Commit 2ce80083 authored by Matthias Braun's avatar Matthias Braun
Browse files

convopt: fix potential bug with modulo shifts, improve cost calculation for...

convopt: fix potential bug with modulo shifts, improve cost calculation for optimizable conv(shift) combinations
parent 35788657
......@@ -47,6 +47,7 @@
#include "irgmod.h"
#include "irgopt.h"
#include "irnode_t.h"
#include "iropt_t.h"
#include "iredges_t.h"
#include "irgwalk.h"
#include "irprintf.h"
......@@ -58,7 +59,7 @@ DEBUG_ONLY(static firm_dbg_module_t *dbg);
static inline int imin(int a, int b) { return a < b ? a : b; }
static bool is_optimizable_node(const ir_node *node)
static bool is_optimizable_node(const ir_node *node, ir_mode *dest_mode)
{
switch (get_irn_opcode(node)) {
case iro_Add:
......@@ -69,9 +70,17 @@ static bool is_optimizable_node(const ir_node *node)
case iro_Not:
case iro_Or:
case iro_Phi:
case iro_Shl:
case iro_Sub:
return true;
case iro_Shl: {
int modulo_shift = get_mode_modulo_shift(dest_mode);
int old_shift = get_mode_modulo_shift(get_irn_mode(node));
/* bail out if modulo shift changes */
if (modulo_shift != old_shift)
return false;
return true;
}
default:
return false;
}
......@@ -116,6 +125,10 @@ static int get_conv_costs(const ir_node *node, ir_mode *dest_mode)
return 1;
}
if (ir_zero_when_converted(node, dest_mode)) {
return -1;
}
#if 0 // TODO
/* Take the minimum of the conversion costs for Phi predecessors as only one
* branch is actually executed at a time */
......@@ -149,7 +162,7 @@ static int get_conv_costs(const ir_node *node, ir_mode *dest_mode)
return get_conv_costs(get_Conv_op(node), dest_mode) - 1;
}
if (!is_optimizable_node(node)) {
if (!is_optimizable_node(node, dest_mode)) {
return 1;
}
......@@ -218,7 +231,7 @@ static ir_node *conv_transform(ir_node *node, ir_mode *dest_mode)
return conv_transform(get_Conv_op(node), dest_mode);
}
if (!is_optimizable_node(node)) {
if (!is_optimizable_node(node, dest_mode)) {
return place_conv(node, dest_mode);
}
......
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