2003-12-10-ExitBlocksProblem.ll 1.1 KB

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  1. ; LoopSimplify is breaking LICM on this testcase because the exit blocks from
  2. ; the loop are reachable from more than just the exit nodes: the exit blocks
  3. ; have predecessors from outside of the loop!
  4. ;
  5. ; This is distilled from a monsterous crafty example.
  6. ; RUN: opt < %s -licm -disable-output
  7. @G = weak global i32 0 ; <i32*> [#uses=7]
  8. define i32 @main() {
  9. entry:
  10. store i32 123, i32* @G
  11. br label %loopentry.i
  12. loopentry.i: ; preds = %endif.1.i, %entry
  13. %tmp.0.i = load i32, i32* @G ; <i32> [#uses=1]
  14. %tmp.1.i = icmp eq i32 %tmp.0.i, 123 ; <i1> [#uses=1]
  15. br i1 %tmp.1.i, label %Out.i, label %endif.0.i
  16. endif.0.i: ; preds = %loopentry.i
  17. %tmp.3.i = load i32, i32* @G ; <i32> [#uses=1]
  18. %tmp.4.i = icmp eq i32 %tmp.3.i, 126 ; <i1> [#uses=1]
  19. br i1 %tmp.4.i, label %ExitBlock.i, label %endif.1.i
  20. endif.1.i: ; preds = %endif.0.i
  21. %tmp.6.i = load i32, i32* @G ; <i32> [#uses=1]
  22. %inc.i = add i32 %tmp.6.i, 1 ; <i32> [#uses=1]
  23. store i32 %inc.i, i32* @G
  24. br label %loopentry.i
  25. Out.i: ; preds = %loopentry.i
  26. store i32 0, i32* @G
  27. br label %ExitBlock.i
  28. ExitBlock.i: ; preds = %Out.i, %endif.0.i
  29. %tmp.7.i = load i32, i32* @G ; <i32> [#uses=1]
  30. ret i32 %tmp.7.i
  31. }