1 files changed, 45 insertions, 5 deletions

diff --git a/Source/JavaScriptCore/dfg/DFGArithMode.h b/Source/JavaScriptCore/dfg/DFGArithMode.h
index 073ed6aba..24a7952dd 100644
--- a/Source/JavaScriptCore/dfg/DFGArithMode.h
+++ b/Source/JavaScriptCore/dfg/DFGArithMode.h
@@ -23,8 +23,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef DFGArithMode_h
-#define DFGArithMode_h
+#pragma once
 
 #if ENABLE(DFG_JIT)
 
@@ -40,6 +39,14 @@ enum Mode {
     CheckOverflowAndNegativeZero, // Check for both overflow and negative zero.
     DoOverflow // Up-convert to the smallest type that soundly represents all possible results after input type speculation.
 };
+
+// Define the type of operation the rounding operation will perform.
+enum class RoundingMode {
+    Int32, // The round operation produces a integer and -0 is considered as 0.
+    Int32WithNegativeZeroCheck, // The round operation produces a integer and checks for -0.
+    Double // The round operation produce a double. The result can be -0, NaN or (+/-)Infinity.
+};
+
 } // namespace Arith
 
 inline bool doesOverflow(Arith::Mode mode)
@@ -97,16 +104,49 @@ inline bool shouldCheckNegativeZero(Arith::Mode mode)
     return true;
 }
 
+inline bool subsumes(Arith::Mode earlier, Arith::Mode later)
+{
+    switch (earlier) {
+    case Arith::CheckOverflow:
+        switch (later) {
+        case Arith::Unchecked:
+        case Arith::CheckOverflow:
+            return true;
+        default:
+            return false;
+        }
+    case Arith::CheckOverflowAndNegativeZero:
+        switch (later) {
+        case Arith::Unchecked:
+        case Arith::CheckOverflow:
+        case Arith::CheckOverflowAndNegativeZero:
+            return true;
+        default:
+            return false;
+        }
+    default:
+        return earlier == later;
+    }
+}
+
+inline bool producesInteger(Arith::RoundingMode mode)
+{
+    return mode == Arith::RoundingMode::Int32WithNegativeZeroCheck || mode == Arith::RoundingMode::Int32;
+}
+
+inline bool shouldCheckNegativeZero(Arith::RoundingMode mode)
+{
+    return mode == Arith::RoundingMode::Int32WithNegativeZeroCheck;
+}
+
 } } // namespace JSC::DFG
 
 namespace WTF {
 
 class PrintStream;
 void printInternal(PrintStream&, JSC::DFG::Arith::Mode);
+void printInternal(PrintStream&, JSC::DFG::Arith::RoundingMode);
 
 } // namespace WTF
 
 #endif // ENABLE(DFG_JIT)
-
-#endif // DFGArithMode_h
-