On Fri, Apr 28, 2023 at 5:31 AM Andrew Pinski via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> This patch converts two_value_replacement function
> into a match.pd pattern.
> It is a direct translation with only one minor change,
> does not check for the {0,+-1} case as that is handled
> before in match.pd so there is no reason to do the extra
> check for it.
>
> OK? Bootstrapped and tested on x86_64-linux-gnu with
> no regressions.
OK.
Thanks,
Richard.
> gcc/ChangeLog:
>
> PR tree-optimization/100958
> * tree-ssa-phiopt.cc (two_value_replacement): Remove.
> (pass_phiopt::execute): Don't call two_value_replacement.
> * match.pd (a !=/== CST1 ? CST2 : CST3): Add pattern to
> handle what two_value_replacement did.
> ---
> gcc/match.pd | 94 ++++++++++++++++++++++++
> gcc/tree-ssa-phiopt.cc | 157 +----------------------------------------
> 2 files changed, 96 insertions(+), 155 deletions(-)
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 31fe5093218..e17597ead26 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -4632,6 +4632,100 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> )
> )
> )
> +
> +/* Optimize
> + # x_5 in range [cst1, cst2] where cst2 = cst1 + 1
> + x_5 ? cstN ? cst4 : cst3
> + # op is == or != and N is 1 or 2
> + to r_6 = x_5 + (min (cst3, cst4) - cst1) or
> + r_6 = (min (cst3, cst4) + cst1) - x_5 depending on op, N and which
> + of cst3 and cst4 is smaller.
> + This was originally done by two_value_replacement in phiopt (PR 88676).
> */
> +(for eqne (ne eq)
> + (simplify
> + (cond (eqne SSA_NAME@0 INTEGER_CST@1) INTEGER_CST@2 INTEGER_CST@3)
> + (if (INTEGRAL_TYPE_P (TREE_TYPE (@0))
> + && INTEGRAL_TYPE_P (type)
> + && (wi::to_widest (@2) + 1 == wi::to_widest (@3)
> + || wi::to_widest (@2) == wi::to_widest (@3) + 1))
> + (with {
> + value_range r;
> + get_range_query (cfun)->range_of_expr (r, @0);
> + if (r.undefined_p ())
> + r.set_varying (TREE_TYPE (@0));
> +
> + wide_int min = r.lower_bound ();
> + wide_int max = r.upper_bound ();
> + }
> + (if (min + 1 == max
> + && (wi::to_wide (@1) == min
> + || wi::to_wide (@1) == max))
> + (with {
> + tree arg0 = @2, arg1 = @3;
> + tree type1;
> + if ((eqne == EQ_EXPR) ^ (wi::to_wide (@1) == min))
> + std::swap (arg0, arg1);
> + if (TYPE_PRECISION (TREE_TYPE (@0)) == TYPE_PRECISION (type))
> + {
> + /* Avoid performing the arithmetics in bool type which has
> different
> + semantics, otherwise prefer unsigned types from the two with
> + the same precision. */
> + if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE
> + || !TYPE_UNSIGNED (type))
> + type1 = TREE_TYPE (@0);
> + else
> + type1 = TREE_TYPE (arg0);
> + }
> + else if (TYPE_PRECISION (TREE_TYPE (@0)) > TYPE_PRECISION (type))
> + type1 = TREE_TYPE (@0);
> + else
> + type1 = type;
> + min = wide_int::from (min, TYPE_PRECISION (type1),
> + TYPE_SIGN (TREE_TYPE (@0)));
> + wide_int a = wide_int::from (wi::to_wide (arg0), TYPE_PRECISION
> (type1),
> + TYPE_SIGN (type));
> + enum tree_code code;
> + wi::overflow_type ovf;
> + if (tree_int_cst_lt (arg0, arg1))
> + {
> + code = PLUS_EXPR;
> + a -= min;
> + if (!TYPE_UNSIGNED (type1))
> + {
> + /* lhs is known to be in range [min, min+1] and we want to add
> a
> + to it. Check if that operation can overflow for those 2
> values
> + and if yes, force unsigned type. */
> + wi::add (min + (wi::neg_p (a) ? 0 : 1), a, SIGNED, &ovf);
> + if (ovf)
> + type1 = unsigned_type_for (type1);
> + }
> + }
> + else
> + {
> + code = MINUS_EXPR;
> + a += min;
> + if (!TYPE_UNSIGNED (type1))
> + {
> + /* lhs is known to be in range [min, min+1] and we want to
> subtract
> + it from a. Check if that operation can overflow for those 2
> + values and if yes, force unsigned type. */
> + wi::sub (a, min + (wi::neg_p (min) ? 0 : 1), SIGNED, &ovf);
> + if (ovf)
> + type1 = unsigned_type_for (type1);
> + }
> + }
> + tree arg = wide_int_to_tree (type1, a);
> + }
> + (if (code == PLUS_EXPR)
> + (convert (plus (convert:type1 @0) { arg; }))
> + (convert (minus { arg; } (convert:type1 @0)))
> + )
> + )
> + )
> + )
> + )
> + )
> +)
> #endif
>
> (simplify
> diff --git a/gcc/tree-ssa-phiopt.cc b/gcc/tree-ssa-phiopt.cc
> index 7fc6ac17b4a..4b43f1abdbc 100644
> --- a/gcc/tree-ssa-phiopt.cc
> +++ b/gcc/tree-ssa-phiopt.cc
> @@ -373,155 +373,6 @@ factor_out_conditional_conversion (edge e0, edge e1,
> gphi *phi,
> return newphi;
> }
>
> -/* Optimize
> - # x_5 in range [cst1, cst2] where cst2 = cst1 + 1
> - if (x_5 op cstN) # where op is == or != and N is 1 or 2
> - goto bb3;
> - else
> - goto bb4;
> - bb3:
> - bb4:
> - # r_6 = PHI<cst3(2), cst4(3)> # where cst3 == cst4 + 1 or cst4 == cst3 + 1
> -
> - to r_6 = x_5 + (min (cst3, cst4) - cst1) or
> - r_6 = (min (cst3, cst4) + cst1) - x_5 depending on op, N and which
> - of cst3 and cst4 is smaller. */
> -
> -static bool
> -two_value_replacement (basic_block cond_bb, basic_block middle_bb,
> - edge e1, gphi *phi, tree arg0, tree arg1)
> -{
> - /* Only look for adjacent integer constants. */
> - if (!INTEGRAL_TYPE_P (TREE_TYPE (arg0))
> - || !INTEGRAL_TYPE_P (TREE_TYPE (arg1))
> - || TREE_CODE (arg0) != INTEGER_CST
> - || TREE_CODE (arg1) != INTEGER_CST
> - || (tree_int_cst_lt (arg0, arg1)
> - ? wi::to_widest (arg0) + 1 != wi::to_widest (arg1)
> - : wi::to_widest (arg1) + 1 != wi::to_widest (arg0)))
> - return false;
> -
> - if (!empty_block_p (middle_bb))
> - return false;
> -
> - gcond *stmt = as_a <gcond *> (*gsi_last_bb (cond_bb));
> - tree lhs = gimple_cond_lhs (stmt);
> - tree rhs = gimple_cond_rhs (stmt);
> -
> - if (TREE_CODE (lhs) != SSA_NAME
> - || !INTEGRAL_TYPE_P (TREE_TYPE (lhs))
> - || TREE_CODE (rhs) != INTEGER_CST)
> - return false;
> -
> - switch (gimple_cond_code (stmt))
> - {
> - case EQ_EXPR:
> - case NE_EXPR:
> - break;
> - default:
> - return false;
> - }
> -
> - /* Defer boolean x ? 0 : {1,-1} or x ? {1,-1} : 0 to
> - match_simplify_replacement. */
> - if (TREE_CODE (TREE_TYPE (lhs)) == BOOLEAN_TYPE
> - && (integer_zerop (arg0)
> - || integer_zerop (arg1)
> - || TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE
> - || (TYPE_PRECISION (TREE_TYPE (arg0))
> - <= TYPE_PRECISION (TREE_TYPE (lhs)))))
> - return false;
> -
> - value_range r;
> - get_range_query (cfun)->range_of_expr (r, lhs);
> - if (r.undefined_p ())
> - r.set_varying (TREE_TYPE (lhs));
> - wide_int min = r.lower_bound ();
> - wide_int max = r.upper_bound ();
> -
> - if (min + 1 != max
> - || (wi::to_wide (rhs) != min
> - && wi::to_wide (rhs) != max))
> - return false;
> -
> - /* We need to know which is the true edge and which is the false
> - edge so that we know when to invert the condition below. */
> - edge true_edge, false_edge;
> - extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge);
> - if ((gimple_cond_code (stmt) == EQ_EXPR)
> - ^ (wi::to_wide (rhs) == max)
> - ^ (e1 == false_edge))
> - std::swap (arg0, arg1);
> -
> - tree type;
> - if (TYPE_PRECISION (TREE_TYPE (lhs)) == TYPE_PRECISION (TREE_TYPE (arg0)))
> - {
> - /* Avoid performing the arithmetics in bool type which has different
> - semantics, otherwise prefer unsigned types from the two with
> - the same precision. */
> - if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE
> - || !TYPE_UNSIGNED (TREE_TYPE (arg0)))
> - type = TREE_TYPE (lhs);
> - else
> - type = TREE_TYPE (arg0);
> - }
> - else if (TYPE_PRECISION (TREE_TYPE (lhs)) > TYPE_PRECISION (TREE_TYPE
> (arg0)))
> - type = TREE_TYPE (lhs);
> - else
> - type = TREE_TYPE (arg0);
> -
> - min = wide_int::from (min, TYPE_PRECISION (type),
> - TYPE_SIGN (TREE_TYPE (lhs)));
> - wide_int a = wide_int::from (wi::to_wide (arg0), TYPE_PRECISION (type),
> - TYPE_SIGN (TREE_TYPE (arg0)));
> - enum tree_code code;
> - wi::overflow_type ovf;
> - if (tree_int_cst_lt (arg0, arg1))
> - {
> - code = PLUS_EXPR;
> - a -= min;
> - if (!TYPE_UNSIGNED (type))
> - {
> - /* lhs is known to be in range [min, min+1] and we want to add a
> - to it. Check if that operation can overflow for those 2 values
> - and if yes, force unsigned type. */
> - wi::add (min + (wi::neg_p (a) ? 0 : 1), a, SIGNED, &ovf);
> - if (ovf)
> - type = unsigned_type_for (type);
> - }
> - }
> - else
> - {
> - code = MINUS_EXPR;
> - a += min;
> - if (!TYPE_UNSIGNED (type))
> - {
> - /* lhs is known to be in range [min, min+1] and we want to subtract
> - it from a. Check if that operation can overflow for those 2
> - values and if yes, force unsigned type. */
> - wi::sub (a, min + (wi::neg_p (min) ? 0 : 1), SIGNED, &ovf);
> - if (ovf)
> - type = unsigned_type_for (type);
> - }
> - }
> -
> - tree arg = wide_int_to_tree (type, a);
> - gimple_seq stmts = NULL;
> - lhs = gimple_convert (&stmts, type, lhs);
> - tree new_rhs;
> - if (code == PLUS_EXPR)
> - new_rhs = gimple_build (&stmts, PLUS_EXPR, type, lhs, arg);
> - else
> - new_rhs = gimple_build (&stmts, MINUS_EXPR, type, arg, lhs);
> - new_rhs = gimple_convert (&stmts, TREE_TYPE (arg0), new_rhs);
> - gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
> - gsi_insert_seq_before (&gsi, stmts, GSI_SAME_STMT);
> -
> - replace_phi_edge_with_variable (cond_bb, e1, phi, new_rhs);
> -
> - /* Note that we optimized this PHI. */
> - return true;
> -}
>
> /* Return TRUE if SEQ/OP pair should be allowed during early phiopt.
> Currently this is to allow MIN/MAX and ABS/NEGATE and constants. */
> @@ -4170,12 +4021,8 @@ pass_phiopt::execute (function *)
> }
>
> /* Do the replacement of conditional if it can be done. */
> - if (!early_p
> - && !diamond_p
> - && two_value_replacement (bb, bb1, e2, phi, arg0, arg1))
> - cfgchanged = true;
> - else if (match_simplify_replacement (bb, bb1, bb2, e1, e2, phi,
> - arg0, arg1, early_p, diamond_p))
> + if (match_simplify_replacement (bb, bb1, bb2, e1, e2, phi,
> + arg0, arg1, early_p, diamond_p))
> cfgchanged = true;
> else if (!early_p
> && !diamond_p
> --
> 2.31.1
>
