noalias-bugs.ll 1.1 KB

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  1. ; RUN: opt -S -basicaa -dse < %s | FileCheck %s
  2. target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
  3. target triple = "x86_64-unknown-linux-gnu"
  4. ; We incorrectly returned noalias in the example below for "ptr.64" and
  5. ; "either_ptr.64".
  6. ; PR18460
  7. %nested = type { %nested.i64 }
  8. %nested.i64 = type { i64 }
  9. define i64 @testcase(%nested * noalias %p1, %nested * noalias %p2,
  10. i32 %a, i32 %b) {
  11. %ptr = getelementptr inbounds %nested, %nested* %p1, i64 -1, i32 0
  12. %ptr.64 = getelementptr inbounds %nested.i64, %nested.i64* %ptr, i64 0, i32 0
  13. %ptr2= getelementptr inbounds %nested, %nested* %p2, i64 0, i32 0
  14. %cmp = icmp ult i32 %a, %b
  15. %either_ptr = select i1 %cmp, %nested.i64* %ptr2, %nested.i64* %ptr
  16. %either_ptr.64 = getelementptr inbounds %nested.i64, %nested.i64* %either_ptr, i64 0, i32 0
  17. ; Because either_ptr.64 and ptr.64 can alias (we used to return noalias)
  18. ; elimination of the first store is not valid.
  19. ; CHECK: store i64 2
  20. ; CHECK: load
  21. ; CHECK; store i64 1
  22. store i64 2, i64* %ptr.64, align 8
  23. %r = load i64, i64* %either_ptr.64, align 8
  24. store i64 1, i64* %ptr.64, align 8
  25. ret i64 %r
  26. }