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Fix GH-22115: Tracing JIT drops loop-PHI CV register from SNAPSHOT #22132

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Fix GH-22115: Tracing JIT drops loop-PHI CV register from SNAPSHOT #22132

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14 changes: 10 additions & 4 deletions ext/opcache/jit/zend_jit_trace.c
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Original file line number Diff line number Diff line change
Expand Up @@ -3215,10 +3215,16 @@ static zend_jit_reg_var* zend_jit_trace_allocate_registers(zend_jit_trace_rec *t
zend_ssa_phi *phi = ssa->blocks[1].phis;

while (phi) {
i = phi->sources[1];
if (RA_HAS_IVAL(i) && !ssa->vars[phi->ssa_var].no_val) {
RA_IVAL_END(i, idx);
RA_IVAL_FLAGS(i) &= ~ZREG_LAST_USE;
if (RA_HAS_IVAL(phi->sources[1]) && !ssa->vars[phi->ssa_var].no_val) {
int cv = ssa->vars[phi->ssa_var].var;
int k;

/* All SSA versions of a loop-carried CV share the same register */
for (k = 0; k < ssa->vars_count; k++) {
if (ssa->vars[k].var == cv && RA_HAS_IVAL(k)) {
RA_IVAL_FLAGS(k) &= ~ZREG_LAST_USE;
}
}
}
phi = phi->next;
}
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35 changes: 35 additions & 0 deletions ext/opcache/tests/jit/gh22115.phpt
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Original file line number Diff line number Diff line change
@@ -0,0 +1,35 @@
--TEST--
GH-22115: Tracing JIT drops loop-PHI CV register from SNAPSHOT after intermediate op1_def
--EXTENSIONS--
opcache
--INI--
opcache.enable=1
opcache.enable_cli=1
opcache.file_update_protection=0
opcache.jit_buffer_size=32M
opcache.jit=tracing
--FILE--
<?php
function f(array $meta, int $n): int {
$s = 0;
$i = 0;
$sink = 0;
while ($i < $n) {
$copy = $s;
$sink += $copy;
$m = (int) $meta[$s];
if (($m & 0xFF) === 1) {
$i++;
$s = ($m >> 16) & 0xFFFF;
continue;
}
return $s;
}
return $s;
}
$meta = [0 => 1 | (1 << 16), 1 => 2 | (2 << 16)];
for ($w = 0; $w < 2000; $w++) f($meta, 3);
var_dump(f($meta, 3));
?>
--EXPECT--
int(1)
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