[PING^3][PATCH] rs6000: load high and low part of 128bit vector independently [PR110040]

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

Ping!

please review.

Thanks & Regards
Jeevitha

On 26/03/24 10:23 am, jeevitha wrote:
> Ping!
> 
> please review.
> 
> Thanks & Regards
> Jeevitha
> 
> 
> On 26/02/24 11:13 am, jeevitha wrote:
>> Hi All,
>>
>> The following patch has been bootstrapped and regtested on powerpc64le-linux.
>>
>> PR110040 exposes an issue concerning moves from vector registers to GPRs.
>> There are two moves, one for upper 64 bits and the other for the lower
>> 64 bits.  In the problematic test case, we are only interested in storing
>> the lower 64 bits.  However, the instruction for copying the upper 64 bits
>> is still emitted and is dead code.  This patch adds a splitter that splits
>> apart the two move instructions so that DCE can remove the dead code after
>> splitting.
>>
>> 2024-02-26  Jeevitha Palanisamy  <jeevitha@linux.ibm.com>
>>
>> gcc/
>> 	PR target/110040
>> 	* config/rs6000/vsx.md (split pattern for V1TI to DI move): Defined.
>>
>> gcc/testsuite/
>> 	PR target/110040
>> 	* gcc.target/powerpc/pr110040-1.c: New testcase.
>> 	* gcc.target/powerpc/pr110040-2.c: New testcase.
>>
>>
>> diff --git a/gcc/config/rs6000/vsx.md b/gcc/config/rs6000/vsx.md
>> index 6111cc90eb7..78457f8fb14 100644
>> --- a/gcc/config/rs6000/vsx.md
>> +++ b/gcc/config/rs6000/vsx.md
>> @@ -6706,3 +6706,19 @@
>>    "vmsumcud %0,%1,%2,%3"
>>    [(set_attr "type" "veccomplex")]
>>  )
>> +
>> +(define_split
>> +  [(set (match_operand:V1TI 0 "int_reg_operand")
>> +       (match_operand:V1TI 1 "vsx_register_operand"))]
>> +  "reload_completed
>> +   && TARGET_DIRECT_MOVE_64BIT"
>> +   [(pc)]
>> +{
>> +  rtx op0 = gen_rtx_REG (DImode, REGNO (operands[0]));
>> +  rtx op1 = gen_rtx_REG (V2DImode, REGNO (operands[1]));
>> +  rtx op2 = gen_rtx_REG (DImode, REGNO (operands[0]) + 1);
>> +  rtx op3 = gen_rtx_REG (V2DImode, REGNO (operands[1]));
>> +  emit_insn (gen_vsx_extract_v2di (op0, op1, GEN_INT (0)));
>> +  emit_insn (gen_vsx_extract_v2di (op2, op3, GEN_INT (1)));
>> +  DONE;
>> +})
>> diff --git a/gcc/testsuite/gcc.target/powerpc/pr110040-1.c b/gcc/testsuite/gcc.target/powerpc/pr110040-1.c
>> new file mode 100644
>> index 00000000000..fb3bd254636
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/powerpc/pr110040-1.c
>> @@ -0,0 +1,14 @@
>> +/* PR target/110040 */
>> +/* { dg-do compile } */
>> +/* { dg-require-effective-target powerpc_p9vector_ok } */
>> +/* { dg-options "-O2 -mdejagnu-cpu=power9" } */
>> +/* { dg-final { scan-assembler-not {\mmfvsrd\M} } } */
>> +
>> +#include <altivec.h>
>> +
>> +void
>> +foo (signed long *dst, vector signed __int128 src)
>> +{
>> +  *dst = (signed long) src[0];
>> +}
>> +
>> diff --git a/gcc/testsuite/gcc.target/powerpc/pr110040-2.c b/gcc/testsuite/gcc.target/powerpc/pr110040-2.c
>> new file mode 100644
>> index 00000000000..f3aa22be4e8
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/powerpc/pr110040-2.c
>> @@ -0,0 +1,13 @@
>> +/* PR target/110040 */
>> +/* { dg-do compile } */
>> +/* { dg-require-effective-target power10_ok } */
>> +/* { dg-options "-O2 -mdejagnu-cpu=power10" } */
>> +/* { dg-final { scan-assembler-not {\mmfvsrd\M} } } */
>> +
>> +#include <altivec.h>
>> +
>> +void
>> +foo (signed int *dst, vector signed __int128 src)
>> +{
>> +  __builtin_vec_xst_trunc (src, 0, dst);
>> +}
>>
>>