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

["J. Johnston" <jjohnstn@redhat.com>]

Kevin Buettner wrote:
> 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];
>     +
>     +};
> 

Actually, number of real raw registers went down to the last non-pseudo
register anyway.  My preference regarding renumbering registers would be
to sync this up with gdbserver later.

> 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?
>

Not a problem.

> ....
> 
> 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.)
>

Could you elaborate about what problems you think existed in the previous
code?

-- Jeff J.

> Kevin
>