Adding weights to utility nodes in BP so that we can give more
importance to
certain utilities. This is useful when we optimize several objectives
jointly.
When LargestTraceSize is a power of two, createBPFunctionNodes does not
allocate a group ID for Trace[LargestTraceSize-1] (as N is off by 1).
Fix
this and change floor+log2 to Log2_64.
BalancedPartitioning::bisect can use unstable sort because `Nodes`
contains distinct `InputOrderIndex`s.
BalancedPartitioning::runIterations: use one DenseMap and simplify the
node renumbering code.
In https://reviews.llvm.org/D147812 I created
`BalancedPartitioningTest.cpp` and inadvertently drastically increased the
number of files needed to compile `SupportTests`. Instead lets move the
`BPFunctionNode` test to `unittests/ProfileData` so we can remove the
extra dependency.
Reviewed By: thakis
Differential Revision: https://reviews.llvm.org/D152325
