#include "case-cfn-macros.h"
static unsigned int tree_ssa_phiopt_worker (bool, bool, bool);
+static bool two_value_replacement (basic_block, basic_block, edge, gphi *,
+ tree, tree);
static bool conditional_replacement (basic_block, basic_block,
edge, edge, gphi *, tree, tree);
static gphi *factor_out_conditional_conversion (edge, edge, gphi *, tree, tree,
}
/* Do the replacement of conditional if it can be done. */
- if (!early_p
- && conditional_replacement (bb, bb1, e1, e2, phi, arg0, arg1))
+ if (two_value_replacement (bb, bb1, e2, phi, arg0, arg1))
+ cfgchanged = true;
+ else if (!early_p
+ && conditional_replacement (bb, bb1, e1, e2, phi,
+ arg0, arg1))
cfgchanged = true;
else if (abs_replacement (bb, bb1, e1, e2, phi, arg0, arg1))
cfgchanged = true;
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 (arg1)))
+ return false;
+
+ if (!empty_block_p (middle_bb))
+ return false;
+
+ gimple *stmt = last_stmt (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 (TREE_TYPE (lhs)) == BOOLEAN_TYPE
+ || TREE_CODE (rhs) != INTEGER_CST)
+ return false;
+
+ switch (gimple_cond_code (stmt))
+ {
+ case EQ_EXPR:
+ case NE_EXPR:
+ break;
+ default:
+ return false;
+ }
+
+ wide_int min, max;
+ if (get_range_info (lhs, &min, &max) != VR_RANGE
+ || 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_stmt_iterator gsi = gsi_for_stmt (stmt);
+ if (!useless_type_conversion_p (type, TREE_TYPE (lhs)))
+ lhs = gimplify_build1 (&gsi, NOP_EXPR, type, lhs);
+ tree new_rhs;
+ if (code == PLUS_EXPR)
+ new_rhs = gimplify_build2 (&gsi, PLUS_EXPR, type, lhs, arg);
+ else
+ new_rhs = gimplify_build2 (&gsi, MINUS_EXPR, type, arg, lhs);
+ if (!useless_type_conversion_p (TREE_TYPE (arg0), type))
+ new_rhs = gimplify_build1 (&gsi, NOP_EXPR, TREE_TYPE (arg0), new_rhs);
+
+ replace_phi_edge_with_variable (cond_bb, e1, phi, new_rhs);
+
+ /* Note that we optimized this PHI. */
+ return true;
+}
+
/* The function conditional_replacement does the main work of doing the
conditional replacement. Return true if the replacement is done.
Otherwise return false.
projects / platform / upstream / gcc.git / commitdiff