dse.ll   [plain text]

; RUN: opt < %s -tbaa -basicaa -dse -S | FileCheck %s

; DSE should make use of TBAA.

; CHECK: @test0_yes
; CHECK-NEXT: load i8* %b
; CHECK-NEXT: store i8 1, i8* %a
; CHECK-NEXT: ret i8 %y
define i8 @test0_yes(i8* %a, i8* %b) nounwind {
  store i8 0, i8* %a, !tbaa !1
  %y = load i8* %b, !tbaa !2
  store i8 1, i8* %a, !tbaa !1
  ret i8 %y
}

; CHECK: @test0_no
; CHECK-NEXT: store i8 0, i8* %a
; CHECK-NEXT: load i8* %b
; CHECK-NEXT: store i8 1, i8* %a
; CHECK-NEXT: ret i8 %y
define i8 @test0_no(i8* %a, i8* %b) nounwind {
  store i8 0, i8* %a, !tbaa !3
  %y = load i8* %b, !tbaa !4
  store i8 1, i8* %a, !tbaa !3
  ret i8 %y
}

; CHECK: @test1_yes
; CHECK-NEXT: load i8* %b
; CHECK-NEXT: store i8 1, i8* %a
; CHECK-NEXT: ret i8 %y
define i8 @test1_yes(i8* %a, i8* %b) nounwind {
  store i8 0, i8* %a
  %y = load i8* %b, !tbaa !5
  store i8 1, i8* %a
  ret i8 %y
}

; CHECK: @test1_no
; CHECK-NEXT: store i8 0, i8* %a
; CHECK-NEXT: load i8* %b
; CHECK-NEXT: store i8 1, i8* %a
; CHECK-NEXT: ret i8 %y
define i8 @test1_no(i8* %a, i8* %b) nounwind {
  store i8 0, i8* %a
  %y = load i8* %b, !tbaa !6
  store i8 1, i8* %a
  ret i8 %y
}

; Root note.
!0 = metadata !{ }
; Some type.
!1 = metadata !{ metadata !"foo", metadata !0 }
; Some other non-aliasing type.
!2 = metadata !{ metadata !"bar", metadata !0 }

; Some type.
!3 = metadata !{ metadata !"foo", metadata !0 }
; Some type in a different type system.
!4 = metadata !{ metadata !"bar", metadata !"different" }

; Invariant memory.
!5 = metadata !{ metadata !"qux", metadata !0, i1 1 }
; Not invariant memory.
!6 = metadata !{ metadata !"qux", metadata !0, i1 0 }