Carry the ClickHouse patches onto v4.5.0 - #12
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thevar1able merged 2 commits intoSep 9, 2026
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The lat/lng <-> H3 cell transforms are dominated by transcendental
function calls. Several hot routines computed sin(x) and cos(x) of the
same angle with two separate library calls, and a few recomputed the
same value more than once:
* _geoToVec3d - sin/cos of the latitude and of the longitude
* _geoAzimuthRads - sin/cos pairs; cos(p2->lat) was evaluated twice
* _geoAzDistanceRads- sin/cos of p1->lat, the distance and the azimuth
were each evaluated twice
* _geoToHex2d - sin/cos of theta
Compute each sin/cos pair together via a small _sincos() helper (it
lowers to a single libm `sincos` call where available and falls back to
separate sin()/cos() otherwise) and reuse already-computed values. The
outputs are bit-for-bit identical; this only removes redundant work.
Measured on 10M rows (clang -O3, no LTO):
cellToLatLng +9..11%
cellToBoundary +14%
cellArea +8%
latLngToCell +3..4%
All 311 existing tests pass unchanged.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
(cherry picked from commit e38f58e)
Since v4.5.0 (uber#1154) coordijk.h is header-only and its inline functions are compiled by every translation unit that includes it, including C++ ones: ClickHouse includes h3Index.h (and hence faceijk.h and coordijk.h) from src/Functions/h3GeometryToCells.cpp. The loop in _unitIjkToDigit incremented a variable of enum type Direction. That is valid C but ill-formed in C++ ("cannot increment expression of enum type 'Direction'"). Iterate with an int and cast the result back to Direction instead. Behaviour is unchanged. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
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This branch moves the ClickHouse fork of h3 from
v4.4.1to upstream tagv4.5.0. It carries Alexey Milovidov's "Speed up geo coordinate transforms: combined sincos + fewer trig calls" (cherry-picked with-x, original author preserved) plus one new fork patch, "Make coordijk.h compile as C++": sincecoordijk.hbecame header-only upstream,_unitIjkToDigitincrements aDirectionenum in a loop, which is valid C but ill-formed C++, and ClickHouse includes that header from C++ viah3Index.h/faceijk.h. It now iterates with anintand casts back, behaviour unchanged; this is upstreamable. No patch was dropped as a whole.Two hunks of the sincos patch became obsolete because upstream refactored the indexing code (uber#1145/uber#1154/uber#1155). In
src/h3lib/lib/latLng.cthe patched_geoAzimuthRadsand_geoAzDistanceRadsno longer exist and have no callers, so upstream's file was kept unchanged.src/h3lib/lib/vec3d.cwas deleted upstream (modify/delete conflict); the file was removed and the_geoToVec3dhunk ported to the header-onlylatLngToVec3insrc/h3lib/include/vec3d.h, using_sincosfor lat and lng and includingmathExtensions.h. The intent of the dropped_geoAzDistanceRadshunk was ported to its replacement path,_hex2dToVec3insrc/h3lib/lib/faceijk.c, by applying_sincosto both the theta and r pairs. ThemathExtensions.hhelper and the_geoToHex2dhunk infaceijk.capplied cleanly.Once merged, ClickHouse's
contrib/h3submodule is bumped to this branch head.