llvm/test/Transforms/LoopUnroll/unroll-unconditional-latch.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -loop-unroll -S %s -verify-loop-info -verify-dom-info -verify-loop-lcssa | FileCheck %s

%struct.spam = type { double, double, double, double, double, double, double }

define void @test2(i32* %arg, i64* %out)  {
; CHECK-LABEL: @test2(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[FOR_HEADER:%.*]]
; CHECK:       for.header:
; CHECK-NEXT:    store i32 0, i32* [[ARG:%.*]], align 4
; CHECK-NEXT:    br label [[FOR_LATCH:%.*]]
; CHECK:       for.latch:
; CHECK-NEXT:    store volatile i64 0, i64* [[OUT:%.*]], align 4
; CHECK-NEXT:    [[PTR_1:%.*]] = getelementptr inbounds i32, i32* [[ARG]], i64 1
; CHECK-NEXT:    store i32 0, i32* [[PTR_1]], align 4
; CHECK-NEXT:    br label [[FOR_LATCH_1:%.*]]
; CHECK:       for.latch.1:
; CHECK-NEXT:    store volatile i64 1, i64* [[OUT]], align 4
; CHECK-NEXT:    [[PTR_2:%.*]] = getelementptr inbounds i32, i32* [[ARG]], i64 2
; CHECK-NEXT:    store i32 0, i32* [[PTR_2]], align 4
; CHECK-NEXT:    br label [[FOR_LATCH_2:%.*]]
; CHECK:       for.latch.2:
; CHECK-NEXT:    store volatile i64 2, i64* [[OUT]], align 4
; CHECK-NEXT:    [[PTR_3:%.*]] = getelementptr inbounds i32, i32* [[ARG]], i64 3
; CHECK-NEXT:    store i32 0, i32* [[PTR_3]], align 4
; CHECK-NEXT:    br i1 true, label [[IF_END_LOOPEXIT:%.*]], label [[FOR_LATCH_3:%.*]]
; CHECK:       for.latch.3:
; CHECK-NEXT:    store volatile i64 3, i64* [[OUT]], align 4
; CHECK-NEXT:    unreachable
; CHECK:       if.end.loopexit:
; CHECK-NEXT:    ret void
;

entry:
  br label %for.header

for.header:                              ; preds = %for.latch, %entry
  %indvars.iv800 = phi i64 [ 0, %entry ], [ %indvars.iv.next801, %for.latch ]
  %ptr = getelementptr inbounds i32, i32* %arg, i64 %indvars.iv800
  store i32 0, i32* %ptr, align 4
  %indvars.iv.next801 = add nuw nsw i64 %indvars.iv800, 1
  %exitcond802 = icmp eq i64 %indvars.iv.next801, 4
  br i1 %exitcond802, label %if.end.loopexit, label %for.latch

for.latch: ; preds = %for.header
  store volatile i64 %indvars.iv800, i64* %out
  br label %for.header

if.end.loopexit:                                  ; preds = %for.header
  ret void
}

define double @test_with_lcssa(double %arg1, double* %arg2) {
; CHECK-LABEL: @test_with_lcssa(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[LOOP_HEADER:%.*]]
; CHECK:       loop.header:
; CHECK-NEXT:    [[RES:%.*]] = fsub double [[ARG1:%.*]], 3.000000e+00
; CHECK-NEXT:    br label [[LOOP_LATCH:%.*]]
; CHECK:       loop.latch:
; CHECK-NEXT:    [[PTR:%.*]] = getelementptr inbounds double, double* [[ARG2:%.*]], i64 1
; CHECK-NEXT:    [[LV:%.*]] = load double, double* [[PTR]], align 8
; CHECK-NEXT:    [[RES_1:%.*]] = fsub double [[LV]], [[RES]]
; CHECK-NEXT:    br i1 true, label [[LOOP_EXIT:%.*]], label [[LOOP_LATCH_1:%.*]]
; CHECK:       loop.latch.1:
; CHECK-NEXT:    unreachable
; CHECK:       loop.exit:
; CHECK-NEXT:    [[RES_LCSSA:%.*]] = phi double [ [[RES_1]], [[LOOP_LATCH]] ]
; CHECK-NEXT:    ret double [[RES_LCSSA]]
;

entry:
  br label %loop.header

loop.header:                                            ; preds = %entry, %loop.latch
  %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop.latch ]
  %d1 = phi double [ %arg1, %entry ], [ %lv, %loop.latch ]
  %d2 = phi double [ 3.0, %entry ], [ %res, %loop.latch ]
  %res = fsub double %d1, %d2
  %iv.next = add nuw nsw i64 %iv, 1
  %cond = icmp eq i64 %iv.next, 2
  br i1 %cond, label %loop.exit, label %loop.latch

loop.latch:                                            ; preds = %bb366
  %ptr = getelementptr inbounds double, double* %arg2, i64 %iv.next
  %lv = load double, double* %ptr, align 8
  br label %loop.header

loop.exit:                                            ; preds = %bb366
  %res.lcssa = phi double [ %res, %loop.header ]
  ret double %res.lcssa
}

; We unroll the outer loop and need to preserve LI for the inner loop.
define void @test_with_nested_loop(i32* %arg)  {
; CHECK-LABEL: @test_with_nested_loop(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[OUTER_HEADER:%.*]]
; CHECK:       outer.header:
; CHECK-NEXT:    br label [[INNER_BODY_PREHEADER:%.*]]
; CHECK:       inner.body.preheader:
; CHECK-NEXT:    br label [[INNER_BODY:%.*]]
; CHECK:       inner.body:
; CHECK-NEXT:    [[J_IV:%.*]] = phi i64 [ [[J_IV_NEXT:%.*]], [[INNER_BODY]] ], [ 0, [[INNER_BODY_PREHEADER]] ]
; CHECK-NEXT:    [[PTR:%.*]] = getelementptr inbounds i32, i32* [[ARG:%.*]], i64 [[J_IV]]
; CHECK-NEXT:    store i32 0, i32* [[PTR]], align 4
; CHECK-NEXT:    [[J_IV_NEXT]] = add nuw nsw i64 [[J_IV]], 1
; CHECK-NEXT:    [[INNER_COND:%.*]] = icmp eq i64 [[J_IV_NEXT]], 40000
; CHECK-NEXT:    br i1 [[INNER_COND]], label [[OUTER_LATCH:%.*]], label [[INNER_BODY]]
; CHECK:       outer.latch:
; CHECK-NEXT:    br label [[INNER_BODY_PREHEADER_1:%.*]]
; CHECK:       inner.body.preheader.1:
; CHECK-NEXT:    br label [[INNER_BODY_1:%.*]]
; CHECK:       inner.body.1:
; CHECK-NEXT:    [[J_IV_1:%.*]] = phi i64 [ [[J_IV_NEXT_1:%.*]], [[INNER_BODY_1]] ], [ 0, [[INNER_BODY_PREHEADER_1]] ]
; CHECK-NEXT:    [[IDX_1:%.*]] = add i64 1, [[J_IV_1]]
; CHECK-NEXT:    [[PTR_1:%.*]] = getelementptr inbounds i32, i32* [[ARG]], i64 [[IDX_1]]
; CHECK-NEXT:    store i32 0, i32* [[PTR_1]], align 4
; CHECK-NEXT:    [[J_IV_NEXT_1]] = add nuw nsw i64 [[J_IV_1]], 1
; CHECK-NEXT:    [[INNER_COND_1:%.*]] = icmp eq i64 [[J_IV_NEXT_1]], 40000
; CHECK-NEXT:    br i1 [[INNER_COND_1]], label [[OUTER_LATCH_1:%.*]], label [[INNER_BODY_1]]
; CHECK:       outer.latch.1:
; CHECK-NEXT:    br i1 true, label [[EXIT:%.*]], label [[INNER_BODY_PREHEADER_2:%.*]]
; CHECK:       inner.body.preheader.2:
; CHECK-NEXT:    br label [[INNER_BODY_2:%.*]]
; CHECK:       inner.body.2:
; CHECK-NEXT:    [[J_IV_2:%.*]] = phi i64 [ [[J_IV_NEXT_2:%.*]], [[INNER_BODY_2]] ], [ 0, [[INNER_BODY_PREHEADER_2]] ]
; CHECK-NEXT:    [[IDX_2:%.*]] = add i64 2, [[J_IV_2]]
; CHECK-NEXT:    [[PTR_2:%.*]] = getelementptr inbounds i32, i32* [[ARG]], i64 [[IDX_2]]
; CHECK-NEXT:    store i32 0, i32* [[PTR_2]], align 4
; CHECK-NEXT:    [[J_IV_NEXT_2]] = add nuw nsw i64 [[J_IV_2]], 1
; CHECK-NEXT:    [[INNER_COND_2:%.*]] = icmp eq i64 [[J_IV_NEXT_2]], 40000
; CHECK-NEXT:    br i1 [[INNER_COND_2]], label [[OUTER_LATCH_2:%.*]], label [[INNER_BODY_2]]
; CHECK:       outer.latch.2:
; CHECK-NEXT:    unreachable
; CHECK:       exit:
; CHECK-NEXT:    ret void
;

entry:
  br label %outer.header

outer.header:                              ; preds = %outer.latch, %entry
  %outer.iv = phi i64 [ 0, %entry ], [ %outer.iv.next, %outer.latch ]
  %outer.iv.next = add nuw nsw i64 %outer.iv, 1
  %outer.cond = icmp eq i64 %outer.iv, 2
  br i1 %outer.cond, label %exit, label %inner.body

inner.body:
  %j.iv = phi i64 [ 0, %outer.header ], [ %j.iv.next, %inner.body ]
  %idx = add i64 %outer.iv, %j.iv
  %ptr = getelementptr inbounds i32, i32* %arg, i64 %idx
  store i32 0, i32* %ptr, align 4
  %j.iv.next = add nuw nsw i64 %j.iv, 1
  %inner.cond = icmp eq i64 %j.iv.next, 40000
  br i1 %inner.cond, label %outer.latch, label %inner.body

outer.latch: ; preds = %inner.body
  br label %outer.header

exit:                                  ; preds = %outer.header
  ret void
}

; We unroll the inner loop and need to preserve LI for the outer loop.
define void @test_with_nested_loop_unroll_inner(i32* %arg)  {
; CHECK-LABEL: @test_with_nested_loop_unroll_inner(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[OUTER_HEADER:%.*]]
; CHECK:       outer.header:
; CHECK-NEXT:    [[OUTER_IV:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[OUTER_IV_NEXT:%.*]], [[INNER_BODY:%.*]] ]
; CHECK-NEXT:    [[OUTER_IV_NEXT]] = add nuw nsw i64 [[OUTER_IV]], 1
; CHECK-NEXT:    [[OUTER_COND:%.*]] = icmp eq i64 [[OUTER_IV]], 40000
; CHECK-NEXT:    br i1 [[OUTER_COND]], label [[EXIT:%.*]], label [[INNER_BODY_PREHEADER:%.*]]
; CHECK:       inner.body.preheader:
; CHECK-NEXT:    br label [[INNER_BODY]]
; CHECK:       inner.body:
; CHECK-NEXT:    [[PTR:%.*]] = getelementptr inbounds i32, i32* [[ARG:%.*]], i64 [[OUTER_IV]]
; CHECK-NEXT:    store i32 0, i32* [[PTR]], align 4
; CHECK-NEXT:    [[IDX_1:%.*]] = add i64 [[OUTER_IV]], 1
; CHECK-NEXT:    [[PTR_1:%.*]] = getelementptr inbounds i32, i32* [[ARG]], i64 [[IDX_1]]
; CHECK-NEXT:    store i32 0, i32* [[PTR_1]], align 4
; CHECK-NEXT:    br label [[OUTER_HEADER]]
; CHECK:       exit:
; CHECK-NEXT:    ret void
;

entry:
  br label %outer.header

outer.header:                              ; preds = %outer.latch, %entry
  %outer.iv = phi i64 [ 0, %entry ], [ %outer.iv.next, %outer.latch ]
  %outer.iv.next = add nuw nsw i64 %outer.iv, 1
  %outer.cond = icmp eq i64 %outer.iv, 40000
  br i1 %outer.cond, label %exit, label %inner.body

inner.body:
  %j.iv = phi i64 [ 0, %outer.header ], [ %j.iv.next, %inner.body ]
  %idx = add i64 %outer.iv, %j.iv
  %ptr = getelementptr inbounds i32, i32* %arg, i64 %idx
  store i32 0, i32* %ptr, align 4
  %j.iv.next = add nuw nsw i64 %j.iv, 1
  %inner.cond = icmp eq i64 %j.iv.next, 2
  br i1 %inner.cond, label %outer.latch, label %inner.body

outer.latch: ; preds = %inner.body
  br label %outer.header

exit:                                  ; preds = %outer.header
  ret void
}



; Check that we do not crash for headers with non-branch instructions, e.g.
; switch. We do not unroll in those cases.
define void @test_switchinst_in_header() {
; CHECK-LABEL: @test_switchinst_in_header(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[WHILE_HEADER:%.*]]
; CHECK:       while.header:
; CHECK-NEXT:    switch i32 undef, label [[EXIT:%.*]] [
; CHECK-NEXT:    i32 11, label [[WHILE_BODY1:%.*]]
; CHECK-NEXT:    i32 5, label [[WHILE_BODY2:%.*]]
; CHECK-NEXT:    ]
; CHECK:       while.body1:
; CHECK-NEXT:    unreachable
; CHECK:       while.body2:
; CHECK-NEXT:    br label [[WHILE_LATCH:%.*]]
; CHECK:       while.latch:
; CHECK-NEXT:    br label [[WHILE_HEADER]]
; CHECK:       exit:
; CHECK-NEXT:    ret void
;

entry:
  br label %while.header

while.header:                               ; preds = %while.latch, %entry
  switch i32 undef, label %exit [
  i32 11, label %while.body1
  i32 5, label %while.body2
  ]

while.body1:                                ; preds = %while.header
  unreachable

while.body2:                                ; preds = %while.header
  br label %while.latch

while.latch:   								; preds = %while.body2
  br label %while.header

exit:                        			    ; preds = %while.header
  ret void
}