ptr_diff.ll 2.6 KB

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  1. ; RUN: opt < %s -instsimplify -S | FileCheck %s
  2. target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
  3. target triple = "x86_64-unknown-linux-gnu"
  4. define i64 @ptrdiff1(i8* %ptr) {
  5. ; CHECK-LABEL: @ptrdiff1(
  6. ; CHECK-NEXT: ret i64 42
  7. %first = getelementptr inbounds i8, i8* %ptr, i32 0
  8. %last = getelementptr inbounds i8, i8* %ptr, i32 42
  9. %first.int = ptrtoint i8* %first to i64
  10. %last.int = ptrtoint i8* %last to i64
  11. %diff = sub i64 %last.int, %first.int
  12. ret i64 %diff
  13. }
  14. define i64 @ptrdiff2(i8* %ptr) {
  15. ; CHECK-LABEL: @ptrdiff2(
  16. ; CHECK-NEXT: ret i64 42
  17. %first1 = getelementptr inbounds i8, i8* %ptr, i32 0
  18. %first2 = getelementptr inbounds i8, i8* %first1, i32 1
  19. %first3 = getelementptr inbounds i8, i8* %first2, i32 2
  20. %first4 = getelementptr inbounds i8, i8* %first3, i32 4
  21. %last1 = getelementptr inbounds i8, i8* %first2, i32 48
  22. %last2 = getelementptr inbounds i8, i8* %last1, i32 8
  23. %last3 = getelementptr inbounds i8, i8* %last2, i32 -4
  24. %last4 = getelementptr inbounds i8, i8* %last3, i32 -4
  25. %first.int = ptrtoint i8* %first4 to i64
  26. %last.int = ptrtoint i8* %last4 to i64
  27. %diff = sub i64 %last.int, %first.int
  28. ret i64 %diff
  29. }
  30. define i64 @ptrdiff3(i8* %ptr) {
  31. ; Don't bother with non-inbounds GEPs.
  32. ; CHECK-LABEL: @ptrdiff3(
  33. ; CHECK: getelementptr
  34. ; CHECK: sub
  35. ; CHECK: ret
  36. %first = getelementptr i8, i8* %ptr, i32 0
  37. %last = getelementptr i8, i8* %ptr, i32 42
  38. %first.int = ptrtoint i8* %first to i64
  39. %last.int = ptrtoint i8* %last to i64
  40. %diff = sub i64 %last.int, %first.int
  41. ret i64 %diff
  42. }
  43. define <4 x i32> @ptrdiff4(<4 x i8*> %arg) nounwind {
  44. ; Handle simple cases of vectors of pointers.
  45. ; CHECK-LABEL: @ptrdiff4(
  46. ; CHECK: ret <4 x i32> zeroinitializer
  47. %p1 = ptrtoint <4 x i8*> %arg to <4 x i32>
  48. %bc = bitcast <4 x i8*> %arg to <4 x i32*>
  49. %p2 = ptrtoint <4 x i32*> %bc to <4 x i32>
  50. %sub = sub <4 x i32> %p1, %p2
  51. ret <4 x i32> %sub
  52. }
  53. %struct.ham = type { i32, [2 x [2 x i32]] }
  54. @global = internal global %struct.ham zeroinitializer, align 4
  55. define i32 @ptrdiff5() nounwind {
  56. bb:
  57. %tmp = getelementptr inbounds %struct.ham, %struct.ham* @global, i32 0, i32 1
  58. %tmp1 = getelementptr inbounds [2 x [2 x i32]], [2 x [2 x i32]]* %tmp, i32 0, i32 0
  59. %tmp2 = bitcast [2 x i32]* %tmp1 to i32*
  60. %tmp3 = ptrtoint i32* %tmp2 to i32
  61. %tmp4 = getelementptr inbounds %struct.ham, %struct.ham* @global, i32 0, i32 1
  62. %tmp5 = getelementptr inbounds [2 x [2 x i32]], [2 x [2 x i32]]* %tmp4, i32 0, i32 0
  63. %tmp6 = ptrtoint [2 x i32]* %tmp5 to i32
  64. %tmp7 = sub i32 %tmp3, %tmp6
  65. ret i32 %tmp7
  66. ; CHECK-LABEL: @ptrdiff5(
  67. ; CHECK: ret i32 0
  68. }