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Use uplifted rustc-stable-hash crate in rustc_data_structures

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This commit is contained in:
Urgau 2024-06-19 21:23:40 +02:00
parent 0c81f94b9a
commit 977439d9b8
11 changed files with 30 additions and 1049 deletions
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7
Cargo.lock
View File

@ -3514,6 +3514,12 @@ version = "1.1.0"
source = "registry+https://github.com/rust-lang/crates.io-index" source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "5be1bdc7edf596692617627bbfeaba522131b18e06ca4df2b6b689e3c5d5ce84" checksum = "5be1bdc7edf596692617627bbfeaba522131b18e06ca4df2b6b689e3c5d5ce84"
[[package]]
name = "rustc-stable-hash"
version = "0.1.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "e5c9f15eec8235d7cb775ee6f81891db79b98fd54ba1ad8fae565b88ef1ae4e2"
[[package]] [[package]]
name = "rustc-std-workspace-alloc" name = "rustc-std-workspace-alloc"
version = "1.99.0" version = "1.99.0"
@ -3852,6 +3858,7 @@ dependencies = [
"portable-atomic", "portable-atomic",
"rustc-hash", "rustc-hash",
"rustc-rayon", "rustc-rayon",
"rustc-stable-hash",
"rustc_arena", "rustc_arena",
"rustc_graphviz", "rustc_graphviz",
"rustc_index", "rustc_index",

1
compiler/rustc_data_structures/Cargo.toml
View File

@ -15,6 +15,7 @@ jobserver_crate = { version = "0.1.28", package = "jobserver" }
measureme = "11" measureme = "11"
rustc-hash = "1.1.0" rustc-hash = "1.1.0"
rustc-rayon = { version = "0.5.0", optional = true } rustc-rayon = { version = "0.5.0", optional = true }
rustc-stable-hash = { version = "0.1.0", features = ["nightly"] }
rustc_arena = { path = "../rustc_arena" } rustc_arena = { path = "../rustc_arena" }
rustc_graphviz = { path = "../rustc_graphviz" } rustc_graphviz = { path = "../rustc_graphviz" }
rustc_index = { path = "../rustc_index", package = "rustc_index" } rustc_index = { path = "../rustc_index", package = "rustc_index" }

9
compiler/rustc_data_structures/src/fingerprint.rs
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@ -1,5 +1,5 @@
use crate::stable_hasher::impl_stable_traits_for_trivial_type; use crate::stable_hasher::impl_stable_traits_for_trivial_type;
use crate::stable_hasher::{Hash64, StableHasher, StableHasherResult}; use crate::stable_hasher::{FromStableHash, Hash64, StableHasherHash};
use rustc_serialize::{Decodable, Decoder, Encodable, Encoder}; use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
use std::hash::{Hash, Hasher}; use std::hash::{Hash, Hasher};
@ -154,10 +154,11 @@ fn write_fingerprint(&mut self, fingerprint: &Fingerprint) {
} }
} }
impl StableHasherResult for Fingerprint { impl FromStableHash for Fingerprint {
type Hash = StableHasherHash;
#[inline] #[inline]
fn finish(hasher: StableHasher) -> Self { fn from(StableHasherHash([_0, _1]): Self::Hash) -> Self {
let (_0, _1) = hasher.finalize();
Fingerprint(_0, _1) Fingerprint(_0, _1)
} }
} }

17
compiler/rustc_data_structures/src/hashes.rs
View File

@ -11,7 +11,7 @@
//! connect the fact that they can only be produced by a `StableHasher` to their //! connect the fact that they can only be produced by a `StableHasher` to their
//! `Encode`/`Decode` impls. //! `Encode`/`Decode` impls.
use crate::stable_hasher::{StableHasher, StableHasherResult}; use crate::stable_hasher::{FromStableHash, StableHasherHash};
use rustc_serialize::{Decodable, Decoder, Encodable, Encoder}; use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
use std::fmt; use std::fmt;
use std::ops::BitXorAssign; use std::ops::BitXorAssign;
@ -56,10 +56,12 @@ fn decode(d: &mut D) -> Self {
} }
} }
impl StableHasherResult for Hash64 { impl FromStableHash for Hash64 {
type Hash = StableHasherHash;
#[inline] #[inline]
fn finish(hasher: StableHasher) -> Self { fn from(StableHasherHash([_0, __1]): Self::Hash) -> Self {
Self { inner: hasher.finalize().0 } Self { inner: _0 }
} }
} }
@ -121,10 +123,11 @@ fn decode(d: &mut D) -> Self {
} }
} }
impl StableHasherResult for Hash128 { impl FromStableHash for Hash128 {
type Hash = StableHasherHash;
#[inline] #[inline]
fn finish(hasher: StableHasher) -> Self { fn from(StableHasherHash([_0, _1]): Self::Hash) -> Self {
let (_0, _1) = hasher.finalize();
Self { inner: u128::from(_0) | (u128::from(_1) << 64) } Self { inner: u128::from(_0) | (u128::from(_1) << 64) }
} }
} }

2
compiler/rustc_data_structures/src/lib.rs
View File

@ -24,7 +24,6 @@
#![feature(core_intrinsics)] #![feature(core_intrinsics)]
#![feature(extend_one)] #![feature(extend_one)]
#![feature(hash_raw_entry)] #![feature(hash_raw_entry)]
#![feature(hasher_prefixfree_extras)]
#![feature(macro_metavar_expr)] #![feature(macro_metavar_expr)]
#![feature(map_try_insert)] #![feature(map_try_insert)]
#![feature(min_specialization)] #![feature(min_specialization)]
@ -67,7 +66,6 @@
pub mod packed; pub mod packed;
pub mod profiling; pub mod profiling;
pub mod sharded; pub mod sharded;
pub mod sip128;
pub mod small_c_str; pub mod small_c_str;
pub mod snapshot_map; pub mod snapshot_map;
pub mod sorted_map; pub mod sorted_map;

505
compiler/rustc_data_structures/src/sip128.rs
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@ -1,505 +0,0 @@
//! This is a copy of `core::hash::sip` adapted to providing 128 bit hashes.
// This code is very hot and uses lots of arithmetic, avoid overflow checks for performance.
// See https://github.com/rust-lang/rust/pull/119440#issuecomment-1874255727
use rustc_serialize::int_overflow::{DebugStrictAdd, DebugStrictSub};
use std::hash::Hasher;
use std::mem::{self, MaybeUninit};
use std::ptr;
#[cfg(test)]
mod tests;
// The SipHash algorithm operates on 8-byte chunks.
const ELEM_SIZE: usize = mem::size_of::<u64>();
// Size of the buffer in number of elements, not including the spill.
//
// The selection of this size was guided by rustc-perf benchmark comparisons of
// different buffer sizes. It should be periodically reevaluated as the compiler
// implementation and input characteristics change.
//
// Using the same-sized buffer for everything we hash is a performance versus
// complexity tradeoff. The ideal buffer size, and whether buffering should even
// be used, depends on what is being hashed. It may be worth it to size the
// buffer appropriately (perhaps by making SipHasher128 generic over the buffer
// size) or disable buffering depending on what is being hashed. But at this
// time, we use the same buffer size for everything.
const BUFFER_CAPACITY: usize = 8;
// Size of the buffer in bytes, not including the spill.
const BUFFER_SIZE: usize = BUFFER_CAPACITY * ELEM_SIZE;
// Size of the buffer in number of elements, including the spill.
const BUFFER_WITH_SPILL_CAPACITY: usize = BUFFER_CAPACITY + 1;
// Size of the buffer in bytes, including the spill.
const BUFFER_WITH_SPILL_SIZE: usize = BUFFER_WITH_SPILL_CAPACITY * ELEM_SIZE;
// Index of the spill element in the buffer.
const BUFFER_SPILL_INDEX: usize = BUFFER_WITH_SPILL_CAPACITY - 1;
#[derive(Debug, Clone)]
#[repr(C)]
pub struct SipHasher128 {
// The access pattern during hashing consists of accesses to `nbuf` and
// `buf` until the buffer is full, followed by accesses to `state` and
// `processed`, and then repetition of that pattern until hashing is done.
// This is the basis for the ordering of fields below. However, in practice
// the cache miss-rate for data access is extremely low regardless of order.
nbuf: usize, // how many bytes in buf are valid
buf: [MaybeUninit<u64>; BUFFER_WITH_SPILL_CAPACITY], // unprocessed bytes le
state: State, // hash State
processed: usize, // how many bytes we've processed
}
#[derive(Debug, Clone, Copy)]
#[repr(C)]
struct State {
// v0, v2 and v1, v3 show up in pairs in the algorithm,
// and simd implementations of SipHash will use vectors
// of v02 and v13. By placing them in this order in the struct,
// the compiler can pick up on just a few simd optimizations by itself.
v0: u64,
v2: u64,
v1: u64,
v3: u64,
}
macro_rules! compress {
($state:expr) => {{ compress!($state.v0, $state.v1, $state.v2, $state.v3) }};
($v0:expr, $v1:expr, $v2:expr, $v3:expr) => {{
$v0 = $v0.wrapping_add($v1);
$v2 = $v2.wrapping_add($v3);
$v1 = $v1.rotate_left(13);
$v1 ^= $v0;
$v3 = $v3.rotate_left(16);
$v3 ^= $v2;
$v0 = $v0.rotate_left(32);
$v2 = $v2.wrapping_add($v1);
$v0 = $v0.wrapping_add($v3);
$v1 = $v1.rotate_left(17);
$v1 ^= $v2;
$v3 = $v3.rotate_left(21);
$v3 ^= $v0;
$v2 = $v2.rotate_left(32);
}};
}
// Copies up to 8 bytes from source to destination. This performs better than
// `ptr::copy_nonoverlapping` on microbenchmarks and may perform better on real
// workloads since all of the copies have fixed sizes and avoid calling memcpy.
//
// This is specifically designed for copies of up to 8 bytes, because that's the
// maximum of number bytes needed to fill an 8-byte-sized element on which
// SipHash operates. Note that for variable-sized copies which are known to be
// less than 8 bytes, this function will perform more work than necessary unless
// the compiler is able to optimize the extra work away.
#[inline]
unsafe fn copy_nonoverlapping_small(src: *const u8, dst: *mut u8, count: usize) {
debug_assert!(count <= 8);
unsafe {
if count == 8 {
ptr::copy_nonoverlapping(src, dst, 8);
return;
}
let mut i = 0;
if i.debug_strict_add(3) < count {
ptr::copy_nonoverlapping(src.add(i), dst.add(i), 4);
i = i.debug_strict_add(4);
}
if i.debug_strict_add(1) < count {
ptr::copy_nonoverlapping(src.add(i), dst.add(i), 2);
i = i.debug_strict_add(2)
}
if i < count {
*dst.add(i) = *src.add(i);
i = i.debug_strict_add(1);
}
debug_assert_eq!(i, count);
}
}
// # Implementation
//
// This implementation uses buffering to reduce the hashing cost for inputs
// consisting of many small integers. Buffering simplifies the integration of
// integer input--the integer write function typically just appends to the
// buffer with a statically sized write, updates metadata, and returns.
//
// Buffering also prevents alternating between writes that do and do not trigger
// the hashing process. Only when the entire buffer is full do we transition
// into hashing. This allows us to keep the hash state in registers for longer,
// instead of loading and storing it before and after processing each element.
//
// When a write fills the buffer, a buffer processing function is invoked to
// hash all of the buffered input. The buffer processing functions are marked
// `#[inline(never)]` so that they aren't inlined into the append functions,
// which ensures the more frequently called append functions remain inlineable
// and don't include register pushing/popping that would only be made necessary
// by inclusion of the complex buffer processing path which uses those
// registers.
//
// The buffer includes a "spill"--an extra element at the end--which simplifies
// the integer write buffer processing path. The value that fills the buffer can
// be written with a statically sized write that may spill over into the spill.
// After the buffer is processed, the part of the value that spilled over can be
// written from the spill to the beginning of the buffer with another statically
// sized write. This write may copy more bytes than actually spilled over, but
// we maintain the metadata such that any extra copied bytes will be ignored by
// subsequent processing. Due to the static sizes, this scheme performs better
// than copying the exact number of bytes needed into the end and beginning of
// the buffer.
//
// The buffer is uninitialized, which improves performance, but may preclude
// efficient implementation of alternative approaches. The improvement is not so
// large that an alternative approach should be disregarded because it cannot be
// efficiently implemented with an uninitialized buffer. On the other hand, an
// uninitialized buffer may become more important should a larger one be used.
//
// # Platform Dependence
//
// The SipHash algorithm operates on byte sequences. It parses the input stream
// as 8-byte little-endian integers. Therefore, given the same byte sequence, it
// produces the same result on big- and little-endian hardware.
//
// However, the Hasher trait has methods which operate on multi-byte integers.
// How they are converted into byte sequences can be endian-dependent (by using
// native byte order) or independent (by consistently using either LE or BE byte
// order). It can also be `isize` and `usize` size dependent (by using the
// native size), or independent (by converting to a common size), supposing the
// values can be represented in 32 bits.
//
// In order to make `SipHasher128` consistent with `SipHasher` in libstd, we
// choose to do the integer to byte sequence conversion in the platform-
// dependent way. Clients can achieve platform-independent hashing by widening
// `isize` and `usize` integers to 64 bits on 32-bit systems and byte-swapping
// integers on big-endian systems before passing them to the writing functions.
// This causes the input byte sequence to look identical on big- and little-
// endian systems (supposing `isize` and `usize` values can be represented in 32
// bits), which ensures platform-independent results.
impl SipHasher128 {
#[inline]
pub fn new_with_keys(key0: u64, key1: u64) -> SipHasher128 {
let mut hasher = SipHasher128 {
nbuf: 0,
buf: [MaybeUninit::uninit(); BUFFER_WITH_SPILL_CAPACITY],
state: State {
v0: key0 ^ 0x736f6d6570736575,
// The XOR with 0xee is only done on 128-bit algorithm version.
v1: key1 ^ (0x646f72616e646f6d ^ 0xee),
v2: key0 ^ 0x6c7967656e657261,
v3: key1 ^ 0x7465646279746573,
},
processed: 0,
};
unsafe {
// Initialize spill because we read from it in `short_write_process_buffer`.
*hasher.buf.get_unchecked_mut(BUFFER_SPILL_INDEX) = MaybeUninit::zeroed();
}
hasher
}
#[inline]
pub fn short_write<const LEN: usize>(&mut self, bytes: [u8; LEN]) {
let nbuf = self.nbuf;
debug_assert!(LEN <= 8);
debug_assert!(nbuf < BUFFER_SIZE);
debug_assert!(nbuf + LEN < BUFFER_WITH_SPILL_SIZE);
if nbuf.debug_strict_add(LEN) < BUFFER_SIZE {
unsafe {
// The memcpy call is optimized away because the size is known.
let dst = (self.buf.as_mut_ptr() as *mut u8).add(nbuf);
ptr::copy_nonoverlapping(bytes.as_ptr(), dst, LEN);
}
self.nbuf = nbuf.debug_strict_add(LEN);
return;
}
unsafe { self.short_write_process_buffer(bytes) }
}
// A specialized write function for values with size <= 8 that should only
// be called when the write would cause the buffer to fill.
//
// SAFETY: the write of `x` into `self.buf` starting at byte offset
// `self.nbuf` must cause `self.buf` to become fully initialized (and not
// overflow) if it wasn't already.
#[inline(never)]
unsafe fn short_write_process_buffer<const LEN: usize>(&mut self, bytes: [u8; LEN]) {
unsafe {
let nbuf = self.nbuf;
debug_assert!(LEN <= 8);
debug_assert!(nbuf < BUFFER_SIZE);
debug_assert!(nbuf + LEN >= BUFFER_SIZE);
debug_assert!(nbuf + LEN < BUFFER_WITH_SPILL_SIZE);
// Copy first part of input into end of buffer, possibly into spill
// element. The memcpy call is optimized away because the size is known.
let dst = (self.buf.as_mut_ptr() as *mut u8).add(nbuf);
ptr::copy_nonoverlapping(bytes.as_ptr(), dst, LEN);
// Process buffer.
for i in 0..BUFFER_CAPACITY {
let elem = self.buf.get_unchecked(i).assume_init().to_le();
self.state.v3 ^= elem;
Sip13Rounds::c_rounds(&mut self.state);
self.state.v0 ^= elem;
}
// Copy remaining input into start of buffer by copying LEN - 1
// elements from spill (at most LEN - 1 bytes could have overflowed
// into the spill). The memcpy call is optimized away because the size
// is known. And the whole copy is optimized away for LEN == 1.
let dst = self.buf.as_mut_ptr() as *mut u8;
let src = self.buf.get_unchecked(BUFFER_SPILL_INDEX) as *const _ as *const u8;
ptr::copy_nonoverlapping(src, dst, LEN - 1);
// This function should only be called when the write fills the buffer.
// Therefore, when LEN == 1, the new `self.nbuf` must be zero.
// LEN is statically known, so the branch is optimized away.
self.nbuf =
if LEN == 1 { 0 } else { nbuf.debug_strict_add(LEN).debug_strict_sub(BUFFER_SIZE) };
self.processed = self.processed.debug_strict_add(BUFFER_SIZE);
}
}
// A write function for byte slices.
#[inline]
fn slice_write(&mut self, msg: &[u8]) {
let length = msg.len();
let nbuf = self.nbuf;
debug_assert!(nbuf < BUFFER_SIZE);
if nbuf.debug_strict_add(length) < BUFFER_SIZE {
unsafe {
let dst = (self.buf.as_mut_ptr() as *mut u8).add(nbuf);
if length <= 8 {
copy_nonoverlapping_small(msg.as_ptr(), dst, length);
} else {
// This memcpy is *not* optimized away.
ptr::copy_nonoverlapping(msg.as_ptr(), dst, length);
}
}
self.nbuf = nbuf.debug_strict_add(length);
return;
}
unsafe { self.slice_write_process_buffer(msg) }
}
// A write function for byte slices that should only be called when the
// write would cause the buffer to fill.
//
// SAFETY: `self.buf` must be initialized up to the byte offset `self.nbuf`,
// and `msg` must contain enough bytes to initialize the rest of the element
// containing the byte offset `self.nbuf`.
#[inline(never)]
unsafe fn slice_write_process_buffer(&mut self, msg: &[u8]) {
unsafe {
let length = msg.len();
let nbuf = self.nbuf;
debug_assert!(nbuf < BUFFER_SIZE);
debug_assert!(nbuf + length >= BUFFER_SIZE);
// Always copy first part of input into current element of buffer.
// This function should only be called when the write fills the buffer,
// so we know that there is enough input to fill the current element.
let valid_in_elem = nbuf % ELEM_SIZE;
let needed_in_elem = ELEM_SIZE.debug_strict_sub(valid_in_elem);
let src = msg.as_ptr();
let dst = (self.buf.as_mut_ptr() as *mut u8).add(nbuf);
copy_nonoverlapping_small(src, dst, needed_in_elem);
// Process buffer.
// Using `nbuf / ELEM_SIZE + 1` rather than `(nbuf + needed_in_elem) /
// ELEM_SIZE` to show the compiler that this loop's upper bound is > 0.
// We know that is true, because last step ensured we have a full
// element in the buffer.
let last = (nbuf / ELEM_SIZE).debug_strict_add(1);
for i in 0..last {
let elem = self.buf.get_unchecked(i).assume_init().to_le();
self.state.v3 ^= elem;
Sip13Rounds::c_rounds(&mut self.state);
self.state.v0 ^= elem;
}
// Process the remaining element-sized chunks of input.
let mut processed = needed_in_elem;
let input_left = length.debug_strict_sub(processed);
let elems_left = input_left / ELEM_SIZE;
let extra_bytes_left = input_left % ELEM_SIZE;
for _ in 0..elems_left {
let elem = (msg.as_ptr().add(processed) as *const u64).read_unaligned().to_le();
self.state.v3 ^= elem;
Sip13Rounds::c_rounds(&mut self.state);
self.state.v0 ^= elem;
processed = processed.debug_strict_add(ELEM_SIZE);
}
// Copy remaining input into start of buffer.
let src = msg.as_ptr().add(processed);
let dst = self.buf.as_mut_ptr() as *mut u8;
copy_nonoverlapping_small(src, dst, extra_bytes_left);
self.nbuf = extra_bytes_left;
self.processed = self.processed.debug_strict_add(nbuf.debug_strict_add(processed));
}
}
#[inline]
pub fn finish128(mut self) -> (u64, u64) {
debug_assert!(self.nbuf < BUFFER_SIZE);
// Process full elements in buffer.
let last = self.nbuf / ELEM_SIZE;
// Since we're consuming self, avoid updating members for a potential
// performance gain.
let mut state = self.state;
for i in 0..last {
let elem = unsafe { self.buf.get_unchecked(i).assume_init().to_le() };
state.v3 ^= elem;
Sip13Rounds::c_rounds(&mut state);
state.v0 ^= elem;
}
// Get remaining partial element.
let elem = if self.nbuf % ELEM_SIZE != 0 {
unsafe {
// Ensure element is initialized by writing zero bytes. At most
// `ELEM_SIZE - 1` are required given the above check. It's safe
// to write this many because we have the spill and we maintain
// `self.nbuf` such that this write will start before the spill.
let dst = (self.buf.as_mut_ptr() as *mut u8).add(self.nbuf);
ptr::write_bytes(dst, 0, ELEM_SIZE - 1);
self.buf.get_unchecked(last).assume_init().to_le()
}
} else {
0
};
// Finalize the hash.
let length = self.processed.debug_strict_add(self.nbuf);
let b: u64 = ((length as u64 & 0xff) << 56) | elem;
state.v3 ^= b;
Sip13Rounds::c_rounds(&mut state);
state.v0 ^= b;
state.v2 ^= 0xee;
Sip13Rounds::d_rounds(&mut state);
let _0 = state.v0 ^ state.v1 ^ state.v2 ^ state.v3;
state.v1 ^= 0xdd;
Sip13Rounds::d_rounds(&mut state);
let _1 = state.v0 ^ state.v1 ^ state.v2 ^ state.v3;
(_0, _1)
}
}
impl Hasher for SipHasher128 {
#[inline]
fn write_u8(&mut self, i: u8) {
self.short_write(i.to_ne_bytes());
}
#[inline]
fn write_u16(&mut self, i: u16) {
self.short_write(i.to_ne_bytes());
}
#[inline]
fn write_u32(&mut self, i: u32) {
self.short_write(i.to_ne_bytes());
}
#[inline]
fn write_u64(&mut self, i: u64) {
self.short_write(i.to_ne_bytes());
}
#[inline]
fn write_usize(&mut self, i: usize) {
self.short_write(i.to_ne_bytes());
}
#[inline]
fn write_i8(&mut self, i: i8) {
self.short_write((i as u8).to_ne_bytes());
}
#[inline]
fn write_i16(&mut self, i: i16) {
self.short_write((i as u16).to_ne_bytes());
}
#[inline]
fn write_i32(&mut self, i: i32) {
self.short_write((i as u32).to_ne_bytes());
}
#[inline]
fn write_i64(&mut self, i: i64) {
self.short_write((i as u64).to_ne_bytes());
}
#[inline]
fn write_isize(&mut self, i: isize) {
self.short_write((i as usize).to_ne_bytes());
}
#[inline]
fn write(&mut self, msg: &[u8]) {
self.slice_write(msg);
}
#[inline]
fn write_str(&mut self, s: &str) {
// This hasher works byte-wise, and `0xFF` cannot show up in a `str`,
// so just hashing the one extra byte is enough to be prefix-free.
self.write(s.as_bytes());
self.write_u8(0xFF);
}
fn finish(&self) -> u64 {
panic!("SipHasher128 cannot provide valid 64 bit hashes")
}
}
#[derive(Debug, Clone, Default)]
struct Sip13Rounds;
impl Sip13Rounds {
#[inline]
fn c_rounds(state: &mut State) {
compress!(state);
}
#[inline]
fn d_rounds(state: &mut State) {
compress!(state);
compress!(state);
compress!(state);
}
}

304
compiler/rustc_data_structures/src/sip128/tests.rs
View File

@ -1,304 +0,0 @@
use super::*;
use std::hash::Hash;
// Hash just the bytes of the slice, without length prefix
struct Bytes<'a>(&'a [u8]);
impl<'a> Hash for Bytes<'a> {
#[allow(unused_must_use)]
fn hash<H: Hasher>(&self, state: &mut H) {
for byte in self.0 {
state.write_u8(*byte);
}
}
}
fn hash_with<T: Hash>(mut st: SipHasher128, x: &T) -> (u64, u64) {
x.hash(&mut st);
st.finish128()
}
fn hash<T: Hash>(x: &T) -> (u64, u64) {
hash_with(SipHasher128::new_with_keys(0, 0), x)
}
#[rustfmt::skip]
const TEST_VECTOR: [[u8; 16]; 64] = [
[0xe7, 0x7e, 0xbc, 0xb2, 0x27, 0x88, 0xa5, 0xbe, 0xfd, 0x62, 0xdb, 0x6a, 0xdd, 0x30, 0x30, 0x01],
[0xfc, 0x6f, 0x37, 0x04, 0x60, 0xd3, 0xed, 0xa8, 0x5e, 0x05, 0x73, 0xcc, 0x2b, 0x2f, 0xf0, 0x63],
[0x75, 0x78, 0x7f, 0x09, 0x05, 0x69, 0x83, 0x9b, 0x85, 0x5b, 0xc9, 0x54, 0x8c, 0x6a, 0xea, 0x95],
[0x6b, 0xc5, 0xcc, 0xfa, 0x1e, 0xdc, 0xf7, 0x9f, 0x48, 0x23, 0x18, 0x77, 0x12, 0xeb, 0xd7, 0x43],
[0x0c, 0x78, 0x4e, 0x71, 0xac, 0x2b, 0x28, 0x5a, 0x9f, 0x8e, 0x92, 0xe7, 0x8f, 0xbf, 0x2c, 0x25],
[0xf3, 0x28, 0xdb, 0x89, 0x34, 0x5b, 0x62, 0x0c, 0x79, 0x52, 0x29, 0xa4, 0x26, 0x95, 0x84, 0x3e],
[0xdc, 0xd0, 0x3d, 0x29, 0xf7, 0x43, 0xe7, 0x10, 0x09, 0x51, 0xb0, 0xe8, 0x39, 0x85, 0xa6, 0xf8],
[0x10, 0x84, 0xb9, 0x23, 0xf2, 0xaa, 0xe0, 0xc3, 0xa6, 0x2f, 0x2e, 0xc8, 0x08, 0x48, 0xab, 0x77],
[0xaa, 0x12, 0xfe, 0xe1, 0xd5, 0xe3, 0xda, 0xb4, 0x72, 0x4f, 0x16, 0xab, 0x35, 0xf9, 0xc7, 0x99],
[0x81, 0xdd, 0xb8, 0x04, 0x2c, 0xf3, 0x39, 0x94, 0xf4, 0x72, 0x0e, 0x00, 0x94, 0x13, 0x7c, 0x42],
[0x4f, 0xaa, 0x54, 0x1d, 0x5d, 0x49, 0x8e, 0x89, 0xba, 0x0e, 0xa4, 0xc3, 0x87, 0xb2, 0x2f, 0xb4],
[0x72, 0x3b, 0x9a, 0xf3, 0x55, 0x44, 0x91, 0xdb, 0xb1, 0xd6, 0x63, 0x3d, 0xfc, 0x6e, 0x0c, 0x4e],
[0xe5, 0x3f, 0x92, 0x85, 0x9e, 0x48, 0x19, 0xa8, 0xdc, 0x06, 0x95, 0x73, 0x9f, 0xea, 0x8c, 0x65],
[0xb2, 0xf8, 0x58, 0xc7, 0xc9, 0xea, 0x80, 0x1d, 0x53, 0xd6, 0x03, 0x59, 0x6d, 0x65, 0x78, 0x44],
[0x87, 0xe7, 0x62, 0x68, 0xdb, 0xc9, 0x22, 0x72, 0x26, 0xb0, 0xca, 0x66, 0x5f, 0x64, 0xe3, 0x78],
[0xc1, 0x7e, 0x55, 0x05, 0xb2, 0xbd, 0x52, 0x6c, 0x29, 0x21, 0xcd, 0xec, 0x1e, 0x7e, 0x01, 0x09],
[0xd0, 0xa8, 0xd9, 0x57, 0x15, 0x51, 0x8e, 0xeb, 0xb5, 0x13, 0xb0, 0xf8, 0x3d, 0x9e, 0x17, 0x93],
[0x23, 0x41, 0x26, 0xf9, 0x3f, 0xbb, 0x66, 0x8d, 0x97, 0x51, 0x12, 0xe8, 0xfe, 0xbd, 0xf7, 0xec],
[0xef, 0x42, 0xf0, 0x3d, 0xb7, 0x8f, 0x70, 0x4d, 0x02, 0x3c, 0x44, 0x9f, 0x16, 0xb7, 0x09, 0x2b],
[0xab, 0xf7, 0x62, 0x38, 0xc2, 0x0a, 0xf1, 0x61, 0xb2, 0x31, 0x4b, 0x4d, 0x55, 0x26, 0xbc, 0xe9],
[0x3c, 0x2c, 0x2f, 0x11, 0xbb, 0x90, 0xcf, 0x0b, 0xe3, 0x35, 0xca, 0x9b, 0x2e, 0x91, 0xe9, 0xb7],
[0x2a, 0x7a, 0x68, 0x0f, 0x22, 0xa0, 0x2a, 0x92, 0xf4, 0x51, 0x49, 0xd2, 0x0f, 0xec, 0xe0, 0xef],
[0xc9, 0xa8, 0xd1, 0x30, 0x23, 0x1d, 0xd4, 0x3e, 0x42, 0xe6, 0x45, 0x69, 0x57, 0xf8, 0x37, 0x79],
[0x1d, 0x12, 0x7b, 0x84, 0x40, 0x5c, 0xea, 0xb9, 0x9f, 0xd8, 0x77, 0x5a, 0x9b, 0xe6, 0xc5, 0x59],
[0x9e, 0x4b, 0xf8, 0x37, 0xbc, 0xfd, 0x92, 0xca, 0xce, 0x09, 0xd2, 0x06, 0x1a, 0x84, 0xd0, 0x4a],
[0x39, 0x03, 0x1a, 0x96, 0x5d, 0x73, 0xb4, 0xaf, 0x5a, 0x27, 0x4d, 0x18, 0xf9, 0x73, 0xb1, 0xd2],
[0x7f, 0x4d, 0x0a, 0x12, 0x09, 0xd6, 0x7e, 0x4e, 0xd0, 0x6f, 0x75, 0x38, 0xe1, 0xcf, 0xad, 0x64],
[0xe6, 0x1e, 0xe2, 0x40, 0xfb, 0xdc, 0xce, 0x38, 0x96, 0x9f, 0x4c, 0xd2, 0x49, 0x27, 0xdd, 0x93],
[0x4c, 0x3b, 0xa2, 0xb3, 0x7b, 0x0f, 0xdd, 0x8c, 0xfa, 0x5e, 0x95, 0xc1, 0x89, 0xb2, 0x94, 0x14],
[0xe0, 0x6f, 0xd4, 0xca, 0x06, 0x6f, 0xec, 0xdd, 0x54, 0x06, 0x8a, 0x5a, 0xd8, 0x89, 0x6f, 0x86],
[0x5c, 0xa8, 0x4c, 0x34, 0x13, 0x9c, 0x65, 0x80, 0xa8, 0x8a, 0xf2, 0x49, 0x90, 0x72, 0x07, 0x06],
[0x42, 0xea, 0x96, 0x1c, 0x5b, 0x3c, 0x85, 0x8b, 0x17, 0xc3, 0xe5, 0x50, 0xdf, 0xa7, 0x90, 0x10],
[0x40, 0x6c, 0x44, 0xde, 0xe6, 0x78, 0x57, 0xb2, 0x94, 0x31, 0x60, 0xf3, 0x0c, 0x74, 0x17, 0xd3],
[0xc5, 0xf5, 0x7b, 0xae, 0x13, 0x20, 0xfc, 0xf4, 0xb4, 0xe8, 0x68, 0xe7, 0x1d, 0x56, 0xc6, 0x6b],
[0x04, 0xbf, 0x73, 0x7a, 0x5b, 0x67, 0x6b, 0xe7, 0xc3, 0xde, 0x05, 0x01, 0x7d, 0xf4, 0xbf, 0xf9],
[0x51, 0x63, 0xc9, 0xc0, 0x3f, 0x19, 0x07, 0xea, 0x10, 0x44, 0xed, 0x5c, 0x30, 0x72, 0x7b, 0x4f],
[0x37, 0xa1, 0x10, 0xf0, 0x02, 0x71, 0x8e, 0xda, 0xd2, 0x4b, 0x3f, 0x9e, 0xe4, 0x53, 0xf1, 0x40],
[0xb9, 0x87, 0x7e, 0x38, 0x1a, 0xed, 0xd3, 0xda, 0x08, 0xc3, 0x3e, 0x75, 0xff, 0x23, 0xac, 0x10],
[0x7c, 0x50, 0x04, 0x00, 0x5e, 0xc5, 0xda, 0x4c, 0x5a, 0xc9, 0x44, 0x0e, 0x5c, 0x72, 0x31, 0x93],
[0x81, 0xb8, 0x24, 0x37, 0x83, 0xdb, 0xc6, 0x46, 0xca, 0x9d, 0x0c, 0xd8, 0x2a, 0xbd, 0xb4, 0x6c],
[0x50, 0x57, 0x20, 0x54, 0x3e, 0xb9, 0xb4, 0x13, 0xd5, 0x0b, 0x3c, 0xfa, 0xd9, 0xee, 0xf9, 0x38],
[0x94, 0x5f, 0x59, 0x4d, 0xe7, 0x24, 0x11, 0xe4, 0xd3, 0x35, 0xbe, 0x87, 0x44, 0x56, 0xd8, 0xf3],
[0x37, 0x92, 0x3b, 0x3e, 0x37, 0x17, 0x77, 0xb2, 0x11, 0x70, 0xbf, 0x9d, 0x7e, 0x62, 0xf6, 0x02],
[0x3a, 0xd4, 0xe7, 0xc8, 0x57, 0x64, 0x96, 0x46, 0x11, 0xeb, 0x0a, 0x6c, 0x4d, 0x62, 0xde, 0x56],
[0xcd, 0x91, 0x39, 0x6c, 0x44, 0xaf, 0x4f, 0x51, 0x85, 0x57, 0x8d, 0x9d, 0xd9, 0x80, 0x3f, 0x0a],
[0xfe, 0x28, 0x15, 0x8e, 0x72, 0x7b, 0x86, 0x8f, 0x39, 0x03, 0xc9, 0xac, 0xda, 0x64, 0xa2, 0x58],
[0x40, 0xcc, 0x10, 0xb8, 0x28, 0x8c, 0xe5, 0xf0, 0xbc, 0x3a, 0xc0, 0xb6, 0x8a, 0x0e, 0xeb, 0xc8],
[0x6f, 0x14, 0x90, 0xf5, 0x40, 0x69, 0x9a, 0x3c, 0xd4, 0x97, 0x44, 0x20, 0xec, 0xc9, 0x27, 0x37],
[0xd5, 0x05, 0xf1, 0xb7, 0x5e, 0x1a, 0x84, 0xa6, 0x03, 0xc4, 0x35, 0x83, 0xb2, 0xed, 0x03, 0x08],
[0x49, 0x15, 0x73, 0xcf, 0xd7, 0x2b, 0xb4, 0x68, 0x2b, 0x7c, 0xa5, 0x88, 0x0e, 0x1c, 0x8d, 0x6f],
[0x3e, 0xd6, 0x9c, 0xfe, 0x45, 0xab, 0x40, 0x3f, 0x2f, 0xd2, 0xad, 0x95, 0x9b, 0xa2, 0x76, 0x66],
[0x8b, 0xe8, 0x39, 0xef, 0x1b, 0x20, 0xb5, 0x7c, 0x83, 0xba, 0x7e, 0xb6, 0xa8, 0xc2, 0x2b, 0x6a],
[0x14, 0x09, 0x18, 0x6a, 0xb4, 0x22, 0x31, 0xfe, 0xde, 0xe1, 0x81, 0x62, 0xcf, 0x1c, 0xb4, 0xca],
[0x2b, 0xf3, 0xcc, 0xc2, 0x4a, 0xb6, 0x72, 0xcf, 0x15, 0x1f, 0xb8, 0xd2, 0xf3, 0xf3, 0x06, 0x9b],
[0xb9, 0xb9, 0x3a, 0x28, 0x82, 0xd6, 0x02, 0x5c, 0xdb, 0x8c, 0x56, 0xfa, 0x13, 0xf7, 0x53, 0x7b],
[0xd9, 0x7c, 0xca, 0x36, 0x94, 0xfb, 0x20, 0x6d, 0xb8, 0xbd, 0x1f, 0x36, 0x50, 0xc3, 0x33, 0x22],
[0x94, 0xec, 0x2e, 0x19, 0xa4, 0x0b, 0xe4, 0x1a, 0xf3, 0x94, 0x0d, 0x6b, 0x30, 0xc4, 0x93, 0x84],
[0x4b, 0x41, 0x60, 0x3f, 0x20, 0x9a, 0x04, 0x5b, 0xe1, 0x40, 0xa3, 0x41, 0xa3, 0xdf, 0xfe, 0x10],
[0x23, 0xfb, 0xcb, 0x30, 0x9f, 0x1c, 0xf0, 0x94, 0x89, 0x07, 0x55, 0xab, 0x1b, 0x42, 0x65, 0x69],
[0xe7, 0xd9, 0xb6, 0x56, 0x90, 0x91, 0x8a, 0x2b, 0x23, 0x2f, 0x2f, 0x5c, 0x12, 0xc8, 0x30, 0x0e],
[0xad, 0xe8, 0x3c, 0xf7, 0xe7, 0xf3, 0x84, 0x7b, 0x36, 0xfa, 0x4b, 0x54, 0xb0, 0x0d, 0xce, 0x61],
[0x06, 0x10, 0xc5, 0xf2, 0xee, 0x57, 0x1c, 0x8a, 0xc8, 0x0c, 0xbf, 0xe5, 0x38, 0xbd, 0xf1, 0xc7],
[0x27, 0x1d, 0x5d, 0x00, 0xfb, 0xdb, 0x5d, 0x15, 0x5d, 0x9d, 0xce, 0xa9, 0x7c, 0xb4, 0x02, 0x18],
[0x4c, 0x58, 0x00, 0xe3, 0x4e, 0xfe, 0x42, 0x6f, 0x07, 0x9f, 0x6b, 0x0a, 0xa7, 0x52, 0x60, 0xad],
];
#[test]
fn test_siphash_1_3_test_vector() {
let k0 = 0x_07_06_05_04_03_02_01_00;
let k1 = 0x_0f_0e_0d_0c_0b_0a_09_08;
let mut input: Vec<u8> = Vec::new();
for i in 0..64 {
let out = hash_with(SipHasher128::new_with_keys(k0, k1), &Bytes(&input[..]));
let expected = (
((TEST_VECTOR[i][0] as u64) << 0)
| ((TEST_VECTOR[i][1] as u64) << 8)
| ((TEST_VECTOR[i][2] as u64) << 16)
| ((TEST_VECTOR[i][3] as u64) << 24)
| ((TEST_VECTOR[i][4] as u64) << 32)
| ((TEST_VECTOR[i][5] as u64) << 40)
| ((TEST_VECTOR[i][6] as u64) << 48)
| ((TEST_VECTOR[i][7] as u64) << 56),
((TEST_VECTOR[i][8] as u64) << 0)
| ((TEST_VECTOR[i][9] as u64) << 8)
| ((TEST_VECTOR[i][10] as u64) << 16)
| ((TEST_VECTOR[i][11] as u64) << 24)
| ((TEST_VECTOR[i][12] as u64) << 32)
| ((TEST_VECTOR[i][13] as u64) << 40)
| ((TEST_VECTOR[i][14] as u64) << 48)
| ((TEST_VECTOR[i][15] as u64) << 56),
);
assert_eq!(out, expected);
input.push(i as u8);
}
}
#[test]
#[cfg(target_arch = "arm")]
fn test_hash_usize() {
let val = 0xdeadbeef_deadbeef_u64;
assert!(hash(&(val as u64)) != hash(&(val as usize)));
assert_eq!(hash(&(val as u32)), hash(&(val as usize)));
}
#[test]
#[cfg(target_arch = "x86_64")]
fn test_hash_usize() {
let val = 0xdeadbeef_deadbeef_u64;
assert_eq!(hash(&(val as u64)), hash(&(val as usize)));
assert!(hash(&(val as u32)) != hash(&(val as usize)));
}
#[test]
#[cfg(target_arch = "x86")]
fn test_hash_usize() {
let val = 0xdeadbeef_deadbeef_u64;
assert!(hash(&(val as u64)) != hash(&(val as usize)));
assert_eq!(hash(&(val as u32)), hash(&(val as usize)));
}
#[test]
fn test_hash_idempotent() {
let val64 = 0xdeadbeef_deadbeef_u64;
assert_eq!(hash(&val64), hash(&val64));
let val32 = 0xdeadbeef_u32;
assert_eq!(hash(&val32), hash(&val32));
}
#[test]
fn test_hash_no_bytes_dropped_64() {
let val = 0xdeadbeef_deadbeef_u64;
assert!(hash(&val) != hash(&zero_byte(val, 0)));
assert!(hash(&val) != hash(&zero_byte(val, 1)));
assert!(hash(&val) != hash(&zero_byte(val, 2)));
assert!(hash(&val) != hash(&zero_byte(val, 3)));
assert!(hash(&val) != hash(&zero_byte(val, 4)));
assert!(hash(&val) != hash(&zero_byte(val, 5)));
assert!(hash(&val) != hash(&zero_byte(val, 6)));
assert!(hash(&val) != hash(&zero_byte(val, 7)));
fn zero_byte(val: u64, byte: usize) -> u64 {
assert!(byte < 8);
val & !(0xff << (byte * 8))
}
}
#[test]
fn test_hash_no_bytes_dropped_32() {
let val = 0xdeadbeef_u32;
assert!(hash(&val) != hash(&zero_byte(val, 0)));
assert!(hash(&val) != hash(&zero_byte(val, 1)));
assert!(hash(&val) != hash(&zero_byte(val, 2)));
assert!(hash(&val) != hash(&zero_byte(val, 3)));
fn zero_byte(val: u32, byte: usize) -> u32 {
assert!(byte < 4);
val & !(0xff << (byte * 8))
}
}
#[test]
fn test_hash_no_concat_alias() {
let s = ("aa", "bb");
let t = ("aabb", "");
let u = ("a", "abb");
assert!(s != t && t != u);
assert!(hash(&s) != hash(&t) && hash(&s) != hash(&u));
let u = [1, 0, 0, 0];
let v = (&u[..1], &u[1..3], &u[3..]);
let w = (&u[..], &u[4..4], &u[4..4]);
assert!(v != w);
assert!(hash(&v) != hash(&w));
}
#[test]
fn test_short_write_works() {
let test_u8 = 0xFF_u8;
let test_u16 = 0x1122_u16;
let test_u32 = 0x22334455_u32;
let test_u64 = 0x33445566_778899AA_u64;
let test_u128 = 0x11223344_55667788_99AABBCC_DDEEFF77_u128;
let test_usize = 0xD0C0B0A0_usize;
let test_i8 = -1_i8;
let test_i16 = -2_i16;
let test_i32 = -3_i32;
let test_i64 = -4_i64;
let test_i128 = -5_i128;
let test_isize = -6_isize;
let mut h1 = SipHasher128::new_with_keys(0, 0);
h1.write(b"bytes");
h1.write(b"string");
h1.write_u8(test_u8);
h1.write_u16(test_u16);
h1.write_u32(test_u32);
h1.write_u64(test_u64);
h1.write_u128(test_u128);
h1.write_usize(test_usize);
h1.write_i8(test_i8);
h1.write_i16(test_i16);
h1.write_i32(test_i32);
h1.write_i64(test_i64);
h1.write_i128(test_i128);
h1.write_isize(test_isize);
let mut h2 = SipHasher128::new_with_keys(0, 0);
h2.write(b"bytes");
h2.write(b"string");
h2.write(&test_u8.to_ne_bytes());
h2.write(&test_u16.to_ne_bytes());
h2.write(&test_u32.to_ne_bytes());
h2.write(&test_u64.to_ne_bytes());
h2.write(&test_u128.to_ne_bytes());
h2.write(&test_usize.to_ne_bytes());
h2.write(&test_i8.to_ne_bytes());
h2.write(&test_i16.to_ne_bytes());
h2.write(&test_i32.to_ne_bytes());
h2.write(&test_i64.to_ne_bytes());
h2.write(&test_i128.to_ne_bytes());
h2.write(&test_isize.to_ne_bytes());
let h1_hash = h1.finish128();
let h2_hash = h2.finish128();
assert_eq!(h1_hash, h2_hash);
}
macro_rules! test_fill_buffer {
($type:ty, $write_method:ident) => {{
// Test filling and overfilling the buffer from all possible offsets
// for a given integer type and its corresponding write method.
const SIZE: usize = std::mem::size_of::<$type>();
let input = [42; BUFFER_SIZE];
let x = 0x01234567_89ABCDEF_76543210_FEDCBA98_u128 as $type;
let x_bytes = &x.to_ne_bytes();
for i in 1..=SIZE {
let s = &input[..BUFFER_SIZE - i];
let mut h1 = SipHasher128::new_with_keys(7, 13);
h1.write(s);
h1.$write_method(x);
let mut h2 = SipHasher128::new_with_keys(7, 13);
h2.write(s);
h2.write(x_bytes);
let h1_hash = h1.finish128();
let h2_hash = h2.finish128();
assert_eq!(h1_hash, h2_hash);
}
}};
}
#[test]
fn test_fill_buffer() {
test_fill_buffer!(u8, write_u8);
test_fill_buffer!(u16, write_u16);
test_fill_buffer!(u32, write_u32);
test_fill_buffer!(u64, write_u64);
test_fill_buffer!(u128, write_u128);
test_fill_buffer!(usize, write_usize);
test_fill_buffer!(i8, write_i8);
test_fill_buffer!(i16, write_i16);
test_fill_buffer!(i32, write_i32);
test_fill_buffer!(i64, write_i64);
test_fill_buffer!(i128, write_i128);
test_fill_buffer!(isize, write_isize);
}

162
compiler/rustc_data_structures/src/stable_hasher.rs
View File

@ -1,8 +1,6 @@
use crate::sip128::SipHasher128;
use rustc_index::bit_set::{self, BitSet}; use rustc_index::bit_set::{self, BitSet};
use rustc_index::{Idx, IndexSlice, IndexVec}; use rustc_index::{Idx, IndexSlice, IndexVec};
use smallvec::SmallVec; use smallvec::SmallVec;
use std::fmt;
use std::hash::{BuildHasher, Hash, Hasher}; use std::hash::{BuildHasher, Hash, Hasher};
use std::marker::PhantomData; use std::marker::PhantomData;
use std::mem; use std::mem;
@ -13,163 +11,9 @@
pub use crate::hashes::{Hash128, Hash64}; pub use crate::hashes::{Hash128, Hash64};
/// When hashing something that ends up affecting properties like symbol names, pub use rustc_stable_hash::FromStableHash;
/// we want these symbol names to be calculated independently of other factors pub use rustc_stable_hash::SipHasher128Hash as StableHasherHash;
/// like what architecture you're compiling *from*. pub use rustc_stable_hash::StableSipHasher128 as StableHasher;
///
/// To that end we always convert integers to little-endian format before
/// hashing and the architecture dependent `isize` and `usize` types are
/// extended to 64 bits if needed.
pub struct StableHasher {
state: SipHasher128,
}
impl fmt::Debug for StableHasher {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{:?}", self.state)
}
}
pub trait StableHasherResult: Sized {
fn finish(hasher: StableHasher) -> Self;
}
impl StableHasher {
#[inline]
pub fn new() -> Self {
StableHasher { state: SipHasher128::new_with_keys(0, 0) }
}
#[inline]
pub fn finish<W: StableHasherResult>(self) -> W {
W::finish(self)
}
}
impl StableHasher {
#[inline]
pub fn finalize(self) -> (u64, u64) {
self.state.finish128()
}
}
impl Hasher for StableHasher {
fn finish(&self) -> u64 {
panic!("use StableHasher::finalize instead");
}
#[inline]
fn write(&mut self, bytes: &[u8]) {
self.state.write(bytes);
}
#[inline]
fn write_str(&mut self, s: &str) {
self.state.write_str(s);
}
#[inline]
fn write_length_prefix(&mut self, len: usize) {
// Our impl for `usize` will extend it if needed.
self.write_usize(len);
}
#[inline]
fn write_u8(&mut self, i: u8) {
self.state.write_u8(i);
}
#[inline]
fn write_u16(&mut self, i: u16) {
self.state.short_write(i.to_le_bytes());
}
#[inline]
fn write_u32(&mut self, i: u32) {
self.state.short_write(i.to_le_bytes());
}
#[inline]
fn write_u64(&mut self, i: u64) {
self.state.short_write(i.to_le_bytes());
}
#[inline]
fn write_u128(&mut self, i: u128) {
self.write_u64(i as u64);
self.write_u64((i >> 64) as u64);
}
#[inline]
fn write_usize(&mut self, i: usize) {
// 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.short_write((i as u64).to_le_bytes());
}
#[inline]
fn write_i8(&mut self, i: i8) {
self.state.write_i8(i);
}
#[inline]
fn write_i16(&mut self, i: i16) {
self.state.short_write((i as u16).to_le_bytes());
}
#[inline]
fn write_i32(&mut self, i: i32) {
self.state.short_write((i as u32).to_le_bytes());
}
#[inline]
fn write_i64(&mut self, i: i64) {
self.state.short_write((i as u64).to_le_bytes());
}
#[inline]
fn write_i128(&mut self, i: i128) {
self.state.write(&(i as u128).to_le_bytes());
}
#[inline]
fn write_isize(&mut self, i: isize) {
// Always treat isize as a 64-bit number so we get the same results on 32 and 64 bit
// platforms. This is important for symbol hashes when cross compiling,
// for example. Sign extending here is preferable as it means that the
// same negative number hashes the same on both 32 and 64 bit platforms.
let value = i as u64;
// Cold path
#[cold]
#[inline(never)]
fn hash_value(state: &mut SipHasher128, value: u64) {
state.write_u8(0xFF);
state.short_write(value.to_le_bytes());
}
// `isize` values often seem to have a small (positive) numeric value in practice.
// To exploit this, if the value is small, we will hash a smaller amount of bytes.
// However, we cannot just skip the leading zero bytes, as that would produce the same hash
// e.g. if you hash two values that have the same bit pattern when they are swapped.
// See https://github.com/rust-lang/rust/pull/93014 for context.
//
// Therefore, we employ the following strategy:
// 1) When we encounter a value that fits within a single byte (the most common case), we
// hash just that byte. This is the most common case that is being optimized. However, we do
// not do this for the value 0xFF, as that is a reserved prefix (a bit like in UTF-8).
// 2) When we encounter a larger value, we hash a "marker" 0xFF and then the corresponding
// 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.
if value < 0xFF {
self.state.write_u8(value as u8);
} else {
hash_value(&mut self.state, value);
}
}
}
/// Something that implements `HashStable<CTX>` can be hashed in a way that is /// Something that implements `HashStable<CTX>` can be hashed in a way that is
/// stable across multiple compilation sessions. /// stable across multiple compilation sessions.

65
compiler/rustc_data_structures/src/stable_hasher/tests.rs
View File

@ -7,71 +7,6 @@
// ways). The expected values depend on the hashing algorithm used, so they // ways). The expected values depend on the hashing algorithm used, so they
// need to be updated whenever StableHasher changes its hashing algorithm. // need to be updated whenever StableHasher changes its hashing algorithm.
#[test]
fn test_hash_integers() {
// Test that integers are handled consistently across platforms.
let test_u8 = 0xAB_u8;
let test_u16 = 0xFFEE_u16;
let test_u32 = 0x445577AA_u32;
let test_u64 = 0x01234567_13243546_u64;
let test_u128 = 0x22114433_66557788_99AACCBB_EEDDFF77_u128;
let test_usize = 0xD0C0B0A0_usize;
let test_i8 = -100_i8;
let test_i16 = -200_i16;
let test_i32 = -300_i32;
let test_i64 = -400_i64;
let test_i128 = -500_i128;
let test_isize = -600_isize;
let mut h = StableHasher::new();
test_u8.hash(&mut h);
test_u16.hash(&mut h);
test_u32.hash(&mut h);
test_u64.hash(&mut h);
test_u128.hash(&mut h);
test_usize.hash(&mut h);
test_i8.hash(&mut h);
test_i16.hash(&mut h);
test_i32.hash(&mut h);
test_i64.hash(&mut h);
test_i128.hash(&mut h);
test_isize.hash(&mut h);
// This depends on the hashing algorithm. See note at top of file.
let expected = (13997337031081104755, 6178945012502239489);
assert_eq!(h.finalize(), expected);
}
#[test]
fn test_hash_usize() {
// Test that usize specifically is handled consistently across platforms.
let test_usize = 0xABCDEF01_usize;
let mut h = StableHasher::new();
test_usize.hash(&mut h);
// This depends on the hashing algorithm. See note at top of file.
let expected = (12037165114281468837, 3094087741167521712);
assert_eq!(h.finalize(), expected);
}
#[test]
fn test_hash_isize() {
// Test that isize specifically is handled consistently across platforms.
let test_isize = -7_isize;
let mut h = StableHasher::new();
test_isize.hash(&mut h);
// This depends on the hashing algorithm. See note at top of file.
let expected = (3979067582695659080, 2322428596355037273);
assert_eq!(h.finalize(), expected);
}
fn hash<T: HashStable<()>>(t: &T) -> Hash128 { fn hash<T: HashStable<()>>(t: &T) -> Hash128 {
let mut h = StableHasher::new(); let mut h = StableHasher::new();
let ctx = &mut (); let ctx = &mut ();

6
compiler/rustc_data_structures/src/tagged_ptr/copy/tests.rs
View File

@ -1,5 +1,6 @@
use std::ptr; use std::ptr;
use crate::hashes::Hash128;
use crate::stable_hasher::{HashStable, StableHasher}; use crate::stable_hasher::{HashStable, StableHasher};
use crate::tagged_ptr::{CopyTaggedPtr, Pointer, Tag, Tag2}; use crate::tagged_ptr::{CopyTaggedPtr, Pointer, Tag, Tag2};
@ -31,14 +32,13 @@ fn stable_hash_hashes_as_tuple() {
let hash_packed = { let hash_packed = {
let mut hasher = StableHasher::new(); let mut hasher = StableHasher::new();
tag_ptr(&12, Tag2::B11).hash_stable(&mut (), &mut hasher); tag_ptr(&12, Tag2::B11).hash_stable(&mut (), &mut hasher);
hasher.finish::<Hash128>()
hasher.finalize()
}; };
let hash_tupled = { let hash_tupled = {
let mut hasher = StableHasher::new(); let mut hasher = StableHasher::new();
(&12, Tag2::B11).hash_stable(&mut (), &mut hasher); (&12, Tag2::B11).hash_stable(&mut (), &mut hasher);
hasher.finalize() hasher.finish::<Hash128>()
}; };
assert_eq!(hash_packed, hash_tupled); assert_eq!(hash_packed, hash_tupled);

1
src/tools/tidy/src/deps.rs
View File

@ -353,6 +353,7 @@
"rustc-hash", "rustc-hash",
"rustc-rayon", "rustc-rayon",
"rustc-rayon-core", "rustc-rayon-core",
"rustc-stable-hash",
"rustc_apfloat", "rustc_apfloat",
"rustc_version", "rustc_version",
"rustix", "rustix",