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Fix PR rtl-optimization/33737
- From: Eric Botcazou <ebotcazou at libertysurf dot fr>
- To: gcc-patches at gcc dot gnu dot org
- Date: Wed, 7 Nov 2007 23:07:31 +0100
- Subject: Fix PR rtl-optimization/33737
This is a regression present on the mainline. The attached testcase triggers
a CFG verification failure at -O2, because of a negative edge probability.
The negative probably is computed in try_crossjump_to_edge
if (!redirect_to->frequency && !src1->frequency)
s->probability = (s->probability + s2->probability) / 2;
else
s->probability
= ((s->probability * redirect_to->frequency +
s2->probability * src1->frequency)
/ (redirect_to->frequency + src1->frequency));
from the overflow of the numerator. redirect_to->frequency happens to be huge
because try_crossjump_to_edge is invoked many times on the same edge and the
frequencies add up for cross-jumping:
redirect_to->count += src1->count;
redirect_to->frequency += src1->frequency;
Frequencies are supposed to be in the range 0..BB_FREQ_MAX and maintained by
means of local updates (see update_bb_profile_for_threading). But conflicts
can arise when jumps are threaded if frequencies have been set artificially
low e.g. by __builtin_expect. This is acknowledged:
/* An edge originally destinating BB of FREQUENCY and COUNT has been proved to
leave the block by TAKEN_EDGE. Update profile of BB such that edge E can be
redirected to destination of TAKEN_EDGE.
This function may leave the profile inconsistent in the case TAKEN_EDGE
frequency or count is believed to be lower than FREQUENCY or COUNT
respectively. */
void
update_bb_profile_for_threading (basic_block bb, int edge_frequency,
gcov_type count, edge taken_edge)
For the testcase at hand, the profile is already inconsistent after the jump
threading at the end of the first VRP pass. A global update would be needed
in order to recover from this inconsistent state.
The patch simply caps the frequencies in try_crossjump_to_edge. It also fixes
a couple of related defects:
1. In try_crossjump_to_edge, the frequencies were added before the weighted
mean for the edge probabilities was computed, thus skewing the weights.
2. In redirect_edges when all incoming edges of a basic block were redirected,
the orphaned basic block was reused for the split of one of its predecessors.
Its count and frequency had been zeroed by update_bb_profile_for_threading and
they weren't updated.
Bootstrapped/regtested on x86_64-suse-linux, applied on the mainline, as
obvious for the tree-ssa-threadupdate.c part.
2007-11-07 Eric Botcazou <ebotcazou@libertysurf.fr>
PR rtl-optimization/33737
* cfgcleanup.c (try_crossjump_to_edge): Add count and frequency of
target block after computing the probabilities of outgoing edges.
Cap the frequency to BB_FREQ_MAX.
* tree-ssa-threadupdate.c (redirect_edges): Also adjust count and
frequency of the basic block if it has been reused.
2007-11-07 Eric Botcazou <ebotcazou@libertysurf.fr>
* gcc.c-torture/compile/20071107-1.c: New test.
--
Eric Botcazou
Index: cfgcleanup.c
===================================================================
--- cfgcleanup.c (revision 129844)
+++ cfgcleanup.c (working copy)
@@ -1699,8 +1699,6 @@ try_crossjump_to_edge (int mode, edge e1
"Cross jumping from bb %i to bb %i; %i common insns\n",
src1->index, src2->index, nmatch);
- redirect_to->count += src1->count;
- redirect_to->frequency += src1->frequency;
/* We may have some registers visible through the block. */
df_set_bb_dirty (redirect_to);
@@ -1757,6 +1755,14 @@ try_crossjump_to_edge (int mode, edge e1
/ (redirect_to->frequency + src1->frequency));
}
+ /* Adjust count and frequency for the block. An earlier jump
+ threading pass may have left the profile in an inconsistent
+ state (see update_bb_profile_for_threading) so we must be
+ prepared for overflows. */
+ redirect_to->count += src1->count;
+ redirect_to->frequency += src1->frequency;
+ if (redirect_to->frequency > BB_FREQ_MAX)
+ redirect_to->frequency = BB_FREQ_MAX;
update_br_prob_note (redirect_to);
/* Edit SRC1 to go to REDIRECT_TO at NEWPOS1. */
Index: tree-ssa-threadupdate.c
===================================================================
--- tree-ssa-threadupdate.c (revision 129844)
+++ tree-ssa-threadupdate.c (working copy)
@@ -442,10 +442,14 @@ redirect_edges (void **slot, void *data)
remove_ctrl_stmt_and_useless_edges (local_info->bb,
rd->outgoing_edge->dest);
- /* And fixup the flags on the single remaining edge. */
+ /* Fixup the flags on the single remaining edge. */
single_succ_edge (local_info->bb)->flags
&= ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE | EDGE_ABNORMAL);
single_succ_edge (local_info->bb)->flags |= EDGE_FALLTHRU;
+
+ /* And adjust count and frequency on BB. */
+ local_info->bb->count = e->count;
+ local_info->bb->frequency = EDGE_FREQUENCY (e);
}
}
/* PR rtl-optimization/33737 */
/* Testcase by Richard Guenther <rguenth@gcc.gnu.org> */
enum { PROP_0, PROP_DOUBLE_CLICK_TIME, PROP_DOUBLE_CLICK_DISTANCE, PROP_CURSOR_BLINK, PROP_CURSOR_BLINK_TIME, PROP_CURSOR_BLINK_TIMEOUT, PROP_SPLIT_CURSOR, PROP_THEME_NAME, PROP_ICON_THEME_NAME, PROP_FALLBACK_ICON_THEME, PROP_KEY_THEME_NAME, PROP_MENU_BAR_ACCEL, PROP_DND_DRAG_THRESHOLD, PROP_FONT_NAME, PROP_ICON_SIZES, PROP_MODULES, PROP_XFT_ANTIALIAS, PROP_XFT_HINTING, PROP_XFT_HINTSTYLE, PROP_XFT_RGBA, PROP_XFT_DPI, PROP_CURSOR_THEME_NAME, PROP_CURSOR_THEME_SIZE, PROP_ALTERNATIVE_BUTTON_ORDER, PROP_ALTERNATIVE_SORT_ARROWS, PROP_SHOW_INPUT_METHOD_MENU, PROP_SHOW_UNICODE_MENU, PROP_TIMEOUT_INITIAL, PROP_TIMEOUT_REPEAT, PROP_TIMEOUT_EXPAND, PROP_COLOR_SCHEME, PROP_ENABLE_ANIMATIONS, PROP_TOUCHSCREEN_MODE, PROP_TOOLTIP_TIMEOUT, PROP_TOOLTIP_BROWSE_TIMEOUT, PROP_TOOLTIP_BROWSE_MODE_TIMEOUT, PROP_KEYNAV_CURSOR_ONLY, PROP_KEYNAV_WRAP_AROUND, PROP_ERROR_BELL, PROP_COLOR_HASH, PROP_FILE_CHOOSER_BACKEND, PROP_PRINT_BACKENDS, PROP_PRINT_PREVIEW_COMMAND, PROP_ENABLE_MNEMONICS, PROP_ENABLE_ACCELS, PROP_RECENT_FILES_LIMIT };
void g_assert_warning (void) __attribute__((__noreturn__));
void gtk_settings_class_init (void)
{
unsigned int result;
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_DOUBLE_CLICK_TIME) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_DOUBLE_CLICK_DISTANCE) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_CURSOR_BLINK) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_CURSOR_BLINK_TIME) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_CURSOR_BLINK_TIMEOUT) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_SPLIT_CURSOR) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_THEME_NAME) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_ICON_THEME_NAME) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_FALLBACK_ICON_THEME) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_KEY_THEME_NAME) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_MENU_BAR_ACCEL) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_DND_DRAG_THRESHOLD) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_FONT_NAME) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_ICON_SIZES) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_MODULES) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_XFT_ANTIALIAS) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_XFT_HINTING) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_XFT_HINTSTYLE) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_XFT_RGBA) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_XFT_DPI) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_CURSOR_THEME_NAME) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_CURSOR_THEME_SIZE) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_ALTERNATIVE_BUTTON_ORDER) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_ALTERNATIVE_SORT_ARROWS) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_SHOW_INPUT_METHOD_MENU) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_SHOW_UNICODE_MENU) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_TOOLTIP_BROWSE_TIMEOUT) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_TOOLTIP_BROWSE_MODE_TIMEOUT) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_KEYNAV_CURSOR_ONLY) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_KEYNAV_WRAP_AROUND) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_ERROR_BELL) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_FILE_CHOOSER_BACKEND) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_PRINT_PREVIEW_COMMAND) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_ENABLE_MNEMONICS) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
result = settings_install_property_parser();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_ENABLE_ACCELS) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
if (__builtin_expect (__extension__ ({
int _g_boolean_var_;
if (result == PROP_RECENT_FILES_LIMIT) _g_boolean_var_ = 1;
else _g_boolean_var_ = 0;
_g_boolean_var_;
}), 1)) {
}
else g_assert_warning();
}