[ignition] Optimize jump checks to range checks

src/interpreter/bytecodes.h

 // Copyright 2015 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_INTERPRETER_BYTECODES_H_
 #define V8_INTERPRETER_BYTECODES_H_
 
 #include <cstdint>
 #include <iosfwd>
 #include <string>
@@ skipping 195 matching lines @@
     OperandType::kIdx, OperandType::kIdx)                                      \
   V(CreateFunctionContext, AccumulatorUse::kWrite, OperandType::kUImm)         \
   V(CreateWithContext, AccumulatorUse::kReadWrite, OperandType::kReg,          \
     OperandType::kIdx)                                                         \
                                                                                \
   /* Arguments allocation */                                                   \
   V(CreateMappedArguments, AccumulatorUse::kWrite)                             \
   V(CreateUnmappedArguments, AccumulatorUse::kWrite)                           \
   V(CreateRestParameter, AccumulatorUse::kWrite)                               \
                                                                                \
-  /* Control Flow */                                                           \
+  /* Control Flow -- carefully ordered for efficient checks */                 \
+  /* - [Unconditional jumps] */                                                \
+  V(JumpLoop, AccumulatorUse::kNone, OperandType::kImm, OperandType::kImm)     \
+  /* - [Forward jumps] */                                                      \
   V(Jump, AccumulatorUse::kNone, OperandType::kImm)                            \
+  /* - [Start constant jumps] */                                               \
   V(JumpConstant, AccumulatorUse::kNone, OperandType::kIdx)                    \
+  /* - [Conditional jumps] */                                                  \
+  /* - [Conditional constant jumps] */                                         \
+  V(JumpIfNullConstant, AccumulatorUse::kRead, OperandType::kIdx)              \
+  V(JumpIfUndefinedConstant, AccumulatorUse::kRead, OperandType::kIdx)         \
+  V(JumpIfTrueConstant, AccumulatorUse::kRead, OperandType::kIdx)              \
+  V(JumpIfFalseConstant, AccumulatorUse::kRead, OperandType::kIdx)             \
+  V(JumpIfNotHoleConstant, AccumulatorUse::kRead, OperandType::kIdx)           \
+  /* - [Start ToBoolean jumps] */                                              \
+  V(JumpIfToBooleanTrueConstant, AccumulatorUse::kRead, OperandType::kIdx)     \
+  V(JumpIfToBooleanFalseConstant, AccumulatorUse::kRead, OperandType::kIdx)    \
+  /* - [End constant jumps] */                                                 \
+  /* - [Conditional immediate jumps] */                                        \
+  V(JumpIfToBooleanTrue, AccumulatorUse::kRead, OperandType::kImm)             \
+  V(JumpIfToBooleanFalse, AccumulatorUse::kRead, OperandType::kImm)            \
+  /* - [End ToBoolean jumps] */                                                \
   V(JumpIfTrue, AccumulatorUse::kRead, OperandType::kImm)                      \
-  V(JumpIfTrueConstant, AccumulatorUse::kRead, OperandType::kIdx)              \
   V(JumpIfFalse, AccumulatorUse::kRead, OperandType::kImm)                     \
-  V(JumpIfFalseConstant, AccumulatorUse::kRead, OperandType::kIdx)             \
-  V(JumpIfToBooleanTrue, AccumulatorUse::kRead, OperandType::kImm)             \
-  V(JumpIfToBooleanTrueConstant, AccumulatorUse::kRead, OperandType::kIdx)     \
-  V(JumpIfToBooleanFalse, AccumulatorUse::kRead, OperandType::kImm)            \
-  V(JumpIfToBooleanFalseConstant, AccumulatorUse::kRead, OperandType::kIdx)    \
   V(JumpIfNull, AccumulatorUse::kRead, OperandType::kImm)                      \
-  V(JumpIfNullConstant, AccumulatorUse::kRead, OperandType::kIdx)              \
   V(JumpIfUndefined, AccumulatorUse::kRead, OperandType::kImm)                 \
-  V(JumpIfUndefinedConstant, AccumulatorUse::kRead, OperandType::kIdx)         \
   V(JumpIfNotHole, AccumulatorUse::kRead, OperandType::kImm)                   \
-  V(JumpIfNotHoleConstant, AccumulatorUse::kRead, OperandType::kIdx)           \
-  V(JumpLoop, AccumulatorUse::kNone, OperandType::kImm, OperandType::kImm)     \
                                                                                \
   /* Complex flow control For..in */                                           \
   V(ForInPrepare, AccumulatorUse::kNone, OperandType::kReg,                    \
     OperandType::kRegOutTriple)                                                \
   V(ForInContinue, AccumulatorUse::kWrite, OperandType::kReg,                  \
     OperandType::kReg)                                                         \
   V(ForInNext, AccumulatorUse::kWrite, OperandType::kReg, OperandType::kReg,   \
     OperandType::kRegPair, OperandType::kIdx)                                  \
   V(ForInStep, AccumulatorUse::kWrite, OperandType::kReg)                      \
                                                                                \
@@ skipping 49 matching lines @@
   V(DebugBreak6)
 
 #define DEBUG_BREAK_PREFIX_BYTECODE_LIST(V) \
   V(DebugBreakWide)                         \
   V(DebugBreakExtraWide)
 
 #define DEBUG_BREAK_BYTECODE_LIST(V) \
   DEBUG_BREAK_PLAIN_BYTECODE_LIST(V) \
   DEBUG_BREAK_PREFIX_BYTECODE_LIST(V)
 
+// List of jump bytecodes.
+#define JUMP_FORWARD_BYTECODE_LIST(V) \
+  V(Jump)                             \
+  V(JumpConstant)                     \
+  V(JumpIfNullConstant)               \
+  V(JumpIfUndefinedConstant)          \
+  V(JumpIfTrueConstant)               \
+  V(JumpIfFalseConstant)              \
+  V(JumpIfNotHoleConstant)            \
+  V(JumpIfToBooleanTrueConstant)      \
+  V(JumpIfToBooleanFalseConstant)     \
+  V(JumpIfToBooleanTrue)              \
+  V(JumpIfToBooleanFalse)             \
+  V(JumpIfTrue)                       \
+  V(JumpIfFalse)                      \
+  V(JumpIfNull)                       \
+  V(JumpIfUndefined)                  \
+  V(JumpIfNotHole)
+
+#define JUMP_CONSTANT_BYTECODE_LIST(V) \
+  V(JumpConstant)                      \
+  V(JumpIfNullConstant)                \
+  V(JumpIfUndefinedConstant)           \
+  V(JumpIfTrueConstant)                \
+  V(JumpIfFalseConstant)               \
+  V(JumpIfNotHoleConstant)             \
+  V(JumpIfToBooleanTrueConstant)       \
+  V(JumpIfToBooleanFalseConstant)
+
+#define JUMP_IMMEDIATE_BYTECODE_LIST(V) \
+  V(JumpLoop)                           \
+  V(Jump)                               \
+  V(JumpIfToBooleanTrue)                \
+  V(JumpIfToBooleanFalse)               \
+  V(JumpIfTrue)                         \
+  V(JumpIfFalse)                        \
+  V(JumpIfNull)                         \
+  V(JumpIfUndefined)                    \
+  V(JumpIfNotHole)
+
+#define JUMP_TO_BOOLEAN_BYTECODE_LIST(V) \
+  V(JumpIfToBooleanTrueConstant)         \
+  V(JumpIfToBooleanFalseConstant)        \
+  V(JumpIfToBooleanTrue)                 \
+  V(JumpIfToBooleanFalse)
+
+#define JUMP_UNCONDITIONAL_BYTECODE_LIST(V) \
+  V(JumpLoop)                               \
+  V(Jump)                                   \
+  V(JumpConstant)
+
+#define JUMP_CONDITIONAL_BYTECODE_LIST(V) \
+  V(JumpIfNullConstant)                   \
+  V(JumpIfUndefinedConstant)              \
+  V(JumpIfTrueConstant)                   \
+  V(JumpIfFalseConstant)                  \
+  V(JumpIfNotHoleConstant)                \
+  V(JumpIfToBooleanTrueConstant)          \
+  V(JumpIfToBooleanFalseConstant)         \
+  V(JumpIfToBooleanTrue)                  \
+  V(JumpIfToBooleanFalse)                 \
+  V(JumpIfTrue)                           \
+  V(JumpIfFalse)                          \
+  V(JumpIfNull)                           \
+  V(JumpIfUndefined)                      \
+  V(JumpIfNotHole)

[rmcilroy, 2016/12/05 14:33:40]

nit - could you build these up so there aren't repeated bytecodes, e.g.,
JUMP_TOBOOLEAN_CONDITIONAL_IMMEDIATE, JUMP_CONDITITIONAL_IMMEDIAIATE
JUMP_TOBOOLEAN_CONDITIONAL_CONSTANT, etc. And then build the other macros out of
these (e.g. CONDITIONAL adding the TOBOOLEAN variants and JUMP_FORWARD adding
everything except JumpLoop.

[Leszek Swirski, 2016/12/05 17:53:11]

Done, except for some duplication in JumpForward caused by JumpLoop being
unconditional.

+
+#define JUMP_BYTECODE_LIST(V) \
+  V(JumpLoop)                 \
+  JUMP_FORWARD_BYTECODE_LIST(V)
+
 // Enumeration of interpreter bytecodes.
 enum class Bytecode : uint8_t {
 #define DECLARE_BYTECODE(Name, ...) k##Name,
   BYTECODE_LIST(DECLARE_BYTECODE)
 #undef DECLARE_BYTECODE
 #define COUNT_BYTECODE(x, ...) +1
   // The COUNT_BYTECODE macro will turn this into kLast = -1 +1 +1... which will
   // evaluate to the same value as the last real bytecode.
   kLast = -1 BYTECODE_LIST(COUNT_BYTECODE)
 #undef COUNT_BYTECODE
@@ skipping 123 matching lines @@
   // Return true if |bytecode| is a register load without effects,
   // e.g. Mov, Star.
   static CONSTEXPR bool IsRegisterLoadWithoutEffects(Bytecode bytecode) {
     return bytecode == Bytecode::kMov || bytecode == Bytecode::kPopContext ||
            bytecode == Bytecode::kPushContext || bytecode == Bytecode::kStar;
   }
 
   // Returns true if the bytecode is a conditional jump taking
   // an immediate byte operand (OperandType::kImm).
   static CONSTEXPR bool IsConditionalJumpImmediate(Bytecode bytecode) {
-    return bytecode == Bytecode::kJumpIfTrue ||
-           bytecode == Bytecode::kJumpIfFalse ||
-           bytecode == Bytecode::kJumpIfToBooleanTrue ||
-           bytecode == Bytecode::kJumpIfToBooleanFalse ||
-           bytecode == Bytecode::kJumpIfNotHole ||
-           bytecode == Bytecode::kJumpIfNull ||
-           bytecode == Bytecode::kJumpIfUndefined;
+    return bytecode >= Bytecode::kJumpIfToBooleanTrue &&
+           bytecode <= Bytecode::kJumpIfNotHole;
   }
 
   // Returns true if the bytecode is a conditional jump taking
   // a constant pool entry (OperandType::kIdx).
   static CONSTEXPR bool IsConditionalJumpConstant(Bytecode bytecode) {
-    return bytecode == Bytecode::kJumpIfTrueConstant ||
-           bytecode == Bytecode::kJumpIfFalseConstant ||
-           bytecode == Bytecode::kJumpIfToBooleanTrueConstant ||
-           bytecode == Bytecode::kJumpIfToBooleanFalseConstant ||
-           bytecode == Bytecode::kJumpIfNotHoleConstant ||
-           bytecode == Bytecode::kJumpIfNullConstant ||
-           bytecode == Bytecode::kJumpIfUndefinedConstant;
+    return bytecode >= Bytecode::kJumpIfNullConstant &&
+           bytecode <= Bytecode::kJumpIfToBooleanFalseConstant;
   }
 
   // Returns true if the bytecode is a conditional jump taking
   // any kind of operand.
   static CONSTEXPR bool IsConditionalJump(Bytecode bytecode) {
-    return IsConditionalJumpImmediate(bytecode) ||
-           IsConditionalJumpConstant(bytecode);
+    return bytecode >= Bytecode::kJumpIfNullConstant &&
+           bytecode <= Bytecode::kJumpIfNotHole;
   }
 
   // Returns true if the bytecode is an unconditional jump.
   static CONSTEXPR bool IsUnconditionalJump(Bytecode bytecode) {
-    return bytecode == Bytecode::kJump || bytecode == Bytecode::kJumpConstant ||
-           bytecode == Bytecode::kJumpLoop;
+    return bytecode >= Bytecode::kJumpLoop &&
+           bytecode <= Bytecode::kJumpConstant;
   }
 
   // Returns true if the bytecode is a jump or a conditional jump taking
   // an immediate byte operand (OperandType::kImm).
   static CONSTEXPR bool IsJumpImmediate(Bytecode bytecode) {
     return bytecode == Bytecode::kJump || bytecode == Bytecode::kJumpLoop ||
            IsConditionalJumpImmediate(bytecode);
   }
 
   // Returns true if the bytecode is a jump or conditional jump taking a
   // constant pool entry (OperandType::kIdx).
   static CONSTEXPR bool IsJumpConstant(Bytecode bytecode) {
-    return bytecode == Bytecode::kJumpConstant ||
-           IsConditionalJumpConstant(bytecode);
+    return bytecode >= Bytecode::kJumpConstant &&
+           bytecode <= Bytecode::kJumpIfToBooleanFalseConstant;
   }
 
   // Returns true if the bytecode is a jump that internally coerces the
   // accumulator to a boolean.
   static CONSTEXPR bool IsJumpIfToBoolean(Bytecode bytecode) {
-    return bytecode == Bytecode::kJumpIfToBooleanTrue ||
-           bytecode == Bytecode::kJumpIfToBooleanFalse ||
-           bytecode == Bytecode::kJumpIfToBooleanTrueConstant ||
-           bytecode == Bytecode::kJumpIfToBooleanFalseConstant;
+    return bytecode >= Bytecode::kJumpIfToBooleanTrueConstant &&
+           bytecode <= Bytecode::kJumpIfToBooleanFalse;
   }
 
   // Returns true if the bytecode is a jump or conditional jump taking
   // any kind of operand.
   static CONSTEXPR bool IsJump(Bytecode bytecode) {
-    return IsJumpImmediate(bytecode) || IsJumpConstant(bytecode);
+    return bytecode >= Bytecode::kJumpLoop &&
+           bytecode <= Bytecode::kJumpIfNotHole;
   }
 
   // Returns true if the bytecode is a forward jump or conditional jump taking
   // any kind of operand.
   static CONSTEXPR bool IsForwardJump(Bytecode bytecode) {
-    return bytecode != Bytecode::kJumpLoop && IsJump(bytecode);
+    return bytecode >= Bytecode::kJump && bytecode <= Bytecode::kJumpIfNotHole;
   }
 
   // Returns true if the bytecode is a conditional jump, a jump, or a return.
   static CONSTEXPR bool IsJumpOrReturn(Bytecode bytecode) {
     return bytecode == Bytecode::kReturn || IsJump(bytecode);
   }
 
   // Return true if |bytecode| is a jump without effects,
   // e.g.  any jump excluding those that include type coercion like
   // JumpIfTrueToBoolean.
@@ skipping 230 matching lines @@
 #undef CONSTEXPR
 
 V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os,
                                            const Bytecode& bytecode);
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_BYTECODES_H_