llvm/test/Transforms/LoopIdiom/X86/logical-right-shift-until-zero-cost.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -loop-idiom -mtriple=x86_64 -mcpu=corei7 < %s -S | FileCheck %s

declare void @escape_inner(i8, i8, i8, i1, i8)
declare void @escape_outer(i8, i8, i8, i1, i8)

; On corei7, lzcount is not cheap, so we don't transform.
define i8 @n(i8 %val, i8 %start, i8 %extraoffset) {
; CHECK-LABEL: @n(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[LOOP:%.*]]
; CHECK:       loop:
; CHECK-NEXT:    [[IV:%.*]] = phi i8 [ [[START:%.*]], [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[LOOP]] ]
; CHECK-NEXT:    [[NBITS:%.*]] = add nsw i8 [[IV]], [[EXTRAOFFSET:%.*]]
; CHECK-NEXT:    [[VAL_SHIFTED:%.*]] = lshr i8 [[VAL:%.*]], [[NBITS]]
; CHECK-NEXT:    [[VAL_SHIFTED_ISZERO:%.*]] = icmp eq i8 [[VAL_SHIFTED]], 0
; CHECK-NEXT:    [[IV_NEXT]] = add i8 [[IV]], 1
; CHECK-NEXT:    call void @escape_inner(i8 [[IV]], i8 [[NBITS]], i8 [[VAL_SHIFTED]], i1 [[VAL_SHIFTED_ISZERO]], i8 [[IV_NEXT]])
; CHECK-NEXT:    br i1 [[VAL_SHIFTED_ISZERO]], label [[END:%.*]], label [[LOOP]]
; CHECK:       end:
; CHECK-NEXT:    [[IV_RES:%.*]] = phi i8 [ [[IV]], [[LOOP]] ]
; CHECK-NEXT:    [[NBITS_RES:%.*]] = phi i8 [ [[NBITS]], [[LOOP]] ]
; CHECK-NEXT:    [[VAL_SHIFTED_RES:%.*]] = phi i8 [ [[VAL_SHIFTED]], [[LOOP]] ]
; CHECK-NEXT:    [[VAL_SHIFTED_ISZERO_RES:%.*]] = phi i1 [ [[VAL_SHIFTED_ISZERO]], [[LOOP]] ]
; CHECK-NEXT:    [[IV_NEXT_RES:%.*]] = phi i8 [ [[IV_NEXT]], [[LOOP]] ]
; CHECK-NEXT:    call void @escape_outer(i8 [[IV_RES]], i8 [[NBITS_RES]], i8 [[VAL_SHIFTED_RES]], i1 [[VAL_SHIFTED_ISZERO_RES]], i8 [[IV_NEXT_RES]])
; CHECK-NEXT:    ret i8 [[IV_RES]]
;
entry:
  br label %loop

loop:
  %iv = phi i8 [ %start, %entry ], [ %iv.next, %loop ]
  %nbits = add nsw i8 %iv, %extraoffset
  %val.shifted = lshr i8 %val, %nbits
  %val.shifted.iszero = icmp eq i8 %val.shifted, 0
  %iv.next = add i8 %iv, 1

  call void @escape_inner(i8 %iv, i8 %nbits, i8 %val.shifted, i1 %val.shifted.iszero, i8 %iv.next)

  br i1 %val.shifted.iszero, label %end, label %loop

end:
  %iv.res = phi i8 [ %iv, %loop ]
  %nbits.res = phi i8 [ %nbits, %loop ]
  %val.shifted.res = phi i8 [ %val.shifted, %loop ]
  %val.shifted.iszero.res = phi i1 [ %val.shifted.iszero, %loop ]
  %iv.next.res = phi i8 [ %iv.next, %loop ]

  call void @escape_outer(i8 %iv.res, i8 %nbits.res, i8 %val.shifted.res, i1 %val.shifted.iszero.res, i8 %iv.next.res)

  ret i8 %iv.res
}