Hi,
On 05/18/2011 11:20 PM, Zdenek Dvorak wrote:
>> + sa_cost = (TREE_CODE (expr) != MINUS_EXPR
>> + ? shiftadd_cost[speed][mode][m]
>> + : (mult == op1
>> + ? shiftsub1_cost[speed][mode][m]
>> + : shiftsub0_cost[speed][mode][m]));
>> + res = new_cost (sa_cost, 0);
>> + res = add_costs (res, mult == op1 ? cost0 : cost1);
>
> just forgetting the cost of the other operand does not seem correct -- what
> if it contains some more complicated subexpression?
>
True. I now added the cost of TREE_OPERAND (mult, 0).
Thanks,
- Tom
2011-05-05 Tom de Vries <t...@codesourcery.com>
PR target/45098
* tree-ssa-loop-ivopts.c: Include expmed.h.
(get_shiftadd_cost): New function.
(force_expr_to_var_cost): Declare forward. Use get_shiftadd_cost.
Index: gcc/tree-ssa-loop-ivopts.c
===================================================================
--- gcc/tree-ssa-loop-ivopts.c (revision 173380)
+++ gcc/tree-ssa-loop-ivopts.c (working copy)
@@ -92,6 +92,12 @@ along with GCC; see the file COPYING3.
#include "tree-inline.h"
#include "tree-ssa-propagate.h"
+/* FIXME: add_cost and zero_cost defined in exprmed.h conflict with local uses.
+ */
+#include "expmed.h"
+#undef add_cost
+#undef zero_cost
+
/* FIXME: Expressions are expanded to RTL in this pass to determine the
cost of different addressing modes. This should be moved to a TBD
interface between the GIMPLE and RTL worlds. */
@@ -377,6 +383,8 @@ struct iv_ca_delta
static VEC(tree,heap) *decl_rtl_to_reset;
+static comp_cost force_expr_to_var_cost (tree, bool);
+
/* Number of uses recorded in DATA. */
static inline unsigned
@@ -3504,6 +3512,42 @@ get_address_cost (bool symbol_present, b
return new_cost (cost + acost, complexity);
}
+ /* Calculate the SPEED or size cost of shiftadd EXPR in MODE. MULT is the
+ the EXPR operand holding the shift. COST0 and COST1 are the costs for
+ calculating the operands of EXPR. Returns true if successful, and returns
+ the cost in COST. */
+
+static bool
+get_shiftadd_cost (tree expr, enum machine_mode mode, comp_cost cost0,
+ comp_cost cost1, tree mult, bool speed, comp_cost *cost)
+{
+ comp_cost res;
+ tree op1 = TREE_OPERAND (expr, 1);
+ tree cst = TREE_OPERAND (mult, 1);
+ tree multop = TREE_OPERAND (mult, 0);
+ int m = exact_log2 (int_cst_value (cst));
+ int maxm = MIN (BITS_PER_WORD, GET_MODE_BITSIZE (mode));
+ int sa_cost;
+
+ if (!(m >= 0 && m < maxm))
+ return false;
+
+ sa_cost = (TREE_CODE (expr) != MINUS_EXPR
+ ? shiftadd_cost[speed][mode][m]
+ : (mult == op1
+ ? shiftsub1_cost[speed][mode][m]
+ : shiftsub0_cost[speed][mode][m]));
+ res = new_cost (sa_cost, 0);
+ res = add_costs (res, mult == op1 ? cost0 : cost1);
+
+ STRIP_NOPS (multop);
+ if (!is_gimple_val (multop))
+ res = add_costs (res, force_expr_to_var_cost (multop, speed));
+
+ *cost = res;
+ return true;
+}
+
/* Estimates cost of forcing expression EXPR into a variable. */
static comp_cost
@@ -3629,6 +3673,21 @@ force_expr_to_var_cost (tree expr, bool
case MINUS_EXPR:
case NEGATE_EXPR:
cost = new_cost (add_cost (mode, speed), 0);
+ if (TREE_CODE (expr) != NEGATE_EXPR)
+ {
+ tree mult = NULL_TREE;
+ comp_cost sa_cost;
+ if (TREE_CODE (op1) == MULT_EXPR)
+ mult = op1;
+ else if (TREE_CODE (op0) == MULT_EXPR)
+ mult = op0;
+
+ if (mult != NULL_TREE
+ && TREE_CODE (TREE_OPERAND (mult, 1)) == INTEGER_CST
+ && get_shiftadd_cost (expr, mode, cost0, cost1, mult, speed,
+ &sa_cost))
+ return sa_cost;
+ }
break;
case MULT_EXPR:
