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After r12-5300-gf98f373dd822b3, value_replacement would be able to look at the
following cfg structure:
```
<bb 5> [local count: 1014686024]:
if (h_6 != 0)
goto <bb 7>; [94.50%]
else
goto <bb 6>; [5.50%]
<bb 6> [local count: 114863530]:
# h_6 = PHI <0(4), 1(5)>
<bb 7> [local count: 1073741824]:
# f_8 = PHI <0(5), h_6(6)>
_9 = f_8 ^ 1;
a.0_10 = a;
_11 = _9 + a.0_10;
if (_11 != -117)
goto <bb 5>; [94.50%]
else
goto <bb 8>; [5.50%]
```
value_replacement would incorrectly think the middle bb (6) was empty and so it decides
to remove condition in bb5 and replacing it with 0 as the function thought it was `h_6 ? 0 : h_6`.
But since the there is an incoming phi node to bb6 defining h_6 that is incorrect.
The fix is to check if there is phi nodes in the middle bb and set empty_or_with_defined_p to false.
This was not needed before r12-5300-gf98f373dd822b3 because the phi would have been dead otherwise due to
other checks.
Bootstrapped and tested on x86_64-linux-gnu.
PR tree-optimization/118922
gcc/ChangeLog:
* tree-ssa-phiopt.cc (value_replacement): Set empty_or_with_defined_p
to false when there is phi nodes for the middle bb.
gcc/testsuite/ChangeLog:
* gcc.dg/torture/pr118922-1.c: New test.
Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
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