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Strength reduce x quotRem 8 #8

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Merged
merged 1 commit into from
Nov 30, 2016
Merged

Strength reduce x quotRem 8 #8

merged 1 commit into from
Nov 30, 2016

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alexbiehl
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Unfortunately GHC < 8.2 doesn't replace x quotRem 8 by more efficient instructions. This patch replaces (i, j) = x quotRem 8 with i = unsafeShiftR x 3 and j = x .&. 3.

@winterland1989
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It seems the decode test is starting failing, would you investigate it?

@alexbiehl
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It's good now. :)

@winterland1989 winterland1989 merged commit 78fc630 into winterland1989:master Nov 30, 2016
@winterland1989
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Ah, nice catch, rem 8 's mask should be 0b111 not 0b11.

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@alexbiehl @winterland1989