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1903d97c2c
was being added to the Result vector, but not being put in the cache. This means that if the cache was reused wholesale for a later query that it would be missing this entry and we'd do an incorrect load elimination. Unfortunately, it's not really possible to write a useful testcase for this, but this unbreaks 255.vortex. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90093 91177308-0d34-0410-b5e6-96231b3b80d8
Analysis Opportunities:
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In test/Transforms/LoopStrengthReduce/quadradic-exit-value.ll, the
ScalarEvolution expression for %r is this:
{1,+,3,+,2}<loop>
Outside the loop, this could be evaluated simply as (%n * %n), however
ScalarEvolution currently evaluates it as
(-2 + (2 * (trunc i65 (((zext i64 (-2 + %n) to i65) * (zext i64 (-1 + %n) to i65)) /u 2) to i64)) + (3 * %n))
In addition to being much more complicated, it involves i65 arithmetic,
which is very inefficient when expanded into code.
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