cse-add-with-overflow.ll 1.0 KB

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  1. ; RUN: llc < %s -mtriple=x86_64-darwin -mcpu=generic | FileCheck %s
  2. ; rdar:15661073 simple example of redundant adds
  3. ;
  4. ; MachineCSE should coalesce trivial subregister copies.
  5. ;
  6. ; The extra movl+addl should be removed during MachineCSE.
  7. ; CHECK-LABEL: redundantadd
  8. ; CHECK: cmpq
  9. ; CHECK: movq
  10. ; CHECK-NOT: movl
  11. ; CHECK: addl
  12. ; CHECK-NOT: addl
  13. ; CHECK: ret
  14. define i64 @redundantadd(i64* %a0, i64* %a1) {
  15. entry:
  16. %tmp8 = load i64* %a0, align 8
  17. %tmp12 = load i64* %a1, align 8
  18. %tmp13 = icmp ult i64 %tmp12, -281474976710656
  19. br i1 %tmp13, label %exit1, label %body
  20. exit1:
  21. unreachable
  22. body:
  23. %tmp14 = trunc i64 %tmp8 to i32
  24. %tmp15 = trunc i64 %tmp12 to i32
  25. %tmp16 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %tmp14, i32 %tmp15)
  26. %tmp17 = extractvalue { i32, i1 } %tmp16, 1
  27. br i1 %tmp17, label %exit2, label %return
  28. exit2:
  29. unreachable
  30. return:
  31. %tmp18 = add i64 %tmp12, %tmp8
  32. %tmp19 = and i64 %tmp18, 4294967295
  33. %tmp20 = or i64 %tmp19, -281474976710656
  34. ret i64 %tmp20
  35. }
  36. declare { i32, i1 } @llvm.sadd.with.overflow.i32(i32, i32)