assume-edge-dom.ll 907 B

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  1. ; RUN: opt -S -jump-threading < %s | FileCheck %s
  2. declare i8* @escape()
  3. declare void @llvm.assume(i1)
  4. define i1 @test1(i1 %cond) {
  5. entry:
  6. br i1 %cond, label %taken, label %not_taken
  7. ; CHECK-LABEL: @test1
  8. ; CHECK: br i1 %cond, label %no, label %yes
  9. ; CHECK: ret i1 true
  10. taken:
  11. %res1 = call i8* @escape()
  12. %a = icmp eq i8* %res1, null
  13. tail call void @llvm.assume(i1 %a)
  14. br label %done
  15. not_taken:
  16. %res2 = call i8* @escape()
  17. %b = icmp ne i8* %res2, null
  18. tail call void @llvm.assume(i1 %b)
  19. br label %done
  20. ; An assume that can be used to simplify this comparison dominates each
  21. ; predecessor branch (although no assume dominates the cmp itself). Make sure
  22. ; this still can be simplified.
  23. done:
  24. %res = phi i8* [ %res1, %taken ], [ %res2, %not_taken ]
  25. %cnd = icmp ne i8* %res, null
  26. br i1 %cnd, label %yes, label %no
  27. yes:
  28. ret i1 true
  29. no:
  30. ret i1 false
  31. }