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Commit bd88a54

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Ensure that type widening converges
Range analysis may fail to converge (the process hangs) when the transfer function zend_inference_calc_range produces a smaller range. Fix by ensuring that the widening operator zend_inference_widening_meet allows only widening. This matches the inference rules in figure 13 of the paper. Fixes GH-19679 Closes GH-19683 
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‎NEWS

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@@ -10,6 +10,7 @@ PHP NEWS
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. Fixed bug GH-19544 (GC treats ZEND_WEAKREF_TAG_MAP references as WeakMap
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references). (Arnaud, timwolla)
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. Fixed bug GH-19613 (Stale array iterator pointer). (ilutov)
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. Fixed bug GH-19679 (zend_ssa_range_widening may fail to converge). (Arnaud)
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- Date:
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. Fixed date_sunrise() and date_sunset() with partial-hour UTC offset.

‎Zend/Optimizer/zend_inference.c

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@@ -1633,12 +1633,16 @@ static bool zend_inference_widening_meet(zend_ssa_var_info *var_info, zend_ssa_r
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r->min < var_info->range.min) {
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r->underflow = 1;
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r->min = ZEND_LONG_MIN;
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} else {
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r->min = var_info->range.min;
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}
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if (r->overflow ||
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var_info->range.overflow ||
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r->max > var_info->range.max) {
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r->overflow = 1;
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r->max = ZEND_LONG_MAX;
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} else {
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r->max = var_info->range.max;
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}
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if (var_info->range.min == r->min &&
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var_info->range.max == r->max &&

‎Zend/tests/gh19679.phpt

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--TEST--
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GH-19679: zend_ssa_range_widening does not converge
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--SKIPIF--
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<?php
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if (PHP_INT_SIZE !== 8) {
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die('skip output depends PHP_INT_SIZE=8');
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}
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?>
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--FILE--
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<?php
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function test() {
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$a = PHP_INT_MIN+1;
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$b = 0;
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while ($b++ < 3) {
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$a = (int) ($a-- - $b - 1);
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}
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return $a;
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}
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var_dump(test() == PHP_INT_MIN);
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?>
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--EXPECT--
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bool(true)

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