Include limits.h for LONG_{MAX,MIN}.

[libfirm] / ir / ir / irarch.c

diff --git a/ir/ir/irarch.c b/ir/ir/irarch.c
index 2e07af6..5f9fdfe 100644 (file)
--- a/ir/ir/irarch.c
+++ b/ir/ir/irarch.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 1995-2007 University of Karlsruhe.  All right reserved.
+ * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
  *
  * This file is part of libFirm.
  *
@@ -229,8 +229,8 @@ static unsigned char *value_to_condensed(mul_env *env, tarval *tv, int *pr) {
  * Calculate the gain when using the generalized complementary technique
  */
 static int calculate_gain(unsigned char *R, int r) {
-       int max_gain = -1;
-       int idx = 0, i;
+       int max_gain = 0;
+       int idx = -1, i;
        int gain;
 
        /* the gain for r == 1 */
@@ -244,9 +244,7 @@ static int calculate_gain(unsigned char *R, int r) {
                        idx = i;
                }
        }
-       if (max_gain > 0)
-               return idx;
-       return -1;
+       return idx;
 }
 
 /**
@@ -518,7 +516,7 @@ static int evaluate_insn(mul_env *env, instruction *inst) {
 /**
  * Evaluate the replacement instructions and build a new graph
  * if faster than the Mul.
- * returns the root of the new graph then or irn otherwise.
+ * Returns the root of the new graph then or irn otherwise.
  *
  * @param irn      the Mul operation
  * @param operand  the multiplication operand
@@ -547,7 +545,7 @@ static ir_node *do_decomposition(ir_node *irn, ir_node *operand, tarval *tv) {
        inst = decompose_mul(&env, R, r, tv);
 
        /* the paper suggests 70% here */
-       mul_costs = (env.evaluate(MUL, tv) * 7) / 10;
+       mul_costs = (env.evaluate(MUL, tv) * 7 + 5) / 10;
        if (evaluate_insn(&env, inst) <= mul_costs && !env.fail) {
                env.op       = operand;
                env.blk      = get_nodes_block(irn);
@@ -853,7 +851,7 @@ static ir_node *replace_div_by_mulh(ir_node *div, tarval *tv) {
 
                /* generate the Mulh instruction */
                c = new_r_Const(current_ir_graph, block, mode, mag.M);
-               q    = new_rd_Mulh(dbg, current_ir_graph, block, n, c, mode);
+               q = new_rd_Mulh(dbg, current_ir_graph, block, n, c, mode);
 
                if (mag.need_add) {
                        if (mag.s > 0) {
@@ -888,7 +886,7 @@ ir_node *arch_dep_replace_div_by_const(ir_node *irn) {
        if (params == NULL || (opts & arch_dep_div_by_const) == 0)
                return irn;
 
-       if (get_irn_opcode(irn) == iro_Div) {
+       if (is_Div(irn)) {
                ir_node *c = get_Div_right(irn);
                ir_node *block, *left;
                ir_mode *mode;
@@ -897,7 +895,7 @@ ir_node *arch_dep_replace_div_by_const(ir_node *irn) {
                int n, bits;
                int k, n_flag;
 
-               if (get_irn_op(c) != op_Const)
+               if (! is_Const(c))
                        return irn;
 
                tv = get_Const_tarval(c);
@@ -932,15 +930,20 @@ ir_node *arch_dep_replace_div_by_const(ir_node *irn) {
                                ir_node *k_node;
                                ir_node *curr = left;
 
-                               if (k != 1) {
-                                       k_node = new_r_Const_long(current_ir_graph, block, mode_Iu, k - 1);
-                                       curr   = new_rd_Shrs(dbg, current_ir_graph, block, left, k_node, mode);
-                               }
+                               /* create the correction code for signed values only if there might be a remainder */
+                               if (! is_Div_remainderless(irn)) {
+                                       if (k != 1) {
+                                               k_node = new_r_Const_long(current_ir_graph, block, mode_Iu, k - 1);
+                                               curr   = new_rd_Shrs(dbg, current_ir_graph, block, left, k_node, mode);
+                                       }
 
-                               k_node = new_r_Const_long(current_ir_graph, block, mode_Iu, bits - k);
-                               curr   = new_rd_Shr(dbg, current_ir_graph, block, curr, k_node, mode);
+                                       k_node = new_r_Const_long(current_ir_graph, block, mode_Iu, bits - k);
+                                       curr   = new_rd_Shr(dbg, current_ir_graph, block, curr, k_node, mode);
 
-                               curr   = new_rd_Add(dbg, current_ir_graph, block, left, curr, mode);
+                                       curr   = new_rd_Add(dbg, current_ir_graph, block, left, curr, mode);
+                               } else {
+                                       k_node = left;
+                               }
 
                                k_node = new_r_Const_long(current_ir_graph, block, mode_Iu, k);
                                res    = new_rd_Shrs(dbg, current_ir_graph, block, curr, k_node, mode);
@@ -979,7 +982,7 @@ ir_node *arch_dep_replace_mod_by_const(ir_node *irn) {
        if (params == NULL || (opts & arch_dep_mod_by_const) == 0)
                return irn;
 
-       if (get_irn_opcode(irn) == iro_Mod) {
+       if (is_Mod(irn)) {
                ir_node *c = get_Mod_right(irn);
                ir_node *block, *left;
                ir_mode *mode;
@@ -988,7 +991,7 @@ ir_node *arch_dep_replace_mod_by_const(ir_node *irn) {
                int n, bits;
                int k;
 
-               if (get_irn_op(c) != op_Const)
+               if (! is_Const(c))
                        return irn;
 
                tv = get_Const_tarval(c);
@@ -1073,7 +1076,7 @@ void arch_dep_replace_divmod_by_const(ir_node **div, ir_node **mod, ir_node *irn
                ((opts & (arch_dep_div_by_const|arch_dep_mod_by_const)) != (arch_dep_div_by_const|arch_dep_mod_by_const)))
                return;
 
-       if (get_irn_opcode(irn) == iro_DivMod) {
+       if (is_DivMod(irn)) {
                ir_node *c = get_DivMod_right(irn);
                ir_node *block, *left;
                ir_mode *mode;
@@ -1082,7 +1085,7 @@ void arch_dep_replace_divmod_by_const(ir_node **div, ir_node **mod, ir_node *irn
                int n, bits;
                int k, n_flag;
 
-               if (get_irn_op(c) != op_Const)
+               if (! is_Const(c))
                        return;
 
                tv = get_Const_tarval(c);