Re: [rfa] Attempt #3: Eliminate HOST_*_FORMAT from arm-*tdep.c

[Fernando Nasser <fnasser at cygnus dot com>]

Andrew Cagney wrote:
> 
> Ping?
> 

Sorry for the delay Andrew.

As per our conversation, this seems to be the correct thing to do.
We haven't heard of any objection, so lets try it.

Please check it in.

Regards,
Fernando


> > Hello,
> >
> > Attatched is another attemt at eliminating the HOST_*_FORMAT references in arm-tdep.c and arm-linux-tdep.c.  I'm definitly getting closer!
> >
> > This time, I also ``fixed'' the functions convert_to_extended() and convert_from_extended() to use portable floatformat_*() functions.
> >
> > With the patch applied testing on a big-endian host using the arm-sim target suggests things do indeed imrove.  The tests:
> >
> > gdb.base/callfuncs.exp: p t_float_values
> > gdb.base/callfuncs.exp: p t_float_values2
> > gdb.base/callfwmall.exp: p t_float_values
> > gdb.base/callfwmall.exp: p t_float_values2
> >
> > all started passing.  At the same time I didn't see any regressions.
> > Interestingly, testing on a little endian host showed no change in the test results.
> >
> > There is one FIXME.  The code always uses floatformat_arm_ext.  I'm windering if there needs to be both floatformat_arm_ext_big and floatformat_arm_ext_little.  Anyone know the exact format used when storing BE/LE extended floats on the arm architecture?
> >
> > Anyway, I'm hopeing this is sufficient improvement over the previous mess to go in.
> >
> >     Andrew
> >
> >
> >
> > 2001-07-24  Andrew Cagney  <ac131313@redhat.com>
> > * arm-tdep.c (convert_from_extended, convert_to_extended): Delete
> >       assembler version of function.
> >       (convert_from_extended, convert_to_extended): Rewrite using
> >       floatformat_to_doublest and floatformat_from_doublest.
> >       (arm_push_arguments): Use extract_floating and
> >       store_floating to perform floating point conversions.
> >       (SWAP_TARGET_AND_HOST): Delete macro.
> >       * arm-linux-tdep.c (arm_linux_push_arguments): Use
> >       extract_floating and store_floating to perform floating point
> >       conversions.
> >
> > Index: arm-linux-tdep.c
> > ===================================================================
> > RCS file: /cvs/src/src/gdb/arm-linux-tdep.c,v
> > retrieving revision 1.9
> > diff -p -r1.9 arm-linux-tdep.c
> > *** arm-linux-tdep.c  2001/07/15 20:10:02     1.9
> > --- arm-linux-tdep.c  2001/07/27 02:44:41
> > *************** arm_linux_push_arguments (int nargs, str
> > *** 159,165 ****
> >       {
> >         int len;
> >         char *val;
> > -       double dbl_arg;
> >         CORE_ADDR regval;
> >         enum type_code typecode;
> >         struct type *arg_type, *target_type;
> > --- 159,164 ----
> > *************** arm_linux_push_arguments (int nargs, str
> > *** 179,192 ****
> >            calling the function.  */
> >         if (TYPE_CODE_FLT == typecode && REGISTER_SIZE == len)
> >       {
> > -       /* Float argument in buffer is in host format.  Read it and
> > -          convert to DOUBLEST, and store it in target double.  */
> >         DOUBLEST dblval;
> > !
> >         len = TARGET_DOUBLE_BIT / TARGET_CHAR_BIT;
> > !       floatformat_to_doublest (HOST_FLOAT_FORMAT, val, &dblval);
> > !       store_floating (&dbl_arg, len, dblval);
> > !       val = (char *) &dbl_arg;
> >       }
> >
> >         /* If the argument is a pointer to a function, and it is a Thumb
> > --- 178,188 ----
> >            calling the function.  */
> >         if (TYPE_CODE_FLT == typecode && REGISTER_SIZE == len)
> >       {
> >         DOUBLEST dblval;
> > !       dblval = extract_floating (val, len);
> >         len = TARGET_DOUBLE_BIT / TARGET_CHAR_BIT;
> > !       val = alloca (len);
> > !       store_floating (val, len, dblval);
> >       }
> >
> >         /* If the argument is a pointer to a function, and it is a Thumb
> > Index: arm-tdep.c
> > ===================================================================
> > RCS file: /cvs/src/src/gdb/arm-tdep.c,v
> > retrieving revision 1.13
> > diff -p -r1.13 arm-tdep.c
> > *** arm-tdep.c        2001/07/15 20:10:02     1.13
> > --- arm-tdep.c        2001/07/27 02:44:46
> > *************** struct frame_extra_info
> > *** 117,140 ****
> >   #define MAKE_THUMB_ADDR(addr)       ((addr) | 1)
> >   #define UNMAKE_THUMB_ADDR(addr) ((addr) & ~1)
> >
> > - #define SWAP_TARGET_AND_HOST(buffer,len)                            \
> > -   do                                                                        \
> > -     {                                                                       \
> > -       if (TARGET_BYTE_ORDER != HOST_BYTE_ORDER)                             \
> > -     {                                                               \
> > -       char tmp;                                                     \
> > -       char *p = (char *)(buffer);                                   \
> > -       char *q = ((char *)(buffer)) + len - 1;                       \
> > -       for (; p < q; p++, q--)                                       \
> > -         {                                                           \
> > -           tmp = *q;                                                 \
> > -           *q = *p;                                                  \
> > -           *p = tmp;                                                 \
> > -         }                                                           \
> > -     }                                                               \
> > -     }                                                                       \
> > -   while (0)
> > -
> >   /* Will a function return an aggregate type in memory or in a
> >      register?  Return 0 if an aggregate type can be returned in a
> >      register, 1 if it must be returned in memory.  */
> > --- 117,122 ----
> > *************** arm_push_arguments (int nargs, struct va
> > *** 1309,1315 ****
> >       {
> >         int len;
> >         char *val;
> > -       double dbl_arg;
> >         CORE_ADDR regval;
> >         enum type_code typecode;
> >         struct type *arg_type, *target_type;
> > --- 1291,1296 ----
> > *************** arm_push_arguments (int nargs, struct va
> > *** 1329,1350 ****
> >            calling the function.  */
> >         if (TYPE_CODE_FLT == typecode && REGISTER_SIZE == len)
> >       {
> > !       float f;
> > !       double d;
> > !       char * bufo = (char *) &d;
> > !       char * bufd = (char *) &dbl_arg;
> > !
> > !       len = sizeof (double);
> > !       f = *(float *) val;
> > !       SWAP_TARGET_AND_HOST (&f, sizeof (float));  /* adjust endianess */
> > !       d = f;
> > !       /* We must revert the longwords so they get loaded into the
> > !          the right registers. */
> > !       memcpy (bufd, bufo + len / 2, len / 2);
> > !       SWAP_TARGET_AND_HOST (bufd, len / 2);  /* adjust endianess */
> > !       memcpy (bufd + len / 2, bufo, len / 2);
> > !       SWAP_TARGET_AND_HOST (bufd + len / 2, len / 2); /* adjust endianess */
> > !       val = (char *) &dbl_arg;
> >       }
> >   #if 1
> >         /* I don't know why this code was disable. The only logical use
> > --- 1310,1320 ----
> >            calling the function.  */
> >         if (TYPE_CODE_FLT == typecode && REGISTER_SIZE == len)
> >       {
> > !       DOUBLEST dblval;
> > !       dblval = extract_floating (val, len);
> > !       len = TARGET_DOUBLE_BIT / TARGET_CHAR_BIT;
> > !       val = alloca (len);
> > !       store_floating (val, len, dblval);
> >       }
> >   #if 1
> >         /* I don't know why this code was disable. The only logical use
> > *************** arm_float_info (void)
> > *** 1464,1507 ****
> >     fputs ("flags: ", stdout);
> >     print_fpu_flags (status);
> >   }
> > -
> > - #if 0
> > - /* FIXME:  The generated assembler works but sucks.  Instead of using
> > -    r0, r1 it pushes them on the stack, then loads them into r3, r4 and
> > -    uses those registers.  I must be missing something.  ScottB  */
> >
> > ! void
> > ! convert_from_extended (void *ptr, void *dbl)
> > ! {
> > !   __asm__ ("
> > !        ldfe f0,[%0]
> > !        stfd f0,[%1] "
> > ! :                           /* no output */
> > ! :      "r" (ptr), "r" (dbl));
> > ! }
> >
> > - void
> > - convert_to_extended (void *dbl, void *ptr)
> > - {
> > -   __asm__ ("
> > -        ldfd f0,[%0]
> > -        stfe f0,[%1] "
> > - :                           /* no output */
> > - :      "r" (dbl), "r" (ptr));
> > - }
> > - #else
> >   static void
> >   convert_from_extended (void *ptr, void *dbl)
> >   {
> > !   *(double *) dbl = *(double *) ptr;
> >   }
> >
> >   void
> >   convert_to_extended (void *dbl, void *ptr)
> >   {
> > !   *(double *) ptr = *(double *) dbl;
> >   }
> > - #endif
> >
> >   /* Nonzero if register N requires conversion from raw format to
> >      virtual format.  */
> > --- 1434,1458 ----
> >     fputs ("flags: ", stdout);
> >     print_fpu_flags (status);
> >   }
> >
> > ! /* FIXME: cagney/2001-07-24: Is floatformat_arm_ext byte order
> > !    dependant or independant? */
> >
> >   static void
> >   convert_from_extended (void *ptr, void *dbl)
> >   {
> > !   DOUBLEST d;
> > !   floatformat_to_doublest (&floatformat_arm_ext, ptr, &d);
> > !   floatformat_from_doublest (TARGET_DOUBLE_FORMAT, &d, dbl);
> >   }
> >
> >   void
> >   convert_to_extended (void *dbl, void *ptr)
> >   {
> > !   DOUBLEST d;
> > !   floatformat_to_doublest (TARGET_DOUBLE_FORMAT, ptr, &d);
> > !   floatformat_from_doublest (&floatformat_arm_ext, &d, dbl);
> >   }
> >
> >   /* Nonzero if register N requires conversion from raw format to
> >      virtual format.  */
> >

-- 
Fernando Nasser
Red Hat - Toronto                       E-Mail:  fnasser@redhat.com
2323 Yonge Street, Suite #300
Toronto, Ontario   M4P 2C9