Re: [PATCH V4 2/2] rs6000: use li;x?oris to build constant

[guojiufu <guojiufu@linux.ibm.com>]

Hi,

On 2023-05-15 14:53, Kewen.Lin wrote:
> Hi Jeff,
> 
> on 2022/12/12 09:38, Jiufu Guo wrote:
>> Hi,
>> 
>> For constant C:
>> If '(c & 0xFFFFFFFF0000FFFFULL) == 0xFFFFFFFF00000000' or say:
>> 32(1) || 1(0) || 15(x) || 16(0), we could use "lis; xoris" to build.
>> 
>> Here N(M) means N continuous bit M, x for M means it is ok for either
>> 1 or 0; '||' means concatenation.
>> 
>> This patch update rs6000_emit_set_long_const to support those 
>> constants.
>> 
>> Compare with previous version:
>> https://gcc.gnu.org/pipermail/gcc-patches/2022-December/607618.htm
>> This patch fix conflicts with trunk.
>> 
>> Bootstrap and regtest pass on ppc64{,le}.
>> 
>> Is this ok for trunk?
> 
> OK for trunk, thanks for improving this.
> 
> btw, the test case needs to be updated a bit as the function names in 
> the
> context changed upstream, please ensure it's tested well before 
> committing,
> thanks!

Yeap! Retested and verified.
Thanks so much for your always insight review and helpful comments!

Committed via r14-923-g5eb7d560626e42.

BR,
Jeff (Jiufu)

> 
>> 
>> BR,
>> Jeff (Jiufu)
>> 
>> 
>> 	PR target/106708
>> 
>> gcc/ChangeLog:
>> 
>> 	* config/rs6000/rs6000.cc (rs6000_emit_set_long_const): Add to build
>> 	constants through "lis; xoris".
> 
> Maybe s/Add to build/Support building/
Yes :)

> 
> BR,
> Kewen
> 
>> 
>> gcc/testsuite/ChangeLog:
>> 
>> 	* gcc.target/powerpc/pr106708.c: Add test function.
>> 
>> ---
>>  gcc/config/rs6000/rs6000.cc                 |  7 +++++++
>>  gcc/testsuite/gcc.target/powerpc/pr106708.c | 10 +++++++++-
>>  2 files changed, 16 insertions(+), 1 deletion(-)
>> 
>> diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
>> index 8c1192a10c8..1138d5e8cd4 100644
>> --- a/gcc/config/rs6000/rs6000.cc
>> +++ b/gcc/config/rs6000/rs6000.cc
>> @@ -10251,6 +10251,13 @@ rs6000_emit_set_long_const (rtx dest, 
>> HOST_WIDE_INT c)
>>        if (ud1 != 0)
>>  	emit_move_insn (dest, gen_rtx_IOR (DImode, temp, GEN_INT (ud1)));
>>      }
>> +  else if (ud4 == 0xffff && ud3 == 0xffff && !(ud2 & 0x8000) && ud1 
>> == 0)
>> +    {
>> +      /* lis; xoris */
>> +      temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
>> +      emit_move_insn (temp, GEN_INT (sext_hwi ((ud2 | 0x8000) << 16, 
>> 32)));
>> +      emit_move_insn (dest, gen_rtx_XOR (DImode, temp, GEN_INT 
>> (0x80000000)));
>> +    }
>>    else if (ud4 == 0xffff && ud3 == 0xffff && (ud1 & 0x8000))
>>      {
>>        /* li; xoris */
>> diff --git a/gcc/testsuite/gcc.target/powerpc/pr106708.c 
>> b/gcc/testsuite/gcc.target/powerpc/pr106708.c
>> index dc9ceda8367..a015c71e630 100644
>> --- a/gcc/testsuite/gcc.target/powerpc/pr106708.c
>> +++ b/gcc/testsuite/gcc.target/powerpc/pr106708.c
>> @@ -4,7 +4,7 @@
>>  /* { dg-require-effective-target has_arch_ppc64 } */
>> 
>>  long long arr[]
>> -  = {0xffffffff7cdeab55LL, 0x98765432LL, 0xabcd0000LL};
>> += {0xffffffff7cdeab55LL, 0x98765432LL, 0xabcd0000LL, 
>> 0xffffffff65430000LL};
>> 
>>  void __attribute__ ((__noipa__)) lixoris (long long *arg)
>>  {
>> @@ -27,6 +27,13 @@ void __attribute__ ((__noipa__)) lisrldicl (long 
>> long *arg)
>>  /* { dg-final { scan-assembler-times {\mlis .*,0xabcd\M} 1 } } */
>>  /* { dg-final { scan-assembler-times {\mrldicl .*,0,32\M} 1 } } */
>> 
>> +void __attribute__ ((__noipa__)) lisxoris (long long *arg)
>> +{
>> +  *arg = 0xffffffff65430000LL;
>> +}
>> +/* { dg-final { scan-assembler-times {\mlis .*,0xe543\M} 1 } } */
>> +/* { dg-final { scan-assembler-times {\mxoris .*0x8000\M} 1 } } */
>> +
>>  int
>>  main ()
>>  {
>> @@ -35,6 +42,7 @@ main ()
>>    lixoris (a);
>>    lioris (a + 1);
>>    lisrldicl (a + 2);
>> +  lisxoris (a + 3);
>>    if (__builtin_memcmp (a, arr, sizeof (arr)) != 0)
>>      __builtin_abort ();
>>    return 0;