fix x86_64 arch detection when cross-compiling on macos arm64#6730
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fix x86_64 arch detection when cross-compiling on macos arm64#6730LudovicoYIN wants to merge 2 commits into
LudovicoYIN wants to merge 2 commits into
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Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## master #6730 +/- ##
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- Coverage 95.96% 95.93% -0.03%
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Files 970 970
Lines 403093 403668 +575
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+ Hits 386820 387273 +453
- Misses 16273 16395 +122 ☔ View full report in Codecov by Sentry. 🚀 New features to boost your workflow:
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Pull request overview
Fixes incorrect target architecture detection when cross-compiling ncnn for x86_64 on Apple Silicon (macOS arm64) with -DCMAKE_OSX_ARCHITECTURES=x86_64, which previously caused the build to be treated as ARM and skipped all x86 SIMD feature detection.
Changes:
- Adjust ARM-architecture detection on Apple platforms to avoid using
CMAKE_SYSTEM_PROCESSOR(host CPU) whenCMAKE_OSX_ARCHITECTURESis explicitly set to a non-ARM architecture. - Ensures x86_64 cross-compiles on macOS arm64 properly follow the x86 feature-probing path (SSE/AVX/etc.).
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Summary
Fix #6505 — when cross-compiling ncnn for x86_64 on macOS arm64 with
-DCMAKE_OSX_ARCHITECTURES=x86_64, the target architecture is incorrectlydetected as ARM, causing all x86 SIMD optimizations (SSE/AVX/AVX2/AVX512)
to be skipped.
Root cause
In
CMakeLists.txt:164,CMAKE_SYSTEM_PROCESSORalways reports the hostCPU (
arm64), even whenCMAKE_OSX_ARCHITECTURESis explicitly set tox86_64. This causes the ARM arch branch to match, settingNCNN_TARGET_ARCHtoarminstead ofx86.Fix
On Apple platforms, skip the
CMAKE_SYSTEM_PROCESSORarm match whenCMAKE_OSX_ARCHITECTURESis explicitly set to a non-arm architecture.Before / After