tree-switch-conversion: Bugfixes for _BitInt [PR113491]

  Hi!

The following patch fixes various issues with large/huge _BitInt used as switch
expressions.
In particular:
1) the indexes in CONSTRUCTORs shouldn't be types with precision larger than
   sizetype precision, varasm uses wi::to_offset on those and too large
   indexes ICE; we've already checked earlier that the cluster is at most
   sizetype bits and arrays can't be larger than that anyway
2) some spots were using SCALAR_INT_TYPE_MODE or
   lang_hooks.types.type_for_mode on TYPE_MODE to determine types to use,
   that obviously doesn't work for the large/huge BITINT_TYPE
3) like the recent change in the C FE, this patch makes sure we don't create
   ARRAY_REFs with indexes with precision above sizetype precision, because
   bitint lowering isn't prepared for that and because the indexes can't be
   larger than sizetype anyway; the subtraction of the cluster minimum from
   the index obviously needs to be done in unsigned __int128 or large/huge
   BITINT_TYPE, but then we cast to sizetype if the precision is larger than
   sizetype

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2024-01-20  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/113491
	* tree-switch-conversion.cc (switch_conversion::build_constructors):
	If elt.index has precision higher than sizetype, fold_convert it to
	sizetype.
	(switch_conversion::array_value_type): Return type if type is
	BITINT_TYPE with precision above MAX_FIXED_MODE_SIZE or with BLKmode.
	(switch_conversion::build_arrays): Use unsigned_type_for rather than
	lang_hooks.types.type_for_mode if utype is BITINT_TYPE with precision
	above MAX_FIXED_MODE_SIZE or with BLKmode.  If utype has precision
	higher than sizetype, use sizetype as tidx type and fold_convert the
	subtraction to sizetype.

	* gcc.dg/torture/bitint-51.c: New test.


	Jakub
  

> Am 20.01.2024 um 10:36 schrieb Jakub Jelinek <jakub@redhat.com>:
> 
> Hi!
> 
> The following patch fixes various issues with large/huge _BitInt used as switch
> expressions.
> In particular:
> 1) the indexes in CONSTRUCTORs shouldn't be types with precision larger than
>   sizetype precision, varasm uses wi::to_offset on those and too large
>   indexes ICE; we've already checked earlier that the cluster is at most
>   sizetype bits and arrays can't be larger than that anyway
> 2) some spots were using SCALAR_INT_TYPE_MODE or
>   lang_hooks.types.type_for_mode on TYPE_MODE to determine types to use,
>   that obviously doesn't work for the large/huge BITINT_TYPE
> 3) like the recent change in the C FE, this patch makes sure we don't create
>   ARRAY_REFs with indexes with precision above sizetype precision, because
>   bitint lowering isn't prepared for that and because the indexes can't be
>   larger than sizetype anyway; the subtraction of the cluster minimum from
>   the index obviously needs to be done in unsigned __int128 or large/huge
>   BITINT_TYPE, but then we cast to sizetype if the precision is larger than
>   sizetype
> 
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

Ok

Richard 

> 2024-01-20  Jakub Jelinek  <jakub@redhat.com>
> 
>    PR tree-optimization/113491
>    * tree-switch-conversion.cc (switch_conversion::build_constructors):
>    If elt.index has precision higher than sizetype, fold_convert it to
>    sizetype.
>    (switch_conversion::array_value_type): Return type if type is
>    BITINT_TYPE with precision above MAX_FIXED_MODE_SIZE or with BLKmode.
>    (switch_conversion::build_arrays): Use unsigned_type_for rather than
>    lang_hooks.types.type_for_mode if utype is BITINT_TYPE with precision
>    above MAX_FIXED_MODE_SIZE or with BLKmode.  If utype has precision
>    higher than sizetype, use sizetype as tidx type and fold_convert the
>    subtraction to sizetype.
> 
>    * gcc.dg/torture/bitint-51.c: New test.
> 
> --- gcc/tree-switch-conversion.cc.jj    2024-01-03 11:51:24.210832797 +0100
> +++ gcc/tree-switch-conversion.cc    2024-01-19 18:13:12.928850888 +0100
> @@ -423,6 +423,9 @@ switch_conversion::build_constructors ()
>          constructor_elt elt;
> 
>          elt.index = int_const_binop (MINUS_EXPR, pos, m_range_min);
> +          if (TYPE_PRECISION (TREE_TYPE (elt.index))
> +          > TYPE_PRECISION (sizetype))
> +        elt.index = fold_convert (sizetype, elt.index);
>          elt.value
>        = unshare_expr_without_location (m_default_values[k]);
>          m_constructors[k]->quick_push (elt);
> @@ -452,6 +455,9 @@ switch_conversion::build_constructors ()
>          constructor_elt elt;
> 
>          elt.index = int_const_binop (MINUS_EXPR, pos, m_range_min);
> +          if (TYPE_PRECISION (TREE_TYPE (elt.index))
> +          > TYPE_PRECISION (sizetype))
> +        elt.index = fold_convert (sizetype, elt.index);
>          elt.value = unshare_expr_without_location (val);
>          m_constructors[j]->quick_push (elt);
> 
> @@ -543,7 +549,10 @@ switch_conversion::array_value_type (tre
> 
>   type = TYPE_MAIN_VARIANT (type);
> 
> -  if (!INTEGRAL_TYPE_P (type))
> +  if (!INTEGRAL_TYPE_P (type)
> +      || (TREE_CODE (type) == BITINT_TYPE
> +      && (TYPE_PRECISION (type) > MAX_FIXED_MODE_SIZE
> +          || TYPE_MODE (type) == BLKmode)))
>     return type;
> 
>   scalar_int_mode type_mode = SCALAR_INT_TYPE_MODE (type);
> @@ -707,7 +716,7 @@ void
> switch_conversion::build_arrays ()
> {
>   tree arr_index_type;
> -  tree tidx, sub, utype;
> +  tree tidx, sub, utype, tidxtype;
>   gimple *stmt;
>   gimple_stmt_iterator gsi;
>   gphi_iterator gpi;
> @@ -720,14 +729,23 @@ switch_conversion::build_arrays ()
>   utype = TREE_TYPE (m_index_expr);
>   if (TREE_TYPE (utype))
>     utype = lang_hooks.types.type_for_mode (TYPE_MODE (TREE_TYPE (utype)), 1);
> +  else if (TREE_CODE (utype) == BITINT_TYPE
> +       && (TYPE_PRECISION (utype) > MAX_FIXED_MODE_SIZE
> +           || TYPE_MODE (utype) == BLKmode))
> +    utype = unsigned_type_for (utype);
>   else
>     utype = lang_hooks.types.type_for_mode (TYPE_MODE (utype), 1);
> +  if (TYPE_PRECISION (utype) > TYPE_PRECISION (sizetype))
> +    tidxtype = sizetype;
> +  else
> +    tidxtype = utype;
> 
>   arr_index_type = build_index_type (m_range_size);
> -  tidx = make_ssa_name (utype);
> +  tidx = make_ssa_name (tidxtype);
>   sub = fold_build2_loc (loc, MINUS_EXPR, utype,
>             fold_convert_loc (loc, utype, m_index_expr),
>             fold_convert_loc (loc, utype, m_range_min));
> +  sub = fold_convert (tidxtype, sub);
>   sub = force_gimple_operand_gsi (&gsi, sub,
>                  false, NULL, true, GSI_SAME_STMT);
>   stmt = gimple_build_assign (tidx, sub);
> --- gcc/testsuite/gcc.dg/torture/bitint-51.c.jj    2024-01-19 18:21:53.013463622 +0100
> +++ gcc/testsuite/gcc.dg/torture/bitint-51.c    2024-01-19 18:21:21.793906456 +0100
> @@ -0,0 +1,88 @@
> +/* PR tree-optimization/113491 */
> +/* { dg-do run { target bitint } } */
> +/* { dg-options "-std=c23 -pedantic-errors" } */
> +/* { dg-skip-if "" { ! run_expensive_tests }  { "*" } { "-O0" "-O2" } } */
> +/* { dg-skip-if "" { ! run_expensive_tests } { "-flto" } { "" } } */
> +
> +#if __BITINT_MAXWIDTH__ >= 2022
> +long a;
> +_BitInt (2022) b;
> +
> +__attribute__((noipa)) void
> +foo (void)
> +{
> +  long e;
> +  switch (b)
> +    {
> +    case 236881099392745653949476092019254703673343952653001806909505866172387514585208299669392000424755912461093218145058550533815207769064511922933470022995816097769135032744756688849360373090388143543095880516133276503510437474354615271669000583762291950374253494970691499065905744428004707234072154531557724197892702081481886955739280363415482836575783505023297999635820743287218509451775188374692338715173350419479853664808666850654180398109587878293637547258643044750595201236843385276543354061680674360041173237330198483330996131123489419291470122643730353591015638976897743657130063384289745055875469886904587wb:
> +      e = 28;
> +      break;
> +    case 236881099392745653949476092019254703673343952653001806909505866172387514585208299669392000424755912461093218145058550533815207769064511922933470022995816097769135032744756688849360373090388143543095880516133276503510437474354615271669000583762291950374253494970691499065905744428004707234072154531557724197892702081481886955739280363415482836575783505023297999635820743287218509451775188374692338715173350419479853664808666850654180398109587878293637547258643044750595201236843385276543354061680674360041173237330198483330996131123489419291470122643730353591015638976897743657130063384289745055875469886904590wb:
> +      e = 6;
> +      break;
> +    case 236881099392745653949476092019254703673343952653001806909505866172387514585208299669392000424755912461093218145058550533815207769064511922933470022995816097769135032744756688849360373090388143543095880516133276503510437474354615271669000583762291950374253494970691499065905744428004707234072154531557724197892702081481886955739280363415482836575783505023297999635820743287218509451775188374692338715173350419479853664808666850654180398109587878293637547258643044750595201236843385276543354061680674360041173237330198483330996131123489419291470122643730353591015638976897743657130063384289745055875469886904607wb:
> +      e = 7;
> +      break;
> +    default:
> +      e = 8;
> +      break;
> +    }
> +  a = e;
> +}
> +#endif
> +
> +int
> +main ()
> +{
> +#if __BITINT_MAXWIDTH__ >= 2022
> +  b = 42wb;
> +  foo ();
> +  if (a != 8)
> +    __builtin_abort ();
> +  b = 236881099392745653949476092019254703673343952653001806909505866172387514585208299669392000424755912461093218145058550533815207769064511922933470022995816097769135032744756688849360373090388143543095880516133276503510437474354615271669000583762291950374253494970691499065905744428004707234072154531557724197892702081481886955739280363415482836575783505023297999635820743287218509451775188374692338715173350419479853664808666850654180398109587878293637547258643044750595201236843385276543354061680674360041173237330198483330996131123489419291470122643730353591015638976897743657130063384289745055875469886904586wb;
> +  foo ();
> +  if (a != 8)
> +    __builtin_abort ();
> +  b = 236881099392745653949476092019254703673343952653001806909505866172387514585208299669392000424755912461093218145058550533815207769064511922933470022995816097769135032744756688849360373090388143543095880516133276503510437474354615271669000583762291950374253494970691499065905744428004707234072154531557724197892702081481886955739280363415482836575783505023297999635820743287218509451775188374692338715173350419479853664808666850654180398109587878293637547258643044750595201236843385276543354061680674360041173237330198483330996131123489419291470122643730353591015638976897743657130063384289745055875469886904587wb;
> +  foo ();
> +  if (a != 28)
> +    __builtin_abort ();
> +  b = 236881099392745653949476092019254703673343952653001806909505866172387514585208299669392000424755912461093218145058550533815207769064511922933470022995816097769135032744756688849360373090388143543095880516133276503510437474354615271669000583762291950374253494970691499065905744428004707234072154531557724197892702081481886955739280363415482836575783505023297999635820743287218509451775188374692338715173350419479853664808666850654180398109587878293637547258643044750595201236843385276543354061680674360041173237330198483330996131123489419291470122643730353591015638976897743657130063384289745055875469886904588wb;
> +  foo ();
> +  if (a != 8)
> +    __builtin_abort ();
> +  b = 236881099392745653949476092019254703673343952653001806909505866172387514585208299669392000424755912461093218145058550533815207769064511922933470022995816097769135032744756688849360373090388143543095880516133276503510437474354615271669000583762291950374253494970691499065905744428004707234072154531557724197892702081481886955739280363415482836575783505023297999635820743287218509451775188374692338715173350419479853664808666850654180398109587878293637547258643044750595201236843385276543354061680674360041173237330198483330996131123489419291470122643730353591015638976897743657130063384289745055875469886904589wb;
> +  foo ();
> +  if (a != 8)
> +    __builtin_abort ();
> +  b = 236881099392745653949476092019254703673343952653001806909505866172387514585208299669392000424755912461093218145058550533815207769064511922933470022995816097769135032744756688849360373090388143543095880516133276503510437474354615271669000583762291950374253494970691499065905744428004707234072154531557724197892702081481886955739280363415482836575783505023297999635820743287218509451775188374692338715173350419479853664808666850654180398109587878293637547258643044750595201236843385276543354061680674360041173237330198483330996131123489419291470122643730353591015638976897743657130063384289745055875469886904590wb;
> +  foo ();
> +  if (a != 6)
> +    __builtin_abort ();
> +  b = 236881099392745653949476092019254703673343952653001806909505866172387514585208299669392000424755912461093218145058550533815207769064511922933470022995816097769135032744756688849360373090388143543095880516133276503510437474354615271669000583762291950374253494970691499065905744428004707234072154531557724197892702081481886955739280363415482836575783505023297999635820743287218509451775188374692338715173350419479853664808666850654180398109587878293637547258643044750595201236843385276543354061680674360041173237330198483330996131123489419291470122643730353591015638976897743657130063384289745055875469886904591wb;
> +  foo ();
> +  if (a != 8)
> +    __builtin_abort ();
> +  b = 236881099392745653949476092019254703673343952653001806909505866172387514585208299669392000424755912461093218145058550533815207769064511922933470022995816097769135032744756688849360373090388143543095880516133276503510437474354615271669000583762291950374253494970691499065905744428004707234072154531557724197892702081481886955739280363415482836575783505023297999635820743287218509451775188374692338715173350419479853664808666850654180398109587878293637547258643044750595201236843385276543354061680674360041173237330198483330996131123489419291470122643730353591015638976897743657130063384289745055875469886904606wb;
> +  foo ();
> +  if (a != 8)
> +    __builtin_abort ();
> +  b = 236881099392745653949476092019254703673343952653001806909505866172387514585208299669392000424755912461093218145058550533815207769064511922933470022995816097769135032744756688849360373090388143543095880516133276503510437474354615271669000583762291950374253494970691499065905744428004707234072154531557724197892702081481886955739280363415482836575783505023297999635820743287218509451775188374692338715173350419479853664808666850654180398109587878293637547258643044750595201236843385276543354061680674360041173237330198483330996131123489419291470122643730353591015638976897743657130063384289745055875469886904607wb;
> +  foo ();
> +  if (a != 7)
> +    __builtin_abort ();
> +  b = 236881099392745653949476092019254703673343952653001806909505866172387514585208299669392000424755912461093218145058550533815207769064511922933470022995816097769135032744756688849360373090388143543095880516133276503510437474354615271669000583762291950374253494970691499065905744428004707234072154531557724197892702081481886955739280363415482836575783505023297999635820743287218509451775188374692338715173350419479853664808666850654180398109587878293637547258643044750595201236843385276543354061680674360041173237330198483330996131123489419291470122643730353591015638976897743657130063384289745055875469886904608wb;
> +  foo ();
> +  if (a != 8)
> +    __builtin_abort ();
> +  b = 240780458385579342400393461351617812815637161357071131707208942081962936661153218844512115504763375697200879163458183553026017242301187821441055479544760906104973534996069938628004474568289906582206917095065620305216254432816950650228843795794816095162791355341943390986975847866692139272448065870433527123346286515814575123941041341323886584452213168407427683905346733773730890398535581783579726464034446453496393589067919979673611753823620422962335479358086639875375670825770647896268644196740771259886611570273762180917307714137084771977480688440721015151914970095703226362506437887288273484956889253937151wb;
> +  foo ();
> +  if (a != 8)
> +    __builtin_abort ();
> +  b = -240780458385579342400393461351617812815637161357071131707208942081962936661153218844512115504763375697200879163458183553026017242301187821441055479544760906104973534996069938628004474568289906582206917095065620305216254432816950650228843795794816095162791355341943390986975847866692139272448065870433527123346286515814575123941041341323886584452213168407427683905346733773730890398535581783579726464034446453496393589067919979673611753823620422962335479358086639875375670825770647896268644196740771259886611570273762180917307714137084771977480688440721015151914970095703226362506437887288273484956889253937151wb;
> +  foo ();
> +  if (a != 8)
> +    __builtin_abort ();
> +#endif
> +  return 0;
> +}
> 
>    Jakub
>