Unverified Commit 69ec84f8 authored by Roman Lebedev's avatar Roman Lebedev
Browse files

[NFC][InstCombine] Add 'x - (x & y)' tests with multi-use 'and' 

If %y is constant, we could still perform the fold
parent 0ba553d1

llvm/test/Transforms/InstCombine/sub.ll

+26 −0
Original line number Diff line number Diff line
@@ -1513,3 +1513,29 @@ define i32 @nsw_inference2(i32 %x, i32 %y) { 
  %z = sub i32 %x2, %y2

  ret i32 %z

}



define i8 @test74(i8 %x, i8 %y) {

; CHECK-LABEL: @test74(

; CHECK-NEXT:    [[T0:%.*]] = and i8 [[X:%.*]], [[Y:%.*]]

; CHECK-NEXT:    call void @use8(i8 [[T0]])

; CHECK-NEXT:    [[T1:%.*]] = sub i8 [[X]], [[T0]]

; CHECK-NEXT:    ret i8 [[T1]]

;

  %t0 = and i8 %x, %y

  call void @use8(i8 %t0)

  %t1 = sub i8 %x, %t0

  ret i8 %t1

}



define i8 @test75(i8 %x) {

; CHECK-LABEL: @test75(

; CHECK-NEXT:    [[T0:%.*]] = and i8 [[X:%.*]], -8

; CHECK-NEXT:    call void @use8(i8 [[T0]])

; CHECK-NEXT:    [[T1:%.*]] = sub i8 [[X]], [[T0]]

; CHECK-NEXT:    ret i8 [[T1]]

;

  %t0 = and i8 %x, -8

  call void @use8(i8 %t0)

  %t1 = sub i8 %x, %t0

  ret i8 %t1

}