1 files changed, 80 insertions, 0 deletions
diff --git a/test/Transforms/PlaceSafepoints/finite-loops.ll b/test/Transforms/PlaceSafepoints/finite-loops.ll
new file mode 100644
index 0000000..8b64d24
--- /dev/null
+++ b/test/Transforms/PlaceSafepoints/finite-loops.ll
@@ -0,0 +1,80 @@
+; Tests to ensure that we are not placing backedge safepoints in
+; loops which are clearly finite.
+;; RUN: opt %s -place-safepoints -S | FileCheck %s
+
+
+; A simple counted loop with trivially known range
+define void @test1(i32) gc "statepoint-example" {
+; CHECK-LABEL: test1
+; CHECK-LABEL: entry
+; CHECK: statepoint
+; CHECK-LABEL: loop
+; CHECK-NOT: statepoint
+
+entry:
+  br label %loop
+
+loop:
+  %counter = phi i32 [ 0 , %entry ], [ %counter.inc , %loop ]
+  %counter.inc = add i32 %counter, 1
+  %counter.cmp = icmp slt i32 %counter.inc, 16
+  br i1 %counter.cmp, label %loop, label %exit
+
+exit:
+  ret void
+}
+
+; The same counted loop, but with an unknown early exit
+define void @test2(i32) gc "statepoint-example" {
+; CHECK-LABEL: test2
+; CHECK-LABEL: entry
+; CHECK: statepoint
+; CHECK-LABEL: loop
+; CHECK-NOT: statepoint
+
+entry:
+  br label %loop
+
+loop:
+  %counter = phi i32 [ 0 , %entry ], [ %counter.inc , %continue ]
+  %counter.inc = add i32 %counter, 1
+  %counter.cmp = icmp slt i32 %counter.inc, 16
+  br i1 undef, label %continue, label %exit
+
+continue:
+  br i1 %counter.cmp, label %loop, label %exit
+
+exit:
+  ret void
+}
+
+; The range is a 8 bit value and we can't overflow
+define void @test3(i8 %upper) gc "statepoint-example" {
+; CHECK-LABEL: test3
+; CHECK-LABEL: entry
+; CHECK: statepoint
+; CHECK-LABEL: loop
+; CHECK-NOT: statepoint
+
+entry:
+  br label %loop
+
+loop:
+  %counter = phi i8 [ 0 , %entry ], [ %counter.inc , %loop ]
+  %counter.inc = add nsw i8 %counter, 1
+  %counter.cmp = icmp slt i8 %counter.inc, %upper
+  br i1 %counter.cmp, label %loop, label %exit
+
+exit:
+  ret void
+}
+
+
+; This function is inlined when inserting a poll.
+declare void @do_safepoint()
+define void @gc.safepoint_poll() {
+; CHECK-LABEL: gc.safepoint_poll
+entry:
+  call void @do_safepoint()
+  ret void
+}