[RFA/mips] Remove mips16 code that seems redundant

Joel Brobecker brobecker@gnat.com
Mon Oct 11 01:39:00 GMT 2004


> This?

Ah, bummer, keep forgetting the patch (that's because my mind is
already further ahead - sorry).

Here is the patch:

Index: mips-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/mips-tdep.c,v
retrieving revision 1.328
diff -u -p -r1.328 mips-tdep.c
--- mips-tdep.c	11 Oct 2004 01:00:57 -0000	1.328
+++ mips-tdep.c	11 Oct 2004 01:10:54 -0000
@@ -2409,36 +2409,6 @@ mips16_heuristic_proc_desc (CORE_ADDR st
       this_cache->saved_regs[NUM_REGS + mips_regnum (current_gdbarch)->pc]
         = this_cache->saved_regs[NUM_REGS + RA_REGNUM];
     }
-
-  /* The MIPS16 entry instruction saves $s0 and $s1 in the reverse
-     order of that normally used by gcc.  Therefore, we have to fetch
-     the first instruction of the function, and if it's an entry
-     instruction that saves $s0 or $s1, correct their saved addresses.  */
-  /* FIXME: brobecker/2004-10-10: This code was moved here from
-     mips_insn16_frame_cache(), but can be merged with the block above
-     handling entry_inst.  Will be done in a separate pass, to make changes
-     more atomic.  Actually, this code seems completely redundant!  */
-    {
-      ULONGEST inst = mips16_fetch_instruction (start_pc);
-      if ((inst & 0xf81f) == 0xe809 && (inst & 0x700) != 0x700) /* entry */
-	{
-	  int reg;
-	  int sreg_count = (inst >> 6) & 3;
-	  CORE_ADDR reg_position = (this_cache->base);
-
-	  /* Check if the ra register was pushed on the stack.  */
-	  if (inst & 0x20)
-	    reg_position -= mips_abi_regsize (current_gdbarch);
-
-	  /* Check if the s0 and s1 registers were pushed on the stack.  */
-	  /* NOTE: cagney/2004-02-08: Huh?  This is doing no such check.  */
-	  for (reg = 16; reg < sreg_count + 16; reg++)
-	    {
-	      this_cache->saved_regs[NUM_REGS + reg].addr = reg_position;
-	      reg_position -= mips_abi_regsize (current_gdbarch);
-	    }
-	}
-    }
 }
 
 /* Mark all the registers as unset in the saved_regs array

>   /* The entry instruction is typically the first instruction in a 
> function,
>      and it stores registers at offsets relative to the value of the old SP
>      (before the prologue).  But the value of the sp parameter to this
>      function is the new SP (after the prologue has been executed).  So we
>      can't calculate those offsets until we've seen the entire prologue,
>      and can calculate what the old SP must have been. */
>   if (entry_inst != 0)
>     {
>       int areg_count = (entry_inst >> 8) & 7;
>       int sreg_count = (entry_inst >> 6) & 3;
> 
>       /* The entry instruction always subtracts 32 from the SP.  */
>       PROC_FRAME_OFFSET (&temp_proc_desc) += 32;
> 
>       /* Now we can calculate what the SP must have been at the
>          start of the function prologue.  */
>       sp += PROC_FRAME_OFFSET (&temp_proc_desc);
> 
>       /* Check if a0-a3 were saved in the caller's argument save area.  */
>       for (reg = 4, offset = 0; reg < areg_count + 4; reg++)
>         {
>           PROC_REG_MASK (&temp_proc_desc) |= 1 << reg;
>           set_reg_offset (this_cache, reg, sp + offset);
>           offset += mips_abi_regsize (current_gdbarch);
>         }
> 
>       /* Check if the ra register was pushed on the stack.  */
>       offset = -4;
>       if (entry_inst & 0x20)
>         {
>           PROC_REG_MASK (&temp_proc_desc) |= 1 << RA_REGNUM;
>           set_reg_offset (this_cache, RA_REGNUM, sp + offset);
>           offset -= mips_abi_regsize (current_gdbarch);
>         }
> 
>       /* Check if the s0 and s1 registers were pushed on the stack.  */
>       for (reg = 16; reg < sreg_count + 16; reg++)
>         {
>           PROC_REG_MASK (&temp_proc_desc) |= 1 << reg;
>           set_reg_offset (this_cache, reg, sp + offset);
>           offset -= mips_abi_regsize (current_gdbarch);
>         }
>     }
> 
> yes, the code should have only one loop.

Which loop where you refering to?

-- 
Joel



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