[turbofan] Implemented the optional Float32RoundDown operator.

src/compiler/machine-operator.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_MACHINE_OPERATOR_H_
 #define V8_COMPILER_MACHINE_OPERATOR_H_
 
 #include "src/base/flags.h"
 #include "src/compiler/machine-type.h"
 
@@ skipping 98 matching lines @@
   // Flags that specify which operations are available. This is useful
   // for operations that are unsupported by some back-ends.
   enum Flag {
     kNoFlags = 0u,
     // Note that Float*Max behaves like `(b < a) ? a : b`, not like Math.max().
     // Note that Float*Min behaves like `(a < b) ? a : b`, not like Math.min().
     kFloat32Max = 1u << 0,
     kFloat32Min = 1u << 1,
     kFloat64Max = 1u << 2,
     kFloat64Min = 1u << 3,
-    kFloat64RoundDown = 1u << 4,
-    kFloat64RoundUp = 1u << 5,
-    kFloat64RoundTruncate = 1u << 6,
-    kFloat64RoundTiesEven = 1u << 7,
-    kFloat64RoundTiesAway = 1u << 8,
-    kInt32DivIsSafe = 1u << 9,
-    kUint32DivIsSafe = 1u << 10,
-    kWord32ShiftIsSafe = 1u << 11,
-    kWord32Ctz = 1u << 12,
-    kWord64Ctz = 1u << 13,
-    kWord32Popcnt = 1u << 14,
-    kWord64Popcnt = 1u << 15,
+    kFloat32RoundDown = 1u << 4,
+    kFloat64RoundDown = 1u << 5,
+    kFloat64RoundUp = 1u << 6,
+    kFloat64RoundTruncate = 1u << 7,
+    kFloat64RoundTiesEven = 1u << 8,
+    kFloat64RoundTiesAway = 1u << 9,
+    kInt32DivIsSafe = 1u << 10,
+    kUint32DivIsSafe = 1u << 11,
+    kWord32ShiftIsSafe = 1u << 12,
+    kWord32Ctz = 1u << 13,
+    kWord64Ctz = 1u << 14,
+    kWord32Popcnt = 1u << 15,
+    kWord64Popcnt = 1u << 16,
     kAllOptionalOps = kFloat32Max | kFloat32Min | kFloat64Max | kFloat64Min |
                       kFloat64RoundDown | kFloat64RoundUp |
                       kFloat64RoundTruncate | kFloat64RoundTiesAway |
                       kFloat64RoundTiesEven | kWord32Ctz | kWord64Ctz |
-                      kWord32Popcnt | kWord64Popcnt
+                      kWord32Popcnt | kWord64Popcnt | kFloat32RoundDown
   };
   typedef base::Flags<Flag, unsigned> Flags;
 
   explicit MachineOperatorBuilder(Zone* zone, MachineType word = kMachPtr,
                                   Flags supportedOperators = kNoFlags);
 
   const Operator* Word32And();
   const Operator* Word32Or();
   const Operator* Word32Xor();
   const Operator* Word32Shl();
@@ skipping 115 matching lines @@
   const OptionalOperator Float64Max();
   const OptionalOperator Float64Min();
 
   // Floating point abs complying to IEEE 754 (single-precision).
   const Operator* Float32Abs();
 
   // Floating point abs complying to IEEE 754 (double-precision).
   const Operator* Float64Abs();
 
   // Floating point rounding.
+  const OptionalOperator Float32RoundDown();
   const OptionalOperator Float64RoundDown();
   const OptionalOperator Float64RoundUp();
   const OptionalOperator Float64RoundTruncate();
   const OptionalOperator Float64RoundTiesAway();
   const OptionalOperator Float64RoundTiesEven();
 
   // Floating point bit representation.
   const Operator* Float64ExtractLowWord32();
   const Operator* Float64ExtractHighWord32();
   const Operator* Float64InsertLowWord32();
@@ skipping 57 matching lines @@
 };
 
 
 DEFINE_OPERATORS_FOR_FLAGS(MachineOperatorBuilder::Flags)
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_MACHINE_OPERATOR_H_