"Kewen.Lin" <li...@linux.ibm.com> writes:
> Hi Jeff,
>
> on 2022/7/19 22:30, Jiufu Guo wrote:
>> Hi,
>>
>> In patch https://gcc.gnu.org/pipermail/gcc-patches/2022-July/597712.html,
>> test case was not added. After more check, a testcase is added for it.
>>
>
> Good to see that you constructed one actual test case, nice! :)
>
>> The high part of the symbol address is invalid for the constant pool.
>> In function rs6000_cannot_force_const_mem, we already return true for
>> "HIGH with UNSPEC" rtx. Below are some examples also indicate the high
>> part of a symbol_ref:
>> (high:DI (const:DI (plus:DI (symbol_ref:DI ("xx") (const_int 12 [0xc])))))
>> (high:DI (symbol_ref:DI ("var_1")..)))
>>
>> This patch updates rs6000_cannot_force_const_mem to return true for
>> rtx with HIGH code.
>>
>> Bootstrapped and regtested on ppc64le and ppc64.
>> Is it ok for trunk?
>
> I think this patch is OK with some nits below tweaked.
Thanks so much for your time to review and helpful comments!
I will update accordingly before commit.
BR,
Jeff(Jiufu)
>
>>
>> BR,
>> Jeff(Jiufu)
>>
>>
>> gcc/ChangeLog:
>>
>> * config/rs6000/rs6000.cc (rs6000_cannot_force_const_mem):
>> Return true for HIGH code rtx.
>>
>> gcc/testsuite/ChangeLog:
>>
>> * gcc.target/powerpc/constpoolcheck.c: New test.
>>
>> ---
>> gcc/config/rs6000/rs6000.cc | 7 +++++--
>> gcc/testsuite/gcc.target/powerpc/constpoolcheck.c | 11 +++++++++++
>> 2 files changed, 16 insertions(+), 2 deletions(-)
>> create mode 100644 gcc/testsuite/gcc.target/powerpc/constpoolcheck.c
>>
>> diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
>> index 0af2085adc0..d56832ebbfc 100644
>> --- a/gcc/config/rs6000/rs6000.cc
>> +++ b/gcc/config/rs6000/rs6000.cc
>> @@ -9704,8 +9704,11 @@ rs6000_init_stack_protect_guard (void)
>> static bool
>> rs6000_cannot_force_const_mem (machine_mode mode ATTRIBUTE_UNUSED, rtx x)
>> {
>> - if (GET_CODE (x) == HIGH
>> - && GET_CODE (XEXP (x, 0)) == UNSPEC)
>> + /* High part of a symbol ref/address can not be put into constant pool.
>> e.g.
>
> Nit: two spaces after the period in "... pool.".
Thanks!
>
>> + (high:DI (symbol_ref:DI ("var")..)) or
>
> Nit: You have one "or" at the end of the above line, I think it's better to
> keep the below line consistent by either removing the above " or" or adding
> one "or" at the end of the below line.
Thanks!
>
>> + (high:DI (unspec:DI [(symbol_ref/u:DI ("*.LC0")..)
>
>
>> + (high:DI (const:DI (plus:DI (symbol_ref:DI ("xx")) (const_int 12)))).
>> */
>> + if (GET_CODE (x) == HIGH)
>> return true;
>>
>> /* A TLS symbol in the TOC cannot contain a sum. */
>> diff --git a/gcc/testsuite/gcc.target/powerpc/constpoolcheck.c
>> b/gcc/testsuite/gcc.target/powerpc/constpoolcheck.c
>> new file mode 100644
>> index 00000000000..ed7a994827b
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/powerpc/constpoolcheck.c
>
> Maybe it's good to name it to "const-pool-check.c" or "not-force-const-mem.c".
Great sugguestion! Thanks.
>
>> @@ -0,0 +1,11 @@
>> +/* { dg-do compile { target powerpc*-*-* } } */
>
> Nit: this "dg-do" line isn't needed since all here are default.
Thanks for your comments!
>
> BR,
> Kewen
>
>> +/* { dg-options "-O1 -mdejagnu-cpu=power10" } */
>> +/* (high:DI (symbol_ref:DI ("var_48")..))) should not cause ICE. */
>> +extern short var_48;
>> +void
>> +foo (double *r)
>> +{
>> + if (var_48)
>> + *r = 1234.5678;
>> +}
>> +
