1 files changed, 69 insertions, 0 deletions
diff --git a/test/Transforms/LICM/preheader-safe.ll b/test/Transforms/LICM/preheader-safe.ll
new file mode 100644
index 0000000..260a5f6
--- /dev/null
+++ b/test/Transforms/LICM/preheader-safe.ll
@@ -0,0 +1,69 @@
+; RUN: opt -S -licm < %s | FileCheck %s
+
+declare void @use_nothrow(i64 %a) nounwind
+declare void @use(i64 %a)
+
+define void @nothrow(i64 %x, i64 %y, i1* %cond) {
+; CHECK-LABEL: nothrow
+; CHECK-LABEL: entry
+; CHECK: %div = udiv i64 %x, %y
+; CHECK-LABEL: loop
+; CHECK: call void @use_nothrow(i64 %div)
+entry:
+  br label %loop
+
+loop:                                         ; preds = %entry, %for.inc
+  %div = udiv i64 %x, %y
+  call void @use_nothrow(i64 %div)
+  br label %loop
+}
+; Negative test
+define void @throw_header(i64 %x, i64 %y, i1* %cond) {
+; CHECK-LABEL: throw_header
+; CHECK-LABEL: loop
+; CHECK: %div = udiv i64 %x, %y
+; CHECK: call void @use(i64 %div)
+entry:
+  br label %loop
+
+loop:                                         ; preds = %entry, %for.inc
+  %div = udiv i64 %x, %y
+  call void @use(i64 %div)
+  br label %loop
+}
+
+; The header is known no throw, but the loop is not.  We can
+; still lift out of the header.
+define void @nothrow_header(i64 %x, i64 %y, i1 %cond) {
+; CHECK-LABEL: nothrow_header
+; CHECK-LABEL: entry
+; CHECK: %div = udiv i64 %x, %y
+; CHECK-LABEL: loop
+; CHECK: call void @use(i64 %div)
+entry:
+  br label %loop
+loop:                                         ; preds = %entry, %for.inc
+  %div = udiv i64 %x, %y
+  br i1 %cond, label %loop-if, label %exit
+loop-if:
+  call void @use(i64 %div)
+  br label %loop
+exit:
+  ret void
+}
+; Negative test - can't move out of throwing block
+define void @nothrow_header_neg(i64 %x, i64 %y, i1 %cond) {
+; CHECK-LABEL: nothrow_header_neg
+; CHECK-LABEL: entry
+; CHECK-LABEL: loop
+; CHECK: %div = udiv i64 %x, %y
+; CHECK: call void @use(i64 %div)
+entry:
+  br label %loop
+loop:                                         ; preds = %entry, %for.inc
+  br label %loop-if
+loop-if:
+  %div = udiv i64 %x, %y
+  call void @use(i64 %div)
+  br label %loop
+}