Title: [276524] trunk/Source/_javascript_Core
- Revision
- 276524
- Author
- [email protected]
- Date
- 2021-04-23 15:14:11 -0700 (Fri, 23 Apr 2021)
Log Message
Fix B3 strength reduction for shl.
https://bugs.webkit.org/show_bug.cgi?id=224913
rdar://76978874
Reviewed by Michael Saboff.
If the operation can potentially either underflow or overflow, then the result
can be any value.
* b3/B3ReduceStrength.cpp:
Modified Paths
Diff
Modified: trunk/Source/_javascript_Core/ChangeLog (276523 => 276524)
--- trunk/Source/_javascript_Core/ChangeLog 2021-04-23 22:06:26 UTC (rev 276523)
+++ trunk/Source/_javascript_Core/ChangeLog 2021-04-23 22:14:11 UTC (rev 276524)
@@ -1,3 +1,16 @@
+2021-04-23 Mark Lam <[email protected]>
+
+ Fix B3 strength reduction for shl.
+ https://bugs.webkit.org/show_bug.cgi?id=224913
+ rdar://76978874
+
+ Reviewed by Michael Saboff.
+
+ If the operation can potentially either underflow or overflow, then the result
+ can be any value.
+
+ * b3/B3ReduceStrength.cpp:
+
2021-04-23 Fujii Hironori <[email protected]>
[JSC][Win] callOperationNoExceptionCheck() also needs to support operations that return SlowPathReturnType
Modified: trunk/Source/_javascript_Core/b3/B3ReduceStrength.cpp (276523 => 276524)
--- trunk/Source/_javascript_Core/b3/B3ReduceStrength.cpp 2021-04-23 22:06:26 UTC (rev 276523)
+++ trunk/Source/_javascript_Core/b3/B3ReduceStrength.cpp 2021-04-23 22:14:11 UTC (rev 276524)
@@ -240,10 +240,11 @@
T newMin = static_cast<T>(m_min) << static_cast<T>(shiftAmount);
T newMax = static_cast<T>(m_max) << static_cast<T>(shiftAmount);
- if ((newMin >> shiftAmount) != static_cast<T>(m_min))
+ if (((newMin >> shiftAmount) != static_cast<T>(m_min))
+ || ((newMax >> shiftAmount) != static_cast<T>(m_max))) {
newMin = std::numeric_limits<T>::min();
- if ((newMax >> shiftAmount) != static_cast<T>(m_max))
newMax = std::numeric_limits<T>::max();
+ }
return IntRange(newMin, newMax);
}
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