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Use const generics in SipHasher128's short_write

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Jakub Beránek 2022-02-04 16:26:36 +01:00
parent 4c55c8362d
commit 5fc2e5623b
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2 changed files with 39 additions and 46 deletions
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24
compiler/rustc_data_structures/src/stable_hasher.rs
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@ -80,22 +80,22 @@ impl Hasher for StableHasher {
#[inline]
fn write_u16(&mut self, i: u16) {
self.state.write_u16(i.to_le());
self.state.short_write(i.to_le_bytes());
}
#[inline]
fn write_u32(&mut self, i: u32) {
self.state.write_u32(i.to_le());
self.state.short_write(i.to_le_bytes());
}
#[inline]
fn write_u64(&mut self, i: u64) {
self.state.write_u64(i.to_le());
self.state.short_write(i.to_le_bytes());
}
#[inline]
fn write_u128(&mut self, i: u128) {
self.state.write_u128(i.to_le());
self.state.write(&i.to_le_bytes());
}
#[inline]
@ -103,7 +103,7 @@ impl Hasher for StableHasher {
// Always treat usize as u64 so we get the same results on 32 and 64 bit
// platforms. This is important for symbol hashes when cross compiling,
// for example.
self.state.write_u64((i as u64).to_le());
self.state.short_write((i as u64).to_le_bytes());
}
#[inline]
@ -113,22 +113,22 @@ impl Hasher for StableHasher {
#[inline]
fn write_i16(&mut self, i: i16) {
self.state.write_i16(i.to_le());
self.state.short_write((i as u16).to_le_bytes());
}
#[inline]
fn write_i32(&mut self, i: i32) {
self.state.write_i32(i.to_le());
self.state.short_write((i as u32).to_le_bytes());
}
#[inline]
fn write_i64(&mut self, i: i64) {
self.state.write_i64(i.to_le());
self.state.short_write((i as u64).to_le_bytes());
}
#[inline]
fn write_i128(&mut self, i: i128) {
self.state.write_i128(i.to_le());
self.state.write(&(i as u128).to_le_bytes());
}
#[inline]
@ -144,7 +144,7 @@ impl Hasher for StableHasher {
#[inline(never)]
fn hash_value(state: &mut SipHasher128, value: u64) {
state.write_u8(0xFF);
state.write_u64(value.to_le());
state.short_write(value.to_le_bytes());
}
// `isize` values often seem to have a small (positive) numeric value in practice.
@ -161,10 +161,6 @@ impl Hasher for StableHasher {
// 8 bytes. Since this prefix cannot occur when we hash a single byte, when we hash two
// `isize`s that fit within a different amount of bytes, they should always produce a different
// byte stream for the hasher.
//
// To ensure that this optimization hashes the exact same bytes on both little-endian and
// big-endian architectures, we compare the value with 0xFF before we convert the number
// into a unified representation (little-endian).
if value < 0xFF {
self.state.write_u8(value as u8);
} else {