; RUN: opt < %s -basicaa -loop-interchange -S | FileCheck %s @A = common global [500 x [500 x i32]] zeroinitializer @X = common global i32 0 @B = common global [500 x [500 x i32]] zeroinitializer @Y = common global i32 0 ;; for( int i=1;i<N;i++) ;; for( int j=1;j<N;j++) ;; X+=A[j][i]; define void @reduction_01(i32 %N) { entry: %cmp16 = icmp sgt i32 %N, 1 br i1 %cmp16, label %for.body3.lr.ph, label %for.end8 for.body3.lr.ph: ; preds = %entry, %for.cond1.for.inc6_crit_edge %indvars.iv18 = phi i64 [ %indvars.iv.next19, %for.cond1.for.inc6_crit_edge ], [ 1, %entry ] %X.promoted = load i32, i32* @X br label %for.body3 for.body3: ; preds = %for.body3, %for.body3.lr.ph %indvars.iv = phi i64 [ 1, %for.body3.lr.ph ], [ %indvars.iv.next, %for.body3 ] %add15 = phi i32 [ %X.promoted, %for.body3.lr.ph ], [ %add, %for.body3 ] %arrayidx5 = getelementptr inbounds [500 x [500 x i32]], [500 x [500 x i32]]* @A, i64 0, i64 %indvars.iv, i64 %indvars.iv18 %0 = load i32, i32* %arrayidx5 %add = add nsw i32 %add15, %0 %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 %lftr.wideiv = trunc i64 %indvars.iv.next to i32 %exitcond = icmp eq i32 %lftr.wideiv, %N br i1 %exitcond, label %for.cond1.for.inc6_crit_edge, label %for.body3 for.cond1.for.inc6_crit_edge: ; preds = %for.body3 store i32 %add, i32* @X %indvars.iv.next19 = add nuw nsw i64 %indvars.iv18, 1 %lftr.wideiv20 = trunc i64 %indvars.iv.next19 to i32 %exitcond21 = icmp eq i32 %lftr.wideiv20, %N br i1 %exitcond21, label %for.end8, label %for.body3.lr.ph for.end8: ; preds = %for.cond1.for.inc6_crit_edge, %entry ret void } ;; Loop is interchanged check that the phi nodes are split and the promoted value is used instead of the reduction phi. ; CHECK-LABEL: @reduction_01 ; 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.body3.lr.ph.preheader ; CHECK: %add = add nsw i32 %X.promoted ;; Test for more than 1 reductions inside a loop. ;; for( int i=1;i<N;i++) ;; for( int j=1;j<N;j++) ;; for( int k=1;k<N;k++) { ;; X+=A[k][j]; ;; Y+=B[k][i]; ;; } define void @reduction_02(i32 %N) { entry: %cmp34 = icmp sgt i32 %N, 1 br i1 %cmp34, label %for.cond4.preheader.preheader, label %for.end19 for.cond4.preheader.preheader: ; preds = %entry, %for.inc17 %indvars.iv40 = phi i64 [ %indvars.iv.next41, %for.inc17 ], [ 1, %entry ] br label %for.body6.lr.ph for.body6.lr.ph: ; preds = %for.cond4.for.inc14_crit_edge, %for.cond4.preheader.preheader %indvars.iv36 = phi i64 [ %indvars.iv.next37, %for.cond4.for.inc14_crit_edge ], [ 1, %for.cond4.preheader.preheader ] %X.promoted = load i32, i32* @X %Y.promoted = load i32, i32* @Y br label %for.body6 for.body6: ; preds = %for.body6, %for.body6.lr.ph %indvars.iv = phi i64 [ 1, %for.body6.lr.ph ], [ %indvars.iv.next, %for.body6 ] %add1331 = phi i32 [ %Y.promoted, %for.body6.lr.ph ], [ %add13, %for.body6 ] %add30 = phi i32 [ %X.promoted, %for.body6.lr.ph ], [ %add, %for.body6 ] %arrayidx8 = getelementptr inbounds [500 x [500 x i32]], [500 x [500 x i32]]* @A, i64 0, i64 %indvars.iv, i64 %indvars.iv36 %0 = load i32, i32* %arrayidx8 %add = add nsw i32 %add30, %0 %arrayidx12 = getelementptr inbounds [500 x [500 x i32]], [500 x [500 x i32]]* @B, i64 0, i64 %indvars.iv, i64 %indvars.iv40 %1 = load i32, i32* %arrayidx12 %add13 = add nsw i32 %add1331, %1 %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 %lftr.wideiv = trunc i64 %indvars.iv.next to i32 %exitcond = icmp eq i32 %lftr.wideiv, %N br i1 %exitcond, label %for.cond4.for.inc14_crit_edge, label %for.body6 for.cond4.for.inc14_crit_edge: ; preds = %for.body6 store i32 %add, i32* @X store i32 %add13, i32* @Y %indvars.iv.next37 = add nuw nsw i64 %indvars.iv36, 1 %lftr.wideiv38 = trunc i64 %indvars.iv.next37 to i32 %exitcond39 = icmp eq i32 %lftr.wideiv38, %N br i1 %exitcond39, label %for.inc17, label %for.body6.lr.ph for.inc17: ; preds = %for.cond4.for.inc14_crit_edge %indvars.iv.next41 = add nuw nsw i64 %indvars.iv40, 1 %lftr.wideiv42 = trunc i64 %indvars.iv.next41 to i32 %exitcond43 = icmp eq i32 %lftr.wideiv42, %N br i1 %exitcond43, label %for.end19, label %for.cond4.preheader.preheader for.end19: ; preds = %for.inc17, %entry ret void } ;; Loop is interchanged check that the phi nodes are split and the promoted value is used instead of the reduction phi. ; CHECK-LABEL: @reduction_02 ; CHECK: for.body6: ; preds = %for.body6.preheader, %for.body6.split ; CHECK: %indvars.iv = phi i64 [ %indvars.iv.next, %for.body6.split ], [ 1, %for.body6.preheader ] ; CHECK: br label %for.cond4.preheader.preheader.preheader ; CHECK: %add13 = add nsw i32 %Y.promoted ;; Not tightly nested. Do not interchange. ;; for( int i=1;i<N;i++) ;; for( int j=1;j<N;j++) { ;; for( int k=1;k<N;k++) { ;; X+=A[k][j]; ;; } ;; Y+=B[j][i]; ;; } define void @reduction_03(i32 %N) { entry: %cmp35 = icmp sgt i32 %N, 1 br i1 %cmp35, label %for.cond4.preheader.lr.ph, label %for.end19 for.cond4.preheader.lr.ph: ; preds = %entry, %for.cond1.for.inc17_crit_edge %indvars.iv41 = phi i64 [ %indvars.iv.next42, %for.cond1.for.inc17_crit_edge ], [ 1, %entry ] %Y.promoted = load i32, i32* @Y br label %for.body6.lr.ph for.body6.lr.ph: ; preds = %for.cond4.preheader.lr.ph, %for.cond4.for.end_crit_edge %indvars.iv37 = phi i64 [ 1, %for.cond4.preheader.lr.ph ], [ %indvars.iv.next38, %for.cond4.for.end_crit_edge ] %add1334 = phi i32 [ %Y.promoted, %for.cond4.preheader.lr.ph ], [ %add13, %for.cond4.for.end_crit_edge ] %X.promoted = load i32, i32* @X br label %for.body6 for.body6: ; preds = %for.body6, %for.body6.lr.ph %indvars.iv = phi i64 [ 1, %for.body6.lr.ph ], [ %indvars.iv.next, %for.body6 ] %add31 = phi i32 [ %X.promoted, %for.body6.lr.ph ], [ %add, %for.body6 ] %arrayidx8 = getelementptr inbounds [500 x [500 x i32]], [500 x [500 x i32]]* @A, i64 0, i64 %indvars.iv, i64 %indvars.iv37 %0 = load i32, i32* %arrayidx8 %add = add nsw i32 %add31, %0 %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 %lftr.wideiv = trunc i64 %indvars.iv.next to i32 %exitcond = icmp eq i32 %lftr.wideiv, %N br i1 %exitcond, label %for.cond4.for.end_crit_edge, label %for.body6 for.cond4.for.end_crit_edge: ; preds = %for.body6 store i32 %add, i32* @X %arrayidx12 = getelementptr inbounds [500 x [500 x i32]], [500 x [500 x i32]]* @B, i64 0, i64 %indvars.iv37, i64 %indvars.iv41 %1 = load i32, i32* %arrayidx12 %add13 = add nsw i32 %add1334, %1 %indvars.iv.next38 = add nuw nsw i64 %indvars.iv37, 1 %lftr.wideiv39 = trunc i64 %indvars.iv.next38 to i32 %exitcond40 = icmp eq i32 %lftr.wideiv39, %N br i1 %exitcond40, label %for.cond1.for.inc17_crit_edge, label %for.body6.lr.ph for.cond1.for.inc17_crit_edge: ; preds = %for.cond4.for.end_crit_edge store i32 %add13, i32* @Y %indvars.iv.next42 = add nuw nsw i64 %indvars.iv41, 1 %lftr.wideiv43 = trunc i64 %indvars.iv.next42 to i32 %exitcond44 = icmp eq i32 %lftr.wideiv43, %N br i1 %exitcond44, label %for.end19, label %for.cond4.preheader.lr.ph for.end19: ; preds = %for.cond1.for.inc17_crit_edge, %entry ret void } ;; Not tightly nested. Do not interchange. ;; Not interchanged hence the phi's in the inner loop will not be split. Check for the same. ; CHECK-LABEL: @reduction_03 ; CHECK: for.body6: ; preds = %for.body6.preheader, %for.body6 ; CHECK: %indvars.iv = phi i64 [ %indvars.iv.next, %for.body6 ], [ 1, %for.body6.preheader ] ; CHECK: %add31 = phi i32 [ %add, %for.body6 ], [ %X.promoted, %for.body6.preheader ] ;; Multiple use of reduction not safe. Do not interchange. ;; for( int i=1;i<N;i++) ;; for( int j=1;j<N;j++) ;; for( int k=1;k<N;k++) { ;; X+=A[k][j]; ;; Y+=X; ;; } define void @reduction_04(i32 %N) { entry: %cmp28 = icmp sgt i32 %N, 1 br i1 %cmp28, label %for.cond4.preheader.preheader, label %for.end15 for.cond4.preheader.preheader: ; preds = %entry, %for.inc13 %i.029 = phi i32 [ %inc14, %for.inc13 ], [ 1, %entry ] br label %for.body6.lr.ph for.body6.lr.ph: ; preds = %for.cond4.for.inc10_crit_edge, %for.cond4.preheader.preheader %indvars.iv30 = phi i64 [ %indvars.iv.next31, %for.cond4.for.inc10_crit_edge ], [ 1, %for.cond4.preheader.preheader ] %X.promoted = load i32, i32* @X %Y.promoted = load i32, i32* @Y br label %for.body6 for.body6: ; preds = %for.body6, %for.body6.lr.ph %indvars.iv = phi i64 [ 1, %for.body6.lr.ph ], [ %indvars.iv.next, %for.body6 ] %add925 = phi i32 [ %Y.promoted, %for.body6.lr.ph ], [ %add9, %for.body6 ] %add24 = phi i32 [ %X.promoted, %for.body6.lr.ph ], [ %add, %for.body6 ] %arrayidx8 = getelementptr inbounds [500 x [500 x i32]], [500 x [500 x i32]]* @A, i64 0, i64 %indvars.iv, i64 %indvars.iv30 %0 = load i32, i32* %arrayidx8 %add = add nsw i32 %add24, %0 %add9 = add nsw i32 %add925, %add %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 %lftr.wideiv = trunc i64 %indvars.iv.next to i32 %exitcond = icmp eq i32 %lftr.wideiv, %N br i1 %exitcond, label %for.cond4.for.inc10_crit_edge, label %for.body6 for.cond4.for.inc10_crit_edge: ; preds = %for.body6 store i32 %add, i32* @X store i32 %add9, i32* @Y %indvars.iv.next31 = add nuw nsw i64 %indvars.iv30, 1 %lftr.wideiv32 = trunc i64 %indvars.iv.next31 to i32 %exitcond33 = icmp eq i32 %lftr.wideiv32, %N br i1 %exitcond33, label %for.inc13, label %for.body6.lr.ph for.inc13: ; preds = %for.cond4.for.inc10_crit_edge %inc14 = add nuw nsw i32 %i.029, 1 %exitcond34 = icmp eq i32 %inc14, %N br i1 %exitcond34, label %for.end15, label %for.cond4.preheader.preheader for.end15: ; preds = %for.inc13, %entry ret void } ;; Not interchanged hence the phi's in the inner loop will not be split. Check for the same. ; CHECK-LABEL: @reduction_04 ; CHECK: for.body6: ; preds = %for.body6.preheader, %for.body6 ; CHECK: %indvars.iv = phi i64 [ %indvars.iv.next, %for.body6 ], [ 1, %for.body6.preheader ] ; CHECK: %add925 = phi i32 [ %add9, %for.body6 ], [ %Y.promoted, %for.body6.preheader ]