lra: Ignore debug insns and notes in combine_reload_insn [PR109179]

We ICE in combine_reload_insn if we've deleted the TO insn operand during
processing, because lra_get_insn_recog_data doesn't expect to see the note
that replaces the deleted insn.  The solution here is to exit early if TO
is a debug insn or note.

2023-03-17  Peter Bergner  <bergner@linux.ibm.com>

gcc/
	PR rtl-optimization/109179
	* lra-constraints.cc (combine_reload_insn): Enforce TO is not a debug
	insn or note.  Move the tests earlier to guard lra_get_insn_recog_data.

diff --git a/gcc/lra-constraints.cc b/gcc/lra-constraints.cc
index 95b534e..405b8b9 100644 (file)
--- a/gcc/lra-constraints.cc
+++ b/gcc/lra-constraints.cc
@@ -5014,14 +5014,19 @@ combine_reload_insn (rtx_insn *from, rtx_insn *to)
   enum reg_class to_class, from_class;
   int n, nop;
   signed char changed_nops[MAX_RECOG_OPERANDS + 1];
-  lra_insn_recog_data_t id = lra_get_insn_recog_data (to);
-  struct lra_static_insn_data *static_id = id->insn_static_data;
   
   /* Check conditions for second memory reload and original insn:  */
   if ((targetm.secondary_memory_needed
        == hook_bool_mode_reg_class_t_reg_class_t_false)
-      || NEXT_INSN (from) != to || CALL_P (to)
-      || id->used_insn_alternative == LRA_UNKNOWN_ALT
+      || NEXT_INSN (from) != to
+      || !NONDEBUG_INSN_P (to)
+      || CALL_P (to))
+    return false;
+
+  lra_insn_recog_data_t id = lra_get_insn_recog_data (to);
+  struct lra_static_insn_data *static_id = id->insn_static_data;
+  
+  if (id->used_insn_alternative == LRA_UNKNOWN_ALT
       || (set = single_set (from)) == NULL_RTX)
     return false;
   from_reg = SET_DEST (set);