[Bug target/98636] [ARM] ICE on passing incompatible options for fp16 - global_options’ are modified in local context

[prathamesh3492 at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98636

--- Comment #13 from prathamesh3492 at gcc dot gnu.org ---
IIUC, the issue comes from the following mismatch in cl_optimization_compare:

  if (ptr1->x_arm_fp16_format != ptr2->x_arm_fp16_format)
    internal_error ("%<global_options%> are modified in local context");

x_arm_fp16_format is of following type defined in arm-opts.h:

/* Which __fp16 format to use.
   The enumeration values correspond to the numbering for the
   Tag_ABI_FP_16bit_format attribute.
 */
enum arm_fp16_format_type
{
  ARM_FP16_FORMAT_NONE = 0,
  ARM_FP16_FORMAT_IEEE = 1,
  ARM_FP16_FORMAT_ALTERNATIVE = 2
};

For the test-case passing -mfp16-format=alternative results in:
ptr1->x_arm_fp16_format == ARM_FP16_FORMAT_ALTERNATIVE and
ptr2->x_arm_fp16_format == ARM_FP16_FORMAT_IEEE,
and the mismatch results in ICE.

Thanks,
Prathamesh