1,193 changes: 1,193 additions & 0 deletions llvm/lib/Transforms/Scalar/LoopInterchange.cpp
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1 change: 1 addition & 0 deletions llvm/lib/Transforms/Scalar/Scalar.cpp
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Expand Up @@ -48,6 +48,7 @@ void llvm::initializeScalarOpts(PassRegistry &Registry) {
initializeLoopDeletionPass(Registry);
initializeLoopAccessAnalysisPass(Registry);
initializeLoopInstSimplifyPass(Registry);
initializeLoopInterchangePass(Registry);
initializeLoopRotatePass(Registry);
initializeLoopStrengthReducePass(Registry);
initializeLoopRerollPass(Registry);
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58 changes: 58 additions & 0 deletions llvm/test/Transforms/LoopInterchange/currentLimitation.ll
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; RUN: opt < %s -basicaa -loop-interchange -S | FileCheck %s
;; These are test that fail to interchange due to current limitation. This will go off once we extend the loop interchange pass.

target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

@A = common global [100 x [100 x i32]] zeroinitializer
@B = common global [100 x [100 x [100 x i32]]] zeroinitializer

;;--------------------------------------Test case 01------------------------------------
;; [FIXME] This loop though valid is currently not interchanged due to the limitation that we cannot split the inner loop latch due to multiple use of inner induction
;; variable.(used to increment the loop counter and to access A[j+1][i+1]
;; for(int i=0;i<N-1;i++)
;; for(int j=1;j<N-1;j++)
;; A[j+1][i+1] = A[j+1][i+1] + k;

define void @interchange_01(i32 %k, i32 %N) {
entry:
%sub = add nsw i32 %N, -1
%cmp26 = icmp sgt i32 %N, 1
br i1 %cmp26, label %for.cond1.preheader.lr.ph, label %for.end17

for.cond1.preheader.lr.ph:
%cmp324 = icmp sgt i32 %sub, 1
%0 = add i32 %N, -2
%1 = sext i32 %sub to i64
br label %for.cond1.preheader

for.cond.loopexit:
%cmp = icmp slt i64 %indvars.iv.next29, %1
br i1 %cmp, label %for.cond1.preheader, label %for.end17

for.cond1.preheader:
%indvars.iv28 = phi i64 [ 0, %for.cond1.preheader.lr.ph ], [ %indvars.iv.next29, %for.cond.loopexit ]
%indvars.iv.next29 = add nuw nsw i64 %indvars.iv28, 1
br i1 %cmp324, label %for.body4, label %for.cond.loopexit

for.body4:
%indvars.iv = phi i64 [ %indvars.iv.next, %for.body4 ], [ 1, %for.cond1.preheader ]
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
%arrayidx7 = getelementptr inbounds [100 x [100 x i32]], [100 x [100 x i32]]* @A, i64 0, i64 %indvars.iv.next, i64 %indvars.iv.next29
%2 = load i32, i32* %arrayidx7
%add8 = add nsw i32 %2, %k
store i32 %add8, i32* %arrayidx7
%lftr.wideiv = trunc i64 %indvars.iv to i32
%exitcond = icmp eq i32 %lftr.wideiv, %0
br i1 %exitcond, label %for.cond.loopexit, label %for.body4

for.end17:
ret void
}
;; Inner loop not split so it is not interchanged.
; CHECK-LABEL: @interchange_01
; CHECK: for.body4:
; CHECK-NEXT: %indvars.iv = phi i64 [ %indvars.iv.next, %for.body4 ], [ 1, %for.body4.preheader ]
; CHECK-NEXT: %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
; CHECK-NEXT: %arrayidx7 = getelementptr inbounds [100 x [100 x i32]], [100 x [100 x i32]]* @A, i64 0, i64 %indvars.iv.next, i64 %indvars.iv.next29

557 changes: 557 additions & 0 deletions llvm/test/Transforms/LoopInterchange/interchange.ll
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205 changes: 205 additions & 0 deletions llvm/test/Transforms/LoopInterchange/profitability.ll
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; RUN: opt < %s -basicaa -loop-interchange -S | FileCheck %s
;; We test profitability model in these test cases.

target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

@A = common global [100 x [100 x i32]] zeroinitializer
@B = common global [100 x [100 x i32]] zeroinitializer

;;---------------------------------------Test case 01---------------------------------
;; Loops interchange will result in code vectorization and hence profitable. Check for interchange.
;; for(int i=1;i<N;i++)
;; for(int j=1;j<N;j++)
;; A[j][i] = A[j - 1][i] + B[j][i];

define void @interchange_01(i32 %N) {
entry:
%cmp27 = icmp sgt i32 %N, 1
br i1 %cmp27, label %for.cond1.preheader.lr.ph, label %for.end16

for.cond1.preheader.lr.ph:
%0 = add i32 %N, -1
br label %for.body3.preheader

for.body3.preheader:
%indvars.iv30 = phi i64 [ 1, %for.cond1.preheader.lr.ph ], [ %indvars.iv.next31, %for.inc14 ]
br label %for.body3

for.body3:
%indvars.iv = phi i64 [ %indvars.iv.next, %for.body3 ], [ 1, %for.body3.preheader ]
%1 = add nsw i64 %indvars.iv, -1
%arrayidx5 = getelementptr inbounds [100 x [100 x i32]], [100 x [100 x i32]]* @A, i64 0, i64 %1, i64 %indvars.iv30
%2 = load i32, i32* %arrayidx5
%arrayidx9 = getelementptr inbounds [100 x [100 x i32]], [100 x [100 x i32]]* @B, i64 0, i64 %indvars.iv, i64 %indvars.iv30
%3 = load i32, i32* %arrayidx9
%add = add nsw i32 %3, %2
%arrayidx13 = getelementptr inbounds [100 x [100 x i32]], [100 x [100 x i32]]* @A, i64 0, i64 %indvars.iv, i64 %indvars.iv30
store i32 %add, i32* %arrayidx13
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
%lftr.wideiv = trunc i64 %indvars.iv to i32
%exitcond = icmp eq i32 %lftr.wideiv, %0
br i1 %exitcond, label %for.inc14, label %for.body3

for.inc14:
%indvars.iv.next31 = add nuw nsw i64 %indvars.iv30, 1
%lftr.wideiv32 = trunc i64 %indvars.iv30 to i32
%exitcond33 = icmp eq i32 %lftr.wideiv32, %0
br i1 %exitcond33, label %for.end16, label %for.body3.preheader

for.end16:
ret void
}
;; Here we are checking partial .ll to check if loop are interchanged.
; CHECK-LABEL: @interchange_01
; CHECK: for.body3.preheader: ; preds = %for.inc14, %for.cond1.preheader.lr.ph
; CHECK: %indvars.iv30 = phi i64 [ 1, %for.cond1.preheader.lr.ph ], [ %indvars.iv.next31, %for.inc14 ]
; CHECK: br label %for.body3.split2

; CHECK: for.body3.preheader1: ; preds = %entry
; CHECK: br label %for.body3

; CHECK: for.body3: ; preds = %for.body3.preheader1, %for.body3.split
; CHECK: %indvars.iv = phi i64 [ %indvars.iv.next, %for.body3.split ], [ 1, %for.body3.preheader1 ]
; CHECK: br label %for.cond1.preheader.lr.ph

; CHECK: for.body3.split2: ; preds = %for.body3.preheader
; CHECK: %1 = add nsw i64 %indvars.iv, -1
; CHECK: %arrayidx5 = getelementptr inbounds [100 x [100 x i32]], [100 x [100 x i32]]* @A, i64 0, i64 %1, i64 %indvars.iv30
; CHECK: %2 = load i32, i32* %arrayidx5
; CHECK: %arrayidx9 = getelementptr inbounds [100 x [100 x i32]], [100 x [100 x i32]]* @B, i64 0, i64 %indvars.iv, i64 %indvars.iv30
; CHECK: %3 = load i32, i32* %arrayidx9
; CHECK: %add = add nsw i32 %3, %2
; CHECK: %arrayidx13 = getelementptr inbounds [100 x [100 x i32]], [100 x [100 x i32]]* @A, i64 0, i64 %indvars.iv, i64 %indvars.iv30
; CHECK: store i32 %add, i32* %arrayidx13
; CHECK: br label %for.inc14


;; ---------------------------------------Test case 02---------------------------------
;; Check loop interchange profitability model.
;; This tests profitability model when operands of getelementpointer and not exactly the induction variable but some
;; arithmetic operation on them.
;; for(int i=1;i<N;i++)
;; for(int j=1;j<N;j++)
;; A[j-1][i-1] = A[j - 1][i-1] + B[j-1][i-1];

define void @interchange_02(i32 %N) {
entry:
%cmp32 = icmp sgt i32 %N, 1
br i1 %cmp32, label %for.cond1.preheader.lr.ph, label %for.end21

for.cond1.preheader.lr.ph:
%0 = add i32 %N, -1
br label %for.body3.lr.ph

for.body3.lr.ph:
%indvars.iv35 = phi i64 [ 1, %for.cond1.preheader.lr.ph ], [ %indvars.iv.next36, %for.inc19 ]
%1 = add nsw i64 %indvars.iv35, -1
br label %for.body3

for.body3:
%indvars.iv = phi i64 [ 1, %for.body3.lr.ph ], [ %indvars.iv.next, %for.body3 ]
%2 = add nsw i64 %indvars.iv, -1
%arrayidx6 = getelementptr inbounds [100 x [100 x i32]], [100 x [100 x i32]]* @A, i64 0, i64 %2, i64 %1
%3 = load i32, i32* %arrayidx6
%arrayidx12 = getelementptr inbounds [100 x [100 x i32]], [100 x [100 x i32]]* @B, i64 0, i64 %2, i64 %1
%4 = load i32, i32* %arrayidx12
%add = add nsw i32 %4, %3
store i32 %add, i32* %arrayidx6
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
%lftr.wideiv = trunc i64 %indvars.iv to i32
%exitcond = icmp eq i32 %lftr.wideiv, %0
br i1 %exitcond, label %for.inc19, label %for.body3

for.inc19:
%indvars.iv.next36 = add nuw nsw i64 %indvars.iv35, 1
%lftr.wideiv38 = trunc i64 %indvars.iv35 to i32
%exitcond39 = icmp eq i32 %lftr.wideiv38, %0
br i1 %exitcond39, label %for.end21, label %for.body3.lr.ph

for.end21:
ret void
}
; CHECK-LABEL: @interchange_02
; CHECK: for.body3.lr.ph: ; preds = %for.inc19, %for.cond1.preheader.lr.ph
; CHECK: %indvars.iv35 = phi i64 [ 1, %for.cond1.preheader.lr.ph ], [ %indvars.iv.next36, %for.inc19 ]
; CHECK: %0 = add nsw i64 %indvars.iv35, -1
; CHECK: br label %for.body3.split1

; CHECK: for.body3.preheader: ; preds = %entry
; CHECK: %1 = add i32 %N, -1
; CHECK: br label %for.body3

; CHECK: for.body3: ; preds = %for.body3.preheader, %for.body3.split
; CHECK: %indvars.iv = phi i64 [ %indvars.iv.next, %for.body3.split ], [ 1, %for.body3.preheader ]
; CHECK: br label %for.cond1.preheader.lr.ph

; CHECK: for.body3.split1: ; preds = %for.body3.lr.ph
; CHECK: %2 = add nsw i64 %indvars.iv, -1
; CHECK: %arrayidx6 = getelementptr inbounds [100 x [100 x i32]], [100 x [100 x i32]]* @A, i64 0, i64 %2, i64 %0
; CHECK: %3 = load i32, i32* %arrayidx6
; CHECK: %arrayidx12 = getelementptr inbounds [100 x [100 x i32]], [100 x [100 x i32]]* @B, i64 0, i64 %2, i64 %0
; CHECK: %4 = load i32, i32* %arrayidx12
; CHECK: %add = add nsw i32 %4, %3
; CHECK: store i32 %add, i32* %arrayidx6
; CHECK: br label %for.inc19


;;---------------------------------------Test case 03---------------------------------
;; Loops interchange is not profitable.
;; for(int i=1;i<N;i++)
;; for(int j=1;j<N;j++)
;; A[i-1][j-1] = A[i - 1][j-1] + B[i][j];

define void @interchange_03(i32 %N){
entry:
%cmp31 = icmp sgt i32 %N, 1
br i1 %cmp31, label %for.cond1.preheader.lr.ph, label %for.end19

for.cond1.preheader.lr.ph:
%0 = add i32 %N, -1
br label %for.body3.lr.ph

for.body3.lr.ph:
%indvars.iv34 = phi i64 [ 1, %for.cond1.preheader.lr.ph ], [ %indvars.iv.next35, %for.inc17 ]
%1 = add nsw i64 %indvars.iv34, -1
br label %for.body3

for.body3:
%indvars.iv = phi i64 [ 1, %for.body3.lr.ph ], [ %indvars.iv.next, %for.body3 ]
%2 = add nsw i64 %indvars.iv, -1
%arrayidx6 = getelementptr inbounds [100 x [100 x i32]], [100 x [100 x i32]]* @A, i64 0, i64 %1, i64 %2
%3 = load i32, i32* %arrayidx6
%arrayidx10 = getelementptr inbounds [100 x [100 x i32]], [100 x [100 x i32]]* @B, i64 0, i64 %indvars.iv34, i64 %indvars.iv
%4 = load i32, i32* %arrayidx10
%add = add nsw i32 %4, %3
store i32 %add, i32* %arrayidx6
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
%lftr.wideiv = trunc i64 %indvars.iv to i32
%exitcond = icmp eq i32 %lftr.wideiv, %0
br i1 %exitcond, label %for.inc17, label %for.body3

for.inc17:
%indvars.iv.next35 = add nuw nsw i64 %indvars.iv34, 1
%lftr.wideiv37 = trunc i64 %indvars.iv34 to i32
%exitcond38 = icmp eq i32 %lftr.wideiv37, %0
br i1 %exitcond38, label %for.end19, label %for.body3.lr.ph

for.end19:
ret void
}

; CHECK-LABEL: @interchange_03
; CHECK: for.body3.lr.ph:
; CHECK: %indvars.iv34 = phi i64 [ 1, %for.cond1.preheader.lr.ph ], [ %indvars.iv.next35, %for.inc17 ]
; CHECK: %1 = add nsw i64 %indvars.iv34, -1
; CHECK: br label %for.body3.preheader
; CHECK: for.body3.preheader:
; CHECK: br label %for.body3
; CHECK: for.body3:
; CHECK: %indvars.iv = phi i64 [ %indvars.iv.next, %for.body3 ], [ 1, %for.body3.preheader ]
; CHECK: %2 = add nsw i64 %indvars.iv, -1
; CHECK: %arrayidx6 = getelementptr inbounds [100 x [100 x i32]], [100 x [100 x i32]]* @A, i64 0, i64 %1, i64 %2
; CHECK: %3 = load i32, i32* %arrayidx6
; CHECK: %arrayidx10 = getelementptr inbounds [100 x [100 x i32]], [100 x [100 x i32]]* @B, i64 0, i64 %indvars.iv34, i64 %indvars.iv
; CHECK: %4 = load i32, i32* %arrayidx10