From 6381cd9173f77b4807332374b09172866d51363b Mon Sep 17 00:00:00 2001
From: Nuno Lopes <nuno.lopes@tecnico.ulisboa.pt>
Date: Mon, 30 Oct 2023 14:40:56 +0000
Subject: [PATCH] fix #951: false-positive condition for loop sinks doesn't
 take nonreturn functions into account

---
 ir/state.cpp                            |  2 +-
 tests/alive-tv/loops/issue951.srctgt.ll | 38 +++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)
 create mode 100644 tests/alive-tv/loops/issue951.srctgt.ll

diff --git a/ir/state.cpp b/ir/state.cpp
index 7fa02d75b..8d8e9d28a 100644
--- a/ir/state.cpp
+++ b/ir/state.cpp
@@ -1238,7 +1238,7 @@ expr State::sinkDomain() const {
 
   OrExpr ret;
   for (auto &[src, data] : I->second) {
-    ret.add(data.path());
+    ret.add(data.path() && *data.UB());
   }
   return ret();
 }
diff --git a/tests/alive-tv/loops/issue951.srctgt.ll b/tests/alive-tv/loops/issue951.srctgt.ll
new file mode 100644
index 000000000..030b029cd
--- /dev/null
+++ b/tests/alive-tv/loops/issue951.srctgt.ll
@@ -0,0 +1,38 @@
+; ERROR: Source is more defined than target
+; TEST-ARGS: -src-unroll=3 -tgt-unroll=3
+
+define i8 @src(i8 %v) {
+entry:
+  %v.nonneg = icmp sgt i8 %v, -1
+  br label %for.body
+
+for.body:
+  %sum = phi i8 [ 0, %entry ], [ %sum.next, %for.body ]
+  %sum.next = add i8 %sum, %v
+  %overflow = icmp ult i8 %sum.next, %sum
+  %cmp.i5.i = xor i1 %v.nonneg, %overflow
+  call void @use(i1 %cmp.i5.i)
+  br i1 %cmp.i5.i, label %for.body, label %cleanup1.loopexit
+
+cleanup1.loopexit:
+  %cmp.not.lcssa.ph = phi i8 [ %sum, %for.body ]
+  ret i8 %cmp.not.lcssa.ph
+}
+
+define i8 @tgt(i8 %v) {
+entry:
+  %v.nonneg = icmp sgt i8 %v, -1
+  br label %for.body
+
+for.body:
+  %sum = phi i8 [ 0, %entry ], [ %sum.next, %for.body ]
+  %sum.next = add i8 %sum, %v
+  call void @use(i1 %v.nonneg)
+  br i1 %v.nonneg, label %for.body, label %cleanup1.loopexit
+
+cleanup1.loopexit:
+  %cmp.not.lcssa.ph = phi i8 [ %sum, %for.body ]
+  ret i8 %cmp.not.lcssa.ph
+}
+
+declare void @use(i1)