| Analysis Opportunities: |
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| //===---------------------------------------------------------------------===// |
| |
| In test/Transforms/LoopStrengthReduce/quadradic-exit-value.ll, the |
| ScalarEvolution expression for %r is this: |
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| {1,+,3,+,2}<loop> |
| |
| Outside the loop, this could be evaluated simply as (%n * %n), however |
| ScalarEvolution currently evaluates it as |
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| (-2 + (2 * (trunc i65 (((zext i64 (-2 + %n) to i65) * (zext i64 (-1 + %n) to i65)) /u 2) to i64)) + (3 * %n)) |
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| In addition to being much more complicated, it involves i65 arithmetic, |
| which is very inefficient when expanded into code. |
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| //===---------------------------------------------------------------------===// |
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| In formatValue in test/CodeGen/X86/lsr-delayed-fold.ll, |
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| ScalarEvolution is forming this expression: |
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| ((trunc i64 (-1 * %arg5) to i32) + (trunc i64 %arg5 to i32) + (-1 * (trunc i64 undef to i32))) |
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| This could be folded to |
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| (-1 * (trunc i64 undef to i32)) |
| |
| //===---------------------------------------------------------------------===// |
