Add `MaskFull` to `Group`.

It is not used at the moment. Usage is planned to be submitted separately.

Useful for faster iterating over all slots in the internal functions.

PiperOrigin-RevId: 590300049
Change-Id: I081f33113268761db868771d29796d94c24e4e7a

1 files changed, 27 insertions, 0 deletions

diff --git a/absl/container/internal/raw_hash_set.h b/absl/container/internal/raw_hash_set.h
index b6d2cf93..3b3c5aa3 100644
--- a/absl/container/internal/raw_hash_set.h
+++ b/absl/container/internal/raw_hash_set.h
@@ -637,6 +637,14 @@ struct GroupSse2Impl {
 #endif
   }
 
+  // Returns a bitmask representing the positions of full slots.
+  // Note: for `is_small()` tables group may contain the "same" slot twice:
+  // original and mirrored.
+  BitMask<uint16_t, kWidth> MaskFull() const {
+    return BitMask<uint16_t, kWidth>(
+        static_cast<uint16_t>(_mm_movemask_epi8(ctrl) ^ 0xffff));
+  }
+
   // Returns a bitmask representing the positions of empty or deleted slots.
   NonIterableBitMask<uint16_t, kWidth> MaskEmptyOrDeleted() const {
     auto special = _mm_set1_epi8(static_cast<char>(ctrl_t::kSentinel));
@@ -692,6 +700,17 @@ struct GroupAArch64Impl {
     return NonIterableBitMask<uint64_t, kWidth, 3>(mask);
   }
 
+  // Returns a bitmask representing the positions of full slots.
+  // Note: for `is_small()` tables group may contain the "same" slot twice:
+  // original and mirrored.
+  BitMask<uint64_t, kWidth, 3> MaskFull() const {
+    uint64_t mask = vget_lane_u64(
+        vreinterpret_u64_u8(vcge_s8(vreinterpret_s8_u8(ctrl),
+                                    vdup_n_s8(static_cast<int8_t>(0)))),
+        0);
+    return BitMask<uint64_t, kWidth, 3>(mask);
+  }
+
   NonIterableBitMask<uint64_t, kWidth, 3> MaskEmptyOrDeleted() const {
     uint64_t mask =
         vget_lane_u64(vreinterpret_u64_u8(vcgt_s8(
@@ -760,6 +779,14 @@ struct GroupPortableImpl {
                                                    msbs);
   }
 
+  // Returns a bitmask representing the positions of full slots.
+  // Note: for `is_small()` tables group may contain the "same" slot twice:
+  // original and mirrored.
+  BitMask<uint64_t, kWidth, 3> MaskFull() const {
+    constexpr uint64_t msbs = 0x8080808080808080ULL;
+    return BitMask<uint64_t, kWidth, 3>((ctrl ^ msbs) & msbs);
+  }
+
   NonIterableBitMask<uint64_t, kWidth, 3> MaskEmptyOrDeleted() const {
     constexpr uint64_t msbs = 0x8080808080808080ULL;
     return NonIterableBitMask<uint64_t, kWidth, 3>((ctrl & ~(ctrl << 7)) &