RFA: modernization of ia64-tdep.c with new frame model for gdb-6.0 branch

[Kevin Buettner]

Hi Jeff,

Sorry for taking so long on your patch...

On Aug 8,  1:32pm, J. Johnston wrote:

> @@ -113,18 +120,18 @@
>    "r8",   "r9",   "r10",  "r11",  "r12",  "r13",  "r14",  "r15",
>    "r16",  "r17",  "r18",  "r19",  "r20",  "r21",  "r22",  "r23",
>    "r24",  "r25",  "r26",  "r27",  "r28",  "r29",  "r30",  "r31",
> -  "r32",  "r33",  "r34",  "r35",  "r36",  "r37",  "r38",  "r39",
> -  "r40",  "r41",  "r42",  "r43",  "r44",  "r45",  "r46",  "r47",
> -  "r48",  "r49",  "r50",  "r51",  "r52",  "r53",  "r54",  "r55",
> -  "r56",  "r57",  "r58",  "r59",  "r60",  "r61",  "r62",  "r63",
> -  "r64",  "r65",  "r66",  "r67",  "r68",  "r69",  "r70",  "r71",
> -  "r72",  "r73",  "r74",  "r75",  "r76",  "r77",  "r78",  "r79",
> -  "r80",  "r81",  "r82",  "r83",  "r84",  "r85",  "r86",  "r87",
> -  "r88",  "r89",  "r90",  "r91",  "r92",  "r93",  "r94",  "r95",
> -  "r96",  "r97",  "r98",  "r99",  "r100", "r101", "r102", "r103",
> -  "r104", "r105", "r106", "r107", "r108", "r109", "r110", "r111",
> -  "r112", "r113", "r114", "r115", "r116", "r117", "r118", "r119",
> -  "r120", "r121", "r122", "r123", "r124", "r125", "r126", "r127",
> +  "",     "",     "",     "",     "",     "",     "",     "",
> +  "",     "",     "",     "",     "",     "",     "",     "",
> +  "",     "",     "",     "",     "",     "",     "",     "",
> +  "",     "",     "",     "",     "",     "",     "",     "",
> +  "",     "",     "",     "",     "",     "",     "",     "",
> +  "",     "",     "",     "",     "",     "",     "",     "",
> +  "",     "",     "",     "",     "",     "",     "",     "",
> +  "",     "",     "",     "",     "",     "",     "",     "",
> +  "",     "",     "",     "",     "",     "",     "",     "",
> +  "",     "",     "",     "",     "",     "",     "",     "",
> +  "",     "",     "",     "",     "",     "",     "",     "",
> +  "",     "",     "",     "",     "",     "",     "",     "",

Okay, I see that you're turning r32-r127 and (not shown) p0-p64
into pseudo registers.  Is there any reason to leave big "holes"
in the register number space?  I.e, why not just get rid of all
of the empty strings above?

(Most of the time, the reason NOT to do this is because remote
targets depend on the order.  The only remote target that I'm
aware of is gdbserver, and I'm not particularly worried about
breaking compatibility.)

If I'm not mistaken, removing these holes will somewhat decrease
the size of struct ia64_frame_cache:

    +struct ia64_frame_cache
    +{
    ...
    +  /* Saved registers.  */
    +  CORE_ADDR saved_regs[NUM_IA64_RAW_REGS];
    +
    +};

Now with regards to struct ia64_frame_cache...

    +struct ia64_frame_cache
    +{
    +  /* Base address.  */
    +  CORE_ADDR base;
    +  CORE_ADDR pc;
    +  CORE_ADDR saved_sp;

Could you (better) document the above three fields?

....

Have you tested the nat bit related code in ia64_pseudo_register_read()
and ia64_pseudo_register_write() ?  My recollection is that my original
code didn't handle the unat bits correctly.  I was wondering if you
had fixed this problem.  (I'm curious about the other NaT bits too.)

Kevin