2003-08-17-FoldSwitch.ll 2.0 KB

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  1. ; RUN: opt < %s -simplifycfg -S | FileCheck %s
  2. ; CHECK-NOT: switch
  3. ; Test normal folding
  4. define i32 @test1() {
  5. switch i32 5, label %Default [
  6. i32 0, label %Foo
  7. i32 1, label %Bar
  8. i32 2, label %Baz
  9. i32 5, label %TheDest
  10. ]
  11. Default: ; preds = %0
  12. ret i32 -1
  13. Foo: ; preds = %0
  14. ret i32 -2
  15. Bar: ; preds = %0
  16. ret i32 -3
  17. Baz: ; preds = %0
  18. ret i32 -4
  19. TheDest: ; preds = %0
  20. ret i32 1234
  21. }
  22. ; Test folding to default dest
  23. define i32 @test2() {
  24. switch i32 3, label %Default [
  25. i32 0, label %Foo
  26. i32 1, label %Bar
  27. i32 2, label %Baz
  28. i32 5, label %TheDest
  29. ]
  30. Default: ; preds = %0
  31. ret i32 1234
  32. Foo: ; preds = %0
  33. ret i32 -2
  34. Bar: ; preds = %0
  35. ret i32 -5
  36. Baz: ; preds = %0
  37. ret i32 -6
  38. TheDest: ; preds = %0
  39. ret i32 -8
  40. }
  41. ; Test folding all to same dest
  42. define i32 @test3(i1 %C) {
  43. br i1 %C, label %Start, label %TheDest
  44. Start: ; preds = %0
  45. switch i32 3, label %TheDest [
  46. i32 0, label %TheDest
  47. i32 1, label %TheDest
  48. i32 2, label %TheDest
  49. i32 5, label %TheDest
  50. ]
  51. TheDest: ; preds = %Start, %Start, %Start, %Start, %Start, %0
  52. ret i32 1234
  53. }
  54. ; Test folding switch -> branch
  55. define i32 @test4(i32 %C) {
  56. switch i32 %C, label %L1 [
  57. i32 0, label %L2
  58. ]
  59. L1: ; preds = %0
  60. ret i32 0
  61. L2: ; preds = %0
  62. ret i32 1
  63. }
  64. ; Can fold into a cond branch!
  65. define i32 @test5(i32 %C) {
  66. switch i32 %C, label %L1 [
  67. i32 0, label %L2
  68. i32 123, label %L1
  69. ]
  70. L1: ; preds = %0, %0
  71. ret i32 0
  72. L2: ; preds = %0
  73. ret i32 1
  74. }