Re: [PATCH]Microblaze: Fixed missing save of r18 in fast_interrupt.

[Michael Eager]

OK to apply.

On 4/4/20 2:18 AM, Nagaraju Mekala wrote:

Hello All,

Fixed missing save of r18 in fast_interrupt.
Register 18 is used as a clobber register, and must be stored when entering a 
fast_interrupt. Before this fix, register 18 was only saved if it was used 
directly in the interrupt function.

However, if the fast_interrupt function called a function that used r18, the register would not be saved, and thus be mangled upon returning from the interrupt. Changelog

         2020-04-04  Klaus Petersen <klauspeter...@gmail.com>
          * gcc/config/microblaze/microblaze.c: Check for fast_interrupt in
             microblaze_must_save_register.

         Signed-off-by: Klaus Petersen <klauspeter...@gmail.com>
         Signed-off-by :Nagaraju Mekala <nmek...@xilix.com>

diff --git a/gcc/config/microblaze/microblaze.c 
b/gcc/config/microblaze/microblaze.c
index b4754b1..67e393d 100644
--- a/gcc/config/microblaze/microblaze.c
+++ b/gcc/config/microblaze/microblaze.c
@@ -2035,7 +2035,7 @@ microblaze_must_save_register (int regno)
      {
        if (df_regs_ever_live_p (regno)
           || regno == MB_ABI_MSR_SAVE_REG
-         || (interrupt_handler
+         || ((interrupt_handler || fast_interrupt)
                && (regno == MB_ABI_ASM_TEMP_REGNUM
                   || regno == MB_ABI_EXCEPTION_RETURN_ADDR_REGNUM)))
         return 1;

Attached is the patch.

Thanks
Nagaraju

--
Michael Eager    ea...@eagercon.com
1960 Park Blvd., Palo Alto, CA 94306