Add note about limitations of insn_field_cmp().

diff --git a/sim/igen/gen.c b/sim/igen/gen.c
index bd10f20..5cc7e76 100644 (file)
--- a/sim/igen/gen.c
+++ b/sim/igen/gen.c
@@ -355,12 +355,15 @@ insn_list_insert (insn_list **cur_insn_ptr,
       switch (duplicate_action)
        {
        case report_duplicate_insns:
-         /* two instructions with the same constant field
-            values across all words and bits */
+         /* It would appear that we have two instructions with the
+            same constant field values across all words and bits.
+            This error can also occure when insn_field_cmp() is
+            failing to differentiate between two instructions that
+            differ only in their conditional fields. */
          warning (insn->line,
                   "Two instructions with identical constant fields\n");
          error ((*cur_insn_ptr)->insn->line,
-                "Location of second (duplicated?) instruction\n");
+                "Location of duplicate instruction\n");
        case merge_duplicate_insns:
          /* Add the opcode path to the instructions list */
          if (opcodes != NULL)