[PATCH] s390: Add -fsplit-stack support

[Marcin Kościelnicki]

On 04/02/16 13:44, Marcin Kościelnicki wrote:
> On 03/02/16 18:27, Ulrich Weigand wrote:
>> Marcin KoÃ
›cielnicki wrote:
>>
>>> libgcc/ChangeLog:
>>>
>>>     * config.host: Use t-stack and t-stack-s390 for s390*-*-linux.
>>>     * config/s390/morestack.S: New file.
>>>     * config/s390/t-stack-s390: New file.
>>>     * generic-morestack.c (__splitstack_find): Add s390-specific code.
>>>
>>> gcc/ChangeLog:
>>>
>>>     * common/config/s390/s390-common.c (s390_supports_split_stack):
>>>     New function.
>>>     (TARGET_SUPPORTS_SPLIT_STACK): New macro.
>>>     * config/s390/s390-protos.h: Add s390_expand_split_stack_prologue.
>>>     * config/s390/s390.c (struct machine_function): New field
>>>     split_stack_varargs_pointer.
>>>     (s390_register_info): Mark r12 as clobbered if it'll be used as temp
>>>     in s390_emit_prologue.
>>>     (s390_emit_prologue): Use r12 as temp if r1 is taken by split-stack
>>>     vararg pointer.
>>>     (morestack_ref): New global.
>>>     (SPLIT_STACK_AVAILABLE): New macro.
>>>     (s390_expand_split_stack_prologue): New function.
>>>     (s390_live_on_entry): New function.
>>>     (s390_va_start): Use split-stack vararg pointer if appropriate.
>>>     (s390_asm_file_end): Emit the split-stack note sections.
>>>     (TARGET_EXTRA_LIVE_ON_ENTRY): New macro.
>>>     * config/s390/s390.md (UNSPEC_STACK_CHECK): New unspec.
>>>     (UNSPECV_SPLIT_STACK_CALL): New unspec.
>>>     (UNSPECV_SPLIT_STACK_DATA): New unspec.
>>>     (split_stack_prologue): New expand.
>>>     (split_stack_space_check): New expand.
>>>     (split_stack_data): New insn.
>>>     (split_stack_call): New expand.
>>>     (split_stack_call_*): New insn.
>>>     (split_stack_cond_call): New expand.
>>>     (split_stack_cond_call_*): New insn.
>>> ---
>>> Changes applied.  Testsuite still running, still works on my simple
>>> tests.
>>>
>>> As for common code prerequisites: #3 is no longer needed, and very
>>> likely
>>> so is #4 (it fixes problems that I've only seen with ESA mode, and
>>> testsuite
>>> runs just fine without it now).
>>
>> OK, I see.  The patch is OK for mainline then, assuming testing passes.
>
> Well, testing passes (as in, is no worse than x86 - the testsuite
> doesn't really agree with -fsplit-stack in a few places involving
> backtraces).  However, there's still the libgo issue to be taken care
> of.  For my tests, I patched it up with:
> [...]

I see the libgo patch has landed today.  Can we get this pushed?

Marcin Kościelnicki