From 5feb287d19c070d9a496a9e17fca95887e4a9cb9 Mon Sep 17 00:00:00 2001
From: Arnold Schwaighofer <aschwaighofer@apple.com>
Date: Wed, 19 Mar 2025 09:26:20 -0700
Subject: [PATCH] LoadableByAddress: Add missing BranchInst in a switch

rdar://146980802
---
 lib/IRGen/LoadableByAddress.cpp    |  5 +++++
 test/IRGen/loadable_by_address.sil | 24 ++++++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/lib/IRGen/LoadableByAddress.cpp b/lib/IRGen/LoadableByAddress.cpp
index 9c08dbbee6b..750c5985b80 100644
--- a/lib/IRGen/LoadableByAddress.cpp
+++ b/lib/IRGen/LoadableByAddress.cpp
@@ -3100,10 +3100,15 @@ void LoadableByAddress::run() {
                 builtinInstrs.insert(instr);
                 break;
               }
+              case SILInstructionKind::BranchInst:
               case SILInstructionKind::StructInst:
               case SILInstructionKind::DebugValueInst:
                 break;
               default:
+#ifndef NDEBUG
+                currInstr->dump();
+                currInstr->getFunction()->dump();
+#endif
                 llvm_unreachable("Unhandled use of FunctionRefInst");
               }
             }
diff --git a/test/IRGen/loadable_by_address.sil b/test/IRGen/loadable_by_address.sil
index fa29655e459..1ff85f37ab3 100644
--- a/test/IRGen/loadable_by_address.sil
+++ b/test/IRGen/loadable_by_address.sil
@@ -53,3 +53,27 @@ entry(%x : $X):
   %retval = tuple ()
   return %retval : $()
 }
+
+sil @branch_inst_f : $@convention(thin) (@owned X, UInt8) -> ()
+sil @branch_inst_f2 : $@convention(thin) (@owned X, UInt8) -> ()
+
+sil @trigger : $@convention(thin) (@owned X) -> ()
+
+// This used to crash.
+sil @branch_inst_test : $@convention(thin) (Builtin.Int1, @owned X) -> (@convention(thin) (@owned X, UInt8) -> ()) {
+entry(%1 : $Builtin.Int1, %t: $X):
+  %f = function_ref @trigger : $@convention(thin) (@owned X) -> ()
+  %x = apply %f(%t) : $@convention(thin) (@owned X) -> ()
+  cond_br %1,  bb1, bb2
+
+bb1:
+  %2 = function_ref @branch_inst_f : $@convention(thin) (@owned X, UInt8) -> ()
+  br bb3(%2)
+
+bb2:
+  %3 = function_ref @branch_inst_f2 : $@convention(thin) (@owned X, UInt8) -> ()
+  br bb3(%3)
+
+bb3(%r : $@convention(thin) (@owned X, UInt8) -> ()):
+  return %r : $@convention(thin) (@owned X, UInt8) -> ()
+}