[BypassSlowDivision] Do not bypass division of hash-like values
Disable bypassing if one of the operands looks like a hash value. Slow
division often occurs in hashtable implementations and fast division is
never taken there because a hash value is extremely unlikely to have
enough upper bits set to zero.
A value is considered to be hash-like if it is produced by
1) XOR operation
2) Multiplication by a constant wider than the shorter type
3) PHI node with all incoming values being hash-like
Differential Revision: https://reviews.llvm.org/D28200
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299329
91177308-0d34-0410-b5e6-
96231b3b80d8
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