Re: [RFA] sh-tdep.c: New patch solving gdb1291.exp (was Re: [RFA] Fix PR tdep/1291, SH prologue scanning bug)

[Corinna Vinschen <vinschen@redhat.com>]

Ping?

Corinna

On Feb 25 17:33, Corinna Vinschen wrote:
> On Feb 19 23:44, Fred Fish wrote:
> > This patch fixes the bug reported in PR 1291.  It is based on the suggested
> > patch included in the PR.  I believe it is small enough to not need a
> > copyright assignment, but recent events may have changed that.  :-(
> > 
> > -Fred
> > 
> > 2004-02-19  Fred Fish  <fnf@redhat.com>
> > 
> > 	Fix for PR tdep/1291 as suggested by inaba@src.ricoh.co.jp
> > 	* sh-tdep.c (IS_MOV_R3): Rename to IS_MOV_IMM_R3 and fix pattern.
> > 	(IS_ADD_R3SP): Rename to IS_ADD_R3_SP for consistency.
> > 	(IS_MOVW_R1): New macro.
> > 	(IS_MOVL_R1): New macro.
> > 	(IS_SUB_R1_SP): New macro.
> > 	(sh_analyze_prologue): Add r1_val local var and initialize to zero.
> > 	Use IS_MOVW_R1, IS_MOVL_R1, and IS_SUB_R1_SP to recognize use of
> > 	stack allocation via constant loaded into r1.
> 
> I've looked into this one and found that there's a very simple patch
> to solve that issue.  Basically the evaluation of the memory address
> to access in PC relative addressing was misbehaving.  The below patch
> evaluates the PC relative memory location now exactly according to the
> descriptions of the PC relative addressing modes with 8 bit displacement
> in the official SH documentation:
> 
>   FOO.w @(disp:8,PC):
> 
>     displacement = (instruction & 0xff) << 1;
>     address = (PC + 4) + displacement;
> 
>   FOO.l @(disp:8,PC):
> 
>     displacement = (instruction & 0xff) << 2;
>     address = ((PC & 0xfffffffc) + 4) + displacement;
> 
> I checked the entire testsuite against sh2, sh2e, sh3, sh4 and sh4-nofpu.
> In all cases, the FAIL count has been reduced by exactly one, the FAIL
> from gdb1291.exp.
> 
> Is that ok to checkin?
> 
> 
> Corinna
> 
> 	* sh-tdep.c (sh_analyze_prologue): Align PC relative addressing
> 	to official documentation.
> 
> Index: sh-tdep.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/sh-tdep.c,v
> retrieving revision 1.165
> diff -u -p -r1.165 sh-tdep.c
> --- sh-tdep.c	20 Feb 2004 00:16:16 -0000	1.165
> +++ sh-tdep.c	25 Feb 2004 15:47:32 -0000
> @@ -440,9 +440,9 @@ sh_analyze_prologue (CORE_ADDR pc, CORE_
>  	      if (reg < 14)
>  		{
>  		  sav_reg = reg;
> -		  offset = (((inst & 0xff) ^ 0x80) - 0x80) << 1;
> +		  offset = (inst & 0xff) << 1;
>  		  sav_offset =
> -		    read_memory_integer (((pc + 4) & ~3) + offset, 2);
> +		    read_memory_integer ((pc + 4) + offset, 2);
>  		}
>  	    }
>  	}
> @@ -450,13 +450,13 @@ sh_analyze_prologue (CORE_ADDR pc, CORE_
>  	{
>  	  if (sav_reg < 0)
>  	    {
> -	      reg = (inst & 0x0f00) >> 8;
> +	      reg = GET_TARGET_REG (inst);
>  	      if (reg < 14)
>  		{
>  		  sav_reg = reg;
> -		  offset = (((inst & 0xff) ^ 0x80) - 0x80) << 1;
> +		  offset = (inst & 0xff) << 2;
>  		  sav_offset =
> -		    read_memory_integer (((pc + 4) & ~3) + offset, 4);
> +		    read_memory_integer (((pc & 0xfffffffc) + 4) + offset, 4);
>  		}
>  	    }
>  	}
> 
> -- 
> Corinna Vinschen
> Cygwin Developer
> Red Hat, Inc.

-- 
Corinna Vinschen
Cygwin Developer
Red Hat, Inc.