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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /dom/base/nsTextFragmentVMX.cpp | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | dom/base/nsTextFragmentVMX.cpp | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/dom/base/nsTextFragmentVMX.cpp b/dom/base/nsTextFragmentVMX.cpp new file mode 100644 index 0000000000..a071adaee7 --- /dev/null +++ b/dom/base/nsTextFragmentVMX.cpp @@ -0,0 +1,101 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +// This file should only be compiled if you're on Power ISA. + +#include "nscore.h" +#include "nsAlgorithm.h" +#include "nsTextFragmentImpl.h" +#include <algorithm> +#include <altivec.h> + +namespace mozilla { +namespace VMX { + +int32_t FirstNon8Bit(const char16_t* str, const char16_t* end) { + const uint32_t numUnicharsPerVector = 8; + const uint32_t numCharsPerVector = 16; + // Paranoia. If this assertion is wrong, change the vector loop below. + MOZ_ASSERT((numCharsPerVector / numUnicharsPerVector) == sizeof(char16_t)); + + typedef Non8BitParameters<sizeof(size_t)> p; + const uint32_t alignMask = p::alignMask(); + const size_t mask = p::mask(); + const uint32_t numUnicharsPerWord = p::numUnicharsPerWord(); + + const uint32_t len = end - str; + + // i shall count the index in unichars; i2 shall count the index in chars. + uint32_t i = 0; + uint32_t i2 = 0; + + // Align ourselves to a 16-byte boundary, as required by VMX loads. + uint32_t alignLen = std::min( + len, uint32_t(((-NS_PTR_TO_UINT32(str)) & 0xf) / sizeof(char16_t))); + + if ((len - alignLen) >= numUnicharsPerVector) { + for (; i < alignLen; i++) { + if (str[i] > 255) return i; + } + + // Construct a vector of shorts. +#if __LITTLE_ENDIAN__ + const vector unsigned short gtcompare = + reinterpret_cast<vector unsigned short>( + vec_mergel(vec_splat_s8(-1), vec_splat_s8(0))); +#else + const vector unsigned short gtcompare = + reinterpret_cast<vector unsigned short>( + vec_mergel(vec_splat_s8(0), vec_splat_s8(-1))); +#endif + const uint32_t vectWalkEnd = + ((len - i) / numUnicharsPerVector) * numUnicharsPerVector; + i2 = i * sizeof(char16_t); + + while (1) { + vector unsigned short vect; + + // Check one VMX register (8 unichars) at a time. The vec_any_gt + // intrinsic does exactly what we want. This loop is manually unrolled; + // it yields notable performance improvements this way. +#define CheckForASCII \ + vect = vec_ld(i2, reinterpret_cast<const unsigned short*>(str)); \ + if (vec_any_gt(vect, gtcompare)) return i; \ + i += numUnicharsPerVector; \ + if (!(i < vectWalkEnd)) break; \ + i2 += numCharsPerVector; + + CheckForASCII CheckForASCII + +#undef CheckForASCII + } + } else { + // Align ourselves to a word boundary. + alignLen = std::min(len, uint32_t(((-NS_PTR_TO_UINT32(str)) & alignMask) / + sizeof(char16_t))); + for (; i < alignLen; i++) { + if (str[i] > 255) return i; + } + } + + // Check one word at a time. + const uint32_t wordWalkEnd = + ((len - i) / numUnicharsPerWord) * numUnicharsPerWord; + for (; i < wordWalkEnd; i += numUnicharsPerWord) { + const size_t word = *reinterpret_cast<const size_t*>(str + i); + if (word & mask) return i; + } + + // Take care of the remainder one character at a time. + for (; i < len; i++) { + if (str[i] > 255) { + return i; + } + } + + return -1; +} + +} // namespace VMX +} // namespace mozilla |