1; REQUIRES: asserts 2; RUN: opt < %s -loop-interchange -simplifycfg -pass-remarks-output=%t \ 3; RUN: -pass-remarks=loop-interchange -pass-remarks-missed=loop-interchange -stats -S 2>&1 \ 4; RUN: | FileCheck -check-prefix=STATS %s 5; RUN: FileCheck -input-file %t %s 6 7 8; no_deps_interchange just accesses a single nested array and can be interchange. 9; CHECK: Name: Interchanged 10; CHECK-NEXT: Function: no_deps_interchange 11define i32 @no_deps_interchange([1024 x i32]* nocapture %Arr) local_unnamed_addr #0 { 12entry: 13 br label %for1.header 14 15for1.header: ; preds = %entry, %for1.inc 16 %indvars.iv19 = phi i64 [ 0, %entry ], [ %indvars.iv.next20, %for1.inc ] 17 br label %for2 18 19for2: ; preds = %for1.header, %for2 20 %indvars.iv = phi i64 [ 0, %for1.header ], [ %indvars.iv.next, %for2 ] 21 %arrayidx6 = getelementptr inbounds [1024 x i32], [1024 x i32]* %Arr, i64 %indvars.iv, i64 %indvars.iv19 22 store i32 0, i32* %arrayidx6, align 4 23 %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 24 %exitcond = icmp ne i64 %indvars.iv.next, 1024 25 br i1 %exitcond, label %for2, label %for1.inc 26 27for1.inc: 28 %indvars.iv.next20 = add nuw nsw i64 %indvars.iv19, 1 29 %exitcond21 = icmp ne i64 %indvars.iv.next20, 1024 30 br i1 %exitcond21, label %for1.header, label %exit 31 32exit: ; preds = %for1.inc 33 ret i32 0 34 35} 36 37; Only the inner loop induction variable is used for memory accesses. 38; Interchanging is not beneficial. 39; CHECK: Name: InterchangeNotProfitable 40; CHECK-NEXT: Function: no_bad_order 41define i32 @no_bad_order(i32* %Arr) { 42entry: 43 br label %for1.header 44 45for1.header: ; preds = %entry, %for1.inc 46 %indvars.iv19 = phi i64 [ 0, %entry ], [ %indvars.iv.next20, %for1.inc ] 47 br label %for2 48 49for2: ; preds = %for1.header, %for2 50 %indvars.iv = phi i64 [ 0, %for1.header ], [ %indvars.iv.next, %for2 ] 51 %arrayidx6 = getelementptr inbounds i32, i32* %Arr, i64 %indvars.iv 52 store i32 0, i32* %arrayidx6, align 4 53 %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 54 %exitcond = icmp ne i64 %indvars.iv.next, 1024 55 br i1 %exitcond, label %for2, label %for1.inc 56 57for1.inc: 58 %indvars.iv.next20 = add nuw nsw i64 %indvars.iv19, 1 59 %exitcond21 = icmp ne i64 %indvars.iv.next20, 1024 60 br i1 %exitcond21, label %for1.header, label %exit 61 62exit: ; preds = %for1.inc 63 ret i32 0 64} 65 66; No memory access using any induction variables, interchanging not beneficial. 67; CHECK: Name: InterchangeNotProfitable 68; CHECK-NEXT: Function: no_mem_instrs 69define i32 @no_mem_instrs(i64* %ptr) { 70entry: 71 br label %for1.header 72 73for1.header: ; preds = %entry, %for1.inc 74 %indvars.iv19 = phi i64 [ 0, %entry ], [ %indvars.iv.next20, %for1.inc ] 75 br label %for2 76 77for2: ; preds = %for1.header, %for2 78 %indvars.iv = phi i64 [ 0, %for1.header ], [ %indvars.iv.next, %for2 ] 79 store i64 %indvars.iv, i64* %ptr, align 4 80 %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 81 %exitcond = icmp ne i64 %indvars.iv.next, 1024 82 br i1 %exitcond, label %for2, label %for1.inc 83 84for1.inc: 85 %indvars.iv.next20 = add nuw nsw i64 %indvars.iv19, 1 86 %exitcond21 = icmp ne i64 %indvars.iv.next20, 1024 87 br i1 %exitcond21, label %for1.header, label %exit 88 89exit: ; preds = %for1.inc 90 ret i32 0 91} 92 93 94; Check stats, we interchanged 1 out of 3 loops. 95; STATS: 1 loop-interchange - Number of loops interchanged 96