Add Float64Round operator.

src/compiler/machine-operator.h

Index: src/compiler/machine-operator.h
diff --git a/src/compiler/machine-operator.h b/src/compiler/machine-operator.h
index 568d3eb2b89acc163584aea605375772ccfed1f0..76289c417940237de7a58b36fd4700fc08ee6eef 100644
--- a/src/compiler/machine-operator.h
+++ b/src/compiler/machine-operator.h
@@ -5,6 +5,7 @@
 #ifndef V8_COMPILER_MACHINE_OPERATOR_H_
 #define V8_COMPILER_MACHINE_OPERATOR_H_
 
+#include "src/base/flags.h"
 #include "src/compiler/machine-type.h"
 
 namespace v8 {
@@ -51,13 +52,25 @@ std::ostream& operator<<(std::ostream&, StoreRepresentation);
 
 StoreRepresentation const& StoreRepresentationOf(Operator const*);
 
+enum SupportedOperator {

[Benedikt Meurer, 2014/10/23 07:11:14]

I'd not name it SupportedOperator, but rather move it to
MachineOperatorBuilder::Flags, because it's not only about the availability of
operators but also about their behavior.

[sigurds, 2014/10/23 10:37:56]

Done.

+  kNoSupportedOperators = 0,
+  kSupportsFloat64Floor = 1 << 0,
+  kSupportsFloat64Ceil = 1 << 1,
+  kSupportsFloat64RoundTiesAway = 1 << 2,
+  kSupportsFloat64RoundTiesTowards = 1 << 3
+};
+
+typedef base::Flags<SupportedOperator, uint8_t> SupportedOperators;
+DEFINE_OPERATORS_FOR_FLAGS(SupportedOperators)
 
 // Interface for building machine-level operators. These operators are
 // machine-level but machine-independent and thus define a language suitable
 // for generating code to run on architectures such as ia32, x64, arm, etc.
 class MachineOperatorBuilder FINAL {
  public:
-  explicit MachineOperatorBuilder(MachineType word = kMachPtr);
+  explicit MachineOperatorBuilder(
+      MachineType word = kMachPtr,
+      SupportedOperators supportedOperators = kNoSupportedOperators);
 
   const Operator* Word32And();
   const Operator* Word32Or();
@@ -135,6 +148,20 @@ class MachineOperatorBuilder FINAL {
   const Operator* Float64LessThan();
   const Operator* Float64LessThanOrEqual();
 
+  // Floating point rounding.
+  const Operator* Float64Floor();
+  const Operator* Float64Ceil();
+  const Operator* Float64RoundAwayFromZero();
+  const Operator* Float64RoundToZero();
+  bool HasFloat64Floor() { return supportedOperators_ & kSupportsFloat64Floor; }
+  bool HasFloat64Ceil() { return supportedOperators_ & kSupportsFloat64Ceil; }
+  bool HasFloat64RoundAwayFromZero() {
+    return supportedOperators_ & kSupportsFloat64RoundTiesAway;
+  }
+  bool HasFloat64RoundToZero() {
+    return supportedOperators_ & kSupportsFloat64RoundTiesTowards;
+  }
+
   // load [base + index]
   const Operator* Load(LoadRepresentation rep);
 
@@ -181,6 +208,7 @@ class MachineOperatorBuilder FINAL {
  private:
   const MachineOperatorBuilderImpl& impl_;
   const MachineType word_;
+  const SupportedOperators supportedOperators_;
 };
 
 }  // namespace compiler