Re: [PATCH] PR rtl-optimization/100263: Ensure register can change mode

[Eric Botcazou]

> For move2add_valid_value_p we also have to ask the target whether a
> register can be accessed in a different mode than it was set before.
> 
> gcc/ChangeLog:
> 
>   PR rtl-optimization/100263
>   * postreload.c (move2add_valid_value_p): Ensure register can
>   change mode.
> 
> Bootstrapped and regtested releases/gcc-{8,9,10,11} and master on IBM Z.
> Ok for those branches?

Yes, OK everywhere, thanks.

-- 
Eric Botcazou

[PATCH] PR rtl-optimization/100263: Ensure register can change mode

[Stefan Schulze Frielinghaus via Gcc-patches]

For move2add_valid_value_p we also have to ask the target whether a
register can be accessed in a different mode than it was set before.

gcc/ChangeLog:

PR rtl-optimization/100263
* postreload.c (move2add_valid_value_p): Ensure register can
change mode.

Bootstrapped and regtested releases/gcc-{8,9,10,11} and master on IBM Z.
Ok for those branches?

---
 gcc/postreload.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gcc/postreload.c b/gcc/postreload.c
index dc67643384d..60a622dbaf3 100644
--- a/gcc/postreload.c
+++ b/gcc/postreload.c
@@ -1725,7 +1725,8 @@ move2add_valid_value_p (int regno, scalar_int_mode mode)
 {
   scalar_int_mode old_mode;
   if (!is_a  (reg_mode[regno], _mode)
- || !MODES_OK_FOR_MOVE2ADD (mode, old_mode))
+ || !MODES_OK_FOR_MOVE2ADD (mode, old_mode)
+ || !REG_CAN_CHANGE_MODE_P (regno, old_mode, mode))
return false;
   /* The value loaded into regno in reg_mode[regno] is also valid in
 mode after truncation only if (REG:mode regno) is the lowpart of
-- 
2.23.0