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Diffstat (limited to 'vendor/encoding_rs/src/ascii.rs')
| -rw-r--r-- | vendor/encoding_rs/src/ascii.rs | 1546 |
1 files changed, 1546 insertions, 0 deletions
diff --git a/vendor/encoding_rs/src/ascii.rs b/vendor/encoding_rs/src/ascii.rs new file mode 100644 index 000000000..90644de7a --- /dev/null +++ b/vendor/encoding_rs/src/ascii.rs @@ -0,0 +1,1546 @@ +// Copyright Mozilla Foundation. See the COPYRIGHT +// file at the top-level directory of this distribution. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// It's assumed that in due course Rust will have explicit SIMD but will not +// be good at run-time selection of SIMD vs. no-SIMD. In such a future, +// x86_64 will always use SSE2 and 32-bit x86 will use SSE2 when compiled with +// a Mozilla-shipped rustc. SIMD support and especially detection on ARM is a +// mess. Under the circumstances, it seems to make sense to optimize the ALU +// case for ARMv7 rather than x86. Annoyingly, I was unable to get useful +// numbers of the actual ARMv7 CPU I have access to, because (thermal?) +// throttling kept interfering. Since Raspberry Pi 3 (ARMv8 core but running +// ARMv7 code) produced reproducible performance numbers, that's the ARM +// computer that this code ended up being optimized for in the ALU case. +// Less popular CPU architectures simply get the approach that was chosen based +// on Raspberry Pi 3 measurements. The UTF-16 and UTF-8 ALU cases take +// different approaches based on benchmarking on Raspberry Pi 3. + +#[cfg(all( + feature = "simd-accel", + any( + target_feature = "sse2", + all(target_endian = "little", target_arch = "aarch64"), + all(target_endian = "little", target_feature = "neon") + ) +))] +use crate::simd_funcs::*; + +cfg_if! { + if #[cfg(feature = "simd-accel")] { + #[allow(unused_imports)] + use ::core::intrinsics::unlikely; + #[allow(unused_imports)] + use ::core::intrinsics::likely; + } else { + #[allow(dead_code)] + #[inline(always)] + fn unlikely(b: bool) -> bool { + b + } + #[allow(dead_code)] + #[inline(always)] + fn likely(b: bool) -> bool { + b + } + } +} + +// `as` truncates, so works on 32-bit, too. +#[allow(dead_code)] +pub const ASCII_MASK: usize = 0x8080_8080_8080_8080u64 as usize; + +// `as` truncates, so works on 32-bit, too. +#[allow(dead_code)] +pub const BASIC_LATIN_MASK: usize = 0xFF80_FF80_FF80_FF80u64 as usize; + +#[allow(unused_macros)] +macro_rules! ascii_naive { + ($name:ident, $src_unit:ty, $dst_unit:ty) => { + #[inline(always)] + pub unsafe fn $name( + src: *const $src_unit, + dst: *mut $dst_unit, + len: usize, + ) -> Option<($src_unit, usize)> { + // Yes, manually omitting the bound check here matters + // a lot for perf. + for i in 0..len { + let code_unit = *(src.add(i)); + if code_unit > 127 { + return Some((code_unit, i)); + } + *(dst.add(i)) = code_unit as $dst_unit; + } + return None; + } + }; +} + +#[allow(unused_macros)] +macro_rules! ascii_alu { + ($name:ident, + $src_unit:ty, + $dst_unit:ty, + $stride_fn:ident) => { + #[cfg_attr(feature = "cargo-clippy", allow(never_loop, cast_ptr_alignment))] + #[inline(always)] + pub unsafe fn $name( + src: *const $src_unit, + dst: *mut $dst_unit, + len: usize, + ) -> Option<($src_unit, usize)> { + let mut offset = 0usize; + // This loop is only broken out of as a `goto` forward + loop { + let mut until_alignment = { + // Check if the other unit aligns if we move the narrower unit + // to alignment. + // if ::core::mem::size_of::<$src_unit>() == ::core::mem::size_of::<$dst_unit>() { + // ascii_to_ascii + let src_alignment = (src as usize) & ALU_ALIGNMENT_MASK; + let dst_alignment = (dst as usize) & ALU_ALIGNMENT_MASK; + if src_alignment != dst_alignment { + break; + } + (ALU_ALIGNMENT - src_alignment) & ALU_ALIGNMENT_MASK + // } else if ::core::mem::size_of::<$src_unit>() < ::core::mem::size_of::<$dst_unit>() { + // ascii_to_basic_latin + // let src_until_alignment = (ALIGNMENT - ((src as usize) & ALIGNMENT_MASK)) & ALIGNMENT_MASK; + // if (dst.add(src_until_alignment) as usize) & ALIGNMENT_MASK != 0 { + // break; + // } + // src_until_alignment + // } else { + // basic_latin_to_ascii + // let dst_until_alignment = (ALIGNMENT - ((dst as usize) & ALIGNMENT_MASK)) & ALIGNMENT_MASK; + // if (src.add(dst_until_alignment) as usize) & ALIGNMENT_MASK != 0 { + // break; + // } + // dst_until_alignment + // } + }; + if until_alignment + ALU_STRIDE_SIZE <= len { + // Moving pointers to alignment seems to be a pessimization on + // x86_64 for operations that have UTF-16 as the internal + // Unicode representation. However, since it seems to be a win + // on ARM (tested ARMv7 code running on ARMv8 [rpi3]), except + // mixed results when encoding from UTF-16 and since x86 and + // x86_64 should be using SSE2 in due course, keeping the move + // to alignment here. It would be good to test on more ARM CPUs + // and on real MIPS and POWER hardware. + while until_alignment != 0 { + let code_unit = *(src.add(offset)); + if code_unit > 127 { + return Some((code_unit, offset)); + } + *(dst.add(offset)) = code_unit as $dst_unit; + offset += 1; + until_alignment -= 1; + } + let len_minus_stride = len - ALU_STRIDE_SIZE; + loop { + if let Some(num_ascii) = $stride_fn( + src.add(offset) as *const usize, + dst.add(offset) as *mut usize, + ) { + offset += num_ascii; + return Some((*(src.add(offset)), offset)); + } + offset += ALU_STRIDE_SIZE; + if offset > len_minus_stride { + break; + } + } + } + break; + } + while offset < len { + let code_unit = *(src.add(offset)); + if code_unit > 127 { + return Some((code_unit, offset)); + } + *(dst.add(offset)) = code_unit as $dst_unit; + offset += 1; + } + None + } + }; +} + +#[allow(unused_macros)] +macro_rules! basic_latin_alu { + ($name:ident, + $src_unit:ty, + $dst_unit:ty, + $stride_fn:ident) => { + #[cfg_attr( + feature = "cargo-clippy", + allow(never_loop, cast_ptr_alignment, cast_lossless) + )] + #[inline(always)] + pub unsafe fn $name( + src: *const $src_unit, + dst: *mut $dst_unit, + len: usize, + ) -> Option<($src_unit, usize)> { + let mut offset = 0usize; + // This loop is only broken out of as a `goto` forward + loop { + let mut until_alignment = { + // Check if the other unit aligns if we move the narrower unit + // to alignment. + // if ::core::mem::size_of::<$src_unit>() == ::core::mem::size_of::<$dst_unit>() { + // ascii_to_ascii + // let src_alignment = (src as usize) & ALIGNMENT_MASK; + // let dst_alignment = (dst as usize) & ALIGNMENT_MASK; + // if src_alignment != dst_alignment { + // break; + // } + // (ALIGNMENT - src_alignment) & ALIGNMENT_MASK + // } else + if ::core::mem::size_of::<$src_unit>() < ::core::mem::size_of::<$dst_unit>() { + // ascii_to_basic_latin + let src_until_alignment = (ALU_ALIGNMENT + - ((src as usize) & ALU_ALIGNMENT_MASK)) + & ALU_ALIGNMENT_MASK; + if (dst.wrapping_add(src_until_alignment) as usize) & ALU_ALIGNMENT_MASK + != 0 + { + break; + } + src_until_alignment + } else { + // basic_latin_to_ascii + let dst_until_alignment = (ALU_ALIGNMENT + - ((dst as usize) & ALU_ALIGNMENT_MASK)) + & ALU_ALIGNMENT_MASK; + if (src.wrapping_add(dst_until_alignment) as usize) & ALU_ALIGNMENT_MASK + != 0 + { + break; + } + dst_until_alignment + } + }; + if until_alignment + ALU_STRIDE_SIZE <= len { + // Moving pointers to alignment seems to be a pessimization on + // x86_64 for operations that have UTF-16 as the internal + // Unicode representation. However, since it seems to be a win + // on ARM (tested ARMv7 code running on ARMv8 [rpi3]), except + // mixed results when encoding from UTF-16 and since x86 and + // x86_64 should be using SSE2 in due course, keeping the move + // to alignment here. It would be good to test on more ARM CPUs + // and on real MIPS and POWER hardware. + while until_alignment != 0 { + let code_unit = *(src.add(offset)); + if code_unit > 127 { + return Some((code_unit, offset)); + } + *(dst.add(offset)) = code_unit as $dst_unit; + offset += 1; + until_alignment -= 1; + } + let len_minus_stride = len - ALU_STRIDE_SIZE; + loop { + if !$stride_fn( + src.add(offset) as *const usize, + dst.add(offset) as *mut usize, + ) { + break; + } + offset += ALU_STRIDE_SIZE; + if offset > len_minus_stride { + break; + } + } + } + break; + } + while offset < len { + let code_unit = *(src.add(offset)); + if code_unit > 127 { + return Some((code_unit, offset)); + } + *(dst.add(offset)) = code_unit as $dst_unit; + offset += 1; + } + None + } + }; +} + +#[allow(unused_macros)] +macro_rules! latin1_alu { + ($name:ident, $src_unit:ty, $dst_unit:ty, $stride_fn:ident) => { + #[cfg_attr( + feature = "cargo-clippy", + allow(never_loop, cast_ptr_alignment, cast_lossless) + )] + #[inline(always)] + pub unsafe fn $name(src: *const $src_unit, dst: *mut $dst_unit, len: usize) { + let mut offset = 0usize; + // This loop is only broken out of as a `goto` forward + loop { + let mut until_alignment = { + if ::core::mem::size_of::<$src_unit>() < ::core::mem::size_of::<$dst_unit>() { + // unpack + let src_until_alignment = (ALU_ALIGNMENT + - ((src as usize) & ALU_ALIGNMENT_MASK)) + & ALU_ALIGNMENT_MASK; + if (dst.wrapping_add(src_until_alignment) as usize) & ALU_ALIGNMENT_MASK + != 0 + { + break; + } + src_until_alignment + } else { + // pack + let dst_until_alignment = (ALU_ALIGNMENT + - ((dst as usize) & ALU_ALIGNMENT_MASK)) + & ALU_ALIGNMENT_MASK; + if (src.wrapping_add(dst_until_alignment) as usize) & ALU_ALIGNMENT_MASK + != 0 + { + break; + } + dst_until_alignment + } + }; + if until_alignment + ALU_STRIDE_SIZE <= len { + while until_alignment != 0 { + let code_unit = *(src.add(offset)); + *(dst.add(offset)) = code_unit as $dst_unit; + offset += 1; + until_alignment -= 1; + } + let len_minus_stride = len - ALU_STRIDE_SIZE; + loop { + $stride_fn( + src.add(offset) as *const usize, + dst.add(offset) as *mut usize, + ); + offset += ALU_STRIDE_SIZE; + if offset > len_minus_stride { + break; + } + } + } + break; + } + while offset < len { + let code_unit = *(src.add(offset)); + *(dst.add(offset)) = code_unit as $dst_unit; + offset += 1; + } + } + }; +} + +#[allow(unused_macros)] +macro_rules! ascii_simd_check_align { + ( + $name:ident, + $src_unit:ty, + $dst_unit:ty, + $stride_both_aligned:ident, + $stride_src_aligned:ident, + $stride_dst_aligned:ident, + $stride_neither_aligned:ident + ) => { + #[inline(always)] + pub unsafe fn $name( + src: *const $src_unit, + dst: *mut $dst_unit, + len: usize, + ) -> Option<($src_unit, usize)> { + let mut offset = 0usize; + if SIMD_STRIDE_SIZE <= len { + let len_minus_stride = len - SIMD_STRIDE_SIZE; + // XXX Should we first process one stride unconditionally as unaligned to + // avoid the cost of the branchiness below if the first stride fails anyway? + // XXX Should we just use unaligned SSE2 access unconditionally? It seems that + // on Haswell, it would make sense to just use unaligned and not bother + // checking. Need to benchmark older architectures before deciding. + let dst_masked = (dst as usize) & SIMD_ALIGNMENT_MASK; + if ((src as usize) & SIMD_ALIGNMENT_MASK) == 0 { + if dst_masked == 0 { + loop { + if !$stride_both_aligned(src.add(offset), dst.add(offset)) { + break; + } + offset += SIMD_STRIDE_SIZE; + if offset > len_minus_stride { + break; + } + } + } else { + loop { + if !$stride_src_aligned(src.add(offset), dst.add(offset)) { + break; + } + offset += SIMD_STRIDE_SIZE; + if offset > len_minus_stride { + break; + } + } + } + } else { + if dst_masked == 0 { + loop { + if !$stride_dst_aligned(src.add(offset), dst.add(offset)) { + break; + } + offset += SIMD_STRIDE_SIZE; + if offset > len_minus_stride { + break; + } + } + } else { + loop { + if !$stride_neither_aligned(src.add(offset), dst.add(offset)) { + break; + } + offset += SIMD_STRIDE_SIZE; + if offset > len_minus_stride { + break; + } + } + } + } + } + while offset < len { + let code_unit = *(src.add(offset)); + if code_unit > 127 { + return Some((code_unit, offset)); + } + *(dst.add(offset)) = code_unit as $dst_unit; + offset += 1; + } + None + } + }; +} + +#[allow(unused_macros)] +macro_rules! ascii_simd_check_align_unrolled { + ( + $name:ident, + $src_unit:ty, + $dst_unit:ty, + $stride_both_aligned:ident, + $stride_src_aligned:ident, + $stride_neither_aligned:ident, + $double_stride_both_aligned:ident, + $double_stride_src_aligned:ident + ) => { + #[inline(always)] + pub unsafe fn $name( + src: *const $src_unit, + dst: *mut $dst_unit, + len: usize, + ) -> Option<($src_unit, usize)> { + let unit_size = ::core::mem::size_of::<$src_unit>(); + let mut offset = 0usize; + // This loop is only broken out of as a goto forward without + // actually looping + 'outer: loop { + if SIMD_STRIDE_SIZE <= len { + // First, process one unaligned + if !$stride_neither_aligned(src, dst) { + break 'outer; + } + offset = SIMD_STRIDE_SIZE; + + // We have now seen 16 ASCII bytes. Let's guess that + // there will be enough more to justify more expense + // in the case of non-ASCII. + // Use aligned reads for the sake of old microachitectures. + let until_alignment = ((SIMD_ALIGNMENT + - ((src.add(offset) as usize) & SIMD_ALIGNMENT_MASK)) + & SIMD_ALIGNMENT_MASK) + / unit_size; + // This addition won't overflow, because even in the 32-bit PAE case the + // address space holds enough code that the slice length can't be that + // close to address space size. + // offset now equals SIMD_STRIDE_SIZE, hence times 3 below. + if until_alignment + (SIMD_STRIDE_SIZE * 3) <= len { + if until_alignment != 0 { + if !$stride_neither_aligned(src.add(offset), dst.add(offset)) { + break; + } + offset += until_alignment; + } + let len_minus_stride_times_two = len - (SIMD_STRIDE_SIZE * 2); + let dst_masked = (dst.add(offset) as usize) & SIMD_ALIGNMENT_MASK; + if dst_masked == 0 { + loop { + if let Some(advance) = + $double_stride_both_aligned(src.add(offset), dst.add(offset)) + { + offset += advance; + let code_unit = *(src.add(offset)); + return Some((code_unit, offset)); + } + offset += SIMD_STRIDE_SIZE * 2; + if offset > len_minus_stride_times_two { + break; + } + } + if offset + SIMD_STRIDE_SIZE <= len { + if !$stride_both_aligned(src.add(offset), dst.add(offset)) { + break 'outer; + } + offset += SIMD_STRIDE_SIZE; + } + } else { + loop { + if let Some(advance) = + $double_stride_src_aligned(src.add(offset), dst.add(offset)) + { + offset += advance; + let code_unit = *(src.add(offset)); + return Some((code_unit, offset)); + } + offset += SIMD_STRIDE_SIZE * 2; + if offset > len_minus_stride_times_two { + break; + } + } + if offset + SIMD_STRIDE_SIZE <= len { + if !$stride_src_aligned(src.add(offset), dst.add(offset)) { + break 'outer; + } + offset += SIMD_STRIDE_SIZE; + } + } + } else { + // At most two iterations, so unroll + if offset + SIMD_STRIDE_SIZE <= len { + if !$stride_neither_aligned(src.add(offset), dst.add(offset)) { + break; + } + offset += SIMD_STRIDE_SIZE; + if offset + SIMD_STRIDE_SIZE <= len { + if !$stride_neither_aligned(src.add(offset), dst.add(offset)) { + break; + } + offset += SIMD_STRIDE_SIZE; + } + } + } + } + break 'outer; + } + while offset < len { + let code_unit = *(src.add(offset)); + if code_unit > 127 { + return Some((code_unit, offset)); + } + *(dst.add(offset)) = code_unit as $dst_unit; + offset += 1; + } + None + } + }; +} + +#[allow(unused_macros)] +macro_rules! latin1_simd_check_align { + ( + $name:ident, + $src_unit:ty, + $dst_unit:ty, + $stride_both_aligned:ident, + $stride_src_aligned:ident, + $stride_dst_aligned:ident, + $stride_neither_aligned:ident + ) => { + #[inline(always)] + pub unsafe fn $name(src: *const $src_unit, dst: *mut $dst_unit, len: usize) { + let mut offset = 0usize; + if SIMD_STRIDE_SIZE <= len { + let len_minus_stride = len - SIMD_STRIDE_SIZE; + let dst_masked = (dst as usize) & SIMD_ALIGNMENT_MASK; + if ((src as usize) & SIMD_ALIGNMENT_MASK) == 0 { + if dst_masked == 0 { + loop { + $stride_both_aligned(src.add(offset), dst.add(offset)); + offset += SIMD_STRIDE_SIZE; + if offset > len_minus_stride { + break; + } + } + } else { + loop { + $stride_src_aligned(src.add(offset), dst.add(offset)); + offset += SIMD_STRIDE_SIZE; + if offset > len_minus_stride { + break; + } + } + } + } else { + if dst_masked == 0 { + loop { + $stride_dst_aligned(src.add(offset), dst.add(offset)); + offset += SIMD_STRIDE_SIZE; + if offset > len_minus_stride { + break; + } + } + } else { + loop { + $stride_neither_aligned(src.add(offset), dst.add(offset)); + offset += SIMD_STRIDE_SIZE; + if offset > len_minus_stride { + break; + } + } + } + } + } + while offset < len { + let code_unit = *(src.add(offset)); + *(dst.add(offset)) = code_unit as $dst_unit; + offset += 1; + } + } + }; +} + +#[allow(unused_macros)] +macro_rules! latin1_simd_check_align_unrolled { + ( + $name:ident, + $src_unit:ty, + $dst_unit:ty, + $stride_both_aligned:ident, + $stride_src_aligned:ident, + $stride_dst_aligned:ident, + $stride_neither_aligned:ident + ) => { + #[inline(always)] + pub unsafe fn $name(src: *const $src_unit, dst: *mut $dst_unit, len: usize) { + let unit_size = ::core::mem::size_of::<$src_unit>(); + let mut offset = 0usize; + if SIMD_STRIDE_SIZE <= len { + let mut until_alignment = ((SIMD_STRIDE_SIZE + - ((src as usize) & SIMD_ALIGNMENT_MASK)) + & SIMD_ALIGNMENT_MASK) + / unit_size; + while until_alignment != 0 { + *(dst.add(offset)) = *(src.add(offset)) as $dst_unit; + offset += 1; + until_alignment -= 1; + } + let len_minus_stride = len - SIMD_STRIDE_SIZE; + if offset + SIMD_STRIDE_SIZE * 2 <= len { + let len_minus_stride_times_two = len_minus_stride - SIMD_STRIDE_SIZE; + if (dst.add(offset) as usize) & SIMD_ALIGNMENT_MASK == 0 { + loop { + $stride_both_aligned(src.add(offset), dst.add(offset)); + offset += SIMD_STRIDE_SIZE; + $stride_both_aligned(src.add(offset), dst.add(offset)); + offset += SIMD_STRIDE_SIZE; + if offset > len_minus_stride_times_two { + break; + } + } + } else { + loop { + $stride_src_aligned(src.add(offset), dst.add(offset)); + offset += SIMD_STRIDE_SIZE; + $stride_src_aligned(src.add(offset), dst.add(offset)); + offset += SIMD_STRIDE_SIZE; + if offset > len_minus_stride_times_two { + break; + } + } + } + } + if offset < len_minus_stride { + $stride_src_aligned(src.add(offset), dst.add(offset)); + offset += SIMD_STRIDE_SIZE; + } + } + while offset < len { + let code_unit = *(src.add(offset)); + // On x86_64, this loop autovectorizes but in the pack + // case there are instructions whose purpose is to make sure + // each u16 in the vector is truncated before packing. However, + // since we don't care about saturating behavior of SSE2 packing + // when the input isn't Latin1, those instructions are useless. + // Unfortunately, using the `assume` intrinsic to lie to the + // optimizer doesn't make LLVM omit the trunctation that we + // don't need. Possibly this loop could be manually optimized + // to do the sort of thing that LLVM does but without the + // ANDing the read vectors of u16 with a constant that discards + // the high half of each u16. As far as I can tell, the + // optimization assumes that doing a SIMD read past the end of + // the array is OK. + *(dst.add(offset)) = code_unit as $dst_unit; + offset += 1; + } + } + }; +} + +#[allow(unused_macros)] +macro_rules! ascii_simd_unalign { + ($name:ident, $src_unit:ty, $dst_unit:ty, $stride_neither_aligned:ident) => { + #[inline(always)] + pub unsafe fn $name( + src: *const $src_unit, + dst: *mut $dst_unit, + len: usize, + ) -> Option<($src_unit, usize)> { + let mut offset = 0usize; + if SIMD_STRIDE_SIZE <= len { + let len_minus_stride = len - SIMD_STRIDE_SIZE; + loop { + if !$stride_neither_aligned(src.add(offset), dst.add(offset)) { + break; + } + offset += SIMD_STRIDE_SIZE; + if offset > len_minus_stride { + break; + } + } + } + while offset < len { + let code_unit = *(src.add(offset)); + if code_unit > 127 { + return Some((code_unit, offset)); + } + *(dst.add(offset)) = code_unit as $dst_unit; + offset += 1; + } + None + } + }; +} + +#[allow(unused_macros)] +macro_rules! latin1_simd_unalign { + ($name:ident, $src_unit:ty, $dst_unit:ty, $stride_neither_aligned:ident) => { + #[inline(always)] + pub unsafe fn $name(src: *const $src_unit, dst: *mut $dst_unit, len: usize) { + let mut offset = 0usize; + if SIMD_STRIDE_SIZE <= len { + let len_minus_stride = len - SIMD_STRIDE_SIZE; + loop { + $stride_neither_aligned(src.add(offset), dst.add(offset)); + offset += SIMD_STRIDE_SIZE; + if offset > len_minus_stride { + break; + } + } + } + while offset < len { + let code_unit = *(src.add(offset)); + *(dst.add(offset)) = code_unit as $dst_unit; + offset += 1; + } + } + }; +} + +#[allow(unused_macros)] +macro_rules! ascii_to_ascii_simd_stride { + ($name:ident, $load:ident, $store:ident) => { + #[inline(always)] + pub unsafe fn $name(src: *const u8, dst: *mut u8) -> bool { + let simd = $load(src); + if !simd_is_ascii(simd) { + return false; + } + $store(dst, simd); + true + } + }; +} + +#[allow(unused_macros)] +macro_rules! ascii_to_ascii_simd_double_stride { + ($name:ident, $store:ident) => { + #[inline(always)] + pub unsafe fn $name(src: *const u8, dst: *mut u8) -> Option<usize> { + let first = load16_aligned(src); + let second = load16_aligned(src.add(SIMD_STRIDE_SIZE)); + $store(dst, first); + if unlikely(!simd_is_ascii(first | second)) { + let mask_first = mask_ascii(first); + if mask_first != 0 { + return Some(mask_first.trailing_zeros() as usize); + } + $store(dst.add(SIMD_STRIDE_SIZE), second); + let mask_second = mask_ascii(second); + return Some(SIMD_STRIDE_SIZE + mask_second.trailing_zeros() as usize); + } + $store(dst.add(SIMD_STRIDE_SIZE), second); + None + } + }; +} + +#[allow(unused_macros)] +macro_rules! ascii_to_basic_latin_simd_stride { + ($name:ident, $load:ident, $store:ident) => { + #[inline(always)] + pub unsafe fn $name(src: *const u8, dst: *mut u16) -> bool { + let simd = $load(src); + if !simd_is_ascii(simd) { + return false; + } + let (first, second) = simd_unpack(simd); + $store(dst, first); + $store(dst.add(8), second); + true + } + }; +} + +#[allow(unused_macros)] +macro_rules! ascii_to_basic_latin_simd_double_stride { + ($name:ident, $store:ident) => { + #[inline(always)] + pub unsafe fn $name(src: *const u8, dst: *mut u16) -> Option<usize> { + let first = load16_aligned(src); + let second = load16_aligned(src.add(SIMD_STRIDE_SIZE)); + let (a, b) = simd_unpack(first); + $store(dst, a); + $store(dst.add(SIMD_STRIDE_SIZE / 2), b); + if unlikely(!simd_is_ascii(first | second)) { + let mask_first = mask_ascii(first); + if mask_first != 0 { + return Some(mask_first.trailing_zeros() as usize); + } + let (c, d) = simd_unpack(second); + $store(dst.add(SIMD_STRIDE_SIZE), c); + $store(dst.add(SIMD_STRIDE_SIZE + (SIMD_STRIDE_SIZE / 2)), d); + let mask_second = mask_ascii(second); + return Some(SIMD_STRIDE_SIZE + mask_second.trailing_zeros() as usize); + } + let (c, d) = simd_unpack(second); + $store(dst.add(SIMD_STRIDE_SIZE), c); + $store(dst.add(SIMD_STRIDE_SIZE + (SIMD_STRIDE_SIZE / 2)), d); + None + } + }; +} + +#[allow(unused_macros)] +macro_rules! unpack_simd_stride { + ($name:ident, $load:ident, $store:ident) => { + #[inline(always)] + pub unsafe fn $name(src: *const u8, dst: *mut u16) { + let simd = $load(src); + let (first, second) = simd_unpack(simd); + $store(dst, first); + $store(dst.add(8), second); + } + }; +} + +#[allow(unused_macros)] +macro_rules! basic_latin_to_ascii_simd_stride { + ($name:ident, $load:ident, $store:ident) => { + #[inline(always)] + pub unsafe fn $name(src: *const u16, dst: *mut u8) -> bool { + let first = $load(src); + let second = $load(src.add(8)); + if simd_is_basic_latin(first | second) { + $store(dst, simd_pack(first, second)); + true + } else { + false + } + } + }; +} + +#[allow(unused_macros)] +macro_rules! pack_simd_stride { + ($name:ident, $load:ident, $store:ident) => { + #[inline(always)] + pub unsafe fn $name(src: *const u16, dst: *mut u8) { + let first = $load(src); + let second = $load(src.add(8)); + $store(dst, simd_pack(first, second)); + } + }; +} + +cfg_if! { + if #[cfg(all(feature = "simd-accel", target_endian = "little", target_arch = "aarch64"))] { + // SIMD with the same instructions for aligned and unaligned loads and stores + + pub const SIMD_STRIDE_SIZE: usize = 16; + + pub const MAX_STRIDE_SIZE: usize = 16; + +// pub const ALIGNMENT: usize = 8; + + pub const ALU_STRIDE_SIZE: usize = 16; + + pub const ALU_ALIGNMENT: usize = 8; + + pub const ALU_ALIGNMENT_MASK: usize = 7; + + ascii_to_ascii_simd_stride!(ascii_to_ascii_stride_neither_aligned, load16_unaligned, store16_unaligned); + + ascii_to_basic_latin_simd_stride!(ascii_to_basic_latin_stride_neither_aligned, load16_unaligned, store8_unaligned); + unpack_simd_stride!(unpack_stride_neither_aligned, load16_unaligned, store8_unaligned); + + basic_latin_to_ascii_simd_stride!(basic_latin_to_ascii_stride_neither_aligned, load8_unaligned, store16_unaligned); + pack_simd_stride!(pack_stride_neither_aligned, load8_unaligned, store16_unaligned); + + ascii_simd_unalign!(ascii_to_ascii, u8, u8, ascii_to_ascii_stride_neither_aligned); + ascii_simd_unalign!(ascii_to_basic_latin, u8, u16, ascii_to_basic_latin_stride_neither_aligned); + ascii_simd_unalign!(basic_latin_to_ascii, u16, u8, basic_latin_to_ascii_stride_neither_aligned); + latin1_simd_unalign!(unpack_latin1, u8, u16, unpack_stride_neither_aligned); + latin1_simd_unalign!(pack_latin1, u16, u8, pack_stride_neither_aligned); + } else if #[cfg(all(feature = "simd-accel", target_endian = "little", target_feature = "neon"))] { + // SIMD with different instructions for aligned and unaligned loads and stores. + // + // Newer microarchitectures are not supposed to have a performance difference between + // aligned and unaligned SSE2 loads and stores when the address is actually aligned, + // but the benchmark results I see don't agree. + + pub const SIMD_STRIDE_SIZE: usize = 16; + + pub const MAX_STRIDE_SIZE: usize = 16; + + pub const SIMD_ALIGNMENT_MASK: usize = 15; + + ascii_to_ascii_simd_stride!(ascii_to_ascii_stride_both_aligned, load16_aligned, store16_aligned); + ascii_to_ascii_simd_stride!(ascii_to_ascii_stride_src_aligned, load16_aligned, store16_unaligned); + ascii_to_ascii_simd_stride!(ascii_to_ascii_stride_dst_aligned, load16_unaligned, store16_aligned); + ascii_to_ascii_simd_stride!(ascii_to_ascii_stride_neither_aligned, load16_unaligned, store16_unaligned); + + ascii_to_basic_latin_simd_stride!(ascii_to_basic_latin_stride_both_aligned, load16_aligned, store8_aligned); + ascii_to_basic_latin_simd_stride!(ascii_to_basic_latin_stride_src_aligned, load16_aligned, store8_unaligned); + ascii_to_basic_latin_simd_stride!(ascii_to_basic_latin_stride_dst_aligned, load16_unaligned, store8_aligned); + ascii_to_basic_latin_simd_stride!(ascii_to_basic_latin_stride_neither_aligned, load16_unaligned, store8_unaligned); + + unpack_simd_stride!(unpack_stride_both_aligned, load16_aligned, store8_aligned); + unpack_simd_stride!(unpack_stride_src_aligned, load16_aligned, store8_unaligned); + unpack_simd_stride!(unpack_stride_dst_aligned, load16_unaligned, store8_aligned); + unpack_simd_stride!(unpack_stride_neither_aligned, load16_unaligned, store8_unaligned); + + basic_latin_to_ascii_simd_stride!(basic_latin_to_ascii_stride_both_aligned, load8_aligned, store16_aligned); + basic_latin_to_ascii_simd_stride!(basic_latin_to_ascii_stride_src_aligned, load8_aligned, store16_unaligned); + basic_latin_to_ascii_simd_stride!(basic_latin_to_ascii_stride_dst_aligned, load8_unaligned, store16_aligned); + basic_latin_to_ascii_simd_stride!(basic_latin_to_ascii_stride_neither_aligned, load8_unaligned, store16_unaligned); + + pack_simd_stride!(pack_stride_both_aligned, load8_aligned, store16_aligned); + pack_simd_stride!(pack_stride_src_aligned, load8_aligned, store16_unaligned); + pack_simd_stride!(pack_stride_dst_aligned, load8_unaligned, store16_aligned); + pack_simd_stride!(pack_stride_neither_aligned, load8_unaligned, store16_unaligned); + + ascii_simd_check_align!(ascii_to_ascii, u8, u8, ascii_to_ascii_stride_both_aligned, ascii_to_ascii_stride_src_aligned, ascii_to_ascii_stride_dst_aligned, ascii_to_ascii_stride_neither_aligned); + ascii_simd_check_align!(ascii_to_basic_latin, u8, u16, ascii_to_basic_latin_stride_both_aligned, ascii_to_basic_latin_stride_src_aligned, ascii_to_basic_latin_stride_dst_aligned, ascii_to_basic_latin_stride_neither_aligned); + ascii_simd_check_align!(basic_latin_to_ascii, u16, u8, basic_latin_to_ascii_stride_both_aligned, basic_latin_to_ascii_stride_src_aligned, basic_latin_to_ascii_stride_dst_aligned, basic_latin_to_ascii_stride_neither_aligned); + latin1_simd_check_align!(unpack_latin1, u8, u16, unpack_stride_both_aligned, unpack_stride_src_aligned, unpack_stride_dst_aligned, unpack_stride_neither_aligned); + latin1_simd_check_align!(pack_latin1, u16, u8, pack_stride_both_aligned, pack_stride_src_aligned, pack_stride_dst_aligned, pack_stride_neither_aligned); + } else if #[cfg(all(feature = "simd-accel", target_feature = "sse2"))] { + // SIMD with different instructions for aligned and unaligned loads and stores. + // + // Newer microarchitectures are not supposed to have a performance difference between + // aligned and unaligned SSE2 loads and stores when the address is actually aligned, + // but the benchmark results I see don't agree. + + pub const SIMD_STRIDE_SIZE: usize = 16; + + pub const SIMD_ALIGNMENT: usize = 16; + + pub const MAX_STRIDE_SIZE: usize = 16; + + pub const SIMD_ALIGNMENT_MASK: usize = 15; + + ascii_to_ascii_simd_double_stride!(ascii_to_ascii_simd_double_stride_both_aligned, store16_aligned); + ascii_to_ascii_simd_double_stride!(ascii_to_ascii_simd_double_stride_src_aligned, store16_unaligned); + + ascii_to_basic_latin_simd_double_stride!(ascii_to_basic_latin_simd_double_stride_both_aligned, store8_aligned); + ascii_to_basic_latin_simd_double_stride!(ascii_to_basic_latin_simd_double_stride_src_aligned, store8_unaligned); + + ascii_to_ascii_simd_stride!(ascii_to_ascii_stride_both_aligned, load16_aligned, store16_aligned); + ascii_to_ascii_simd_stride!(ascii_to_ascii_stride_src_aligned, load16_aligned, store16_unaligned); + ascii_to_ascii_simd_stride!(ascii_to_ascii_stride_neither_aligned, load16_unaligned, store16_unaligned); + + ascii_to_basic_latin_simd_stride!(ascii_to_basic_latin_stride_both_aligned, load16_aligned, store8_aligned); + ascii_to_basic_latin_simd_stride!(ascii_to_basic_latin_stride_src_aligned, load16_aligned, store8_unaligned); + ascii_to_basic_latin_simd_stride!(ascii_to_basic_latin_stride_neither_aligned, load16_unaligned, store8_unaligned); + + unpack_simd_stride!(unpack_stride_both_aligned, load16_aligned, store8_aligned); + unpack_simd_stride!(unpack_stride_src_aligned, load16_aligned, store8_unaligned); + + basic_latin_to_ascii_simd_stride!(basic_latin_to_ascii_stride_both_aligned, load8_aligned, store16_aligned); + basic_latin_to_ascii_simd_stride!(basic_latin_to_ascii_stride_src_aligned, load8_aligned, store16_unaligned); + basic_latin_to_ascii_simd_stride!(basic_latin_to_ascii_stride_dst_aligned, load8_unaligned, store16_aligned); + basic_latin_to_ascii_simd_stride!(basic_latin_to_ascii_stride_neither_aligned, load8_unaligned, store16_unaligned); + + pack_simd_stride!(pack_stride_both_aligned, load8_aligned, store16_aligned); + pack_simd_stride!(pack_stride_src_aligned, load8_aligned, store16_unaligned); + + ascii_simd_check_align_unrolled!(ascii_to_ascii, u8, u8, ascii_to_ascii_stride_both_aligned, ascii_to_ascii_stride_src_aligned, ascii_to_ascii_stride_neither_aligned, ascii_to_ascii_simd_double_stride_both_aligned, ascii_to_ascii_simd_double_stride_src_aligned); + ascii_simd_check_align_unrolled!(ascii_to_basic_latin, u8, u16, ascii_to_basic_latin_stride_both_aligned, ascii_to_basic_latin_stride_src_aligned, ascii_to_basic_latin_stride_neither_aligned, ascii_to_basic_latin_simd_double_stride_both_aligned, ascii_to_basic_latin_simd_double_stride_src_aligned); + + ascii_simd_check_align!(basic_latin_to_ascii, u16, u8, basic_latin_to_ascii_stride_both_aligned, basic_latin_to_ascii_stride_src_aligned, basic_latin_to_ascii_stride_dst_aligned, basic_latin_to_ascii_stride_neither_aligned); + latin1_simd_check_align_unrolled!(unpack_latin1, u8, u16, unpack_stride_both_aligned, unpack_stride_src_aligned, unpack_stride_dst_aligned, unpack_stride_neither_aligned); + latin1_simd_check_align_unrolled!(pack_latin1, u16, u8, pack_stride_both_aligned, pack_stride_src_aligned, pack_stride_dst_aligned, pack_stride_neither_aligned); + } else if #[cfg(all(target_endian = "little", target_pointer_width = "64"))] { + // Aligned ALU word, little-endian, 64-bit + + pub const ALU_STRIDE_SIZE: usize = 16; + + pub const MAX_STRIDE_SIZE: usize = 16; + + pub const ALU_ALIGNMENT: usize = 8; + + pub const ALU_ALIGNMENT_MASK: usize = 7; + + #[inline(always)] + unsafe fn unpack_alu(word: usize, second_word: usize, dst: *mut usize) { + let first = ((0x0000_0000_FF00_0000usize & word) << 24) | + ((0x0000_0000_00FF_0000usize & word) << 16) | + ((0x0000_0000_0000_FF00usize & word) << 8) | + (0x0000_0000_0000_00FFusize & word); + let second = ((0xFF00_0000_0000_0000usize & word) >> 8) | + ((0x00FF_0000_0000_0000usize & word) >> 16) | + ((0x0000_FF00_0000_0000usize & word) >> 24) | + ((0x0000_00FF_0000_0000usize & word) >> 32); + let third = ((0x0000_0000_FF00_0000usize & second_word) << 24) | + ((0x0000_0000_00FF_0000usize & second_word) << 16) | + ((0x0000_0000_0000_FF00usize & second_word) << 8) | + (0x0000_0000_0000_00FFusize & second_word); + let fourth = ((0xFF00_0000_0000_0000usize & second_word) >> 8) | + ((0x00FF_0000_0000_0000usize & second_word) >> 16) | + ((0x0000_FF00_0000_0000usize & second_word) >> 24) | + ((0x0000_00FF_0000_0000usize & second_word) >> 32); + *dst = first; + *(dst.add(1)) = second; + *(dst.add(2)) = third; + *(dst.add(3)) = fourth; + } + + #[inline(always)] + unsafe fn pack_alu(first: usize, second: usize, third: usize, fourth: usize, dst: *mut usize) { + let word = ((0x00FF_0000_0000_0000usize & second) << 8) | + ((0x0000_00FF_0000_0000usize & second) << 16) | + ((0x0000_0000_00FF_0000usize & second) << 24) | + ((0x0000_0000_0000_00FFusize & second) << 32) | + ((0x00FF_0000_0000_0000usize & first) >> 24) | + ((0x0000_00FF_0000_0000usize & first) >> 16) | + ((0x0000_0000_00FF_0000usize & first) >> 8) | + (0x0000_0000_0000_00FFusize & first); + let second_word = ((0x00FF_0000_0000_0000usize & fourth) << 8) | + ((0x0000_00FF_0000_0000usize & fourth) << 16) | + ((0x0000_0000_00FF_0000usize & fourth) << 24) | + ((0x0000_0000_0000_00FFusize & fourth) << 32) | + ((0x00FF_0000_0000_0000usize & third) >> 24) | + ((0x0000_00FF_0000_0000usize & third) >> 16) | + ((0x0000_0000_00FF_0000usize & third) >> 8) | + (0x0000_0000_0000_00FFusize & third); + *dst = word; + *(dst.add(1)) = second_word; + } + } else if #[cfg(all(target_endian = "little", target_pointer_width = "32"))] { + // Aligned ALU word, little-endian, 32-bit + + pub const ALU_STRIDE_SIZE: usize = 8; + + pub const MAX_STRIDE_SIZE: usize = 8; + + pub const ALU_ALIGNMENT: usize = 4; + + pub const ALU_ALIGNMENT_MASK: usize = 3; + + #[inline(always)] + unsafe fn unpack_alu(word: usize, second_word: usize, dst: *mut usize) { + let first = ((0x0000_FF00usize & word) << 8) | + (0x0000_00FFusize & word); + let second = ((0xFF00_0000usize & word) >> 8) | + ((0x00FF_0000usize & word) >> 16); + let third = ((0x0000_FF00usize & second_word) << 8) | + (0x0000_00FFusize & second_word); + let fourth = ((0xFF00_0000usize & second_word) >> 8) | + ((0x00FF_0000usize & second_word) >> 16); + *dst = first; + *(dst.add(1)) = second; + *(dst.add(2)) = third; + *(dst.add(3)) = fourth; + } + + #[inline(always)] + unsafe fn pack_alu(first: usize, second: usize, third: usize, fourth: usize, dst: *mut usize) { + let word = ((0x00FF_0000usize & second) << 8) | + ((0x0000_00FFusize & second) << 16) | + ((0x00FF_0000usize & first) >> 8) | + (0x0000_00FFusize & first); + let second_word = ((0x00FF_0000usize & fourth) << 8) | + ((0x0000_00FFusize & fourth) << 16) | + ((0x00FF_0000usize & third) >> 8) | + (0x0000_00FFusize & third); + *dst = word; + *(dst.add(1)) = second_word; + } + } else if #[cfg(all(target_endian = "big", target_pointer_width = "64"))] { + // Aligned ALU word, big-endian, 64-bit + + pub const ALU_STRIDE_SIZE: usize = 16; + + pub const MAX_STRIDE_SIZE: usize = 16; + + pub const ALU_ALIGNMENT: usize = 8; + + pub const ALU_ALIGNMENT_MASK: usize = 7; + + #[inline(always)] + unsafe fn unpack_alu(word: usize, second_word: usize, dst: *mut usize) { + let first = ((0xFF00_0000_0000_0000usize & word) >> 8) | + ((0x00FF_0000_0000_0000usize & word) >> 16) | + ((0x0000_FF00_0000_0000usize & word) >> 24) | + ((0x0000_00FF_0000_0000usize & word) >> 32); + let second = ((0x0000_0000_FF00_0000usize & word) << 24) | + ((0x0000_0000_00FF_0000usize & word) << 16) | + ((0x0000_0000_0000_FF00usize & word) << 8) | + (0x0000_0000_0000_00FFusize & word); + let third = ((0xFF00_0000_0000_0000usize & second_word) >> 8) | + ((0x00FF_0000_0000_0000usize & second_word) >> 16) | + ((0x0000_FF00_0000_0000usize & second_word) >> 24) | + ((0x0000_00FF_0000_0000usize & second_word) >> 32); + let fourth = ((0x0000_0000_FF00_0000usize & second_word) << 24) | + ((0x0000_0000_00FF_0000usize & second_word) << 16) | + ((0x0000_0000_0000_FF00usize & second_word) << 8) | + (0x0000_0000_0000_00FFusize & second_word); + *dst = first; + *(dst.add(1)) = second; + *(dst.add(2)) = third; + *(dst.add(3)) = fourth; + } + + #[inline(always)] + unsafe fn pack_alu(first: usize, second: usize, third: usize, fourth: usize, dst: *mut usize) { + let word = ((0x00FF0000_00000000usize & first) << 8) | + ((0x000000FF_00000000usize & first) << 16) | + ((0x00000000_00FF0000usize & first) << 24) | + ((0x00000000_000000FFusize & first) << 32) | + ((0x00FF0000_00000000usize & second) >> 24) | + ((0x000000FF_00000000usize & second) >> 16) | + ((0x00000000_00FF0000usize & second) >> 8) | + (0x00000000_000000FFusize & second); + let second_word = ((0x00FF0000_00000000usize & third) << 8) | + ((0x000000FF_00000000usize & third) << 16) | + ((0x00000000_00FF0000usize & third) << 24) | + ((0x00000000_000000FFusize & third) << 32) | + ((0x00FF0000_00000000usize & fourth) >> 24) | + ((0x000000FF_00000000usize & fourth) >> 16) | + ((0x00000000_00FF0000usize & fourth) >> 8) | + (0x00000000_000000FFusize & fourth); + *dst = word; + *(dst.add(1)) = second_word; + } + } else if #[cfg(all(target_endian = "big", target_pointer_width = "32"))] { + // Aligned ALU word, big-endian, 32-bit + + pub const ALU_STRIDE_SIZE: usize = 8; + + pub const MAX_STRIDE_SIZE: usize = 8; + + pub const ALU_ALIGNMENT: usize = 4; + + pub const ALU_ALIGNMENT_MASK: usize = 3; + + #[inline(always)] + unsafe fn unpack_alu(word: usize, second_word: usize, dst: *mut usize) { + let first = ((0xFF00_0000usize & word) >> 8) | + ((0x00FF_0000usize & word) >> 16); + let second = ((0x0000_FF00usize & word) << 8) | + (0x0000_00FFusize & word); + let third = ((0xFF00_0000usize & second_word) >> 8) | + ((0x00FF_0000usize & second_word) >> 16); + let fourth = ((0x0000_FF00usize & second_word) << 8) | + (0x0000_00FFusize & second_word); + *dst = first; + *(dst.add(1)) = second; + *(dst.add(2)) = third; + *(dst.add(3)) = fourth; + } + + #[inline(always)] + unsafe fn pack_alu(first: usize, second: usize, third: usize, fourth: usize, dst: *mut usize) { + let word = ((0x00FF_0000usize & first) << 8) | + ((0x0000_00FFusize & first) << 16) | + ((0x00FF_0000usize & second) >> 8) | + (0x0000_00FFusize & second); + let second_word = ((0x00FF_0000usize & third) << 8) | + ((0x0000_00FFusize & third) << 16) | + ((0x00FF_0000usize & fourth) >> 8) | + (0x0000_00FFusize & fourth); + *dst = word; + *(dst.add(1)) = second_word; + } + } else { + ascii_naive!(ascii_to_ascii, u8, u8); + ascii_naive!(ascii_to_basic_latin, u8, u16); + ascii_naive!(basic_latin_to_ascii, u16, u8); + } +} + +cfg_if! { + if #[cfg(target_endian = "little")] { + #[allow(dead_code)] + #[inline(always)] + fn count_zeros(word: usize) -> u32 { + word.trailing_zeros() + } + } else { + #[allow(dead_code)] + #[inline(always)] + fn count_zeros(word: usize) -> u32 { + word.leading_zeros() + } + } +} + +cfg_if! { + if #[cfg(all(feature = "simd-accel", target_endian = "little", target_arch = "disabled"))] { + #[inline(always)] + pub fn validate_ascii(slice: &[u8]) -> Option<(u8, usize)> { + let src = slice.as_ptr(); + let len = slice.len(); + let mut offset = 0usize; + if SIMD_STRIDE_SIZE <= len { + let len_minus_stride = len - SIMD_STRIDE_SIZE; + loop { + let simd = unsafe { load16_unaligned(src.add(offset)) }; + if !simd_is_ascii(simd) { + break; + } + offset += SIMD_STRIDE_SIZE; + if offset > len_minus_stride { + break; + } + } + } + while offset < len { + let code_unit = slice[offset]; + if code_unit > 127 { + return Some((code_unit, offset)); + } + offset += 1; + } + None + } + } else if #[cfg(all(feature = "simd-accel", target_feature = "sse2"))] { + #[inline(always)] + pub fn validate_ascii(slice: &[u8]) -> Option<(u8, usize)> { + let src = slice.as_ptr(); + let len = slice.len(); + let mut offset = 0usize; + if SIMD_STRIDE_SIZE <= len { + // First, process one unaligned vector + let simd = unsafe { load16_unaligned(src) }; + let mask = mask_ascii(simd); + if mask != 0 { + offset = mask.trailing_zeros() as usize; + let non_ascii = unsafe { *src.add(offset) }; + return Some((non_ascii, offset)); + } + offset = SIMD_STRIDE_SIZE; + + // We have now seen 16 ASCII bytes. Let's guess that + // there will be enough more to justify more expense + // in the case of non-ASCII. + // Use aligned reads for the sake of old microachitectures. + let until_alignment = unsafe { (SIMD_ALIGNMENT - ((src.add(offset) as usize) & SIMD_ALIGNMENT_MASK)) & SIMD_ALIGNMENT_MASK }; + // This addition won't overflow, because even in the 32-bit PAE case the + // address space holds enough code that the slice length can't be that + // close to address space size. + // offset now equals SIMD_STRIDE_SIZE, hence times 3 below. + if until_alignment + (SIMD_STRIDE_SIZE * 3) <= len { + if until_alignment != 0 { + let simd = unsafe { load16_unaligned(src.add(offset)) }; + let mask = mask_ascii(simd); + if mask != 0 { + offset += mask.trailing_zeros() as usize; + let non_ascii = unsafe { *src.add(offset) }; + return Some((non_ascii, offset)); + } + offset += until_alignment; + } + let len_minus_stride_times_two = len - (SIMD_STRIDE_SIZE * 2); + loop { + let first = unsafe { load16_aligned(src.add(offset)) }; + let second = unsafe { load16_aligned(src.add(offset + SIMD_STRIDE_SIZE)) }; + if !simd_is_ascii(first | second) { + let mask_first = mask_ascii(first); + if mask_first != 0 { + offset += mask_first.trailing_zeros() as usize; + } else { + let mask_second = mask_ascii(second); + offset += SIMD_STRIDE_SIZE + mask_second.trailing_zeros() as usize; + } + let non_ascii = unsafe { *src.add(offset) }; + return Some((non_ascii, offset)); + } + offset += SIMD_STRIDE_SIZE * 2; + if offset > len_minus_stride_times_two { + break; + } + } + if offset + SIMD_STRIDE_SIZE <= len { + let simd = unsafe { load16_aligned(src.add(offset)) }; + let mask = mask_ascii(simd); + if mask != 0 { + offset += mask.trailing_zeros() as usize; + let non_ascii = unsafe { *src.add(offset) }; + return Some((non_ascii, offset)); + } + offset += SIMD_STRIDE_SIZE; + } + } else { + // At most two iterations, so unroll + if offset + SIMD_STRIDE_SIZE <= len { + let simd = unsafe { load16_unaligned(src.add(offset)) }; + let mask = mask_ascii(simd); + if mask != 0 { + offset += mask.trailing_zeros() as usize; + let non_ascii = unsafe { *src.add(offset) }; + return Some((non_ascii, offset)); + } + offset += SIMD_STRIDE_SIZE; + if offset + SIMD_STRIDE_SIZE <= len { + let simd = unsafe { load16_unaligned(src.add(offset)) }; + let mask = mask_ascii(simd); + if mask != 0 { + offset += mask.trailing_zeros() as usize; + let non_ascii = unsafe { *src.add(offset) }; + return Some((non_ascii, offset)); + } + offset += SIMD_STRIDE_SIZE; + } + } + } + } + while offset < len { + let code_unit = unsafe { *(src.add(offset)) }; + if code_unit > 127 { + return Some((code_unit, offset)); + } + offset += 1; + } + None + } + } else { + #[inline(always)] + fn find_non_ascii(word: usize, second_word: usize) -> Option<usize> { + let word_masked = word & ASCII_MASK; + let second_masked = second_word & ASCII_MASK; + if (word_masked | second_masked) == 0 { + return None; + } + if word_masked != 0 { + let zeros = count_zeros(word_masked); + // `zeros` now contains 7 (for the seven bits of non-ASCII) + // plus 8 times the number of ASCII in text order before the + // non-ASCII byte in the little-endian case or 8 times the number of ASCII in + // text order before the non-ASCII byte in the big-endian case. + let num_ascii = (zeros >> 3) as usize; + return Some(num_ascii); + } + let zeros = count_zeros(second_masked); + // `zeros` now contains 7 (for the seven bits of non-ASCII) + // plus 8 times the number of ASCII in text order before the + // non-ASCII byte in the little-endian case or 8 times the number of ASCII in + // text order before the non-ASCII byte in the big-endian case. + let num_ascii = (zeros >> 3) as usize; + Some(ALU_ALIGNMENT + num_ascii) + } + + #[inline(always)] + unsafe fn validate_ascii_stride(src: *const usize) -> Option<usize> { + let word = *src; + let second_word = *(src.add(1)); + find_non_ascii(word, second_word) + } + + #[cfg_attr(feature = "cargo-clippy", allow(cast_ptr_alignment))] + #[inline(always)] + pub fn validate_ascii(slice: &[u8]) -> Option<(u8, usize)> { + let src = slice.as_ptr(); + let len = slice.len(); + let mut offset = 0usize; + let mut until_alignment = (ALU_ALIGNMENT - ((src as usize) & ALU_ALIGNMENT_MASK)) & ALU_ALIGNMENT_MASK; + if until_alignment + ALU_STRIDE_SIZE <= len { + while until_alignment != 0 { + let code_unit = slice[offset]; + if code_unit > 127 { + return Some((code_unit, offset)); + } + offset += 1; + until_alignment -= 1; + } + let len_minus_stride = len - ALU_STRIDE_SIZE; + loop { + let ptr = unsafe { src.add(offset) as *const usize }; + if let Some(num_ascii) = unsafe { validate_ascii_stride(ptr) } { + offset += num_ascii; + return Some((unsafe { *(src.add(offset)) }, offset)); + } + offset += ALU_STRIDE_SIZE; + if offset > len_minus_stride { + break; + } + } + } + while offset < len { + let code_unit = slice[offset]; + if code_unit > 127 { + return Some((code_unit, offset)); + } + offset += 1; + } + None + } + + } +} + +cfg_if! { + if #[cfg(all(feature = "simd-accel", any(target_feature = "sse2", all(target_endian = "little", target_arch = "aarch64"))))] { + + } else if #[cfg(all(feature = "simd-accel", target_endian = "little", target_feature = "neon"))] { + // Even with NEON enabled, we use the ALU path for ASCII validation, because testing + // on Exynos 5 indicated that using NEON isn't worthwhile where there are only + // vector reads without vector writes. + + pub const ALU_STRIDE_SIZE: usize = 8; + + pub const ALU_ALIGNMENT: usize = 4; + + pub const ALU_ALIGNMENT_MASK: usize = 3; + } else { + #[inline(always)] + unsafe fn unpack_latin1_stride_alu(src: *const usize, dst: *mut usize) { + let word = *src; + let second_word = *(src.add(1)); + unpack_alu(word, second_word, dst); + } + + #[inline(always)] + unsafe fn pack_latin1_stride_alu(src: *const usize, dst: *mut usize) { + let first = *src; + let second = *(src.add(1)); + let third = *(src.add(2)); + let fourth = *(src.add(3)); + pack_alu(first, second, third, fourth, dst); + } + + #[inline(always)] + unsafe fn ascii_to_basic_latin_stride_alu(src: *const usize, dst: *mut usize) -> bool { + let word = *src; + let second_word = *(src.add(1)); + // Check if the words contains non-ASCII + if (word & ASCII_MASK) | (second_word & ASCII_MASK) != 0 { + return false; + } + unpack_alu(word, second_word, dst); + true + } + + #[inline(always)] + unsafe fn basic_latin_to_ascii_stride_alu(src: *const usize, dst: *mut usize) -> bool { + let first = *src; + let second = *(src.add(1)); + let third = *(src.add(2)); + let fourth = *(src.add(3)); + if (first & BASIC_LATIN_MASK) | (second & BASIC_LATIN_MASK) | (third & BASIC_LATIN_MASK) | (fourth & BASIC_LATIN_MASK) != 0 { + return false; + } + pack_alu(first, second, third, fourth, dst); + true + } + + #[inline(always)] + unsafe fn ascii_to_ascii_stride(src: *const usize, dst: *mut usize) -> Option<usize> { + let word = *src; + let second_word = *(src.add(1)); + *dst = word; + *(dst.add(1)) = second_word; + find_non_ascii(word, second_word) + } + + basic_latin_alu!(ascii_to_basic_latin, u8, u16, ascii_to_basic_latin_stride_alu); + basic_latin_alu!(basic_latin_to_ascii, u16, u8, basic_latin_to_ascii_stride_alu); + latin1_alu!(unpack_latin1, u8, u16, unpack_latin1_stride_alu); + latin1_alu!(pack_latin1, u16, u8, pack_latin1_stride_alu); + ascii_alu!(ascii_to_ascii, u8, u8, ascii_to_ascii_stride); + } +} + +pub fn ascii_valid_up_to(bytes: &[u8]) -> usize { + match validate_ascii(bytes) { + None => bytes.len(), + Some((_, num_valid)) => num_valid, + } +} + +pub fn iso_2022_jp_ascii_valid_up_to(bytes: &[u8]) -> usize { + for (i, b_ref) in bytes.iter().enumerate() { + let b = *b_ref; + if b >= 0x80 || b == 0x1B || b == 0x0E || b == 0x0F { + return i; + } + } + bytes.len() +} + +// Any copyright to the test code below this comment is dedicated to the +// Public Domain. http://creativecommons.org/publicdomain/zero/1.0/ + +#[cfg(all(test, feature = "alloc"))] +mod tests { + use super::*; + use alloc::vec::Vec; + + macro_rules! test_ascii { + ($test_name:ident, $fn_tested:ident, $src_unit:ty, $dst_unit:ty) => { + #[test] + fn $test_name() { + let mut src: Vec<$src_unit> = Vec::with_capacity(32); + let mut dst: Vec<$dst_unit> = Vec::with_capacity(32); + for i in 0..32 { + src.clear(); + dst.clear(); + dst.resize(32, 0); + for j in 0..32 { + let c = if i == j { 0xAA } else { j + 0x40 }; + src.push(c as $src_unit); + } + match unsafe { $fn_tested(src.as_ptr(), dst.as_mut_ptr(), 32) } { + None => unreachable!("Should always find non-ASCII"), + Some((non_ascii, num_ascii)) => { + assert_eq!(non_ascii, 0xAA); + assert_eq!(num_ascii, i); + for j in 0..i { + assert_eq!(dst[j], (j + 0x40) as $dst_unit); + } + } + } + } + } + }; + } + + test_ascii!(test_ascii_to_ascii, ascii_to_ascii, u8, u8); + test_ascii!(test_ascii_to_basic_latin, ascii_to_basic_latin, u8, u16); + test_ascii!(test_basic_latin_to_ascii, basic_latin_to_ascii, u16, u8); +} |