mips-elf linker error: jump to stub routine which is not jal

["Ting-Cheng Hsu" <tc-hsu at ali dot com dot tw>]

Hello,

I got the error message from ld when I compiled and linked
the following assembly code:

     .set mips1
_start:
     la   v0, m16_start
     jr   v0
     nop

     .set mips16
m16_start:
     addiu     v1, 2
     ...
     ...

Searching for binutils mail archives, the cause is stated
in http://sources.redhat.com/ml/binutils/1999-12/msg00021.html.
The linker would consider the reference of m16_start to be
error since it's not a jal(x) instruction which needs relocation.

If the restriction does exist, then I won't be able to write
codes like the above example, right?

According to the require_jalxp statement in bfd/elf32-mips.c:

  /* Calls from 16-bit code to 32-bit code and vice versa require the
     special jalx instruction.  */
  *require_jalxp = (!info->relocateable
      && ((r_type == R_MIPS16_26) != target_is_16_bit_code_p));

the same "la" peudo-instruction in mips16 code region which
references a label in mips32 code region won't generate the
"jump to stub ..." error message.

I modified bfd/elf32-mips.c to the following (Dmitri's solution
in msg00021.html):

  *require_jalxp = (!info->relocateable
      && (((r_type == R_MIPS16_26) && !target_is_16_bit_code_p)
   || ((r_type == R_MIPS_26) && target_is_16_bit_code_p)));

the above assembly code is successfully linked. But I have another
problem :(

When I link a simple C code against newlib stdlib (mips16 MULTILIB),
numerous error messages come out:

/usr/local/mips/mips-elf/lib/soft-float/mips16/libc.a(dtoa.o): In function `_dto
a_r':
/home/hsutc/mips-dev-tool/build/gcc-2.95.3/mips-elf/soft-float/mips16/newlib/lib
c/stdlib/../../../../../../../../source/gcc-2.95.3/newlib/libc/stdlib/dtoa.c:392
: undefined reference to `$L57'
/home/hsutc/mips-dev-tool/build/gcc-2.95.3/mips-elf/soft-float/mips16/newlib/lib
c/stdlib/../../../../../../../../source/gcc-2.95.3/newlib/libc/stdlib/dtoa.c:392
: undefined reference to `$L57'
/home/hsutc/mips-dev-tool/build/gcc-2.95.3/mips-elf/soft-float/mips16/newlib/lib
c/stdlib/../../../../../../../../source/gcc-2.95.3/newlib/libc/stdlib/dtoa.c:392
: undefined reference to `$L58'
/home/hsutc/mips-dev-tool/build/gcc-2.95.3/mips-elf/soft-float/mips16/newlib/lib
c/stdlib/../../../../../../../../source/gcc-2.95.3/newlib/libc/stdlib/dtoa.c:392
: undefined reference to `$L61'
/home/hsutc/mips-dev-tool/build/gcc-2.95.3/mips-elf/soft-float/mips16/newlib/lib
c/stdlib/../../../../../../../../source/gcc-2.95.3/newlib/libc/stdlib/dtoa.c:392
: undefined reference to `$L59'
/home/hsutc/mips-dev-tool/build/gcc-2.95.3/mips-elf/soft-float/mips16/newlib/lib
c/stdlib/../../../../../../../../source/gcc-2.95.3/newlib/libc/stdlib/dtoa.c:392
: undefined reference to `$L62'
(many "undefined reference" follows)


Beginning from line 392 of dtoa.c is the following code:

  switch (mode)
    {
    case 0:
    case 1:
      i = 18;
      ndigits = 0;
      break;
    case 2:
      leftright = 0;
      /* no break */
    case 4:
      if (ndigits <= 0)
     ndigits = 1;
      ilim = ilim1 = i = ndigits;
      break;
    case 3:
      leftright = 0;
      /* no break */
    case 5:
      i = ndigits + k + 1;
      ilim = i;
      ilim1 = i - 1;
      if (i <= 0)
     i = 1;
    }

Here the six cases map to the six '$Lxx' undefined reference, right?
Why would this happen? Does it relate to the modification of
elf32-mips.c (surely it does)? If the '*require_jalxp' assignment is
really a bug, why is it still not fixed in recent release of binutils?

My ultimate goal: mixing 16 bit and 32 bit mips codes without errors.
Anyone has any ideas? Thanks for any help.

Regards,
Ting-Cheng
Acer Labs, Inc.