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Peter Collingbourne
2c6c4893c7
The current code that handles personality functions when creating a module summary does not correctly handle the case where a function's personality function operand refers to the function indirectly (e.g. via a bitcast). This patch handles such cases by treating personality function references like any other reference, i.e. by adding them to the function's reference list. This has the minor side benefit of allowing personality functions to participate in early dead stripping. We do this by calling findRefEdges on the function itself. This way we also end up handling other function operands (specifically prefix data and prologue data) for free. Differential Revision: https://reviews.llvm.org/D37553 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312698 91177308-0d34-0410-b5e6-96231b3b80d8
Analysis Opportunities:
//===---------------------------------------------------------------------===//
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.
//===---------------------------------------------------------------------===//
In formatValue in test/CodeGen/X86/lsr-delayed-fold.ll,
ScalarEvolution is forming this expression:
((trunc i64 (-1 * %arg5) to i32) + (trunc i64 %arg5 to i32) + (-1 * (trunc i64 undef to i32)))
This could be folded to
(-1 * (trunc i64 undef to i32))
//===---------------------------------------------------------------------===//