fix bootstrap on !altivec powerpc configurations

[Olivier Hainque <hainque at adacore dot com>]

Hello,

Since a series of changes introduced from
 http://gcc.gnu.org/ml/gcc-patches/2009-07/txt00039.txt

bootstrap is broken for powerpc targets missing altivec support. We
noticed trying to build for aix 5.2.

The failure comes from errors compiling rs6000_expand_ternop_builtin:

  if (icode == CODE_FOR_nothing)
    /* Builtin not supported on this processor.  */
    return 0;
  ...
  switch (icode)
    {
    case CODE_FOR_altivec_vsldoi_v4sf:
    case CODE_FOR_altivec_vsldoi_v4si:
    case CODE_FOR_altivec_vsldoi_v8hi:
  ...

where the switch statement has multiple "CODE_FOR_nothing" alternatives.

The attached patch fixes this by rewriting the switch as a sequence of
'if's. This fixed our build on aix 5.2, and was bootstrapped + reg tested
on aix 5.3.

OK ?

Thanks in avdance,

2010-10-06  Olivier Hainque  <hainque@adacore.com>

	* config/rs6000/rs6000.c (rs6000_expand_ternop_builtin): Rewrite
	switch on insn codes as sequence of ifs.

Attachment: aixswitch.dif
Description: Text document