1 files changed, 76 insertions, 0 deletions
diff --git a/test/Transforms/LICM/unrolled-deeply-nested.ll b/test/Transforms/LICM/unrolled-deeply-nested.ll
new file mode 100644
index 000000000000..c0f2c9818000
--- /dev/null
+++ b/test/Transforms/LICM/unrolled-deeply-nested.ll
@@ -0,0 +1,76 @@
+; Test that LICM correctly detects conflicting accesses to memory in deeply
+; nested subloops. This works in the legacy PM due to a special retained map of
+; alias information for inner loops, and in the new PM it is recomputed for each
+; loop.
+;
+; RUN: opt -S -aa-pipeline=basic-aa -passes='require<opt-remark-emit>,loop(licm)' < %s | FileCheck %s
+; RUN: opt -S -basicaa -licm < %s | FileCheck %s
+
+define i32 @test(i32* %a, i64 %n.0, i64 %n.0.0, i64 %n.0.0.0, i64 %n.0.0.0.0) nounwind uwtable readonly {
+; CHECK-LABEL: define i32 @test
+entry:
+  %b = alloca i32
+  %c = alloca i32
+  %a.i8 = bitcast i32* %a to i8*
+  %b.i8 = bitcast i32* %b to i8*
+  %c.i8 = bitcast i32* %c to i8*
+  br label %l.0.header
+; CHECK: %b = alloca i32
+; CHECK: %c = alloca i32
+; CHECK: %[[AI8:.*]] = bitcast i32* %a to i8*
+; CHECK: %[[BI8:.*]] = bitcast i32* %b to i8*
+; CHECK: %[[CI8:.*]] = bitcast i32* %c to i8*
+; CHECK-NOT: load
+; CHECK: br
+
+l.0.header:
+  %iv.0 = phi i64 [ %iv.0.next, %l.0.latch ], [ 0, %entry ]
+  %iv.0.next = add i64 %iv.0, 1
+  %exitcond.0 = icmp eq i64 %iv.0.next, %n.0
+  %a.val = load i32, i32* %a
+  store i32 %a.val, i32* %b
+  %c.val = trunc i64 %iv.0 to i32
+  store i32 %c.val, i32* %c
+  br label %l.0.0.header
+; CHECK: %[[AV:.*]] = load i32, i32* %a
+; CHECK: store i32 %[[AV]], i32* %b
+; CHECK: %[[CT:.*]] = trunc i64 {{.*}} to i32
+; CHECK: store i32 %[[CT]], i32* %c
+; CHECK: br
+
+l.0.0.header:
+  %iv.0.0 = phi i64 [ %iv.0.0.next, %l.0.0.latch ], [ 0, %l.0.header ]
+  %iv.0.0.next = add i64 %iv.0.0, 1
+  %exitcond.0.0 = icmp eq i64 %iv.0.0.next, %n.0.0
+  br label %l.0.0.0.header
+; CHECK: br
+
+l.0.0.0.header:
+  %iv.0.0.0 = phi i64 [ %iv.0.0.0.next, %l.0.0.0.header ], [ 0, %l.0.0.header ]
+  %iv.0.0.0.next = add i64 %iv.0.0.0, 1
+  %exitcond.0.0.0 = icmp eq i64 %iv.0.0.0.next, %n.0.0.0
+  call void @llvm.memcpy.p0i8.p0i8.i64(i8* %a.i8, i8* %c.i8, i64 4, i32 1, i1 false)
+  call void @llvm.memcpy.p0i8.p0i8.i64(i8* %b.i8, i8* %c.i8, i64 4, i32 1, i1 false)
+  br i1 %exitcond.0.0.0, label %l.0.0.0.header, label %l.0.0.latch
+; CHECK: call void @llvm.memcpy.{{.*}}(i8* %[[AI8]], i8* %[[CI8]], i64 4
+; CHECK: call void @llvm.memcpy.{{.*}}(i8* %[[BI8]], i8* %[[CI8]], i64 4
+; CHECK: br
+
+l.0.0.latch:
+  br i1 %exitcond.0.0, label %l.0.0.header, label %l.0.latch
+; CHECK: br
+
+l.0.latch:
+  %b.val = load i32, i32* %b
+  br i1 %exitcond.0, label %exit, label %l.0.header
+; CHECK: %[[BV:.*]] = load i32, i32* %b
+; CHECK: br
+
+exit:
+  %result.lcssa = phi i32 [ %b.val, %l.0.latch ]
+  ret i32 %b.val
+; CHECK: %[[LCSSA:.*]] = phi i32 [ %[[BV]], %{{.*}} ]
+; CHECK: ret i32 %[[LCSSA]]
+}
+
+declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture writeonly, i8* nocapture readonly, i64, i32, i1)