http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56195
--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-02-07
20:02:20 UTC ---
Actually, that one doesn't really work, because we have pseudo rather than hard
reg at that point, which will never simplify.
With this:
--- lra-constraints.c.jj 2013-02-07 18:34:39.000000000 +0100
+++ lra-constraints.c 2013-02-07 20:58:25.558920536 +0100
@@ -421,8 +421,20 @@ 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;
- regno = REGNO (*result_reg);
+ rtx reg = curr_insn_input_reloads[i].reg;
+ regno = REGNO (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 = lowpart_subreg (mode, reg, GET_MODE (reg));
+ if (reg == NULL_RTX || GET_CODE (reg) != SUBREG)
+ continue;
+ }
+ *result_reg = reg;
if (lra_dump_file != NULL)
{
fprintf (lra_dump_file, " Reuse r%d for reload ", regno);
the assembly difference is:
- cmpl (%rdi), %rdi
+ cmpl (%rdi), %edi
which is desirable in this case, but not sure if all get_reload_reg callers
will grok a SUBREG instead of REG returned in *result_reg.
