Rollup merge of #59283 - SimonSapin:branchless-ascii-case, r=joshtriplett
Make ASCII case conversions more than 4× faster Reformatted output of `./x.py bench src/libcore --test-args ascii` below. The `libcore` benchmark calls `[u8]::make_ascii_lowercase`. `lookup` has code (effectively) identical to that before this PR, and ~~`branchless`~~ `mask_shifted_bool_match_range` after this PR. ~~See [code comments](https://github.com/rust-lang/rust/pull/59283/commits/ce933f77c865a15670855ac5941fe200752b739f#diff-01076f91a26400b2db49663d787c2576R3796) in `u8::to_ascii_uppercase` in `src/libcore/num/mod.rs` for an explanation of the branchless algorithm.~~ **Update:** the algorithm was simplified while keeping the performance. See `branchless` v.s. `mask_shifted_bool_match_range` benchmarks. Credits to @raphlinus for the idea in https://twitter.com/raphlinus/status/1107654782544736261, which extends this algorithm to “fake SIMD” on `u32` to convert four bytes at a time. The `fake_simd_u32` benchmarks implements this with [`let (before, aligned, after) = bytes.align_to_mut::<u32>()`](https://doc.rust-lang.org/std/primitive.slice.html#method.align_to_mut). Note however that this is buggy when addition carries/overflows into the next byte (which does not happen if the input is known to be ASCII). This could be fixed (to optimize `[u8]::make_ascii_lowercase` and `[u8]::make_ascii_uppercase` in `src/libcore/slice/mod.rs`) either with some more bitwise trickery that I didn’t quite figure out, or by using “real” SIMD intrinsics for byte-wise addition. I did not pursue this however because the current (incorrect) fake SIMD algorithm is only marginally faster than the one-byte-at-a-time branchless algorithm. This is because LLVM auto-vectorizes the latter, as can be seen on https://rust.godbolt.org/z/anKtbR. Benchmark results on Linux x64 with Intel i7-7700K: (updated from https://github.com/rust-lang/rust/pull/59283#issuecomment-474146863) ```rust 6830 bytes string: alloc_only ... bench: 112 ns/iter (+/- 0) = 62410 MB/s black_box_read_each_byte ... bench: 1,733 ns/iter (+/- 8) = 4033 MB/s lookup_table ... bench: 1,766 ns/iter (+/- 11) = 3958 MB/s branch_and_subtract ... bench: 417 ns/iter (+/- 1) = 16762 MB/s branch_and_mask ... bench: 401 ns/iter (+/- 1) = 17431 MB/s branchless ... bench: 365 ns/iter (+/- 0) = 19150 MB/s libcore ... bench: 367 ns/iter (+/- 1) = 19046 MB/s fake_simd_u32 ... bench: 361 ns/iter (+/- 2) = 19362 MB/s fake_simd_u64 ... bench: 361 ns/iter (+/- 1) = 19362 MB/s mask_mult_bool_branchy_lookup_table ... bench: 6,309 ns/iter (+/- 19) = 1107 MB/s mask_mult_bool_lookup_table ... bench: 4,183 ns/iter (+/- 29) = 1671 MB/s mask_mult_bool_match_range ... bench: 339 ns/iter (+/- 0) = 20619 MB/s mask_shifted_bool_match_range ... bench: 339 ns/iter (+/- 1) = 20619 MB/s 32 bytes string: alloc_only ... bench: 15 ns/iter (+/- 0) = 2133 MB/s black_box_read_each_byte ... bench: 29 ns/iter (+/- 0) = 1103 MB/s lookup_table ... bench: 24 ns/iter (+/- 4) = 1333 MB/s branch_and_subtract ... bench: 16 ns/iter (+/- 0) = 2000 MB/s branch_and_mask ... bench: 16 ns/iter (+/- 0) = 2000 MB/s branchless ... bench: 16 ns/iter (+/- 0) = 2000 MB/s libcore ... bench: 15 ns/iter (+/- 0) = 2133 MB/s fake_simd_u32 ... bench: 17 ns/iter (+/- 0) = 1882 MB/s fake_simd_u64 ... bench: 16 ns/iter (+/- 0) = 2000 MB/s mask_mult_bool_branchy_lookup_table ... bench: 42 ns/iter (+/- 0) = 761 MB/s mask_mult_bool_lookup_table ... bench: 35 ns/iter (+/- 0) = 914 MB/s mask_mult_bool_match_range ... bench: 16 ns/iter (+/- 0) = 2000 MB/s mask_shifted_bool_match_range ... bench: 16 ns/iter (+/- 0) = 2000 MB/s 7 bytes string: alloc_only ... bench: 14 ns/iter (+/- 0) = 500 MB/s black_box_read_each_byte ... bench: 22 ns/iter (+/- 0) = 318 MB/s lookup_table ... bench: 16 ns/iter (+/- 0) = 437 MB/s branch_and_subtract ... bench: 16 ns/iter (+/- 0) = 437 MB/s branch_and_mask ... bench: 16 ns/iter (+/- 0) = 437 MB/s branchless ... bench: 19 ns/iter (+/- 0) = 368 MB/s libcore ... bench: 20 ns/iter (+/- 0) = 350 MB/s fake_simd_u32 ... bench: 18 ns/iter (+/- 0) = 388 MB/s fake_simd_u64 ... bench: 21 ns/iter (+/- 0) = 333 MB/s mask_mult_bool_branchy_lookup_table ... bench: 20 ns/iter (+/- 0) = 350 MB/s mask_mult_bool_lookup_table ... bench: 19 ns/iter (+/- 0) = 368 MB/s mask_mult_bool_match_range ... bench: 19 ns/iter (+/- 0) = 368 MB/s mask_shifted_bool_match_range ... bench: 19 ns/iter (+/- 0) = 368 MB/s ```
This commit is contained in:
Josh Stone
GitHub
commit
c70cdc0ed4
3 changed files with 374 additions and 135 deletions
349
src/libcore/benches/ascii.rs
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349
src/libcore/benches/ascii.rs
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@ -0,0 +1,349 @@
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// Lower-case ASCII 'a' is the first byte that has its highest bit set
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// after wrap-adding 0x1F:
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//
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// b'a' + 0x1F == 0x80 == 0b1000_0000
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// b'z' + 0x1F == 0x98 == 0b10011000
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//
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// Lower-case ASCII 'z' is the last byte that has its highest bit unset
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// after wrap-adding 0x05:
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//
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// b'a' + 0x05 == 0x66 == 0b0110_0110
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// b'z' + 0x05 == 0x7F == 0b0111_1111
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//
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// … except for 0xFB to 0xFF, but those are in the range of bytes
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// that have the highest bit unset again after adding 0x1F.
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//
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// So `(byte + 0x1f) & !(byte + 5)` has its highest bit set
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// iff `byte` is a lower-case ASCII letter.
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//
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// Lower-case ASCII letters all have the 0x20 bit set.
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// (Two positions right of 0x80, the highest bit.)
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// Unsetting that bit produces the same letter, in upper-case.
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//
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// Therefore:
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fn branchless_to_ascii_upper_case(byte: u8) -> u8 {
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byte &
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!(
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(
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byte.wrapping_add(0x1f) &
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!byte.wrapping_add(0x05) &
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0x80
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) >> 2
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)
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}
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macro_rules! benches {
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($( fn $name: ident($arg: ident: &mut [u8]) $body: block )+ @iter $( $is_: ident, )+) => {
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benches! {@
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$( fn $name($arg: &mut [u8]) $body )+
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$( fn $is_(bytes: &mut [u8]) { bytes.iter().all(u8::$is_) } )+
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}
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};
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(@$( fn $name: ident($arg: ident: &mut [u8]) $body: block )+) => {
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benches!(mod short SHORT $($name $arg $body)+);
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benches!(mod medium MEDIUM $($name $arg $body)+);
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benches!(mod long LONG $($name $arg $body)+);
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};
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(mod $mod_name: ident $input: ident $($name: ident $arg: ident $body: block)+) => {
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mod $mod_name {
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use super::*;
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$(
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#[bench]
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fn $name(bencher: &mut Bencher) {
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bencher.bytes = $input.len() as u64;
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bencher.iter(|| {
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let mut vec = $input.as_bytes().to_vec();
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{
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let $arg = &mut vec[..];
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black_box($body);
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}
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vec
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})
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}
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)+
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}
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}
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}
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use test::black_box;
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use test::Bencher;
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benches! {
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fn case00_alloc_only(_bytes: &mut [u8]) {}
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fn case01_black_box_read_each_byte(bytes: &mut [u8]) {
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for byte in bytes {
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black_box(*byte);
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}
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}
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fn case02_lookup_table(bytes: &mut [u8]) {
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for byte in bytes {
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*byte = ASCII_UPPERCASE_MAP[*byte as usize]
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}
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}
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fn case03_branch_and_subtract(bytes: &mut [u8]) {
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for byte in bytes {
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*byte = if b'a' <= *byte && *byte <= b'z' {
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*byte - b'a' + b'A'
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} else {
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*byte
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}
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}
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}
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fn case04_branch_and_mask(bytes: &mut [u8]) {
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for byte in bytes {
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*byte = if b'a' <= *byte && *byte <= b'z' {
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*byte & !0x20
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} else {
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*byte
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}
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}
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}
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fn case05_branchless(bytes: &mut [u8]) {
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for byte in bytes {
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*byte = branchless_to_ascii_upper_case(*byte)
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}
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}
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fn case06_libcore(bytes: &mut [u8]) {
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bytes.make_ascii_uppercase()
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}
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fn case07_fake_simd_u32(bytes: &mut [u8]) {
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let (before, aligned, after) = unsafe {
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bytes.align_to_mut::<u32>()
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};
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for byte in before {
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*byte = branchless_to_ascii_upper_case(*byte)
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}
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for word in aligned {
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// FIXME: this is incorrect for some byte values:
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// addition within a byte can carry/overflow into the next byte.
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// Test case: b"\xFFz "
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*word &= !(
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(
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word.wrapping_add(0x1f1f1f1f) &
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!word.wrapping_add(0x05050505) &
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0x80808080
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) >> 2
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)
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}
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for byte in after {
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*byte = branchless_to_ascii_upper_case(*byte)
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}
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}
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fn case08_fake_simd_u64(bytes: &mut [u8]) {
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let (before, aligned, after) = unsafe {
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bytes.align_to_mut::<u64>()
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};
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for byte in before {
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*byte = branchless_to_ascii_upper_case(*byte)
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}
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for word in aligned {
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// FIXME: like above, this is incorrect for some byte values.
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*word &= !(
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(
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word.wrapping_add(0x1f1f1f1f_1f1f1f1f) &
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!word.wrapping_add(0x05050505_05050505) &
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0x80808080_80808080
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) >> 2
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)
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}
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for byte in after {
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*byte = branchless_to_ascii_upper_case(*byte)
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}
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}
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fn case09_mask_mult_bool_branchy_lookup_table(bytes: &mut [u8]) {
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fn is_ascii_lowercase(b: u8) -> bool {
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if b >= 0x80 { return false }
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match ASCII_CHARACTER_CLASS[b as usize] {
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L | Lx => true,
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_ => false,
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}
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}
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for byte in bytes {
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*byte &= !(0x20 * (is_ascii_lowercase(*byte) as u8))
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}
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}
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fn case10_mask_mult_bool_lookup_table(bytes: &mut [u8]) {
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fn is_ascii_lowercase(b: u8) -> bool {
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match ASCII_CHARACTER_CLASS[b as usize] {
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L | Lx => true,
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_ => false
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}
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}
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for byte in bytes {
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*byte &= !(0x20 * (is_ascii_lowercase(*byte) as u8))
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}
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}
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fn case11_mask_mult_bool_match_range(bytes: &mut [u8]) {
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fn is_ascii_lowercase(b: u8) -> bool {
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match b {
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b'a'...b'z' => true,
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_ => false
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}
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}
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for byte in bytes {
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*byte &= !(0x20 * (is_ascii_lowercase(*byte) as u8))
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}
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}
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fn case12_mask_shifted_bool_match_range(bytes: &mut [u8]) {
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fn is_ascii_lowercase(b: u8) -> bool {
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match b {
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b'a'...b'z' => true,
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_ => false
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}
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}
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for byte in bytes {
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*byte &= !((is_ascii_lowercase(*byte) as u8) << 5)
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}
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}
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fn case13_subtract_shifted_bool_match_range(bytes: &mut [u8]) {
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fn is_ascii_lowercase(b: u8) -> bool {
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match b {
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b'a'...b'z' => true,
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_ => false
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}
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}
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for byte in bytes {
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*byte -= (is_ascii_lowercase(*byte) as u8) << 5
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}
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}
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fn case14_subtract_multiplied_bool_match_range(bytes: &mut [u8]) {
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fn is_ascii_lowercase(b: u8) -> bool {
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match b {
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b'a'...b'z' => true,
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_ => false
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}
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}
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for byte in bytes {
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*byte -= (b'a' - b'A') * is_ascii_lowercase(*byte) as u8
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}
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}
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@iter
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is_ascii,
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is_ascii_alphabetic,
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is_ascii_uppercase,
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is_ascii_lowercase,
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is_ascii_alphanumeric,
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is_ascii_digit,
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is_ascii_hexdigit,
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is_ascii_punctuation,
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is_ascii_graphic,
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is_ascii_whitespace,
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is_ascii_control,
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}
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macro_rules! repeat {
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($s: expr) => { concat!($s, $s, $s, $s, $s, $s, $s, $s, $s, $s) }
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}
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const SHORT: &'static str = "Alice's";
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const MEDIUM: &'static str = "Alice's Adventures in Wonderland";
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const LONG: &'static str = repeat!(r#"
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La Guida di Bragia, a Ballad Opera for the Marionette Theatre (around 1850)
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Alice's Adventures in Wonderland (1865)
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Phantasmagoria and Other Poems (1869)
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Through the Looking-Glass, and What Alice Found There
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(includes "Jabberwocky" and "The Walrus and the Carpenter") (1871)
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The Hunting of the Snark (1876)
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Rhyme? And Reason? (1883) – shares some contents with the 1869 collection,
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including the long poem "Phantasmagoria"
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A Tangled Tale (1885)
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Sylvie and Bruno (1889)
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Sylvie and Bruno Concluded (1893)
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Pillow Problems (1893)
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What the Tortoise Said to Achilles (1895)
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Three Sunsets and Other Poems (1898)
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The Manlet (1903)[106]
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"#);
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const ASCII_UPPERCASE_MAP: [u8; 256] = [
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0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
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0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
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0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
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0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
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b' ', b'!', b'"', b'#', b'$', b'%', b'&', b'\'',
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b'(', b')', b'*', b'+', b',', b'-', b'.', b'/',
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b'0', b'1', b'2', b'3', b'4', b'5', b'6', b'7',
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b'8', b'9', b':', b';', b'<', b'=', b'>', b'?',
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b'@', b'A', b'B', b'C', b'D', b'E', b'F', b'G',
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b'H', b'I', b'J', b'K', b'L', b'M', b'N', b'O',
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b'P', b'Q', b'R', b'S', b'T', b'U', b'V', b'W',
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b'X', b'Y', b'Z', b'[', b'\\', b']', b'^', b'_',
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b'`',
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b'A', b'B', b'C', b'D', b'E', b'F', b'G',
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b'H', b'I', b'J', b'K', b'L', b'M', b'N', b'O',
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b'P', b'Q', b'R', b'S', b'T', b'U', b'V', b'W',
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b'X', b'Y', b'Z',
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b'{', b'|', b'}', b'~', 0x7f,
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0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
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0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
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0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
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0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
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0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
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0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
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0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
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0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
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0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
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0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
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0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
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0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
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0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
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0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
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0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
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0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
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];
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enum AsciiCharacterClass {
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C, // control
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Cw, // control whitespace
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W, // whitespace
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D, // digit
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L, // lowercase
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Lx, // lowercase hex digit
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U, // uppercase
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Ux, // uppercase hex digit
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P, // punctuation
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N, // Non-ASCII
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}
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use self::AsciiCharacterClass::*;
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static ASCII_CHARACTER_CLASS: [AsciiCharacterClass; 256] = [
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// _0 _1 _2 _3 _4 _5 _6 _7 _8 _9 _a _b _c _d _e _f
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C, C, C, C, C, C, C, C, C, Cw,Cw,C, Cw,Cw,C, C, // 0_
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C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, // 1_
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W, P, P, P, P, P, P, P, P, P, P, P, P, P, P, P, // 2_
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D, D, D, D, D, D, D, D, D, D, P, P, P, P, P, P, // 3_
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P, Ux,Ux,Ux,Ux,Ux,Ux,U, U, U, U, U, U, U, U, U, // 4_
|
||||
U, U, U, U, U, U, U, U, U, U, U, P, P, P, P, P, // 5_
|
||||
P, Lx,Lx,Lx,Lx,Lx,Lx,L, L, L, L, L, L, L, L, L, // 6_
|
||||
L, L, L, L, L, L, L, L, L, L, L, P, P, P, P, C, // 7_
|
||||
N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
|
||||
N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
|
||||
N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
|
||||
N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
|
||||
N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
|
||||
N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
|
||||
N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
|
||||
N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
|
||||
];
|
||||
|
|
@ -5,6 +5,7 @@ extern crate core;
|
|||
extern crate test;
|
||||
|
||||
mod any;
|
||||
mod ascii;
|
||||
mod char;
|
||||
mod hash;
|
||||
mod iter;
|
||||
|
|
|
|||
|
|
@ -3794,7 +3794,8 @@ impl u8 {
|
|||
#[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")]
|
||||
#[inline]
|
||||
pub fn to_ascii_uppercase(&self) -> u8 {
|
||||
ASCII_UPPERCASE_MAP[*self as usize]
|
||||
// Unset the fith bit if this is a lowercase letter
|
||||
*self & !((self.is_ascii_lowercase() as u8) << 5)
|
||||
}
|
||||
|
||||
/// Makes a copy of the value in its ASCII lower case equivalent.
|
||||
|
|
@ -3816,7 +3817,8 @@ impl u8 {
|
|||
#[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")]
|
||||
#[inline]
|
||||
pub fn to_ascii_lowercase(&self) -> u8 {
|
||||
ASCII_LOWERCASE_MAP[*self as usize]
|
||||
// Set the fith bit if this is an uppercase letter
|
||||
*self | ((self.is_ascii_uppercase() as u8) << 5)
|
||||
}
|
||||
|
||||
/// Checks that two values are an ASCII case-insensitive match.
|
||||
|
|
@ -3918,9 +3920,8 @@ impl u8 {
|
|||
#[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
|
||||
#[inline]
|
||||
pub fn is_ascii_alphabetic(&self) -> bool {
|
||||
if *self >= 0x80 { return false; }
|
||||
match ASCII_CHARACTER_CLASS[*self as usize] {
|
||||
L | Lx | U | Ux => true,
|
||||
match *self {
|
||||
b'A'...b'Z' | b'a'...b'z' => true,
|
||||
_ => false
|
||||
}
|
||||
}
|
||||
|
|
@ -3954,9 +3955,8 @@ impl u8 {
|
|||
#[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
|
||||
#[inline]
|
||||
pub fn is_ascii_uppercase(&self) -> bool {
|
||||
if *self >= 0x80 { return false }
|
||||
match ASCII_CHARACTER_CLASS[*self as usize] {
|
||||
U | Ux => true,
|
||||
match *self {
|
||||
b'A'...b'Z' => true,
|
||||
_ => false
|
||||
}
|
||||
}
|
||||
|
|
@ -3990,9 +3990,8 @@ impl u8 {
|
|||
#[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
|
||||
#[inline]
|
||||
pub fn is_ascii_lowercase(&self) -> bool {
|
||||
if *self >= 0x80 { return false }
|
||||
match ASCII_CHARACTER_CLASS[*self as usize] {
|
||||
L | Lx => true,
|
||||
match *self {
|
||||
b'a'...b'z' => true,
|
||||
_ => false
|
||||
}
|
||||
}
|
||||
|
|
@ -4029,9 +4028,8 @@ impl u8 {
|
|||
#[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
|
||||
#[inline]
|
||||
pub fn is_ascii_alphanumeric(&self) -> bool {
|
||||
if *self >= 0x80 { return false }
|
||||
match ASCII_CHARACTER_CLASS[*self as usize] {
|
||||
D | L | Lx | U | Ux => true,
|
||||
match *self {
|
||||
b'0'...b'9' | b'A'...b'Z' | b'a'...b'z' => true,
|
||||
_ => false
|
||||
}
|
||||
}
|
||||
|
|
@ -4065,9 +4063,8 @@ impl u8 {
|
|||
#[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
|
||||
#[inline]
|
||||
pub fn is_ascii_digit(&self) -> bool {
|
||||
if *self >= 0x80 { return false }
|
||||
match ASCII_CHARACTER_CLASS[*self as usize] {
|
||||
D => true,
|
||||
match *self {
|
||||
b'0'...b'9' => true,
|
||||
_ => false
|
||||
}
|
||||
}
|
||||
|
|
@ -4104,9 +4101,8 @@ impl u8 {
|
|||
#[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
|
||||
#[inline]
|
||||
pub fn is_ascii_hexdigit(&self) -> bool {
|
||||
if *self >= 0x80 { return false }
|
||||
match ASCII_CHARACTER_CLASS[*self as usize] {
|
||||
D | Lx | Ux => true,
|
||||
match *self {
|
||||
b'0'...b'9' | b'A'...b'F' | b'a'...b'f' => true,
|
||||
_ => false
|
||||
}
|
||||
}
|
||||
|
|
@ -4144,9 +4140,8 @@ impl u8 {
|
|||
#[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
|
||||
#[inline]
|
||||
pub fn is_ascii_punctuation(&self) -> bool {
|
||||
if *self >= 0x80 { return false }
|
||||
match ASCII_CHARACTER_CLASS[*self as usize] {
|
||||
P => true,
|
||||
match *self {
|
||||
b'!'...b'/' | b':'...b'@' | b'['...b'`' | b'{'...b'~' => true,
|
||||
_ => false
|
||||
}
|
||||
}
|
||||
|
|
@ -4180,9 +4175,8 @@ impl u8 {
|
|||
#[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
|
||||
#[inline]
|
||||
pub fn is_ascii_graphic(&self) -> bool {
|
||||
if *self >= 0x80 { return false; }
|
||||
match ASCII_CHARACTER_CLASS[*self as usize] {
|
||||
Ux | U | Lx | L | D | P => true,
|
||||
match *self {
|
||||
b'!'...b'~' => true,
|
||||
_ => false
|
||||
}
|
||||
}
|
||||
|
|
@ -4233,9 +4227,8 @@ impl u8 {
|
|||
#[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
|
||||
#[inline]
|
||||
pub fn is_ascii_whitespace(&self) -> bool {
|
||||
if *self >= 0x80 { return false; }
|
||||
match ASCII_CHARACTER_CLASS[*self as usize] {
|
||||
Cw | W => true,
|
||||
match *self {
|
||||
b'\t' | b'\n' | b'\x0C' | b'\r' | b' ' => true,
|
||||
_ => false
|
||||
}
|
||||
}
|
||||
|
|
@ -4271,9 +4264,8 @@ impl u8 {
|
|||
#[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
|
||||
#[inline]
|
||||
pub fn is_ascii_control(&self) -> bool {
|
||||
if *self >= 0x80 { return false; }
|
||||
match ASCII_CHARACTER_CLASS[*self as usize] {
|
||||
C | Cw => true,
|
||||
match *self {
|
||||
b'\0'...b'\x1F' | b'\x7F' => true,
|
||||
_ => false
|
||||
}
|
||||
}
|
||||
|
|
@ -4939,106 +4931,3 @@ impl_from! { u32, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0"
|
|||
|
||||
// Float -> Float
|
||||
impl_from! { f32, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")] }
|
||||
|
||||
static ASCII_LOWERCASE_MAP: [u8; 256] = [
|
||||
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
|
||||
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
|
||||
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
|
||||
0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
|
||||
b' ', b'!', b'"', b'#', b'$', b'%', b'&', b'\'',
|
||||
b'(', b')', b'*', b'+', b',', b'-', b'.', b'/',
|
||||
b'0', b'1', b'2', b'3', b'4', b'5', b'6', b'7',
|
||||
b'8', b'9', b':', b';', b'<', b'=', b'>', b'?',
|
||||
b'@',
|
||||
|
||||
b'a', b'b', b'c', b'd', b'e', b'f', b'g',
|
||||
b'h', b'i', b'j', b'k', b'l', b'm', b'n', b'o',
|
||||
b'p', b'q', b'r', b's', b't', b'u', b'v', b'w',
|
||||
b'x', b'y', b'z',
|
||||
|
||||
b'[', b'\\', b']', b'^', b'_',
|
||||
b'`', b'a', b'b', b'c', b'd', b'e', b'f', b'g',
|
||||
b'h', b'i', b'j', b'k', b'l', b'm', b'n', b'o',
|
||||
b'p', b'q', b'r', b's', b't', b'u', b'v', b'w',
|
||||
b'x', b'y', b'z', b'{', b'|', b'}', b'~', 0x7f,
|
||||
0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
|
||||
0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
|
||||
0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
|
||||
0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
|
||||
0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
|
||||
0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
|
||||
0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
|
||||
0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
|
||||
0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
|
||||
0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
|
||||
0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
|
||||
0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
|
||||
0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
|
||||
0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
|
||||
0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
|
||||
0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
|
||||
];
|
||||
|
||||
static ASCII_UPPERCASE_MAP: [u8; 256] = [
|
||||
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
|
||||
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
|
||||
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
|
||||
0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
|
||||
b' ', b'!', b'"', b'#', b'$', b'%', b'&', b'\'',
|
||||
b'(', b')', b'*', b'+', b',', b'-', b'.', b'/',
|
||||
b'0', b'1', b'2', b'3', b'4', b'5', b'6', b'7',
|
||||
b'8', b'9', b':', b';', b'<', b'=', b'>', b'?',
|
||||
b'@', b'A', b'B', b'C', b'D', b'E', b'F', b'G',
|
||||
b'H', b'I', b'J', b'K', b'L', b'M', b'N', b'O',
|
||||
b'P', b'Q', b'R', b'S', b'T', b'U', b'V', b'W',
|
||||
b'X', b'Y', b'Z', b'[', b'\\', b']', b'^', b'_',
|
||||
b'`',
|
||||
|
||||
b'A', b'B', b'C', b'D', b'E', b'F', b'G',
|
||||
b'H', b'I', b'J', b'K', b'L', b'M', b'N', b'O',
|
||||
b'P', b'Q', b'R', b'S', b'T', b'U', b'V', b'W',
|
||||
b'X', b'Y', b'Z',
|
||||
|
||||
b'{', b'|', b'}', b'~', 0x7f,
|
||||
0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
|
||||
0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
|
||||
0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
|
||||
0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
|
||||
0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
|
||||
0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
|
||||
0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
|
||||
0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
|
||||
0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
|
||||
0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
|
||||
0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
|
||||
0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
|
||||
0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
|
||||
0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
|
||||
0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
|
||||
0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
|
||||
];
|
||||
|
||||
enum AsciiCharacterClass {
|
||||
C, // control
|
||||
Cw, // control whitespace
|
||||
W, // whitespace
|
||||
D, // digit
|
||||
L, // lowercase
|
||||
Lx, // lowercase hex digit
|
||||
U, // uppercase
|
||||
Ux, // uppercase hex digit
|
||||
P, // punctuation
|
||||
}
|
||||
use self::AsciiCharacterClass::*;
|
||||
|
||||
static ASCII_CHARACTER_CLASS: [AsciiCharacterClass; 128] = [
|
||||
// _0 _1 _2 _3 _4 _5 _6 _7 _8 _9 _a _b _c _d _e _f
|
||||
C, C, C, C, C, C, C, C, C, Cw,Cw,C, Cw,Cw,C, C, // 0_
|
||||
C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, // 1_
|
||||
W, P, P, P, P, P, P, P, P, P, P, P, P, P, P, P, // 2_
|
||||
D, D, D, D, D, D, D, D, D, D, P, P, P, P, P, P, // 3_
|
||||
P, Ux,Ux,Ux,Ux,Ux,Ux,U, U, U, U, U, U, U, U, U, // 4_
|
||||
U, U, U, U, U, U, U, U, U, U, U, P, P, P, P, P, // 5_
|
||||
P, Lx,Lx,Lx,Lx,Lx,Lx,L, L, L, L, L, L, L, L, L, // 6_
|
||||
L, L, L, L, L, L, L, L, L, L, L, P, P, P, P, C, // 7_
|
||||
];
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue