Commit 70b487f0 authored by Michael Beck's avatar Michael Beck
Browse files

Confirm optimizations honor the exception region attribute.

[r14295]
parent 7918ce94
......@@ -97,15 +97,35 @@ static tarval *compare_iv_dbg(const interval_t *l_iv, const interval_t *r_iv, pn
* This is a often needed case, so we handle here Confirm
* nodes too.
*/
int value_not_zero(ir_node *n, ir_node **confirm) {
int value_not_zero(ir_node *blk, ir_node *n, ir_node **confirm) {
#define RET_ON(x) if (x) { *confirm = n; return 1; }; break
tarval *tv;
ir_mode *mode = get_irn_mode(n);
pn_Cmp pnc;
if (get_irg_pinned(get_irn_irg(blk)) != op_pin_state_pinned)
blk = NULL;
*confirm = NULL;
while (get_irn_op(n) == op_Confirm) {
/* there might be several Confirms one after other that form an interval */
for (; is_Confirm(n); n = get_Confirm_value(n)) {
unsigned long region = get_Confirm_region(n);
/* check if it's legal to use this confirm. */
if (region != 0) {
ir_node *curr_blk = get_irn_n(n, -1);
/* this confirm is bound to a region. */
if (! blk)
continue;
if (get_Block_exc_region(curr_blk) != region)
continue;
/* all went fine, the current Confirm belongs to the same region */
}
/*
* Note: A Confirm is never after a Const. So,
* we simply can check the bound for being a Const
......@@ -141,9 +161,6 @@ int value_not_zero(ir_node *n, ir_node **confirm) {
default:
break;
}
/* there might be several Confirms one after other that form an interval */
n = get_Confirm_value(n);
}
tv = value_of(n);
......@@ -167,11 +184,14 @@ int value_not_zero(ir_node *n, ir_node **confirm) {
* - A SymConst(entity) is NEVER a NULL pointer
* - Confirms are evaluated
*/
int value_not_null(ir_node *n, ir_node **confirm) {
int value_not_null(ir_node *blk, ir_node *n, ir_node **confirm) {
ir_op *op;
if (get_irg_pinned(get_irn_irg(blk)) != op_pin_state_pinned)
blk = NULL;
*confirm = NULL;
n = skip_Cast(n);
op = get_irn_op(n);
assert(mode_is_reference(get_irn_mode(n)));
if (get_opt_sel_based_null_check_elim()) {
......@@ -188,11 +208,28 @@ int value_not_null(ir_node *n, ir_node **confirm) {
if (tv != tarval_bad && classify_tarval(tv) != TV_CLASSIFY_NULL)
return 1;
} else if (op == op_Confirm) {
if (get_Confirm_cmp(n) == pn_Cmp_Lg &&
classify_Const(get_Confirm_bound(n)) == CNST_NULL) {
*confirm = n;
return 1;
} else {
for (; is_Confirm(n); n = skip_Cast(get_Confirm_value(n))) {
unsigned long region = get_Confirm_region(n);
/* check if it's legal to use this confirm. */
if (region != 0) {
ir_node *curr_blk = get_irn_n(n, -1);
/* this confirm is bound to a region. */
if (! blk)
continue;
if (get_Block_exc_region(curr_blk) != region)
continue;
/* all went fine, the current Confirm belongs to the same region */
}
if (get_Confirm_cmp(n) == pn_Cmp_Lg &&
classify_Const(get_Confirm_bound(n)) == CNST_NULL) {
*confirm = n;
return 1;
}
}
}
return 0;
......@@ -571,6 +608,25 @@ static int is_transitive(pn_Cmp pnc) {
return (pn_Cmp_False < pnc && pnc < pn_Cmp_Lg);
} /* is_transitive */
/**
* returns a confirm node starting from n that is allowed to be used in the exception
* region.
*
* @param region the exception region
* @param n the node
*/
static ir_node *get_allowed_confirm(unsigned long region, ir_node *n) {
for (; is_Confirm(n); n = get_Confirm_value(n)) {
unsigned long reg = get_Confirm_region(n);
if (reg == 0 || reg == region) {
/* found an allowed Confirm */
return n;
}
}
return NULL;
} /* get_allowed_confirm */
/**
* Return the value of a Cmp if one or both predecessors
......@@ -582,22 +638,25 @@ static int is_transitive(pn_Cmp pnc) {
* @param pnc the compare relation
*/
tarval *computed_value_Cmp_Confirm(ir_node *cmp, ir_node *left, ir_node *right, pn_Cmp pnc) {
ir_node *l_bound;
pn_Cmp l_pnc, res_pnc, neg_pnc;
interval_t l_iv, r_iv;
tarval *tv;
ir_mode *mode;
ir_node *l_bound, *confirm;
pn_Cmp l_pnc, res_pnc, neg_pnc;
interval_t l_iv, r_iv;
tarval *tv;
ir_mode *mode;
unsigned long region;
if (get_irn_op(right) == op_Confirm) {
ir_node *t;
/* Cmp is pinned, so this always gives the right exception region. */
region = get_Block_exc_region(get_nodes_block(cmp));
if ((confirm = get_allowed_confirm(region, right)) != NULL) {
/* we want the Confirm on the left side */
t = left;
left = right;
right = t;
right = left;
left = confirm;
pnc = get_inversed_pnc(pnc);
} else if (get_irn_op(left) != op_Confirm) {
} else if ((confirm = get_allowed_confirm(region, left)) != NULL) {
left = confirm;
} else {
/* no Confirm on either one side, finish */
return tarval_bad;
}
......@@ -606,16 +665,16 @@ tarval *computed_value_Cmp_Confirm(ir_node *cmp, ir_node *left, ir_node *right,
l_bound = get_Confirm_bound(left);
l_pnc = get_Confirm_cmp(left);
if (get_irn_op(right) == op_Confirm) {
if (is_Confirm(right)) {
/*
* both sides are Confirm's. Check some rare cases first.
*/
* both sides are Confirm's. Check some rare cases first.
*/
ir_node *r_bound = get_Confirm_bound(right);
pn_Cmp r_pnc = get_Confirm_cmp(right);
pn_Cmp r_pnc = get_Confirm_cmp(right);
/*
* some check can be made WITHOUT constant bounds
*/
* some check can be made WITHOUT constant bounds
*/
if (r_bound == l_bound) {
if (is_transitive(l_pnc)) {
pn_Cmp r_inc_pnc = get_inversed_pnc(r_pnc);
......
......@@ -22,19 +22,15 @@
* @brief Optimizations regarding Confirm nodes.
* @author Michael Beck
* @version $Id$
*/
#ifndef FIRM_OPT_CONFIRMS_H
#define FIRM_OPT_CONFIRMS_H
#include "firm_types.h"
/**a
* @file opt_confirms.h
*
* Optimizations regarding Confirm nodes.
* These optimizations are not means to be run from
* frontends, they are called from iropt.
*/
#ifndef FIRM_OPT_CONFIRMS_H
#define FIRM_OPT_CONFIRMS_H
#include "firm_types.h"
/**
* Check, if the value of a node is != 0.
......@@ -42,35 +38,37 @@
* This is a often needed case, so we handle here Confirm
* nodes too.
*
* @param blk the block for which the check is done
* @param n a node representing the value
* @param confirm if n is confirmed to be != 0, returns
* the the Confirm-node, else NULL
*/
int value_not_zero(ir_node *n, ir_node **confirm);
int value_not_zero(ir_node *blk, ir_node *n, ir_node **confirm);
/**
* Check, if the value of a node cannot represent a NULL pointer.
*
* - If sel_based_null_check_elim is enabled, all
* - If option sel_based_null_check_elim is enabled, all
* Sel nodes can be skipped.
* - A SymConst(entity) is NEVER a NULL pointer
* - A Const != NULL is NEVER a NULL pointer
* - Confirms are evaluated
*
* @param blk the block for which the check is done
* @param n a node representing the value
* @param confirm if n is confirmed to be != NULL, returns
* the the Confirm-node, else NULL
*/
int value_not_null(ir_node *n, ir_node **confirm);
int value_not_null(ir_node *blk, ir_node *n, ir_node **confirm);
/**
* Possible return values of value_classify().
*/
typedef enum _value_classify_sign {
value_classified_unknown = 0, /**< could not classify */
value_classified_positive = 1, /**< value is positive, i.e. >= 0 */
value_classified_negative = -1 /**< value is negative, i.e. <= 0 if
no signed zero exists or < 0 else */
value_classified_unknown = 0, /**< could not classify */
value_classified_positive = 1, /**< value is positive, i.e. >= 0 */
value_classified_negative = -1 /**< value is negative, i.e. <= 0 if
no signed zero exists or < 0 else */
} value_classify_sign;
/**
......
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