[V4,1/3] rs6000: accurate num_insns_constant_gpr

  Hi,

Trunk gcc supports more constants to be built via two instructions:
e.g. "li/lis; xori/xoris/rldicl/rldicr/rldic".
And then num_insns_constant should also be updated.

Function "rs6000_emit_set_long_const" is used to build complicated
constants; and "num_insns_constant_gpr" is used to compute 'how
many instructions are needed" to build the constant. So, these 
two functions should be aligned.

The idea of this patch is: to reuse "rs6000_emit_set_long_const" to
compute/record the instruction number(when computing the insn_num, 
then do not emit instructions).

Compare with the previous version,
https://gcc.gnu.org/pipermail/gcc-patches/2023-December/639491.html
this version updates a lambda usage and comments.

Bootstrap & regtest pass ppc64{,le}.
Is this ok for trunk?

BR,
Jeff (Jiufu Guo)

gcc/ChangeLog:

	* config/rs6000/rs6000.cc (rs6000_emit_set_long_const): Add new
	parameter to record number of instructions to build the constant.
	(num_insns_constant_gpr): Call rs6000_emit_set_long_const to compute
	num_insn.

---
 gcc/config/rs6000/rs6000.cc | 284 ++++++++++++++++++------------------
 1 file changed, 146 insertions(+), 138 deletions(-)
  

Hi Jeff,

on 2023/12/11 11:26, Jiufu Guo wrote:
> Hi,
> 
> Trunk gcc supports more constants to be built via two instructions:
> e.g. "li/lis; xori/xoris/rldicl/rldicr/rldic".
> And then num_insns_constant should also be updated.
> 
> Function "rs6000_emit_set_long_const" is used to build complicated
> constants; and "num_insns_constant_gpr" is used to compute 'how
> many instructions are needed" to build the constant. So, these 
> two functions should be aligned.
> 
> The idea of this patch is: to reuse "rs6000_emit_set_long_const" to
> compute/record the instruction number(when computing the insn_num, 
> then do not emit instructions).
> 
> Compare with the previous version,
> https://gcc.gnu.org/pipermail/gcc-patches/2023-December/639491.html
> this version updates a lambda usage and comments.
> 
> Bootstrap & regtest pass ppc64{,le}.
> Is this ok for trunk?

OK for trunk, thanks for the patience.

BR,
Kewen

> 
> BR,
> Jeff (Jiufu Guo)
> 
> gcc/ChangeLog:
> 
> 	* config/rs6000/rs6000.cc (rs6000_emit_set_long_const): Add new
> 	parameter to record number of instructions to build the constant.
> 	(num_insns_constant_gpr): Call rs6000_emit_set_long_const to compute
> 	num_insn.
> 
> ---
>  gcc/config/rs6000/rs6000.cc | 284 ++++++++++++++++++------------------
>  1 file changed, 146 insertions(+), 138 deletions(-)
> 
> diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
> index cee22c359f3..1e3d1f7fc08 100644
> --- a/gcc/config/rs6000/rs6000.cc
> +++ b/gcc/config/rs6000/rs6000.cc
> @@ -1115,7 +1115,7 @@ static tree rs6000_handle_longcall_attribute (tree *, tree, tree, int, bool *);
>  static tree rs6000_handle_altivec_attribute (tree *, tree, tree, int, bool *);
>  static tree rs6000_handle_struct_attribute (tree *, tree, tree, int, bool *);
>  static tree rs6000_builtin_vectorized_libmass (combined_fn, tree, tree);
> -static void rs6000_emit_set_long_const (rtx, HOST_WIDE_INT);
> +static void rs6000_emit_set_long_const (rtx, HOST_WIDE_INT, int * = nullptr);
>  static int rs6000_memory_move_cost (machine_mode, reg_class_t, bool);
>  static bool rs6000_debug_rtx_costs (rtx, machine_mode, int, int, int *, bool);
>  static int rs6000_debug_address_cost (rtx, machine_mode, addr_space_t,
> @@ -6054,21 +6054,9 @@ num_insns_constant_gpr (HOST_WIDE_INT value)
>  
>    else if (TARGET_POWERPC64)
>      {
> -      HOST_WIDE_INT low = sext_hwi (value, 32);
> -      HOST_WIDE_INT high = value >> 31;
> -
> -      if (high == 0 || high == -1)
> -	return 2;
> -
> -      high >>= 1;
> -
> -      if (low == 0 || low == high)
> -	return num_insns_constant_gpr (high) + 1;
> -      else if (high == 0)
> -	return num_insns_constant_gpr (low) + 1;
> -      else
> -	return (num_insns_constant_gpr (high)
> -		+ num_insns_constant_gpr (low) + 1);
> +      int num_insns = 0;
> +      rs6000_emit_set_long_const (nullptr, value, &num_insns);
> +      return num_insns;
>      }
>  
>    else
> @@ -10494,14 +10482,13 @@ can_be_built_by_li_and_rldic (HOST_WIDE_INT c, int *shift, HOST_WIDE_INT *mask)
>  
>  /* Subroutine of rs6000_emit_set_const, handling PowerPC64 DImode.
>     Output insns to set DEST equal to the constant C as a series of
> -   lis, ori and shl instructions.  */
> +   lis, ori and shl instructions.  If NUM_INSNS is not NULL, then
> +   only increase *NUM_INSNS as the number of insns, and do not emit
> +   any insns.  */
>  
>  static void
> -rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c)
> +rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c, int *num_insns)
>  {
> -  rtx temp;
> -  int shift;
> -  HOST_WIDE_INT mask;
>    HOST_WIDE_INT ud1, ud2, ud3, ud4;
>  
>    ud1 = c & 0xffff;
> @@ -10509,168 +10496,189 @@ rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c)
>    ud3 = (c >> 32) & 0xffff;
>    ud4 = (c >> 48) & 0xffff;
>  
> -  if ((ud4 == 0xffff && ud3 == 0xffff && ud2 == 0xffff && (ud1 & 0x8000))
> -      || (ud4 == 0 && ud3 == 0 && ud2 == 0 && ! (ud1 & 0x8000)))
> -    emit_move_insn (dest, GEN_INT (sext_hwi (ud1, 16)));
> +  /* This lambda is used to emit one insn or just increase the insn count.
> +     When counting the insn number, no need to emit the insn.  */
> +  auto count_or_emit_insn = [&num_insns] (rtx dest_or_insn, rtx src = nullptr) {
> +    if (num_insns)
> +      {
> +	(*num_insns)++;
> +	return;
> +      }
> +
> +    if (src)
> +      emit_move_insn (dest_or_insn, src);
> +    else
> +      emit_insn (dest_or_insn);
> +  };
>  
> -  else if ((ud4 == 0xffff && ud3 == 0xffff && (ud2 & 0x8000))
> -	   || (ud4 == 0 && ud3 == 0 && ! (ud2 & 0x8000)))
> +  if ((ud4 == 0xffff && ud3 == 0xffff && ud2 == 0xffff && (ud1 & 0x8000))
> +      || (ud4 == 0 && ud3 == 0 && ud2 == 0 && !(ud1 & 0x8000)))
>      {
> -      temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
> +      /* li */
> +      count_or_emit_insn (dest, GEN_INT (sext_hwi (ud1, 16)));
> +      return;
> +    }
> +
> +  rtx temp
> +    = (num_insns || !can_create_pseudo_p ()) ? dest : gen_reg_rtx (DImode);
>  
> -      emit_move_insn (ud1 != 0 ? temp : dest,
> -		      GEN_INT (sext_hwi (ud2 << 16, 32)));
> +  if ((ud4 == 0xffff && ud3 == 0xffff && (ud2 & 0x8000))
> +      || (ud4 == 0 && ud3 == 0 && !(ud2 & 0x8000)))
> +    {
> +      /* lis[; ori] */
> +      count_or_emit_insn (ud1 != 0 ? temp : dest,
> +			  GEN_INT (sext_hwi (ud2 << 16, 32)));
>        if (ud1 != 0)
> -	emit_move_insn (dest, gen_rtx_IOR (DImode, temp, GEN_INT (ud1)));
> +	count_or_emit_insn (dest, gen_rtx_IOR (DImode, temp, GEN_INT (ud1)));
> +      return;
>      }
> -  else if (ud4 == 0xffff && ud3 == 0xffff && !(ud2 & 0x8000) && ud1 == 0)
> +
> +  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)));
> +      count_or_emit_insn (temp, GEN_INT (sext_hwi ((ud2 | 0x8000) << 16, 32)));
> +      count_or_emit_insn (dest,
> +			  gen_rtx_XOR (DImode, temp, GEN_INT (0x80000000)));
> +      return;
>      }
> -  else if (ud4 == 0xffff && ud3 == 0xffff && (ud1 & 0x8000))
> +
> +  if (ud4 == 0xffff && ud3 == 0xffff && (ud1 & 0x8000))
>      {
>        /* li; xoris */
> -      temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
> -      emit_move_insn (temp, GEN_INT (sext_hwi (ud1, 16)));
> -      emit_move_insn (dest, gen_rtx_XOR (DImode, temp,
> -					 GEN_INT ((ud2 ^ 0xffff) << 16)));
> +      count_or_emit_insn (temp, GEN_INT (sext_hwi (ud1, 16)));
> +      count_or_emit_insn (dest, gen_rtx_XOR (DImode, temp,
> +					     GEN_INT ((ud2 ^ 0xffff) << 16)));
> +      return;
>      }
> -  else if (can_be_built_by_li_lis_and_rotldi (c, &shift, &mask)
> -	   || can_be_built_by_li_lis_and_rldicl (c, &shift, &mask)
> -	   || can_be_built_by_li_lis_and_rldicr (c, &shift, &mask)
> -	   || can_be_built_by_li_and_rldic (c, &shift, &mask))
> +
> +  int shift;
> +  HOST_WIDE_INT mask;
> +  if (can_be_built_by_li_lis_and_rotldi (c, &shift, &mask)
> +      || can_be_built_by_li_lis_and_rldicl (c, &shift, &mask)
> +      || can_be_built_by_li_lis_and_rldicr (c, &shift, &mask)
> +      || can_be_built_by_li_and_rldic (c, &shift, &mask))
>      {
> -      temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
> +      /* li/lis; rldicX */
>        unsigned HOST_WIDE_INT imm = (c | ~mask);
>        imm = (imm >> shift) | (imm << (HOST_BITS_PER_WIDE_INT - shift));
>  
> -      emit_move_insn (temp, GEN_INT (imm));
> +      count_or_emit_insn (temp, GEN_INT (imm));
>        if (shift != 0)
>  	temp = gen_rtx_ROTATE (DImode, temp, GEN_INT (shift));
>        if (mask != HOST_WIDE_INT_M1)
>  	temp = gen_rtx_AND (DImode, temp, GEN_INT (mask));
> -      emit_move_insn (dest, temp);
> -    }
> -  else if (ud3 == 0 && ud4 == 0)
> -    {
> -      temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
> +      count_or_emit_insn (dest, temp);
>  
> -      gcc_assert (ud2 & 0x8000);
> +      return;
> +    }
>  
> -      if (ud1 == 0)
> -	{
> -	  /* lis; rldicl */
> -	  emit_move_insn (temp, GEN_INT (sext_hwi (ud2 << 16, 32)));
> -	  emit_move_insn (dest,
> -			  gen_rtx_AND (DImode, temp, GEN_INT (0xffffffff)));
> -	}
> -      else if (!(ud1 & 0x8000))
> +  if (ud3 == 0 && ud4 == 0)
> +    {
> +      gcc_assert ((ud2 & 0x8000) && ud1 != 0);
> +      if (!(ud1 & 0x8000))
>  	{
>  	  /* li; oris */
> -	  emit_move_insn (temp, GEN_INT (ud1));
> -	  emit_move_insn (dest,
> -			  gen_rtx_IOR (DImode, temp, GEN_INT (ud2 << 16)));
> +	  count_or_emit_insn (temp, GEN_INT (ud1));
> +	  count_or_emit_insn (dest,
> +			      gen_rtx_IOR (DImode, temp, GEN_INT (ud2 << 16)));
> +	  return;
>  	}
> -      else
> -	{
> -	  /* lis; ori; rldicl */
> -	  emit_move_insn (temp, GEN_INT (sext_hwi (ud2 << 16, 32)));
> -	  emit_move_insn (temp, gen_rtx_IOR (DImode, temp, GEN_INT (ud1)));
> -	  emit_move_insn (dest,
> +
> +      /* lis; ori; rldicl */
> +      count_or_emit_insn (temp, GEN_INT (sext_hwi (ud2 << 16, 32)));
> +      count_or_emit_insn (temp, gen_rtx_IOR (DImode, temp, GEN_INT (ud1)));
> +      count_or_emit_insn (dest,
>  			  gen_rtx_AND (DImode, temp, GEN_INT (0xffffffff)));
> -	}
> +      return;
>      }
> -  else if (ud1 == ud3 && ud2 == ud4)
> +
> +  if (ud1 == ud3 && ud2 == ud4)
>      {
> -      temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
> +      /* load low 32bits first, e.g. "lis; ori", then "rldimi".  */
>        HOST_WIDE_INT num = (ud2 << 16) | ud1;
> -      rs6000_emit_set_long_const (temp, sext_hwi (num, 32));
> -      rtx one = gen_rtx_AND (DImode, temp, GEN_INT (0xffffffff));
> -      rtx two = gen_rtx_ASHIFT (DImode, temp, GEN_INT (32));
> -      emit_move_insn (dest, gen_rtx_IOR (DImode, one, two));
> +      rs6000_emit_set_long_const (temp, sext_hwi (num, 32), num_insns);
> +
> +      rtx rldimi = gen_rotldi3_insert_3 (dest, temp, GEN_INT (32), temp,
> +					 GEN_INT (0xffffffff));
> +      count_or_emit_insn (rldimi);
> +      return;
>      }
> -  else if ((ud4 == 0xffff && (ud3 & 0x8000))
> -	   || (ud4 == 0 && ! (ud3 & 0x8000)))
> -    {
> -      temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
>  
> -      emit_move_insn (temp, GEN_INT (sext_hwi (ud3 << 16, 32)));
> +  if ((ud4 == 0xffff && (ud3 & 0x8000)) || (ud4 == 0 && !(ud3 & 0x8000)))
> +    {
> +      /* li; [ori;] rldicl [;oir].  */
> +      count_or_emit_insn (temp, GEN_INT (sext_hwi (ud3 << 16, 32)));
>        if (ud2 != 0)
> -	emit_move_insn (temp, gen_rtx_IOR (DImode, temp, GEN_INT (ud2)));
> -      emit_move_insn (ud1 != 0 ? temp : dest,
> -		      gen_rtx_ASHIFT (DImode, temp, GEN_INT (16)));
> +	count_or_emit_insn (temp, gen_rtx_IOR (DImode, temp, GEN_INT (ud2)));
> +      count_or_emit_insn (ud1 != 0 ? temp : dest,
> +			  gen_rtx_ASHIFT (DImode, temp, GEN_INT (16)));
>        if (ud1 != 0)
> -	emit_move_insn (dest, gen_rtx_IOR (DImode, temp, GEN_INT (ud1)));
> +	count_or_emit_insn (dest, gen_rtx_IOR (DImode, temp, GEN_INT (ud1)));
> +      return;
>      }
> -  else if (TARGET_PREFIXED)
> +
> +  if (TARGET_PREFIXED)
>      {
>        if (can_create_pseudo_p ())
>  	{
> -	  /* pli A,L + pli B,H + rldimi A,B,32,0.  */
> -	  temp = gen_reg_rtx (DImode);
> -	  rtx temp1 = gen_reg_rtx (DImode);
> -	  emit_move_insn (temp, GEN_INT ((ud4 << 16) | ud3));
> -	  emit_move_insn (temp1, GEN_INT ((ud2 << 16) | ud1));
> -
> -	  emit_insn (gen_rotldi3_insert_3 (dest, temp, GEN_INT (32), temp1,
> -					   GEN_INT (0xffffffff)));
> +	  /* pli A,L; pli B,H; rldimi A,B,32,0.  */
> +	  rtx temp1 = num_insns ? nullptr : gen_reg_rtx (DImode);
> +	  count_or_emit_insn (temp, GEN_INT ((ud4 << 16) | ud3));
> +	  count_or_emit_insn (temp1, GEN_INT ((ud2 << 16) | ud1));
> +	  rtx rldimi = gen_rotldi3_insert_3 (dest, temp, GEN_INT (32), temp1,
> +					     GEN_INT (0xffffffff));
> +	  count_or_emit_insn (rldimi);
> +	  return;
>  	}
> -      else
> -	{
> -	  /* pli A,H + sldi A,32 + paddi A,A,L.  */
> -	  emit_move_insn (dest, GEN_INT ((ud4 << 16) | ud3));
> -
> -	  emit_move_insn (dest, gen_rtx_ASHIFT (DImode, dest, GEN_INT (32)));
>  
> -	  bool can_use_paddi = REGNO (dest) != FIRST_GPR_REGNO;
> +      /* pli A,H; sldi A,32; paddi A,A,L.  */
> +      count_or_emit_insn (dest, GEN_INT ((ud4 << 16) | ud3));
> +      count_or_emit_insn (dest, gen_rtx_ASHIFT (DImode, dest, GEN_INT (32)));
>  
> -	  /* Use paddi for the low 32 bits.  */
> -	  if (ud2 != 0 && ud1 != 0 && can_use_paddi)
> -	    emit_move_insn (dest, gen_rtx_PLUS (DImode, dest,
> +      bool can_use_paddi = dest ? REGNO (dest) != FIRST_GPR_REGNO : false;
> +      /* Use paddi for the low 32 bits.  */
> +      if (ud2 != 0 && ud1 != 0 && can_use_paddi)
> +	count_or_emit_insn (dest, gen_rtx_PLUS (DImode, dest,
>  						GEN_INT ((ud2 << 16) | ud1)));
> -
> -	  /* Use oris, ori for low 32 bits.  */
> -	  if (ud2 != 0 && (ud1 == 0 || !can_use_paddi))
> -	    emit_move_insn (dest,
> +      /* Use oris, ori for low 32 bits.  */
> +      if (ud2 != 0 && (ud1 == 0 || !can_use_paddi))
> +	count_or_emit_insn (dest,
>  			    gen_rtx_IOR (DImode, dest, GEN_INT (ud2 << 16)));
> -	  if (ud1 != 0 && (ud2 == 0 || !can_use_paddi))
> -	    emit_move_insn (dest, gen_rtx_IOR (DImode, dest, GEN_INT (ud1)));
> -	}
> +      if (ud1 != 0 && (ud2 == 0 || !can_use_paddi))
> +	count_or_emit_insn (dest, gen_rtx_IOR (DImode, dest, GEN_INT (ud1)));
> +      return;
>      }
> -  else
> +
> +  if (can_create_pseudo_p ())
>      {
> -      if (can_create_pseudo_p ())
> -	{
> -	  /* lis HIGH,UD4 ; ori HIGH,UD3 ;
> -	     lis LOW,UD2 ; ori LOW,UD1 ; rldimi LOW,HIGH,32,0.  */
> -	  rtx high = gen_reg_rtx (DImode);
> -	  rtx low = gen_reg_rtx (DImode);
> -	  HOST_WIDE_INT num = (ud2 << 16) | ud1;
> -	  rs6000_emit_set_long_const (low, sext_hwi (num, 32));
> -	  num = (ud4 << 16) | ud3;
> -	  rs6000_emit_set_long_const (high, sext_hwi (num, 32));
> -	  emit_insn (gen_rotldi3_insert_3 (dest, high, GEN_INT (32), low,
> -					   GEN_INT (0xffffffff)));
> -	}
> -      else
> -	{
> -	  /* lis DEST,UD4 ; ori DEST,UD3 ; rotl DEST,32 ;
> -	     oris DEST,UD2 ; ori DEST,UD1.  */
> -	  emit_move_insn (dest, GEN_INT (sext_hwi (ud4 << 16, 32)));
> -	  if (ud3 != 0)
> -	    emit_move_insn (dest, gen_rtx_IOR (DImode, dest, GEN_INT (ud3)));
> +      /* lis HIGH,UD4 ; ori HIGH,UD3 ;
> +	 lis LOW,UD2 ; ori LOW,UD1 ; rldimi LOW,HIGH,32,0.  */
> +      rtx high = num_insns ? nullptr : gen_reg_rtx (DImode);
> +      rtx low = num_insns ? nullptr : gen_reg_rtx (DImode);
> +      HOST_WIDE_INT num = (ud2 << 16) | ud1;
> +      rs6000_emit_set_long_const (low, sext_hwi (num, 32), num_insns);
> +      num = (ud4 << 16) | ud3;
> +      rs6000_emit_set_long_const (high, sext_hwi (num, 32), num_insns);
>  
> -	  emit_move_insn (dest, gen_rtx_ASHIFT (DImode, dest, GEN_INT (32)));
> -	  if (ud2 != 0)
> -	    emit_move_insn (dest,
> -			    gen_rtx_IOR (DImode, dest, GEN_INT (ud2 << 16)));
> -	  if (ud1 != 0)
> -	    emit_move_insn (dest, gen_rtx_IOR (DImode, dest, GEN_INT (ud1)));
> -	}
> +      rtx rldimi = gen_rotldi3_insert_3 (dest, high, GEN_INT (32), low,
> +					 GEN_INT (0xffffffff));
> +      count_or_emit_insn (rldimi);
> +      return;
>      }
> +
> +  /* lis DEST,UD4 ; ori DEST,UD3 ; rotl DEST,32 ;
> +     oris DEST,UD2 ; ori DEST,UD1.  */
> +  count_or_emit_insn (dest, GEN_INT (sext_hwi (ud4 << 16, 32)));
> +  if (ud3 != 0)
> +    count_or_emit_insn (dest, gen_rtx_IOR (DImode, dest, GEN_INT (ud3)));
> +
> +  count_or_emit_insn (dest, gen_rtx_ASHIFT (DImode, dest, GEN_INT (32)));
> +  if (ud2 != 0)
> +    count_or_emit_insn (dest, gen_rtx_IOR (DImode, dest, GEN_INT (ud2 << 16)));
> +  if (ud1 != 0)
> +    count_or_emit_insn (dest, gen_rtx_IOR (DImode, dest, GEN_INT (ud1)));
> +
> +  return;
>  }
>  
>  /* Helper for the following.  Get rid of [r+r] memory refs
  

Hi,

"Kewen.Lin" <linkw@linux.ibm.com> writes:

> Hi Jeff,
>
> on 2023/12/11 11:26, Jiufu Guo wrote:
>> Hi,
>> 
>> Trunk gcc supports more constants to be built via two instructions:
>> e.g. "li/lis; xori/xoris/rldicl/rldicr/rldic".
>> And then num_insns_constant should also be updated.
>> 
>> Function "rs6000_emit_set_long_const" is used to build complicated
>> constants; and "num_insns_constant_gpr" is used to compute 'how
>> many instructions are needed" to build the constant. So, these 
>> two functions should be aligned.
>> 
>> The idea of this patch is: to reuse "rs6000_emit_set_long_const" to
>> compute/record the instruction number(when computing the insn_num, 
>> then do not emit instructions).
>> 
>> Compare with the previous version,
>> https://gcc.gnu.org/pipermail/gcc-patches/2023-December/639491.html
>> this version updates a lambda usage and comments.
>> 
>> Bootstrap & regtest pass ppc64{,le}.
>> Is this ok for trunk?
>
> OK for trunk, thanks for the patience.

Committed via r14-6476.
Thanks for your kind review and great comments!

BR,
Jeff (Jiufu Guo)

>
> BR,
> Kewen
>
>> 
>> BR,
>> Jeff (Jiufu Guo)
>> 
>> gcc/ChangeLog:
>> 
>> 	* config/rs6000/rs6000.cc (rs6000_emit_set_long_const): Add new
>> 	parameter to record number of instructions to build the constant.
>> 	(num_insns_constant_gpr): Call rs6000_emit_set_long_const to compute
>> 	num_insn.
>> 
>> ---
>>  gcc/config/rs6000/rs6000.cc | 284 ++++++++++++++++++------------------
>>  1 file changed, 146 insertions(+), 138 deletions(-)
>> 
>> diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
>> index cee22c359f3..1e3d1f7fc08 100644
>> --- a/gcc/config/rs6000/rs6000.cc
>> +++ b/gcc/config/rs6000/rs6000.cc
>> @@ -1115,7 +1115,7 @@ static tree rs6000_handle_longcall_attribute (tree *, tree, tree, int, bool *);
>>  static tree rs6000_handle_altivec_attribute (tree *, tree, tree, int, bool *);
>>  static tree rs6000_handle_struct_attribute (tree *, tree, tree, int, bool *);
>>  static tree rs6000_builtin_vectorized_libmass (combined_fn, tree, tree);
>> -static void rs6000_emit_set_long_const (rtx, HOST_WIDE_INT);
>> +static void rs6000_emit_set_long_const (rtx, HOST_WIDE_INT, int * = nullptr);
>>  static int rs6000_memory_move_cost (machine_mode, reg_class_t, bool);
>>  static bool rs6000_debug_rtx_costs (rtx, machine_mode, int, int, int *, bool);
>>  static int rs6000_debug_address_cost (rtx, machine_mode, addr_space_t,
>> @@ -6054,21 +6054,9 @@ num_insns_constant_gpr (HOST_WIDE_INT value)
>>  
>>    else if (TARGET_POWERPC64)
>>      {
>> -      HOST_WIDE_INT low = sext_hwi (value, 32);
>> -      HOST_WIDE_INT high = value >> 31;
>> -
>> -      if (high == 0 || high == -1)
>> -	return 2;
>> -
>> -      high >>= 1;
>> -
>> -      if (low == 0 || low == high)
>> -	return num_insns_constant_gpr (high) + 1;
>> -      else if (high == 0)
>> -	return num_insns_constant_gpr (low) + 1;
>> -      else
>> -	return (num_insns_constant_gpr (high)
>> -		+ num_insns_constant_gpr (low) + 1);
>> +      int num_insns = 0;
>> +      rs6000_emit_set_long_const (nullptr, value, &num_insns);
>> +      return num_insns;
>>      }
>>  
>>    else
>> @@ -10494,14 +10482,13 @@ can_be_built_by_li_and_rldic (HOST_WIDE_INT c, int *shift, HOST_WIDE_INT *mask)
>>  
>>  /* Subroutine of rs6000_emit_set_const, handling PowerPC64 DImode.
>>     Output insns to set DEST equal to the constant C as a series of
>> -   lis, ori and shl instructions.  */
>> +   lis, ori and shl instructions.  If NUM_INSNS is not NULL, then
>> +   only increase *NUM_INSNS as the number of insns, and do not emit
>> +   any insns.  */
>>  
>>  static void
>> -rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c)
>> +rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c, int *num_insns)
>>  {
>> -  rtx temp;
>> -  int shift;
>> -  HOST_WIDE_INT mask;
>>    HOST_WIDE_INT ud1, ud2, ud3, ud4;
>>  
>>    ud1 = c & 0xffff;
>> @@ -10509,168 +10496,189 @@ rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c)
>>    ud3 = (c >> 32) & 0xffff;
>>    ud4 = (c >> 48) & 0xffff;
>>  
>> -  if ((ud4 == 0xffff && ud3 == 0xffff && ud2 == 0xffff && (ud1 & 0x8000))
>> -      || (ud4 == 0 && ud3 == 0 && ud2 == 0 && ! (ud1 & 0x8000)))
>> -    emit_move_insn (dest, GEN_INT (sext_hwi (ud1, 16)));
>> +  /* This lambda is used to emit one insn or just increase the insn count.
>> +     When counting the insn number, no need to emit the insn.  */
>> +  auto count_or_emit_insn = [&num_insns] (rtx dest_or_insn, rtx src = nullptr) {
>> +    if (num_insns)
>> +      {
>> +	(*num_insns)++;
>> +	return;
>> +      }
>> +
>> +    if (src)
>> +      emit_move_insn (dest_or_insn, src);
>> +    else
>> +      emit_insn (dest_or_insn);
>> +  };
>>  
>> -  else if ((ud4 == 0xffff && ud3 == 0xffff && (ud2 & 0x8000))
>> -	   || (ud4 == 0 && ud3 == 0 && ! (ud2 & 0x8000)))
>> +  if ((ud4 == 0xffff && ud3 == 0xffff && ud2 == 0xffff && (ud1 & 0x8000))
>> +      || (ud4 == 0 && ud3 == 0 && ud2 == 0 && !(ud1 & 0x8000)))
>>      {
>> -      temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
>> +      /* li */
>> +      count_or_emit_insn (dest, GEN_INT (sext_hwi (ud1, 16)));
>> +      return;
>> +    }
>> +
>> +  rtx temp
>> +    = (num_insns || !can_create_pseudo_p ()) ? dest : gen_reg_rtx (DImode);
>>  
>> -      emit_move_insn (ud1 != 0 ? temp : dest,
>> -		      GEN_INT (sext_hwi (ud2 << 16, 32)));
>> +  if ((ud4 == 0xffff && ud3 == 0xffff && (ud2 & 0x8000))
>> +      || (ud4 == 0 && ud3 == 0 && !(ud2 & 0x8000)))
>> +    {
>> +      /* lis[; ori] */
>> +      count_or_emit_insn (ud1 != 0 ? temp : dest,
>> +			  GEN_INT (sext_hwi (ud2 << 16, 32)));
>>        if (ud1 != 0)
>> -	emit_move_insn (dest, gen_rtx_IOR (DImode, temp, GEN_INT (ud1)));
>> +	count_or_emit_insn (dest, gen_rtx_IOR (DImode, temp, GEN_INT (ud1)));
>> +      return;
>>      }
>> -  else if (ud4 == 0xffff && ud3 == 0xffff && !(ud2 & 0x8000) && ud1 == 0)
>> +
>> +  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)));
>> +      count_or_emit_insn (temp, GEN_INT (sext_hwi ((ud2 | 0x8000) << 16, 32)));
>> +      count_or_emit_insn (dest,
>> +			  gen_rtx_XOR (DImode, temp, GEN_INT (0x80000000)));
>> +      return;
>>      }
>> -  else if (ud4 == 0xffff && ud3 == 0xffff && (ud1 & 0x8000))
>> +
>> +  if (ud4 == 0xffff && ud3 == 0xffff && (ud1 & 0x8000))
>>      {
>>        /* li; xoris */
>> -      temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
>> -      emit_move_insn (temp, GEN_INT (sext_hwi (ud1, 16)));
>> -      emit_move_insn (dest, gen_rtx_XOR (DImode, temp,
>> -					 GEN_INT ((ud2 ^ 0xffff) << 16)));
>> +      count_or_emit_insn (temp, GEN_INT (sext_hwi (ud1, 16)));
>> +      count_or_emit_insn (dest, gen_rtx_XOR (DImode, temp,
>> +					     GEN_INT ((ud2 ^ 0xffff) << 16)));
>> +      return;
>>      }
>> -  else if (can_be_built_by_li_lis_and_rotldi (c, &shift, &mask)
>> -	   || can_be_built_by_li_lis_and_rldicl (c, &shift, &mask)
>> -	   || can_be_built_by_li_lis_and_rldicr (c, &shift, &mask)
>> -	   || can_be_built_by_li_and_rldic (c, &shift, &mask))
>> +
>> +  int shift;
>> +  HOST_WIDE_INT mask;
>> +  if (can_be_built_by_li_lis_and_rotldi (c, &shift, &mask)
>> +      || can_be_built_by_li_lis_and_rldicl (c, &shift, &mask)
>> +      || can_be_built_by_li_lis_and_rldicr (c, &shift, &mask)
>> +      || can_be_built_by_li_and_rldic (c, &shift, &mask))
>>      {
>> -      temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
>> +      /* li/lis; rldicX */
>>        unsigned HOST_WIDE_INT imm = (c | ~mask);
>>        imm = (imm >> shift) | (imm << (HOST_BITS_PER_WIDE_INT - shift));
>>  
>> -      emit_move_insn (temp, GEN_INT (imm));
>> +      count_or_emit_insn (temp, GEN_INT (imm));
>>        if (shift != 0)
>>  	temp = gen_rtx_ROTATE (DImode, temp, GEN_INT (shift));
>>        if (mask != HOST_WIDE_INT_M1)
>>  	temp = gen_rtx_AND (DImode, temp, GEN_INT (mask));
>> -      emit_move_insn (dest, temp);
>> -    }
>> -  else if (ud3 == 0 && ud4 == 0)
>> -    {
>> -      temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
>> +      count_or_emit_insn (dest, temp);
>>  
>> -      gcc_assert (ud2 & 0x8000);
>> +      return;
>> +    }
>>  
>> -      if (ud1 == 0)
>> -	{
>> -	  /* lis; rldicl */
>> -	  emit_move_insn (temp, GEN_INT (sext_hwi (ud2 << 16, 32)));
>> -	  emit_move_insn (dest,
>> -			  gen_rtx_AND (DImode, temp, GEN_INT (0xffffffff)));
>> -	}
>> -      else if (!(ud1 & 0x8000))
>> +  if (ud3 == 0 && ud4 == 0)
>> +    {
>> +      gcc_assert ((ud2 & 0x8000) && ud1 != 0);
>> +      if (!(ud1 & 0x8000))
>>  	{
>>  	  /* li; oris */
>> -	  emit_move_insn (temp, GEN_INT (ud1));
>> -	  emit_move_insn (dest,
>> -			  gen_rtx_IOR (DImode, temp, GEN_INT (ud2 << 16)));
>> +	  count_or_emit_insn (temp, GEN_INT (ud1));
>> +	  count_or_emit_insn (dest,
>> +			      gen_rtx_IOR (DImode, temp, GEN_INT (ud2 << 16)));
>> +	  return;
>>  	}
>> -      else
>> -	{
>> -	  /* lis; ori; rldicl */
>> -	  emit_move_insn (temp, GEN_INT (sext_hwi (ud2 << 16, 32)));
>> -	  emit_move_insn (temp, gen_rtx_IOR (DImode, temp, GEN_INT (ud1)));
>> -	  emit_move_insn (dest,
>> +
>> +      /* lis; ori; rldicl */
>> +      count_or_emit_insn (temp, GEN_INT (sext_hwi (ud2 << 16, 32)));
>> +      count_or_emit_insn (temp, gen_rtx_IOR (DImode, temp, GEN_INT (ud1)));
>> +      count_or_emit_insn (dest,
>>  			  gen_rtx_AND (DImode, temp, GEN_INT (0xffffffff)));
>> -	}
>> +      return;
>>      }
>> -  else if (ud1 == ud3 && ud2 == ud4)
>> +
>> +  if (ud1 == ud3 && ud2 == ud4)
>>      {
>> -      temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
>> +      /* load low 32bits first, e.g. "lis; ori", then "rldimi".  */
>>        HOST_WIDE_INT num = (ud2 << 16) | ud1;
>> -      rs6000_emit_set_long_const (temp, sext_hwi (num, 32));
>> -      rtx one = gen_rtx_AND (DImode, temp, GEN_INT (0xffffffff));
>> -      rtx two = gen_rtx_ASHIFT (DImode, temp, GEN_INT (32));
>> -      emit_move_insn (dest, gen_rtx_IOR (DImode, one, two));
>> +      rs6000_emit_set_long_const (temp, sext_hwi (num, 32), num_insns);
>> +
>> +      rtx rldimi = gen_rotldi3_insert_3 (dest, temp, GEN_INT (32), temp,
>> +					 GEN_INT (0xffffffff));
>> +      count_or_emit_insn (rldimi);
>> +      return;
>>      }
>> -  else if ((ud4 == 0xffff && (ud3 & 0x8000))
>> -	   || (ud4 == 0 && ! (ud3 & 0x8000)))
>> -    {
>> -      temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
>>  
>> -      emit_move_insn (temp, GEN_INT (sext_hwi (ud3 << 16, 32)));
>> +  if ((ud4 == 0xffff && (ud3 & 0x8000)) || (ud4 == 0 && !(ud3 & 0x8000)))
>> +    {
>> +      /* li; [ori;] rldicl [;oir].  */
>> +      count_or_emit_insn (temp, GEN_INT (sext_hwi (ud3 << 16, 32)));
>>        if (ud2 != 0)
>> -	emit_move_insn (temp, gen_rtx_IOR (DImode, temp, GEN_INT (ud2)));
>> -      emit_move_insn (ud1 != 0 ? temp : dest,
>> -		      gen_rtx_ASHIFT (DImode, temp, GEN_INT (16)));
>> +	count_or_emit_insn (temp, gen_rtx_IOR (DImode, temp, GEN_INT (ud2)));
>> +      count_or_emit_insn (ud1 != 0 ? temp : dest,
>> +			  gen_rtx_ASHIFT (DImode, temp, GEN_INT (16)));
>>        if (ud1 != 0)
>> -	emit_move_insn (dest, gen_rtx_IOR (DImode, temp, GEN_INT (ud1)));
>> +	count_or_emit_insn (dest, gen_rtx_IOR (DImode, temp, GEN_INT (ud1)));
>> +      return;
>>      }
>> -  else if (TARGET_PREFIXED)
>> +
>> +  if (TARGET_PREFIXED)
>>      {
>>        if (can_create_pseudo_p ())
>>  	{
>> -	  /* pli A,L + pli B,H + rldimi A,B,32,0.  */
>> -	  temp = gen_reg_rtx (DImode);
>> -	  rtx temp1 = gen_reg_rtx (DImode);
>> -	  emit_move_insn (temp, GEN_INT ((ud4 << 16) | ud3));
>> -	  emit_move_insn (temp1, GEN_INT ((ud2 << 16) | ud1));
>> -
>> -	  emit_insn (gen_rotldi3_insert_3 (dest, temp, GEN_INT (32), temp1,
>> -					   GEN_INT (0xffffffff)));
>> +	  /* pli A,L; pli B,H; rldimi A,B,32,0.  */
>> +	  rtx temp1 = num_insns ? nullptr : gen_reg_rtx (DImode);
>> +	  count_or_emit_insn (temp, GEN_INT ((ud4 << 16) | ud3));
>> +	  count_or_emit_insn (temp1, GEN_INT ((ud2 << 16) | ud1));
>> +	  rtx rldimi = gen_rotldi3_insert_3 (dest, temp, GEN_INT (32), temp1,
>> +					     GEN_INT (0xffffffff));
>> +	  count_or_emit_insn (rldimi);
>> +	  return;
>>  	}
>> -      else
>> -	{
>> -	  /* pli A,H + sldi A,32 + paddi A,A,L.  */
>> -	  emit_move_insn (dest, GEN_INT ((ud4 << 16) | ud3));
>> -
>> -	  emit_move_insn (dest, gen_rtx_ASHIFT (DImode, dest, GEN_INT (32)));
>>  
>> -	  bool can_use_paddi = REGNO (dest) != FIRST_GPR_REGNO;
>> +      /* pli A,H; sldi A,32; paddi A,A,L.  */
>> +      count_or_emit_insn (dest, GEN_INT ((ud4 << 16) | ud3));
>> +      count_or_emit_insn (dest, gen_rtx_ASHIFT (DImode, dest, GEN_INT (32)));
>>  
>> -	  /* Use paddi for the low 32 bits.  */
>> -	  if (ud2 != 0 && ud1 != 0 && can_use_paddi)
>> -	    emit_move_insn (dest, gen_rtx_PLUS (DImode, dest,
>> +      bool can_use_paddi = dest ? REGNO (dest) != FIRST_GPR_REGNO : false;
>> +      /* Use paddi for the low 32 bits.  */
>> +      if (ud2 != 0 && ud1 != 0 && can_use_paddi)
>> +	count_or_emit_insn (dest, gen_rtx_PLUS (DImode, dest,
>>  						GEN_INT ((ud2 << 16) | ud1)));
>> -
>> -	  /* Use oris, ori for low 32 bits.  */
>> -	  if (ud2 != 0 && (ud1 == 0 || !can_use_paddi))
>> -	    emit_move_insn (dest,
>> +      /* Use oris, ori for low 32 bits.  */
>> +      if (ud2 != 0 && (ud1 == 0 || !can_use_paddi))
>> +	count_or_emit_insn (dest,
>>  			    gen_rtx_IOR (DImode, dest, GEN_INT (ud2 << 16)));
>> -	  if (ud1 != 0 && (ud2 == 0 || !can_use_paddi))
>> -	    emit_move_insn (dest, gen_rtx_IOR (DImode, dest, GEN_INT (ud1)));
>> -	}
>> +      if (ud1 != 0 && (ud2 == 0 || !can_use_paddi))
>> +	count_or_emit_insn (dest, gen_rtx_IOR (DImode, dest, GEN_INT (ud1)));
>> +      return;
>>      }
>> -  else
>> +
>> +  if (can_create_pseudo_p ())
>>      {
>> -      if (can_create_pseudo_p ())
>> -	{
>> -	  /* lis HIGH,UD4 ; ori HIGH,UD3 ;
>> -	     lis LOW,UD2 ; ori LOW,UD1 ; rldimi LOW,HIGH,32,0.  */
>> -	  rtx high = gen_reg_rtx (DImode);
>> -	  rtx low = gen_reg_rtx (DImode);
>> -	  HOST_WIDE_INT num = (ud2 << 16) | ud1;
>> -	  rs6000_emit_set_long_const (low, sext_hwi (num, 32));
>> -	  num = (ud4 << 16) | ud3;
>> -	  rs6000_emit_set_long_const (high, sext_hwi (num, 32));
>> -	  emit_insn (gen_rotldi3_insert_3 (dest, high, GEN_INT (32), low,
>> -					   GEN_INT (0xffffffff)));
>> -	}
>> -      else
>> -	{
>> -	  /* lis DEST,UD4 ; ori DEST,UD3 ; rotl DEST,32 ;
>> -	     oris DEST,UD2 ; ori DEST,UD1.  */
>> -	  emit_move_insn (dest, GEN_INT (sext_hwi (ud4 << 16, 32)));
>> -	  if (ud3 != 0)
>> -	    emit_move_insn (dest, gen_rtx_IOR (DImode, dest, GEN_INT (ud3)));
>> +      /* lis HIGH,UD4 ; ori HIGH,UD3 ;
>> +	 lis LOW,UD2 ; ori LOW,UD1 ; rldimi LOW,HIGH,32,0.  */
>> +      rtx high = num_insns ? nullptr : gen_reg_rtx (DImode);
>> +      rtx low = num_insns ? nullptr : gen_reg_rtx (DImode);
>> +      HOST_WIDE_INT num = (ud2 << 16) | ud1;
>> +      rs6000_emit_set_long_const (low, sext_hwi (num, 32), num_insns);
>> +      num = (ud4 << 16) | ud3;
>> +      rs6000_emit_set_long_const (high, sext_hwi (num, 32), num_insns);
>>  
>> -	  emit_move_insn (dest, gen_rtx_ASHIFT (DImode, dest, GEN_INT (32)));
>> -	  if (ud2 != 0)
>> -	    emit_move_insn (dest,
>> -			    gen_rtx_IOR (DImode, dest, GEN_INT (ud2 << 16)));
>> -	  if (ud1 != 0)
>> -	    emit_move_insn (dest, gen_rtx_IOR (DImode, dest, GEN_INT (ud1)));
>> -	}
>> +      rtx rldimi = gen_rotldi3_insert_3 (dest, high, GEN_INT (32), low,
>> +					 GEN_INT (0xffffffff));
>> +      count_or_emit_insn (rldimi);
>> +      return;
>>      }
>> +
>> +  /* lis DEST,UD4 ; ori DEST,UD3 ; rotl DEST,32 ;
>> +     oris DEST,UD2 ; ori DEST,UD1.  */
>> +  count_or_emit_insn (dest, GEN_INT (sext_hwi (ud4 << 16, 32)));
>> +  if (ud3 != 0)
>> +    count_or_emit_insn (dest, gen_rtx_IOR (DImode, dest, GEN_INT (ud3)));
>> +
>> +  count_or_emit_insn (dest, gen_rtx_ASHIFT (DImode, dest, GEN_INT (32)));
>> +  if (ud2 != 0)
>> +    count_or_emit_insn (dest, gen_rtx_IOR (DImode, dest, GEN_INT (ud2 << 16)));
>> +  if (ud1 != 0)
>> +    count_or_emit_insn (dest, gen_rtx_IOR (DImode, dest, GEN_INT (ud1)));
>> +
>> +  return;
>>  }
>>  
>>  /* Helper for the following.  Get rid of [r+r] memory refs