1 files changed, 44 insertions, 0 deletions
diff --git a/test/Transforms/LoopUnroll/ephemeral.ll b/test/Transforms/LoopUnroll/ephemeral.ll
new file mode 100644
index 0000000..9d40613
--- /dev/null
+++ b/test/Transforms/LoopUnroll/ephemeral.ll
@@ -0,0 +1,44 @@
+; RUN: opt < %s -S -loop-unroll -unroll-threshold=50 | FileCheck %s
+
+; Make sure this loop is completely unrolled...
+; CHECK-LABEL: @test1
+; CHECK: for.body:
+; CHECK-NOT: for.end:
+
+define i32 @test1(i32* nocapture %a) nounwind uwtable readonly {
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %for.body, %entry
+  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+  %sum.01 = phi i32 [ 0, %entry ], [ %add, %for.body ]
+  %arrayidx = getelementptr inbounds i32* %a, i64 %indvars.iv
+  %0 = load i32* %arrayidx, align 4
+
+  ; This loop will be completely unrolled, even with these extra instructions,
+  ; but only because they're ephemeral (and, thus, free).
+  %1 = add nsw i32 %0, 2
+  %2 = add nsw i32 %1, 4
+  %3 = add nsw i32 %2, 4
+  %4 = add nsw i32 %3, 4
+  %5 = add nsw i32 %4, 4
+  %6 = add nsw i32 %5, 4
+  %7 = add nsw i32 %6, 4
+  %8 = add nsw i32 %7, 4
+  %9 = add nsw i32 %8, 4
+  %10 = add nsw i32 %9, 4
+  %ca = icmp sgt i32 %10, -7
+  call void @llvm.assume(i1 %ca)
+
+  %add = add nsw i32 %0, %sum.01
+  %indvars.iv.next = add i64 %indvars.iv, 1
+  %lftr.wideiv = trunc i64 %indvars.iv.next to i32
+  %exitcond = icmp eq i32 %lftr.wideiv, 5
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:                                          ; preds = %for.body
+  ret i32 %add
+}
+
+declare void @llvm.assume(i1) nounwind
+