quantize_fp32_to_int8 cast roundf(v) straight to int8_t. With scale = amax/127
the value should never exceed 127, but one ULP of error in iscale can round to
128, which wraps to -128 and injects a sign-flipped activation outlier. The
int4 path already clamped to +/-7; int8 did not.
Latent, not active: greedy output on gemma-4-12b-it-Q8_0 is byte-identical
before and after (sha 11b2174379e0c2040246, 708 B). This is insurance.
Found by a source review of the NPU math path.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EWpfhDgYNA21tETDP9ueBE
mfritsche
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