Re: [PATCH-1v2, rs6000] Enable SImode in FP registers on P7 [PR88558]

["Kewen.Lin" <linkw@linux.ibm.com>]

Hi Haochen,

on 2023/9/4 13:33, HAO CHEN GUI wrote:
> Hi,
>   This patch enables SImode in FP registers on P7. Instruction "fctiw"
> stores its integer output in an FP register. So SImode in FP register
> needs be enabled on P7 if we want support "fctiw" on P7.
> 
>   The test case is in the second patch which implements 32bit inline
> lrint.
> 
>   Compared to the last version, the main change it to remove disparaging
> on the alternatives of "fmr". Test shows it doesn't cause regression.

Ok, at least regression testing doesn't expose any needs to do disparaging
for this.  Could you also test this patch with SPEC2017 for P7 and P8
separately at options like -O2 or -O3, to see if there is any assembly
change, and if yes filtering out some typical to check it's expected or
not?  I think it can help us to better evaluate the impact.  Thanks!

BR,
Kewen

> https://gcc.gnu.org/pipermail/gcc-patches/2023-August/628435.html
> 
>   Bootstrapped and tested on powerpc64-linux BE and LE with no regressions.
> 
> 
> ChangeLog
> rs6000: enable SImode in FP register on P7
> 
> gcc/
> 	PR target/88558
> 	* config/rs6000/rs6000.cc (rs6000_hard_regno_mode_ok_uncached):
> 	Enable SImode in FP registers on P7.
> 	* config/rs6000/rs6000.md (*movsi_internal1): Add fmr for SImode
> 	move between FP registers.  Set attribute isa of stfiwx to "*"
> 	and attribute of stxsiwx to "p7".
> 
> patch.diff
> diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
> index 44b448d2ba6..99085c2cdd7 100644
> --- a/gcc/config/rs6000/rs6000.cc
> +++ b/gcc/config/rs6000/rs6000.cc
> @@ -1903,7 +1903,7 @@ rs6000_hard_regno_mode_ok_uncached (int regno, machine_mode mode)
>  	  if(GET_MODE_SIZE (mode) == UNITS_PER_FP_WORD)
>  	    return 1;
> 
> -	  if (TARGET_P8_VECTOR && (mode == SImode))
> +	  if (TARGET_POPCNTD && mode == SImode)
>  	    return 1;
> 
>  	  if (TARGET_P9_VECTOR && (mode == QImode || mode == HImode))
> diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
> index cdab49fbb91..edf49bd74e3 100644
> --- a/gcc/config/rs6000/rs6000.md
> +++ b/gcc/config/rs6000/rs6000.md
> @@ -7566,7 +7566,7 @@ (define_split
> 
>  (define_insn "*movsi_internal1"
>    [(set (match_operand:SI 0 "nonimmediate_operand"
> -	  "=r,         r,
> +	  "=r,         r,          d,
>  	   r,          d,          v,
>  	   m,          ?Z,         ?Z,
>  	   r,          r,          r,          r,
> @@ -7575,7 +7575,7 @@ (define_insn "*movsi_internal1"
>  	   wa,         r,
>  	   r,          *h,         *h")
>  	(match_operand:SI 1 "input_operand"
> -	  "r,          U,
> +	  "r,          U,          d,
>  	   m,          ?Z,         ?Z,
>  	   r,          d,          v,
>  	   I,          L,          eI,         n,
> @@ -7588,6 +7588,7 @@ (define_insn "*movsi_internal1"
>    "@
>     mr %0,%1
>     la %0,%a1
> +   fmr %0,%1
>     lwz%U1%X1 %0,%1
>     lfiwzx %0,%y1
>     lxsiwzx %x0,%y1
> @@ -7611,7 +7612,7 @@ (define_insn "*movsi_internal1"
>     mt%0 %1
>     nop"
>    [(set_attr "type"
> -	  "*,          *,
> +	  "*,          *,          fpsimple,
>  	   load,       fpload,     fpload,
>  	   store,      fpstore,    fpstore,
>  	   *,          *,          *,          *,
> @@ -7620,7 +7621,7 @@ (define_insn "*movsi_internal1"
>  	   mtvsr,      mfvsr,
>  	   *,          *,          *")
>     (set_attr "length"
> -	  "*,          *,
> +	  "*,          *,          *,
>  	   *,          *,          *,
>  	   *,          *,          *,
>  	   *,          *,          *,          8,
> @@ -7629,9 +7630,9 @@ (define_insn "*movsi_internal1"
>  	   *,          *,
>  	   *,          *,          *")
>     (set_attr "isa"
> -	  "*,          *,
> -	   *,          p8v,        p8v,
> -	   *,          p8v,        p8v,
> +	  "*,          *,          *,
> +	   *,          p7,         p8v,
> +	   *,          *,          p8v,
>  	   *,          *,          p10,        *,
>  	   p8v,        p9v,        p9v,        p8v,
>  	   p9v,        p8v,        p9v,
>