nir_lower_subgroups.c
+++ b/src/compiler/nir/nir_lower_subgroups.c
@@ -292,6 +292,15 @@ lower_subgroups_filter(const nir_instr *instr, const void *_options)
    return instr->type == nir_instr_type_intrinsic;
 }
 
+static nir_ssa_def *
+build_subgroup_mask(nir_builder *b, unsigned bit_size,
+                    const nir_lower_subgroups_options *options)
+{
+   return nir_ushr(b, nir_imm_intN_t(b, ~0ull, bit_size),
+                      nir_isub(b, nir_imm_int(b, bit_size),
+                                  nir_load_subgroup_size(b)));
+}
+
 static nir_ssa_def *
 lower_subgroups_instr(nir_builder *b, nir_instr *instr, void *_options)
 {
@@ -343,9 +352,6 @@ lower_subgroups_instr(nir_builder *b, nir_instr *instr, void *_options)
       const unsigned bit_size = MAX2(options->ballot_bit_size,
                                      intrin->dest.ssa.bit_size);
 
-      assert(options->subgroup_size <= 64);
-      uint64_t group_mask = ~0ull >> (64 - options->subgroup_size);
-
       nir_ssa_def *count = nir_load_subgroup_invocation(b);
       nir_ssa_def *val;
       switch (intrin->intrinsic) {
@@ -354,11 +360,11 @@ lower_subgroups_instr(nir_builder *b, nir_instr *instr, void *_options)
          break;
       case nir_intrinsic_load_subgroup_ge_mask:
          val = nir_iand(b, nir_ishl(b, nir_imm_intN_t(b, ~0ull, bit_size), count),
-                           nir_imm_intN_t(b, group_mask, bit_size));
+                           build_subgroup_mask(b, bit_size, options));
          break;
       case nir_intrinsic_load_subgroup_gt_mask:
          val = nir_iand(b, nir_ishl(b, nir_imm_intN_t(b, ~1ull, bit_size), count),
-                           nir_imm_intN_t(b, group_mask, bit_size));
+                           build_subgroup_mask(b, bit_size, options));
          break;
       case nir_intrinsic_load_subgroup_le_mask:
          val = nir_inot(b, nir_ishl(b, nir_imm_intN_t(b, ~1ull, bit_size), count));