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new 541cba859c GH-47784: [C++] Patch vendored pcg library to enable msvc
arm64 intrinsics (#47779)
541cba859c is described below
commit 541cba859c3cdb4cc6cb3f456aaae79f67c7d57d
Author: Jonathan Giannuzzi <[email protected]>
AuthorDate: Wed Oct 15 18:18:00 2025 +0300
GH-47784: [C++] Patch vendored pcg library to enable msvc arm64 intrinsics
(#47779)
### Rationale for this change
This change enables building Arrow C++ for Windows ARM64 with MSVC when
setting `ARROW_SIMD_LEVEL` to `NONE`. This is useful to be able to build Arrow
with `vcpkg` and use it as a dependency.
Setting `ARROW_SIMD_LEVEL` to `NONE` is done to disable the use of `xsimd`,
which does not yet support msvc arm64 intrinsics, and is non-trivial to fix.
### What changes are included in this PR?
A patch to the vendored `pcg` library, based on
https://github.com/imneme/pcg-cpp/pull/99. The upstream pcg library has not
been updated in the past 3 years, so this may never get merged.
### Are these changes tested?
Yes, the changes have been tested in
https://github.com/microsoft/vcpkg/pull/47750 (the same patch for `vcpkg`,
which this change would alleviate) and in
https://github.com/jgiannuzzi/ParquetSharp/actions/runs/18354286294 (a full run
of the ParquetSharp CI, using this patch to build Arrow with `vcpkg`).
### Are there any user-facing changes?
Not really, unless you consider adding the ability to build Arrow on
Windows ARM64 user-facing?
* GitHub Issue: #47784
Authored-by: Jonathan Giannuzzi <[email protected]>
Signed-off-by: Antoine Pitrou <[email protected]>
---
cpp/src/arrow/vendored/pcg/README.md | 1 +
cpp/src/arrow/vendored/pcg/pcg_uint128.hpp | 15 ++++++++++++++-
2 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/cpp/src/arrow/vendored/pcg/README.md
b/cpp/src/arrow/vendored/pcg/README.md
index b58504f3b3..7a949723da 100644
--- a/cpp/src/arrow/vendored/pcg/README.md
+++ b/cpp/src/arrow/vendored/pcg/README.md
@@ -25,4 +25,5 @@ Sources are taken from git changeset
ffd522e7188bef30a00c74dc7eb9de5faff90092
Changes:
- enclosed in `arrow_vendored` namespace
- remove `struct arbitrary_seed` definition because of
https://github.com/apache/arrow/issues/35596
+- enable MSVC ARM64 intrinsics to allow building on Windows ARM64 with Visual
Studio - see https://github.com/apache/arrow/pull/47779
diff --git a/cpp/src/arrow/vendored/pcg/pcg_uint128.hpp
b/cpp/src/arrow/vendored/pcg/pcg_uint128.hpp
index 0181e69e4e..012f3d6682 100644
--- a/cpp/src/arrow/vendored/pcg/pcg_uint128.hpp
+++ b/cpp/src/arrow/vendored/pcg/pcg_uint128.hpp
@@ -67,7 +67,7 @@
#define PCG_LITTLE_ENDIAN 1
#elif __BIG_ENDIAN__ || _BIG_ENDIAN
#define PCG_LITTLE_ENDIAN 0
- #elif __x86_64 || __x86_64__ || _M_X64 || __i386 || __i386__ || _M_IX86
+ #elif __x86_64 || __x86_64__ || _M_X64 || __i386 || __i386__ || _M_IX86 ||
_M_ARM64
#define PCG_LITTLE_ENDIAN 1
#elif __powerpc__ || __POWERPC__ || __ppc__ || __PPC__ \
|| __m68k__ || __mc68000__
@@ -734,7 +734,13 @@ uint_x4<UInt,UIntX2> operator*(const uint_x4<UInt,UIntX2>&
a,
#if PCG_64BIT_SPECIALIZATIONS
#if defined(_MSC_VER)
+#if defined(_M_X64) || defined(_M_IX86)
#pragma intrinsic(_umul128)
+#elif defined(_M_ARM64)
+#pragma intrinsic(__umulh)
+#else
+#error Unsupported architecture
+#endif
#endif
#if defined(_MSC_VER) || __SIZEOF_INT128__
@@ -743,8 +749,15 @@ uint_x4<UInt32,uint64_t> operator*(const
uint_x4<UInt32,uint64_t>& a,
const uint_x4<UInt32,uint64_t>& b)
{
#if defined(_MSC_VER)
+#if defined(_M_X64) || defined(_M_IX86)
uint64_t hi;
uint64_t lo = _umul128(a.d.v01, b.d.v01, &hi);
+#elif defined(_M_ARM64)
+ uint64_t lo = a.d.v01 * b.d.v01;
+ uint64_t hi = __umulh(a.d.v01, b.d.v01);
+#else
+#error Unsupported architecture
+#endif
#else
__uint128_t r = __uint128_t(a.d.v01) * __uint128_t(b.d.v01);
uint64_t lo = uint64_t(r);
