* SH: double pseudo registers little-endian/big-endian
@ 2012-08-30 15:53 Thomas Schwinge
2012-09-07 8:19 ` Thomas Schwinge
0 siblings, 1 reply; 3+ messages in thread
From: Thomas Schwinge @ 2012-08-30 15:53 UTC (permalink / raw)
To: gdb-patches; +Cc: Kevin Buettner
[-- Attachment #1: Type: text/plain, Size: 6365 bytes --]
Hi!
Little-endian SH GDB:
(gdb) set $dr0 = -1
(gdb) info registers dr0 fr0 fr1
dr0 -1 (raw 0xbff0000000000000)
fr0 -1.875 (raw 0xbff00000)
fr1 0 (raw 0x00000000)
This is correct. Big-endian SH GDB:
(gdb) set $dr0 = -1
(gdb) info registers dr0 fr0 fr1
dr0 -1 (raw 0xbff0000000000000)
fr0 8.63634257e-41 (raw 0x0000f0bf)
fr1 0 (raw 0x00000000)
Here, the value stored in fr0 is bogus. This comes from the
sh_register_convert_to_virtual conversion: as the commentary says, this
should be applied in the little-endian case only. The reasons that dr0
is displayed correctly nevertheless is due to sh_register_convert_to_raw
(erroneously) doing the same conversion backwards, too.
A similar problem exists when displaying double values loaded as part of
the program text.
Here is a patch (basically copying code from sh64-tdep.c which got this
right), and also fixes some commentary. OK to commit?
gdb/
sh-tdep.c (sh_register_convert_to_virtual)
(sh_register_convert_to_raw): Add a gdbarch parameter. Update
all callers. Just do a memcpy if not the little-endian case.
Index: sh-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/sh-tdep.c,v
retrieving revision 1.246
diff -u -p -r1.246 sh-tdep.c
--- sh-tdep.c 22 Jul 2012 16:52:41 -0000 1.246
+++ sh-tdep.c 30 Aug 2012 15:43:24 -0000
@@ -342,15 +342,16 @@ sh_sh4_register_name (struct gdbarch *gd
"r0b0", "r1b0", "r2b0", "r3b0", "r4b0", "r5b0", "r6b0", "r7b0",
/* bank 1 51 - 58 */
"r0b1", "r1b1", "r2b1", "r3b1", "r4b1", "r5b1", "r6b1", "r7b1",
+ /* 59 - 66 */
"", "", "", "", "", "", "", "",
/* pseudo bank register. */
"",
- /* double precision (pseudo) 59 - 66 */
+ /* double precision (pseudo) 68 - 75 */
"dr0", "dr2", "dr4", "dr6", "dr8", "dr10", "dr12", "dr14",
- /* vectors (pseudo) 67 - 70 */
+ /* vectors (pseudo) 76 - 79 */
"fv0", "fv4", "fv8", "fv12",
- /* FIXME: missing XF 71 - 86 */
- /* FIXME: missing XD 87 - 94 */
+ /* FIXME: missing XF */
+ /* FIXME: missing XD */
};
if (reg_nr < 0)
return NULL;
@@ -379,12 +380,13 @@ sh_sh4_nofpu_register_name (struct gdbar
"r0b0", "r1b0", "r2b0", "r3b0", "r4b0", "r5b0", "r6b0", "r7b0",
/* bank 1 51 - 58 */
"r0b1", "r1b1", "r2b1", "r3b1", "r4b1", "r5b1", "r6b1", "r7b1",
+ /* 59 - 66 */
"", "", "", "", "", "", "", "",
/* pseudo bank register. */
"",
- /* double precision (pseudo) 59 - 66 -- not for nofpu target */
+ /* double precision (pseudo) 68 - 75 -- not for nofpu target */
"", "", "", "", "", "", "", "",
- /* vectors (pseudo) 67 - 70 -- not for nofpu target */
+ /* vectors (pseudo) 76 - 79 -- not for nofpu target */
"", "", "", "",
};
if (reg_nr < 0)
@@ -1521,16 +1523,16 @@ sh_register_reggroup_p (struct gdbarch *
/* On the sh4, the DRi pseudo registers are problematic if the target
is little endian. When the user writes one of those registers, for
- instance with 'ser var $dr0=1', we want the double to be stored
+ instance with 'set var $dr0=1', we want the double to be stored
like this:
- fr0 = 0x00 0x00 0x00 0x00 0x00 0xf0 0x3f
- fr1 = 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+ fr0 = 0x00 0x00 0xf0 0x3f
+ fr1 = 0x00 0x00 0x00 0x00
This corresponds to little endian byte order & big endian word
order. However if we let gdb write the register w/o conversion, it
will write fr0 and fr1 this way:
- fr0 = 0x00 0x00 0x00 0x00 0x00 0x00 0x00
- fr1 = 0x00 0x00 0x00 0x00 0x00 0xf0 0x3f
+ fr0 = 0x00 0x00 0x00 0x00
+ fr1 = 0x00 0x00 0xf0 0x3f
because it will consider fr0 and fr1 as a single LE stretch of memory.
To achieve what we want we must force gdb to store things in
@@ -1539,16 +1541,23 @@ sh_register_reggroup_p (struct gdbarch *
In case the target is big endian, there is no problem, the
raw bytes will look like:
- fr0 = 0x3f 0xf0 0x00 0x00 0x00 0x00 0x00
- fr1 = 0x00 0x00 0x00 0x00 0x00 0x00 0x00
+ fr0 = 0x3f 0xf0 0x00 0x00
+ fr1 = 0x00 0x00 0x00 0x00
The other pseudo registers (the FVs) also don't pose a problem
because they are stored as 4 individual FP elements. */
static void
-sh_register_convert_to_virtual (int regnum, struct type *type,
- char *from, char *to)
+sh_register_convert_to_virtual (struct gdbarch *gdbarch, int regnum,
+ struct type *type, char *from, char *to)
{
+ if (gdbarch_byte_order (gdbarch) != BFD_ENDIAN_LITTLE)
+ {
+ /* It is a no-op. */
+ memcpy (to, from, register_size (gdbarch, regnum));
+ return;
+ }
+
if (regnum >= DR0_REGNUM && regnum <= DR_LAST_REGNUM)
{
DOUBLEST val;
@@ -1562,9 +1571,16 @@ sh_register_convert_to_virtual (int regn
}
static void
-sh_register_convert_to_raw (struct type *type, int regnum,
- const void *from, void *to)
+sh_register_convert_to_raw (struct gdbarch *gdbarch, struct type *type,
+ int regnum, const void *from, void *to)
{
+ if (gdbarch_byte_order (gdbarch) != BFD_ENDIAN_LITTLE)
+ {
+ /* It is a no-op. */
+ memcpy (to, from, register_size (gdbarch, regnum));
+ return;
+ }
+
if (regnum >= DR0_REGNUM && regnum <= DR_LAST_REGNUM)
{
DOUBLEST val = extract_typed_floating (from, type);
@@ -1643,7 +1659,7 @@ sh_pseudo_register_read (struct gdbarch
if (status == REG_VALID)
{
/* We must pay attention to the endiannes. */
- sh_register_convert_to_virtual (reg_nr,
+ sh_register_convert_to_virtual (gdbarch, reg_nr,
register_type (gdbarch, reg_nr),
temp_buffer, buffer);
}
@@ -1685,7 +1701,7 @@ sh_pseudo_register_write (struct gdbarch
base_regnum = dr_reg_base_num (gdbarch, reg_nr);
/* We must pay attention to the endiannes. */
- sh_register_convert_to_raw (register_type (gdbarch, reg_nr),
+ sh_register_convert_to_raw (gdbarch, register_type (gdbarch, reg_nr),
reg_nr, buffer, temp_buffer);
/* Write the real regs for which this one is an alias. */
Grüße,
Thomas
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: SH: double pseudo registers little-endian/big-endian
2012-08-30 15:53 SH: double pseudo registers little-endian/big-endian Thomas Schwinge
@ 2012-09-07 8:19 ` Thomas Schwinge
2012-09-18 17:20 ` Joel Brobecker
0 siblings, 1 reply; 3+ messages in thread
From: Thomas Schwinge @ 2012-09-07 8:19 UTC (permalink / raw)
To: gdb-patches; +Cc: Kevin Buettner
[-- Attachment #1: Type: text/plain, Size: 6750 bytes --]
Hi!
Ping.
On Thu, 30 Aug 2012 17:52:36 +0200, I wrote:
> Little-endian SH GDB:
>
> (gdb) set $dr0 = -1
> (gdb) info registers dr0 fr0 fr1
> dr0 -1 (raw 0xbff0000000000000)
> fr0 -1.875 (raw 0xbff00000)
> fr1 0 (raw 0x00000000)
>
> This is correct. Big-endian SH GDB:
>
> (gdb) set $dr0 = -1
> (gdb) info registers dr0 fr0 fr1
> dr0 -1 (raw 0xbff0000000000000)
> fr0 8.63634257e-41 (raw 0x0000f0bf)
> fr1 0 (raw 0x00000000)
>
> Here, the value stored in fr0 is bogus. This comes from the
> sh_register_convert_to_virtual conversion: as the commentary says, this
> should be applied in the little-endian case only. The reasons that dr0
> is displayed correctly nevertheless is due to sh_register_convert_to_raw
> (erroneously) doing the same conversion backwards, too.
>
> A similar problem exists when displaying double values loaded as part of
> the program text.
>
> Here is a patch (basically copying code from sh64-tdep.c which got this
> right), and also fixes some commentary. OK to commit?
>
> gdb/
> sh-tdep.c (sh_register_convert_to_virtual)
> (sh_register_convert_to_raw): Add a gdbarch parameter. Update
> all callers. Just do a memcpy if not the little-endian case.
>
> Index: sh-tdep.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/sh-tdep.c,v
> retrieving revision 1.246
> diff -u -p -r1.246 sh-tdep.c
> --- sh-tdep.c 22 Jul 2012 16:52:41 -0000 1.246
> +++ sh-tdep.c 30 Aug 2012 15:43:24 -0000
> @@ -342,15 +342,16 @@ sh_sh4_register_name (struct gdbarch *gd
> "r0b0", "r1b0", "r2b0", "r3b0", "r4b0", "r5b0", "r6b0", "r7b0",
> /* bank 1 51 - 58 */
> "r0b1", "r1b1", "r2b1", "r3b1", "r4b1", "r5b1", "r6b1", "r7b1",
> + /* 59 - 66 */
> "", "", "", "", "", "", "", "",
> /* pseudo bank register. */
> "",
> - /* double precision (pseudo) 59 - 66 */
> + /* double precision (pseudo) 68 - 75 */
> "dr0", "dr2", "dr4", "dr6", "dr8", "dr10", "dr12", "dr14",
> - /* vectors (pseudo) 67 - 70 */
> + /* vectors (pseudo) 76 - 79 */
> "fv0", "fv4", "fv8", "fv12",
> - /* FIXME: missing XF 71 - 86 */
> - /* FIXME: missing XD 87 - 94 */
> + /* FIXME: missing XF */
> + /* FIXME: missing XD */
> };
> if (reg_nr < 0)
> return NULL;
> @@ -379,12 +380,13 @@ sh_sh4_nofpu_register_name (struct gdbar
> "r0b0", "r1b0", "r2b0", "r3b0", "r4b0", "r5b0", "r6b0", "r7b0",
> /* bank 1 51 - 58 */
> "r0b1", "r1b1", "r2b1", "r3b1", "r4b1", "r5b1", "r6b1", "r7b1",
> + /* 59 - 66 */
> "", "", "", "", "", "", "", "",
> /* pseudo bank register. */
> "",
> - /* double precision (pseudo) 59 - 66 -- not for nofpu target */
> + /* double precision (pseudo) 68 - 75 -- not for nofpu target */
> "", "", "", "", "", "", "", "",
> - /* vectors (pseudo) 67 - 70 -- not for nofpu target */
> + /* vectors (pseudo) 76 - 79 -- not for nofpu target */
> "", "", "", "",
> };
> if (reg_nr < 0)
> @@ -1521,16 +1523,16 @@ sh_register_reggroup_p (struct gdbarch *
>
> /* On the sh4, the DRi pseudo registers are problematic if the target
> is little endian. When the user writes one of those registers, for
> - instance with 'ser var $dr0=1', we want the double to be stored
> + instance with 'set var $dr0=1', we want the double to be stored
> like this:
> - fr0 = 0x00 0x00 0x00 0x00 0x00 0xf0 0x3f
> - fr1 = 0x00 0x00 0x00 0x00 0x00 0x00 0x00
> + fr0 = 0x00 0x00 0xf0 0x3f
> + fr1 = 0x00 0x00 0x00 0x00
>
> This corresponds to little endian byte order & big endian word
> order. However if we let gdb write the register w/o conversion, it
> will write fr0 and fr1 this way:
> - fr0 = 0x00 0x00 0x00 0x00 0x00 0x00 0x00
> - fr1 = 0x00 0x00 0x00 0x00 0x00 0xf0 0x3f
> + fr0 = 0x00 0x00 0x00 0x00
> + fr1 = 0x00 0x00 0xf0 0x3f
> because it will consider fr0 and fr1 as a single LE stretch of memory.
>
> To achieve what we want we must force gdb to store things in
> @@ -1539,16 +1541,23 @@ sh_register_reggroup_p (struct gdbarch *
>
> In case the target is big endian, there is no problem, the
> raw bytes will look like:
> - fr0 = 0x3f 0xf0 0x00 0x00 0x00 0x00 0x00
> - fr1 = 0x00 0x00 0x00 0x00 0x00 0x00 0x00
> + fr0 = 0x3f 0xf0 0x00 0x00
> + fr1 = 0x00 0x00 0x00 0x00
>
> The other pseudo registers (the FVs) also don't pose a problem
> because they are stored as 4 individual FP elements. */
>
> static void
> -sh_register_convert_to_virtual (int regnum, struct type *type,
> - char *from, char *to)
> +sh_register_convert_to_virtual (struct gdbarch *gdbarch, int regnum,
> + struct type *type, char *from, char *to)
> {
> + if (gdbarch_byte_order (gdbarch) != BFD_ENDIAN_LITTLE)
> + {
> + /* It is a no-op. */
> + memcpy (to, from, register_size (gdbarch, regnum));
> + return;
> + }
> +
> if (regnum >= DR0_REGNUM && regnum <= DR_LAST_REGNUM)
> {
> DOUBLEST val;
> @@ -1562,9 +1571,16 @@ sh_register_convert_to_virtual (int regn
> }
>
> static void
> -sh_register_convert_to_raw (struct type *type, int regnum,
> - const void *from, void *to)
> +sh_register_convert_to_raw (struct gdbarch *gdbarch, struct type *type,
> + int regnum, const void *from, void *to)
> {
> + if (gdbarch_byte_order (gdbarch) != BFD_ENDIAN_LITTLE)
> + {
> + /* It is a no-op. */
> + memcpy (to, from, register_size (gdbarch, regnum));
> + return;
> + }
> +
> if (regnum >= DR0_REGNUM && regnum <= DR_LAST_REGNUM)
> {
> DOUBLEST val = extract_typed_floating (from, type);
> @@ -1643,7 +1659,7 @@ sh_pseudo_register_read (struct gdbarch
> if (status == REG_VALID)
> {
> /* We must pay attention to the endiannes. */
> - sh_register_convert_to_virtual (reg_nr,
> + sh_register_convert_to_virtual (gdbarch, reg_nr,
> register_type (gdbarch, reg_nr),
> temp_buffer, buffer);
> }
> @@ -1685,7 +1701,7 @@ sh_pseudo_register_write (struct gdbarch
> base_regnum = dr_reg_base_num (gdbarch, reg_nr);
>
> /* We must pay attention to the endiannes. */
> - sh_register_convert_to_raw (register_type (gdbarch, reg_nr),
> + sh_register_convert_to_raw (gdbarch, register_type (gdbarch, reg_nr),
> reg_nr, buffer, temp_buffer);
>
> /* Write the real regs for which this one is an alias. */
Grüße,
Thomas
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: SH: double pseudo registers little-endian/big-endian
2012-09-07 8:19 ` Thomas Schwinge
@ 2012-09-18 17:20 ` Joel Brobecker
0 siblings, 0 replies; 3+ messages in thread
From: Joel Brobecker @ 2012-09-18 17:20 UTC (permalink / raw)
To: Thomas Schwinge; +Cc: gdb-patches, Kevin Buettner
Hi Thomas,
Sorry for the delay in reviewing this.
> > gdb/
> > sh-tdep.c (sh_register_convert_to_virtual)
> > (sh_register_convert_to_raw): Add a gdbarch parameter. Update
> > all callers. Just do a memcpy if not the little-endian case.
This patch looks OK to me. Please go ahead and commit.
--
Joel
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