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Make quot/rem/div/mod with known divisors fast

GHC (with NCG) currently optimizes Int division by powers of two, but not by other known divisors. The Intel Optimization Manual section 9.2.4 describes a general technique for replacing division by known, sufficiently small, divisors with multiplication. LLVM appears to go further in some fashion. There's no reason we can't do something similar.

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Trac field Value
Version 7.9
Type Task
TypeOfFailure OtherFailure
Priority normal
Resolution Unresolved
Component Compiler
Test case
Differential revisions
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Blocking
CC
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