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; 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
}
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