[Arith] Updated incorrect simplification rule #13922
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The rules that rewrite `min(floordiv(x + (A-1), A) * A, max(x, A))` and `min(truncdiv(x + (A-1), A) * A, max(x, A))` into `max(x, A)` did not have sufficiently tight bounds. The `truncdiv` rule required that `x >= 0`, while the `floordiv` rule had no requirement on `x`. In both cases, the simplification was incorrect when `x==0`, as it would result in a rewrite from `min(0, max(0, A))` into `max(0, A)`. This commit updates the rules to require that `x >= 0` for each of these rules.
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Hi :) , is it a typo for |
wrongtest-intellif
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Feb 7, 2023
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LGTM!
Another helper view is when x % A == 0, min(ceildiv(x, A), max(x, a)) == x, thus we should exclude the case x==0 when max(x, A) != x
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Thank you, and yes, that was a typo. The condition was updated to require |
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The rules that rewrite
min(floordiv(x + (A-1), A) * A, max(x, A))andmin(truncdiv(x + (A-1), A) * A, max(x, A))intomax(x, A)did not have sufficiently tight bounds. Thetruncdivrule required thatx >= 0, while thefloordivrule had no requirement onx. In both cases, the simplification was incorrect whenx==0, as it would result in a rewrite frommin(0, max(0, A))intomax(0, A).This commit updates the rules to require that
x >= 0for each of these rules.