[Bug rtl-optimization/56195] [4.8 Regression] Error: incorrect register `%rdi' used with `l' suffix (at -O2)

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56195

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-02-07 19:47:04 UTC ---
So something like:

--- lra-constraints.c.jj    2013-02-07 18:34:39.000000000 +0100
+++ lra-constraints.c    2013-02-07 20:41:17.051986353 +0100
@@ -421,7 +421,21 @@ get_reload_reg (enum op_type type, enum
       if (rtx_equal_p (curr_insn_input_reloads[i].input, original)
       && in_class_p (curr_insn_input_reloads[i].reg, rclass, &new_class))
     {
-      *result_reg = curr_insn_input_reloads[i].reg;
+      rtx reg = curr_insn_input_reloads[i].reg;
+      /* If input is equal to original and both are VOIDmode,
+         GET_MODE (reg) might be still different from mode.
+         Ensure we don't return *result_reg with wrong mode.  */
+      if (GET_MODE (reg) != mode)
+        {
+          if (GET_MODE_SIZE (GET_MODE (reg)) < GET_MODE_SIZE (mode))
+        continue;
+          reg = simplify_subreg (mode, reg, GET_MODE (reg),
+                     subreg_lowpart_offset (mode,
+                                GET_MODE (reg)));
+          if (reg == NULL_RTX || !REG_P (reg))
+        continue;
+        }
+      *result_reg = reg;
       regno = REGNO (*result_reg);
       if (lra_dump_file != NULL)
         {

?