If make_uses_available was called twice for the same use,
we could end up trying to create duplicate definitions for
the same extended live range.
gcc/
* rtl-ssa/blocks.cc (function_info::create_degenerate_phi): Check
whether the requested phi already exists.
---
gcc/rtl-ssa/blocks.cc | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/gcc/rtl-ssa/blocks.cc b/gcc/rtl-ssa/blocks.cc
index d46cbf1e388..ecce7a68c59 100644
--- a/gcc/rtl-ssa/blocks.cc
+++ b/gcc/rtl-ssa/blocks.cc
@@ -525,6 +525,11 @@ function_info::create_phi (ebb_info *ebb, resource_info
resource,
phi_info *
function_info::create_degenerate_phi (ebb_info *ebb, set_info *def)
{
+ // Allow the function to be called twice in succession for the same def.
+ def_lookup dl = find_def (def->resource (), ebb->phi_insn ());
+ if (set_info *set = dl.matching_set ())
+ return as_a<phi_info *> (set);
+
access_info *input = def;
phi_info *phi = create_phi (ebb, def->resource (), &input, 1);
if (def->is_reg ())
--
2.25.1
