llvm/test/Transforms/LoopVectorize/first-order-recurrence-multiply-recurrences.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN:opt -loop-vectorize -force-vector-width=4 -force-vector-interleave=1 -S %s | FileCheck %s

; For %for.1, we are fine initially, because the previous value %for.1.next dominates the
; user of %for.1. But for %for.2, we have to sink the user (%for.1.next) past the previous
; value %for.2.next. This however breaks the condition we have for %for.1. We cannot fix
; both first order recurrences and cannot vectorize the loop.
define i32 @c(i32 %N) {
; CHECK-LABEL: @c(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
; CHECK:       for.body:
; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[INC:%.*]], [[FOR_BODY]] ], [ 10, [[ENTRY:%.*]] ]
; CHECK-NEXT:    [[FOR_1:%.*]] = phi i32 [ [[FOR_1_NEXT:%.*]], [[FOR_BODY]] ], [ 20, [[ENTRY]] ]
; CHECK-NEXT:    [[FOR_2:%.*]] = phi i32 [ [[FOR_2_NEXT:%.*]], [[FOR_BODY]] ], [ 11, [[ENTRY]] ]
; CHECK-NEXT:    [[FOR_1_NEXT]] = add nsw i32 [[FOR_2]], 1
; CHECK-NEXT:    [[FOR_2_NEXT]] = shl i32 [[FOR_1]], 24
; CHECK-NEXT:    [[INC]] = add nsw i32 [[IV]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp eq i32 [[INC]], [[N:%.*]]
; CHECK-NEXT:    br i1 [[EXITCOND]], label [[FOR_COND1_FOR_END_CRIT_EDGE:%.*]], label [[FOR_BODY]]
; CHECK:       for.cond1.for.end_crit_edge:
; CHECK-NEXT:    [[ADD_LCSSA:%.*]] = phi i32 [ [[FOR_1_NEXT]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[SEXT_LCSSA:%.*]] = phi i32 [ [[FOR_2_NEXT]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[RES:%.*]] = add i32 [[ADD_LCSSA]], [[SEXT_LCSSA]]
; CHECK-NEXT:    ret i32 [[RES]]
;
entry:
  br label %for.body

for.body:                                         ; preds = %for.body.preheader, %for.body
  %iv  = phi i32 [ %inc, %for.body ], [ 10, %entry ]
  %for.1 = phi i32 [ %for.1.next, %for.body ], [ 20, %entry ]
  %for.2 = phi i32 [ %for.2.next, %for.body ], [ 11, %entry ]
  %for.1.next = add nsw i32 %for.2, 1
  %for.2.next = shl i32 %for.1, 24
  %inc = add nsw i32 %iv, 1
  %exitcond = icmp eq i32 %inc, %N
  br i1 %exitcond, label %for.cond1.for.end_crit_edge, label %for.body

for.cond1.for.end_crit_edge:                      ; preds = %for.body
  %add.lcssa = phi i32 [ %for.1.next, %for.body ]
  %sext.lcssa = phi i32 [ %for.2.next, %for.body ]
  %res = add i32 %add.lcssa, %sext.lcssa
  ret i32 %res
}