Introduce `Group::MaskNonFull` without usage.

It can be used instead of `MaskEmptyOrDeleted` in case of inserting to empty table.
`MaskNonFull` requires less operations, in particular it eliminates `_mm_set1_epi8` and `_mm_cmpgt_epi8` operations.

PiperOrigin-RevId: 607587394
Change-Id: Ia48f922d1ca6de38cc91e7ab0d608c45f8f2c446

1 files changed, 22 insertions, 0 deletions

diff --git a/absl/container/internal/raw_hash_set_benchmark.cc b/absl/container/internal/raw_hash_set_benchmark.cc
index bc8184d4..8cd43fb5 100644
--- a/absl/container/internal/raw_hash_set_benchmark.cc
+++ b/absl/container/internal/raw_hash_set_benchmark.cc
@@ -479,6 +479,17 @@ void BM_Group_MaskEmptyOrDeleted(benchmark::State& state) {
 }
 BENCHMARK(BM_Group_MaskEmptyOrDeleted);
 
+void BM_Group_MaskNonFull(benchmark::State& state) {
+  std::array<ctrl_t, Group::kWidth> group;
+  Iota(group.begin(), group.end(), -4);
+  Group g{group.data()};
+  for (auto _ : state) {
+    ::benchmark::DoNotOptimize(g);
+    ::benchmark::DoNotOptimize(g.MaskNonFull());
+  }
+}
+BENCHMARK(BM_Group_MaskNonFull);
+
 void BM_Group_CountLeadingEmptyOrDeleted(benchmark::State& state) {
   std::array<ctrl_t, Group::kWidth> group;
   Iota(group.begin(), group.end(), -2);
@@ -501,6 +512,17 @@ void BM_Group_MatchFirstEmptyOrDeleted(benchmark::State& state) {
 }
 BENCHMARK(BM_Group_MatchFirstEmptyOrDeleted);
 
+void BM_Group_MatchFirstNonFull(benchmark::State& state) {
+  std::array<ctrl_t, Group::kWidth> group;
+  Iota(group.begin(), group.end(), -2);
+  Group g{group.data()};
+  for (auto _ : state) {
+    ::benchmark::DoNotOptimize(g);
+    ::benchmark::DoNotOptimize(g.MaskNonFull().LowestBitSet());
+  }
+}
+BENCHMARK(BM_Group_MatchFirstNonFull);
+
 void BM_DropDeletes(benchmark::State& state) {
   constexpr size_t capacity = (1 << 20) - 1;
   std::vector<ctrl_t> ctrl(capacity + 1 + Group::kWidth);