fix: prevent int16 overflow in NEON non-dotprod fallback path#459
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Mindev27 wants to merge 1 commit intomicrosoft:mainfrom
Open
fix: prevent int16 overflow in NEON non-dotprod fallback path#459Mindev27 wants to merge 1 commit intomicrosoft:mainfrom
Mindev27 wants to merge 1 commit intomicrosoft:mainfrom
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The non-dotprod NEON fallback accumulates vmlal_s8 results into int16x8_t across 32 loop iterations (256 multiply-adds total), which overflows int16 range and produces garbage output on ARMv8.0 CPUs like Cortex-A53/A73.
Fix by widening to int32 each iteration instead of every 32. Applied to all three dot product variants (1x1, 1xN, Nx1).
Partially addresses #411 (items 5 and 6).
Tested on M4 Pro (dotprod path) inference runs fine. Don't have ARMv8.0 hardware to test the non-dotprod path directly.