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Re: [PATCH v3 7/7] powerpc64le: Enable float128
On 6/28/17 11:30 AM, Szabolcs Nagy wrote:
> On 27/06/17 22:41, Florian Weimer wrote:
>> * Peter Bergner:
>>> Yes, we emit a symbol only defined by libcs that support this and
>>> yes, __parse_hwcap_and_convert_at_platform is that symbol:
>>>
>>> if (cpu_builtin_p)
>>> {
>>> /* We have expanded a CPU builtin, so we need to emit a reference to
>>> the special symbol that LIBC uses to declare it supports the
>>> AT_PLATFORM and AT_HWCAP/AT_HWCAP2 in the TCB feature. */
>>> switch_to_section (data_section);
>>> fprintf (asm_out_file, "\t.align %u\n", TARGET_32BIT ? 2 : 3);
>>> fprintf (asm_out_file, "\t%s %s\n",
>>> TARGET_32BIT ? ".long" : ".quad", tcb_verification_symbol);
>>> }
>>
>> I see, so everything is fine. Nice!
>>
>
> well using the new builtin means glibc build will fail with old gcc.
How so? The usage of __builtin_cpu_supports() we're talking about is in
libgcc's float128-ifunc.c source file, so it's not part of GLIBC's build.
Peter