[Interpreter] Add wide context slot load / store operations.

test/cctest/interpreter/test-bytecode-generator.cc

 // 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.
 
 #include "src/v8.h"
 
 #include "src/compiler.h"
 #include "src/interpreter/bytecode-array-iterator.h"
 #include "src/interpreter/bytecode-generator.h"
 #include "src/interpreter/interpreter.h"
@@ skipping 93 matching lines @@
 #define U16(x) static_cast<uint8_t>(((x) >> kBitsPerByte) & 0xff),   \
                static_cast<uint8_t>((x) & 0xff)
 #define U16I(x) static_cast<uint8_t>(((x) >> kBitsPerByte) & 0xff),  \
                 static_cast<uint8_t>((x++) & 0xff)
 #else
 #error Unknown byte ordering
 #endif
 
 #define COMMA() ,
 #define SPACE()
+#define UNIQUE_VAR() "var a" XSTR(__COUNTER__) " = 0;\n"

[oth, 2016/01/11 11:31:11]

Does this need to be flagged with the core v8 team before adding to the code
base? It's the only instance of __COUNTER__ in the code base and it's a non-Cxx
standard that's implemented in assorted compilers.

[rmcilroy, 2016/01/11 15:47:19]

I think this is OK (assuming it passes the bots) - it is only in tests, and is
used all over the place in Chromium.

 
 #define REPEAT_2(SEP, ...)                      \
   __VA_ARGS__ SEP() __VA_ARGS__
 #define REPEAT_4(SEP, ...)  \
   REPEAT_2(SEP, __VA_ARGS__) SEP() REPEAT_2(SEP, __VA_ARGS__)
 #define REPEAT_8(SEP, ...)  \
   REPEAT_4(SEP, __VA_ARGS__) SEP() REPEAT_4(SEP, __VA_ARGS__)
 #define REPEAT_16(SEP, ...)  \
   REPEAT_8(SEP, __VA_ARGS__) SEP() REPEAT_8(SEP, __VA_ARGS__)
 #define REPEAT_32(SEP, ...)  \
   REPEAT_16(SEP, __VA_ARGS__) SEP() REPEAT_16(SEP, __VA_ARGS__)
 #define REPEAT_64(SEP, ...)  \
   REPEAT_32(SEP, __VA_ARGS__) SEP() REPEAT_32(SEP, __VA_ARGS__)
 #define REPEAT_128(SEP, ...)  \
   REPEAT_64(SEP, __VA_ARGS__) SEP() REPEAT_64(SEP, __VA_ARGS__)
 #define REPEAT_256(SEP, ...)  \
   REPEAT_128(SEP, __VA_ARGS__) SEP() REPEAT_128(SEP, __VA_ARGS__)
 
 #define REPEAT_127(SEP, ...)                                           \
   REPEAT_64(SEP, __VA_ARGS__) SEP() REPEAT_32(SEP, __VA_ARGS__) SEP()  \
   REPEAT_16(SEP, __VA_ARGS__) SEP() REPEAT_8(SEP, __VA_ARGS__) SEP()   \
   REPEAT_4(SEP, __VA_ARGS__) SEP() REPEAT_2(SEP, __VA_ARGS__) SEP()    \
   __VA_ARGS__
 
+#define REPEAT_249(SEP, ...)                                            \
+  REPEAT_127(SEP, __VA_ARGS__) SEP() REPEAT_64(SEP, __VA_ARGS__) SEP()  \
+  REPEAT_32(SEP, __VA_ARGS__) SEP() REPEAT_16(SEP, __VA_ARGS__) SEP()   \
+  REPEAT_8(SEP, __VA_ARGS__) SEP() REPEAT_2(SEP, __VA_ARGS__)
+
+#define REPEAT_249_UNIQUE_VARS()                                        \
+UNIQUE_VAR() REPEAT_127(UNIQUE_VAR) UNIQUE_VAR() REPEAT_64(UNIQUE_VAR)  \
+UNIQUE_VAR() REPEAT_32(UNIQUE_VAR) UNIQUE_VAR() REPEAT_16(UNIQUE_VAR)   \
+UNIQUE_VAR() REPEAT_8(UNIQUE_VAR) UNIQUE_VAR() REPEAT_2(UNIQUE_VAR)
+
 // Structure for containing expected bytecode snippets.
 template<typename T, int C = 6>
 struct ExpectedSnippet {
   const char* code_snippet;
   int frame_size;
   int parameter_count;
   int bytecode_length;
   const uint8_t bytecode[2048];
   int constant_count;
   T constants[C];
@@ skipping 3861 matching lines @@
   BytecodeGeneratorHelper helper;
   Zone zone;
 
   FeedbackVectorSpec feedback_spec(&zone);
   FeedbackVectorSlot slot = feedback_spec.AddCallICSlot();
 
   Handle<i::TypeFeedbackVector> vector =
       i::NewTypeFeedbackVector(helper.isolate(), &feedback_spec);
 
   int closure = Register::function_closure().index();
+  int new_target = Register::new_target().index();
   int first_context_slot = Context::MIN_CONTEXT_SLOTS;
+
+  int wide_slot = first_context_slot + 3;

[oth, 2016/01/11 11:31:11]

This code could STATIC_ASSERT that the limit of wide slot <= 255 as this'll be
wrong as fast failure.

[rmcilroy, 2016/01/11 15:47:19]

Done.

   ExpectedSnippet<InstanceType> snippets[] = {
       {"var a; return function() { a = 1; };",
        1 * kPointerSize,
        1,
        11,
        {
            B(CallRuntime), U16(Runtime::kNewFunctionContext),  //
                            R(closure), U8(1),                  //
            B(PushContext), R(0),                               //
            B(CreateClosure), U8(0), U8(0),                     //
@@ skipping 72 matching lines @@
            B(LdaTheHole),                                                 //
            B(StaContextSlot), R(1), U8(first_context_slot),               //
            B(LdaSmi8), U8(2),                                             //
            B(StaContextSlot), R(1), U8(first_context_slot),               //
            B(CreateClosure), U8(1), U8(0),                                //
            B(Return),                                                     //
        },
        2,
        {InstanceType::FIXED_ARRAY_TYPE,
         InstanceType::SHARED_FUNCTION_INFO_TYPE}},
+      {"'use strict';\n"
+       REPEAT_249_UNIQUE_VARS()
+       "eval();"
+       "var b = 100;"
+       "return b",
+       3 * kPointerSize,
+       1,
+       1041,
+       {
+           B(CallRuntime), U16(Runtime::kNewFunctionContext), R(closure),  //
+                           U8(1),                                          //
+           B(PushContext), R(0),                                           //
+           B(Ldar), THIS(1),                                               //
+           B(StaContextSlot), R(0), U8(first_context_slot),                //
+           B(CreateUnmappedArguments),                                     //
+           B(StaContextSlot), R(0), U8(first_context_slot + 1),            //
+           B(Ldar), R(new_target),                                         //
+           B(StaContextSlot), R(0), U8(first_context_slot + 2),            //
+           REPEAT_249(COMMA,                                               //
+                      B(LdaZero),                                          //
+                      B(StaContextSlot), R(0), U8(wide_slot++)),           //
+           B(LdaUndefined),                                                //
+           B(Star), R(2),                                                  //
+           B(LdaGlobalStrict), U8(0), U8(1),                               //
+           B(Star), R(1),                                                  //
+           B(Call), R(1), R(2), U8(0), U8(0),                              //
+           B(LdaSmi8), U8(100),                                            //
+           B(StaContextSlotWide), R(0), U16(256),                          //
+           B(LdaContextSlotWide), R(0), U16(256),                          //
+           B(Return),                                                      //
+       },
+       1,
+       {InstanceType::ONE_BYTE_INTERNALIZED_STRING_TYPE}},
   };
 
   for (size_t i = 0; i < arraysize(snippets); i++) {
     Handle<BytecodeArray> bytecode_array =
         helper.MakeBytecodeForFunctionBody(snippets[i].code_snippet);
     CheckBytecodeArrayEqual(snippets[i], bytecode_array);
   }
 }
 
 
@@ skipping 2144 matching lines @@
                          std::string(function_epilogue);
     Handle<BytecodeArray> bytecode_array =
         helper.MakeBytecode(script.c_str(), "t", "f");
     CheckBytecodeArrayEqual(snippets[i], bytecode_array);
   }
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8