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For precise_compare_value, the boundary tests extend >>> naturally — the function must return the exact result regardless >>> of which code path (fast approximate or precise fallback) is taken. >>> >>> For the two-counter APIs, I noticed that the combined accuracy >>> is always symmetric: over_a + under_b = under_a + over_b = >>> (bs_a + bs_b - 1) * multiplier, so the asymmetric gap test >>> doesn't apply there. But boundary tests at the combined accuracy >>> limit still provide useful coverage. >> >> In order to do a relevant test for the two-counter APIs, we'll need >> to initialize each of the two counters with different batch sizes. >> This will ensure that the limits are asymmetric, and therefore allow >> more precise testing of the limit conditions. >> >> Thanks, >> >> Mathieu > > I looked into this but since accuracy_multiplier is a single global > constant, the combined accuracy ends up symmetric regardless of > batch sizes. For the two-counter comparison: > > accuracy_pos = over_a + under_b > accuracy_neg = under_a + over_b > > Since under = batch_size * M and over = (batch_size - 1) * M, > both sides always simplify to the same value. So the asymmetric > gap test only applies to the single-value comparison APIs. > > Should I keep the two-counter test with symmetric boundary > coverage, or did you have something else in mind? No, you're right, after simplification they become equivalent. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. https://www.efficios.com