| 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)) | |
| //===---------------------------------------------------------------------===// |