RISC-V: Search for mapping symbols from the last one found

With previous behaviour, multiple mapping symbols within the same
function would result in all the mapping symbols being searched.
This could slow down disassembly dramatically.

Multiple mapping symbols within a function can be a result of encoding
instructions as data, like sometimes seen in random instruction
generators.

opcodes/ChangeLog:

	* riscv-dis.c (riscv_search_mapping_symbol): Use last mapping
	symbol if it exists.

diff --git a/opcodes/riscv-dis.c b/opcodes/riscv-dis.c
index 684098d386a83b7aa00d2a21683014b704f97039..e6596c47423b832d5f885480dec198ec9f33fcaa 100644 (file)
--- a/opcodes/riscv-dis.c
+++ b/opcodes/riscv-dis.c
@@ -1076,11 +1076,9 @@ riscv_search_mapping_symbol (bfd_vma memaddr,
   from_last_map_symbol = (last_map_symbol >= 0
                          && info->stop_offset == last_stop_offset);
 
-  /* Start scanning at the start of the function, or wherever
-     we finished last time.  */
-  n = info->symtab_pos + 1;
-  if (from_last_map_symbol && n >= last_map_symbol)
-    n = last_map_symbol;
+  /* Start scanning from wherever we finished last time, or the start
+     of the function.  */
+  n = from_last_map_symbol ? last_map_symbol : info->symtab_pos + 1;
 
   /* Find the suitable mapping symbol to dump.  */
   for (; n < info->symtab_size; n++)
@@ -1105,9 +1103,7 @@ riscv_search_mapping_symbol (bfd_vma memaddr,
      can pick up a text mapping symbol of a preceeding section.  */
   if (!found)
     {
-      n = info->symtab_pos;
-      if (from_last_map_symbol && n >= last_map_symbol)
-       n = last_map_symbol;
+      n = from_last_map_symbol ? last_map_symbol : info->symtab_pos;
 
       for (; n >= 0; n--)
        {