value-relation: Small tweaks to tables

  Hi!

As I said earlier, all these tables are used solely in value-relation.cc
and never modified, plus because VREL_LAST is small especially the
two-dimensional arrays are vast a lot of .data (or .rodata) space
- 576 bytes each.  The following patch makes those arrays static const
and uses unsigned char instead of relation_kind so that the
two-dimensional arrays shrink to 144 bytes.

Build-tested, ok for trunk if it passes bootstrap/regtest?

2023-01-26  Jakub Jelinek  <jakub@redhat.com>

	* value-relation.cc (kind_string): Add const.
	(rr_negate_table, rr_swap_table, rr_intersect_table,
	rr_union_table, rr_transitive_table): Add static const, change
	element type from relation_kind to unsigned char.
	(relation_negate, relation_swap, relation_intersect, relation_union,
	relation_transitive): Cast rr_*_table element to relation_kind.
	(relation_to_code): Add static const.
	(relation_tests): Assert VREL_LAST is smaller than UCHAR_MAX.


	Jakub
  

On Thu, 26 Jan 2023, Jakub Jelinek wrote:

> Hi!
> 
> As I said earlier, all these tables are used solely in value-relation.cc
> and never modified, plus because VREL_LAST is small especially the
> two-dimensional arrays are vast a lot of .data (or .rodata) space
> - 576 bytes each.  The following patch makes those arrays static const
> and uses unsigned char instead of relation_kind so that the
> two-dimensional arrays shrink to 144 bytes.
> 
> Build-tested, ok for trunk if it passes bootstrap/regtest?

OK.

Richard.

> 2023-01-26  Jakub Jelinek  <jakub@redhat.com>
> 
> 	* value-relation.cc (kind_string): Add const.
> 	(rr_negate_table, rr_swap_table, rr_intersect_table,
> 	rr_union_table, rr_transitive_table): Add static const, change
> 	element type from relation_kind to unsigned char.
> 	(relation_negate, relation_swap, relation_intersect, relation_union,
> 	relation_transitive): Cast rr_*_table element to relation_kind.
> 	(relation_to_code): Add static const.
> 	(relation_tests): Assert VREL_LAST is smaller than UCHAR_MAX.
> 
> --- gcc/value-relation.cc.jj	2023-01-19 23:26:31.887212157 +0100
> +++ gcc/value-relation.cc	2023-01-26 11:12:42.798750916 +0100
> @@ -32,7 +32,7 @@ along with GCC; see the file COPYING3.
>  #include "alloc-pool.h"
>  #include "dominance.h"
>  
> -static const char *kind_string[VREL_LAST] =
> +static const char *const kind_string[VREL_LAST] =
>  { "varying", "undefined", "<", "<=", ">", ">=", "==", "!=", "pe8", "pe16",
>    "pe32", "pe64" };
>  
> @@ -45,7 +45,7 @@ print_relation (FILE *f, relation_kind r
>  }
>  
>  // This table is used to negate the operands.  op1 REL op2 -> !(op1 REL op2).
> -relation_kind rr_negate_table[VREL_LAST] = {
> +static const unsigned char rr_negate_table[VREL_LAST] = {
>    VREL_VARYING, VREL_UNDEFINED, VREL_GE, VREL_GT, VREL_LE, VREL_LT, VREL_NE,
>    VREL_EQ };
>  
> @@ -54,11 +54,11 @@ relation_kind rr_negate_table[VREL_LAST]
>  relation_kind
>  relation_negate (relation_kind r)
>  {
> -  return rr_negate_table [r];
> +  return relation_kind (rr_negate_table [r]);
>  }
>  
>  // This table is used to swap the operands.  op1 REL op2 -> op2 REL op1.
> -relation_kind rr_swap_table[VREL_LAST] = {
> +static const unsigned char rr_swap_table[VREL_LAST] = {
>    VREL_VARYING, VREL_UNDEFINED, VREL_GT, VREL_GE, VREL_LT, VREL_LE, VREL_EQ,
>    VREL_NE };
>  
> @@ -67,12 +67,12 @@ relation_kind rr_swap_table[VREL_LAST] =
>  relation_kind
>  relation_swap (relation_kind r)
>  {
> -  return rr_swap_table [r];
> +  return relation_kind (rr_swap_table [r]);
>  }
>  
>  // This table is used to perform an intersection between 2 relations.
>  
> -relation_kind rr_intersect_table[VREL_LAST][VREL_LAST] = {
> +static const unsigned char rr_intersect_table[VREL_LAST][VREL_LAST] = {
>  // VREL_VARYING
>    { VREL_VARYING, VREL_UNDEFINED, VREL_LT, VREL_LE, VREL_GT, VREL_GE, VREL_EQ,
>      VREL_NE },
> @@ -104,13 +104,13 @@ relation_kind rr_intersect_table[VREL_LA
>  relation_kind
>  relation_intersect (relation_kind r1, relation_kind r2)
>  {
> -  return rr_intersect_table[r1][r2];
> +  return relation_kind (rr_intersect_table[r1][r2]);
>  }
>  
>  
>  // This table is used to perform a union between 2 relations.
>  
> -relation_kind rr_union_table[VREL_LAST][VREL_LAST] = {
> +static const unsigned char rr_union_table[VREL_LAST][VREL_LAST] = {
>  // VREL_VARYING
>    { VREL_VARYING, VREL_VARYING, VREL_VARYING, VREL_VARYING, VREL_VARYING,
>      VREL_VARYING, VREL_VARYING, VREL_VARYING },
> @@ -141,14 +141,14 @@ relation_kind rr_union_table[VREL_LAST][
>  relation_kind
>  relation_union (relation_kind r1, relation_kind r2)
>  {
> -  return rr_union_table[r1][r2];
> +  return relation_kind (rr_union_table[r1][r2]);
>  }
>  
>  
>  // This table is used to determine transitivity between 2 relations.
>  // (A relation0 B) and (B relation1 C) implies  (A result C)
>  
> -relation_kind rr_transitive_table[VREL_LAST][VREL_LAST] = {
> +static const unsigned char rr_transitive_table[VREL_LAST][VREL_LAST] = {
>  // VREL_VARYING
>    { VREL_VARYING, VREL_VARYING, VREL_VARYING, VREL_VARYING, VREL_VARYING,
>      VREL_VARYING, VREL_VARYING, VREL_VARYING },
> @@ -180,12 +180,12 @@ relation_kind rr_transitive_table[VREL_L
>  relation_kind
>  relation_transitive (relation_kind r1, relation_kind r2)
>  {
> -  return rr_transitive_table[r1][r2];
> +  return relation_kind (rr_transitive_table[r1][r2]);
>  }
>  
>  // This vector maps a relation to the equivalent tree code.
>  
> -tree_code relation_to_code [VREL_LAST] = {
> +static const tree_code relation_to_code [VREL_LAST] = {
>    ERROR_MARK, ERROR_MARK, LT_EXPR, LE_EXPR, GT_EXPR, GE_EXPR, EQ_EXPR,
>    NE_EXPR };
>  
> @@ -1727,6 +1727,8 @@ namespace selftest
>  void
>  relation_tests ()
>  {
> +  // rr_*_table tables use unsigned char rather than relation_kind.
> +  ASSERT_LT (VREL_LAST, UCHAR_MAX);
>    // Verify commutativity of relation_intersect and relation_union.
>    for (relation_kind r1 = VREL_VARYING; r1 < VREL_PE8;
>         r1 = relation_kind (r1 + 1))
> 
> 	Jakub
> 
>