[PATCH 4/5] Partial revert of r243782 to restore previous behavior

[PATCH 4/5] Partial revert of r243782 to restore previous behavior

[Matthew Fortune]

Hi,

This patch partially reverts r243782 where a return false was added
expecting it to be a no-op.  Detailed inspection shows this was not
true.  Despite no bug being identified following the change, removing
the early return is likely to be safer than leaving it in place.

This is supported by the discussion here:
https://gcc.gnu.org/ml/gcc/2017-02/msg00007.html

Thanks,
Matthew

gcc/
	* lra-constraints.c (simplify_operand_subreg): Remove early
	return false.
---
 gcc/lra-constraints.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c
index 484a70d..0b7ae34 100644
--- a/gcc/lra-constraints.c
+++ b/gcc/lra-constraints.c
@@ -1607,7 +1607,8 @@ simplify_operand_subreg (int nop, machine_mode reg_mode)
 	 the memory.  Typical case is when the index scale should
 	 correspond the memory.  */
       *curr_id->operand_loc[nop] = operand;
-      return false;
+      /* Do not return false here as the MEM_P (reg) will be processed
+	 later in this function.  */
     }
   else if (REG_P (reg) && REGNO (reg) < FIRST_PSEUDO_REGISTER)
     {
-- 
2.2.1

Re: [PATCH 4/5] Partial revert of r243782 to restore previous behavior

[Vladimir Makarov]

On 02/07/2017 09:08 AM, Matthew Fortune wrote:
> Hi,
>
> This patch partially reverts r243782 where a return false was added
> expecting it to be a no-op.  Detailed inspection shows this was not
> true.  Despite no bug being identified following the change, removing
> the early return is likely to be safer than leaving it in place.
>
> This is supported by the discussion here:
> https://gcc.gnu.org/ml/gcc/2017-02/msg00007.html
>
OK for the trunk.  Matt, thank you very much for efforts to clean 
simplify_operand_subreg up.
> gcc/
> 	* lra-constraints.c (simplify_operand_subreg): Remove early
> 	return false.
> ---
>   gcc/lra-constraints.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c
> index 484a70d..0b7ae34 100644
> --- a/gcc/lra-constraints.c
> +++ b/gcc/lra-constraints.c
> @@ -1607,7 +1607,8 @@ simplify_operand_subreg (int nop, machine_mode reg_mode)
>   	 the memory.  Typical case is when the index scale should
>   	 correspond the memory.  */
>         *curr_id->operand_loc[nop] = operand;
> -      return false;
> +      /* Do not return false here as the MEM_P (reg) will be processed
> +	 later in this function.  */
>       }
>     else if (REG_P (reg) && REGNO (reg) < FIRST_PSEUDO_REGISTER)
>       {

RE: [PATCH 4/5] Partial revert of r243782 to restore previous behavior

[Matthew Fortune]

Vladimir Makarov <vmakarov@redhat.com> writes:
> On 02/07/2017 09:08 AM, Matthew Fortune wrote:
> > Hi,
> >
> > This patch partially reverts r243782 where a return false was added
> > expecting it to be a no-op.  Detailed inspection shows this was not
> > true.  Despite no bug being identified following the change, removing
> > the early return is likely to be safer than leaving it in place.
> >
> > This is supported by the discussion here:
> > https://gcc.gnu.org/ml/gcc/2017-02/msg00007.html
> >
> OK for the trunk.  Matt, thank you very much for efforts to clean
> simplify_operand_subreg up.

Committed as r245600.

Thanks,
Matthew