test/Transforms/LoopInterchange/reductions-across-inner-and-outer-loop.ll

; RUN: opt < %s -passes=loop-interchange -cache-line-size=64 -pass-remarks-missed='loop-interchange' -pass-remarks-output=%t -S \
; RUN:     -verify-dom-info -verify-loop-info -verify-loop-lcssa -stats 2>&1 | FileCheck %s
; RUN: FileCheck --input-file=%t --check-prefix=REMARKS %s


target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"

; REMARKS: --- !Passed
; REMARKS-NEXT: Pass:            loop-interchange
; REMARKS-NEXT: Name:            Interchanged
; REMARKS-NEXT: Function:        test1

define i64 @test1(ptr %Arr) {
; CHECK-LABEL: @test1(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[FOR2_PREHEADER:%.*]]
; CHECK:       for1.header.preheader:
; CHECK-NEXT:    br label [[FOR1_HEADER:%.*]]
; CHECK:       for1.header:
; CHECK-NEXT:    [[INDVARS_IV23:%.*]] = phi i64 [ [[INDVARS_IV_NEXT24:%.*]], [[FOR1_INC:%.*]] ], [ 0, [[FOR1_HEADER_PREHEADER:%.*]] ]
; CHECK-NEXT:    [[SUM_INNER:%.*]] = phi i64 [ [[SUM_INC:%.*]], [[FOR1_INC]] ], [ [[SUM_OUTER:%.*]], [[FOR1_HEADER_PREHEADER]] ]
; CHECK-NEXT:    br label [[FOR2_SPLIT1:%.*]]
; CHECK:       for2.preheader:
; CHECK-NEXT:    br label [[FOR2:%.*]]
; CHECK:       for2:
; CHECK-NEXT:    [[INDVARS_IV:%.*]] = phi i64 [ [[INDVARS_IV_NEXT_3:%.*]], [[FOR2_SPLIT:%.*]] ], [ 0, [[FOR2_PREHEADER]] ]
; CHECK-NEXT:    [[SUM_OUTER]] = phi i64 [ [[SUM_INC_LCSSA:%.*]], [[FOR2_SPLIT]] ], [ 0, [[FOR2_PREHEADER]] ]
; CHECK-NEXT:    br label [[FOR1_HEADER_PREHEADER]]
; CHECK:       for2.split1:
; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds [100 x [100 x i64]], ptr [[ARR:%.*]], i64 0, i64 [[INDVARS_IV]], i64 [[INDVARS_IV23]]
; CHECK-NEXT:    [[LV:%.*]] = load i64, ptr [[ARRAYIDX]], align 4
; CHECK-NEXT:    [[SUM_INC]] = add i64 [[SUM_INNER]], [[LV]]
; CHECK-NEXT:    [[IV_ORIGINAL:%.*]] = add nuw nsw i64 [[INDVARS_IV]], 1
; CHECK-NEXT:    [[EXIT1_ORIGINAL:%.*]] = icmp eq i64 [[IV_ORIGINAL]], 100
; CHECK-NEXT:    br label [[FOR1_INC]]
; CHECK:       for2.split:
; CHECK-NEXT:    [[SUM_INC_LCSSA]] = phi i64 [ [[SUM_INC]], %for1.inc ]
; CHECK-NEXT:    [[INDVARS_IV_NEXT_3]] = add nuw nsw i64 [[INDVARS_IV]], 1
; CHECK-NEXT:    [[EXIT1:%.*]] = icmp eq i64 [[INDVARS_IV_NEXT_3]], 100
; CHECK-NEXT:    br i1 [[EXIT1]], label [[FOR1_LOOPEXIT:%.*]], label [[FOR2]]
; CHECK:       for1.inc:
; CHECK-NEXT:    [[INDVARS_IV_NEXT24]] = add nuw nsw i64 [[INDVARS_IV23]], 1
; CHECK-NEXT:    [[EXIT2:%.*]] = icmp eq i64 [[INDVARS_IV_NEXT24]], 100
; CHECK-NEXT:    br i1 [[EXIT2]], label [[FOR2_SPLIT]], label [[FOR1_HEADER]]
; CHECK:       for1.loopexit:
; CHECK-NEXT:    [[SUM_INC_LCSSA2:%.*]] = phi i64 [ [[SUM_INC_LCSSA]], [[FOR2_SPLIT]] ]
; CHECK-NEXT:    ret i64 [[SUM_INC_LCSSA2]]
;
entry:
  br label %for1.header

for1.header:                                         ; preds = %for1.inc, %entry
  %indvars.iv23 = phi i64 [ 0, %entry ], [ %indvars.iv.next24, %for1.inc ]
  %sum.outer = phi i64 [ 0, %entry ], [ %sum.inc.lcssa, %for1.inc ]
  br label %for2

for2:                                        ; preds = %for2, %for1.header
  %indvars.iv = phi i64 [ 0, %for1.header ], [ %indvars.iv.next.3, %for2 ]
  %sum.inner = phi i64 [ %sum.outer, %for1.header ], [ %sum.inc, %for2 ]
  %arrayidx = getelementptr inbounds [100 x [100 x i64]], ptr %Arr, i64 0, i64 %indvars.iv, i64 %indvars.iv23
  %lv = load i64, ptr %arrayidx, align 4
  %sum.inc = add i64 %sum.inner, %lv
  %indvars.iv.next.3 = add nuw nsw i64 %indvars.iv, 1
  %exit1 = icmp eq i64 %indvars.iv.next.3, 100
  br i1 %exit1, label %for1.inc, label %for2

for1.inc:                                ; preds = %for2
  %sum.inc.lcssa = phi i64 [ %sum.inc, %for2 ]
  %indvars.iv.next24 = add nuw nsw i64 %indvars.iv23, 1
  %exit2 = icmp eq i64 %indvars.iv.next24, 100
  br i1 %exit2, label %for1.loopexit, label %for1.header

for1.loopexit:                                 ; preds = %for1.inc
  %sum.inc.lcssa2 = phi i64 [ %sum.inc.lcssa, %for1.inc ]
  ret i64 %sum.inc.lcssa2
}

; In this test case, the inner reduction PHI %inner does not involve the outer
; reduction PHI %sum.outer, do not interchange.
; REMARKS: --- !Missed
; REMARKS-NEXT: Pass:            loop-interchange
; REMARKS-NEXT: Name:            UnsupportedPHIOuter
; REMARKS-NEXT: Function:        test2

define i64 @test2(ptr %Arr) {
entry:
  br label %for1.header

for1.header:                                         ; preds = %for1.inc, %entry
  %indvars.iv23 = phi i64 [ 0, %entry ], [ %indvars.iv.next24, %for1.inc ]
  %sum.outer = phi i64 [ 0, %entry ], [ %sum.inc.lcssa, %for1.inc ]
  br label %for2

for2:                                        ; preds = %for2, %for1.header
  %indvars.iv = phi i64 [ 0, %for1.header ], [ %indvars.iv.next.3, %for2 ]
  %inner = phi i64 [ %indvars.iv23, %for1.header ], [ %sum.inc, %for2 ]
  %arrayidx = getelementptr inbounds [100 x [100 x i64]], ptr %Arr, i64 0, i64 %indvars.iv, i64 %indvars.iv23
  %lv = load i64, ptr %arrayidx, align 4
  %sum.inc = add i64 %inner, %lv
  %indvars.iv.next.3 = add nuw nsw i64 %indvars.iv, 1
  %exit1 = icmp eq i64 %indvars.iv.next.3, 100
  br i1 %exit1, label %for1.inc, label %for2

for1.inc:                                ; preds = %for2
  %sum.inc.lcssa = phi i64 [ %sum.inc, %for2 ]
  %indvars.iv.next24 = add nuw nsw i64 %indvars.iv23, 1
  %exit2 = icmp eq i64 %indvars.iv.next24, 100
  br i1 %exit2, label %for1.loopexit, label %for1.header

for1.loopexit:                                 ; preds = %for1.inc
  %sum.inc.lcssa2 = phi i64 [ %sum.inc.lcssa, %for1.inc ]
  ret i64 %sum.inc.lcssa2
}

; Check that we do not interchange if there is an additional instruction
; between the outer and inner reduction PHIs.
; REMARKS: --- !Missed
; REMARKS-NEXT: Pass:            loop-interchange
; REMARKS-NEXT: Name:            UnsupportedPHIOuter
; REMARKS-NEXT: Function:        test3

define i64 @test3(ptr %Arr) {
entry:
  br label %for1.header

for1.header:                                         ; preds = %for1.inc, %entry
  %indvars.iv23 = phi i64 [ 0, %entry ], [ %indvars.iv.next24, %for1.inc ]
  %sum.outer = phi i64 [ 0, %entry ], [ %sum.inc.lcssa, %for1.inc ]
  %so = add i64 %sum.outer, 10
  br label %for2

for2:                                        ; preds = %for2, %for1.header
  %indvars.iv = phi i64 [ 0, %for1.header ], [ %indvars.iv.next.3, %for2 ]
  %sum.inner = phi i64 [ %so, %for1.header ], [ %sum.inc, %for2 ]
  %arrayidx = getelementptr inbounds [100 x [100 x i64]], ptr %Arr, i64 0, i64 %indvars.iv, i64 %indvars.iv23
  %lv = load i64, ptr %arrayidx, align 4
  %sum.inc = add i64 %sum.inner, %lv
  %indvars.iv.next.3 = add nuw nsw i64 %indvars.iv, 1
  %exit1 = icmp eq i64 %indvars.iv.next.3, 100
  br i1 %exit1, label %for1.inc, label %for2

for1.inc:                                ; preds = %for2
  %sum.inc.lcssa = phi i64 [ %sum.inc, %for2 ]
  %indvars.iv.next24 = add nuw nsw i64 %indvars.iv23, 1
  %exit2 = icmp eq i64 %indvars.iv.next24, 100
  br i1 %exit2, label %for1.loopexit, label %for1.header

for1.loopexit:                                 ; preds = %for1.inc
  %sum.inc.lcssa2 = phi i64 [ %sum.inc.lcssa, %for1.inc ]
  ret i64 %sum.inc.lcssa2
}

; Check that we do not interchange if reduction is stored in an invariant address inside inner loop
; REMARKS: --- !Missed
; REMARKS-NEXT: Pass:            loop-interchange
; REMARKS-NEXT: Name:            UnsupportedPHIOuter
; REMARKS-NEXT: Function:        test4

define i64 @test4(ptr %Arr, ptr %dst) {
entry:
  %gep.dst = getelementptr inbounds i64, ptr %dst, i64 42
  br label %for1.header

for1.header:                                         ; preds = %for1.inc, %entry
  %indvars.iv23 = phi i64 [ 0, %entry ], [ %indvars.iv.next24, %for1.inc ]
  %sum.outer = phi i64 [ 0, %entry ], [ %sum.inc.lcssa, %for1.inc ]
  br label %for2

for2:                                        ; preds = %for2, %for1.header
  %indvars.iv = phi i64 [ 0, %for1.header ], [ %indvars.iv.next.3, %for2 ]
  %sum.inner = phi i64 [ %sum.outer, %for1.header ], [ %sum.inc, %for2 ]
  %arrayidx = getelementptr inbounds [100 x [100 x i64]], ptr %Arr, i64 0, i64 %indvars.iv, i64 %indvars.iv23
  %lv = load i64, ptr %arrayidx, align 4
  %sum.inc = add i64 %sum.inner, %lv
  store i64 %sum.inc, ptr %gep.dst, align 4
  %indvars.iv.next.3 = add nuw nsw i64 %indvars.iv, 1
  %exit1 = icmp eq i64 %indvars.iv.next.3, 100
  br i1 %exit1, label %for1.inc, label %for2

for1.inc:                                ; preds = %for2
  %sum.inc.lcssa = phi i64 [ %sum.inc, %for2 ]
  %indvars.iv.next24 = add nuw nsw i64 %indvars.iv23, 1
  %exit2 = icmp eq i64 %indvars.iv.next24, 100
  br i1 %exit2, label %for1.loopexit, label %for1.header

for1.loopexit:                                 ; preds = %for1.inc
  %sum.inc.lcssa2 = phi i64 [ %sum.inc.lcssa, %for1.inc ]
  ret i64 %sum.inc.lcssa2
}

; Check that we do not interchange or crash if the PHI in the outer loop gets a
; constant from the inner loop.
; REMARKS: --- !Missed
; REMARKS-NEXT: Pass:            loop-interchange
; REMARKS-NEXT: Name:            UnsupportedPHIOuter
; REMARKS-NEXT: Function:        test_constant_inner_loop_res

define i64 @test_constant_inner_loop_res(ptr %Arr) {
entry:
  br label %for1.header

for1.header:                                         ; preds = %for1.inc, %entry
  %indvars.iv23 = phi i64 [ 0, %entry ], [ %indvars.iv.next24, %for1.inc ]
  %sum.outer = phi i64 [ 0, %entry ], [ %sum.inc.amend, %for1.inc ]
  br label %for2

for2:                                        ; preds = %for2, %for1.header
  %indvars.iv = phi i64 [ 0, %for1.header ], [ %indvars.iv.next.3, %for2 ]
  %sum.inner = phi i64 [ %sum.outer, %for1.header ], [ %sum.inc, %for2 ]
  %arrayidx = getelementptr inbounds [100 x [100 x i64]], ptr %Arr, i64 0, i64 %indvars.iv, i64 %indvars.iv23
  %lv = load i64, ptr %arrayidx, align 4
  %sum.inc = add i64 %sum.inner, %lv
  %indvars.iv.next.3 = add nuw nsw i64 %indvars.iv, 1
  %exit1 = icmp eq i64 %indvars.iv.next.3, 100
  br i1 %exit1, label %for1.inc, label %for2

for1.inc:                                ; preds = %for2
  %sum.inc.lcssa = phi i64 [ %sum.inc, %for2 ]
  %const.lcssa = phi i64 [ 0, %for2 ]
  %sum.inc.amend = add i64 %const.lcssa, %sum.inc.lcssa
  %indvars.iv.next24 = add nuw nsw i64 %indvars.iv23, 1
  %exit2 = icmp eq i64 %indvars.iv.next24, 100
  br i1 %exit2, label %for1.loopexit, label %for1.header

for1.loopexit:                                 ; preds = %for1.inc
  %il.res.lcssa2 = phi i64 [ %sum.inc.amend, %for1.inc ]
  ret i64 %il.res.lcssa2
}

; Floating point reductions are interchanged if all the fp instructions
; involved allow reassociation.
; REMARKS: --- !Passed
; REMARKS-NEXT: Pass:            loop-interchange
; REMARKS-NEXT: Name:            Interchanged
; REMARKS-NEXT: Function:        test5

define float @test5(ptr %Arr, ptr %Arr2) {
entry:
  br label %outer.header

outer.header:                                     ; preds = %outer.inc, %entry
  %iv.outer = phi i64 [ 1, %entry ], [ %iv.outer.next, %outer.inc ]
  %float.outer = phi float [ 1.000000e+00, %entry ], [ %float.inner.lcssa, %outer.inc ]
  br label %for.body3

for.body3:                                        ; preds = %for.body3, %outer.header
  %float.inner = phi float [ %float.outer , %outer.header ], [ %float.inner.inc.inc, %for.body3 ]
  %iv.inner = phi i64 [ %iv.inner.next, %for.body3 ], [ 1, %outer.header ]
  %arrayidx5 = getelementptr inbounds [100 x [100 x float]], ptr %Arr, i64 0, i64 %iv.inner, i64 %iv.outer
  %vA = load float, ptr %arrayidx5
  %float.inner.inc = fadd fast float %float.inner, %vA
  %arrayidx6 = getelementptr inbounds [100 x [100 x float]], ptr %Arr2, i64 0, i64 %iv.inner, i64 %iv.outer
  %vB = load float, ptr %arrayidx6
  %float.inner.inc.inc = fadd fast float %float.inner.inc, %vB
  %iv.inner.next = add nuw nsw i64 %iv.inner, 1
  %exitcond = icmp eq i64 %iv.inner.next, 100
  br i1 %exitcond, label %outer.inc, label %for.body3

outer.inc:                                        ; preds = %for.body3
  %float.inner.lcssa = phi float [ %float.inner.inc.inc, %for.body3 ]
  %iv.outer.next = add nsw i64 %iv.outer, 1
  %cmp = icmp eq i64 %iv.outer.next, 100
  br i1 %cmp, label %outer.header, label %for.exit

for.exit:                                         ; preds = %outer.inc
  %float.outer.lcssa = phi float [ %float.inner.lcssa, %outer.inc ]
  ret float %float.outer.lcssa
}

; Floating point reductions are not interchanged if not all the fp instructions
; involved allow reassociation.
; REMARKS: --- !Missed
; REMARKS-NEXT: Pass:            loop-interchange
; REMARKS-NEXT: Name:            UnsupportedPHIOuter
; REMARKS-NEXT: Function:        test6

define float @test6(ptr %Arr, ptr %Arr2) {
entry:
  br label %outer.header

outer.header:                                     ; preds = %outer.inc, %entry
  %iv.outer = phi i64 [ 1, %entry ], [ %iv.outer.next, %outer.inc ]
  %float.outer = phi float [ 1.000000e+00, %entry ], [ %float.inner.lcssa, %outer.inc ]
  br label %for.body3

for.body3:                                        ; preds = %for.body3, %outer.header
  %float.inner = phi float [ %float.outer , %outer.header ], [ %float.inner.inc.inc, %for.body3 ]
  %iv.inner = phi i64 [ %iv.inner.next, %for.body3 ], [ 1, %outer.header ]
  %arrayidx5 = getelementptr inbounds [100 x [100 x float]], ptr %Arr, i64 0, i64 %iv.inner, i64 %iv.outer
  %vA = load float, ptr %arrayidx5
  %float.inner.inc = fadd float %float.inner, %vA ; do not allow reassociation
  %arrayidx6 = getelementptr inbounds [100 x [100 x float]], ptr %Arr2, i64 0, i64 %iv.inner, i64 %iv.outer
  %vB = load float, ptr %arrayidx6
  %float.inner.inc.inc = fadd fast float %float.inner.inc, %vB
  %iv.inner.next = add nuw nsw i64 %iv.inner, 1
  %exitcond = icmp eq i64 %iv.inner.next, 100
  br i1 %exitcond, label %outer.inc, label %for.body3

outer.inc:                                        ; preds = %for.body3
  %float.inner.lcssa = phi float [ %float.inner.inc.inc, %for.body3 ]
  %iv.outer.next = add nsw i64 %iv.outer, 1
  %cmp = icmp eq i64 %iv.outer.next, 100
  br i1 %cmp, label %outer.header, label %for.exit

for.exit:                                         ; preds = %outer.inc
  %float.outer.lcssa = phi float [ %float.inner.lcssa, %outer.inc ]
  ret float %float.outer.lcssa
}