; REQUIRES: asserts ; RUN: opt -passes=loop-interchange -debug -disable-output %s 2>&1 | FileCheck %s @A = global [16 x [16 x i32]] zeroinitializer ; Check that the CacheCost is calculated only when required. In this case, it ; is computed after passing the legality check. ; ; for (i = 0; i < 16; i++) ; for (j = 0; j < 16; j++) ; A[j][i] += 1; ; CHECK: Loops are legal to interchange ; CHECK: Compute CacheCost define void @legal_to_interchange() { entry: br label %for.i.header for.i.header: %i = phi i32 [ 0, %entry ], [ %i.next, %for.i.latch ] br label %for.j for.j: %j = phi i32 [ 0, %for.i.header ], [ %j.next, %for.j ] %idx = getelementptr inbounds [16 x [16 x i32]], ptr @A, i32 0, i32 %j, i32 %i %val = load i32, ptr %idx %inc = add i32 %val, 1 store i32 %inc, ptr %idx %j.next = add i32 %j, 1 %j.exit = icmp eq i32 %j.next, 16 br i1 %j.exit, label %for.i.latch, label %for.j for.i.latch: %i.next = add i32 %i, 1 %i.exit = icmp eq i32 %i.next, 16 br i1 %i.exit, label %exit, label %for.i.header exit: ret void } ; Check that the CacheCost is not calculated when not required. In this case, ; the legality check always fails so that we do not need to compute the ; CacheCost. ; ; for (i = 0; i < 16; i++) ; for (j = 0; j < 16; j++) ; A[j][i] = A[i][j]; ; CHECK-NOT: Compute CacheCost define void @illegal_to_interchange() { entry: br label %for.i.header for.i.header: %i = phi i32 [ 0, %entry ], [ %i.next, %for.i.latch ] br label %for.j for.j: %j = phi i32 [ 0, %for.i.header ], [ %j.next, %for.j ] %idx.load = getelementptr inbounds [16 x [16 x i32]], ptr @A, i32 0, i32 %i, i32 %j %idx.store = getelementptr inbounds [16 x [16 x i32]], ptr @A, i32 0, i32 %j, i32 %i %val = load i32, ptr %idx.load store i32 %val, ptr %idx.store %j.next = add i32 %j, 1 %j.exit = icmp eq i32 %j.next, 16 br i1 %j.exit, label %for.i.latch, label %for.j for.i.latch: %i.next = add i32 %i, 1 %i.exit = icmp eq i32 %i.next, 16 br i1 %i.exit, label %exit, label %for.i.header exit: ret void }