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std: hash_map: optimize isFree/isTombstone #10562

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Merged
andrewrk merged 2 commits into from
Jan 11, 2022
Merged

std: hash_map: optimize isFree/isTombstone #10562

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d1c8fb5
std: hash_map: optimize isFree/isTombstone
sentientwaffle Dec 20, 2021
3379258
std: hash_map: fix formatting
sentientwaffle Jan 10, 2022
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13 changes: 10 additions & 3 deletions lib/std/hash_map.zig
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Original file line number Diff line number Diff line change
Expand Up @@ -750,12 +750,19 @@ pub fn HashMapUnmanaged(
fingerprint: FingerPrint = free,
used: u1 = 0,

const slot_free = @bitCast(u8, Metadata{ .fingerprint = free });
const slot_tombstone = @bitCast(u8, Metadata{ .fingerprint = tombstone });

pub fn isUsed(self: Metadata) bool {
return self.used == 1;
}

pub fn isTombstone(self: Metadata) bool {
return !self.isUsed() and self.fingerprint == tombstone;
return @bitCast(u8, self) == slot_tombstone;
}

pub fn isFree(self: Metadata) bool {
return @bitCast(u8, self) == slot_free;
}

pub fn takeFingerprint(hash: Hash) FingerPrint {
Expand Down Expand Up @@ -1115,7 +1122,7 @@ pub fn HashMapUnmanaged(
var idx = @truncate(usize, hash & mask);

var metadata = self.metadata.? + idx;
while ((metadata[0].isUsed() or metadata[0].isTombstone()) and limit != 0) {
while (!metadata[0].isFree() and limit != 0) {
if (metadata[0].isUsed() and metadata[0].fingerprint == fingerprint) {
const test_key = &self.keys()[idx];
// If you get a compile error on this line, it means that your generic eql
Expand Down Expand Up @@ -1294,7 +1301,7 @@ pub fn HashMapUnmanaged(

var first_tombstone_idx: usize = self.capacity(); // invalid index
var metadata = self.metadata.? + idx;
while ((metadata[0].isUsed() or metadata[0].isTombstone()) and limit != 0) {
while (!metadata[0].isFree() and limit != 0) {
if (metadata[0].isUsed() and metadata[0].fingerprint == fingerprint) {
const test_key = &self.keys()[idx];
// If you get a compile error on this line, it means that your generic eql
Expand Down