[gcc r13-6150] xtensa: Enforce return address saving when -Og is specified

[Max Filippov]

https://gcc.gnu.org/g:a804419c89db9e1c0b99e772dda6c95095bab0bf

commit r13-6150-ga804419c89db9e1c0b99e772dda6c95095bab0bf
Author: Takayuki 'January June' Suwa <jjsuwa_sys3175@yahoo.co.jp>
Date:   Sat Feb 18 13:54:10 2023 +0900

    xtensa: Enforce return address saving when -Og is specified
    
    Leaf function often omits saving its return address to the stack slot,
    and this feature often makes debugging very confusing, especially for
    stack dump analysis.
    
    gcc/ChangeLog:
    
            * config/xtensa/xtensa.cc (xtensa_call_save_reg): Change to return
            true if register A0 (return address register) when -Og is specified.

Diff:
---
 gcc/config/xtensa/xtensa.cc | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/gcc/config/xtensa/xtensa.cc b/gcc/config/xtensa/xtensa.cc
index 3e2e22d4cbe..d0320efe21d 100644
--- a/gcc/config/xtensa/xtensa.cc
+++ b/gcc/config/xtensa/xtensa.cc
@@ -3223,8 +3223,11 @@ xtensa_call_save_reg (int regno)
     return false;
 
   if (regno == A0_REG)
-    return crtl->profile || !crtl->is_leaf || crtl->calls_eh_return ||
-      df_regs_ever_live_p (regno);
+    /* Ensure the return address to be saved to the stack slot in order
+       to assist stack dump analysis when -Og is specified.  */
+    return optimize_debug
+	   || crtl->profile || !crtl->is_leaf || crtl->calls_eh_return
+	   || df_regs_ever_live_p (regno);
 
   if (crtl->calls_eh_return && IN_RANGE (regno, 2, 3))
     return true;