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      1 // Copyright 2012 the V8 project authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "src/codegen.h"
      6 
      7 #if defined(V8_OS_AIX)
      8 #include <fenv.h>  // NOLINT(build/c++11)
      9 #endif
     10 #include "src/ast/prettyprinter.h"
     11 #include "src/bootstrapper.h"
     12 #include "src/compiler.h"
     13 #include "src/debug/debug.h"
     14 #include "src/parsing/parser.h"
     15 #include "src/runtime/runtime.h"
     16 
     17 namespace v8 {
     18 namespace internal {
     19 
     20 
     21 #if defined(V8_OS_WIN)
     22 double modulo(double x, double y) {
     23   // Workaround MS fmod bugs. ECMA-262 says:
     24   // dividend is finite and divisor is an infinity => result equals dividend
     25   // dividend is a zero and divisor is nonzero finite => result equals dividend
     26   if (!(std::isfinite(x) && (!std::isfinite(y) && !std::isnan(y))) &&
     27       !(x == 0 && (y != 0 && std::isfinite(y)))) {
     28     x = fmod(x, y);
     29   }
     30   return x;
     31 }
     32 #else  // POSIX
     33 
     34 double modulo(double x, double y) {
     35 #if defined(V8_OS_AIX)
     36   // AIX raises an underflow exception for (Number.MIN_VALUE % Number.MAX_VALUE)
     37   feclearexcept(FE_ALL_EXCEPT);
     38   double result = std::fmod(x, y);
     39   int exception = fetestexcept(FE_UNDERFLOW);
     40   return (exception ? x : result);
     41 #else
     42   return std::fmod(x, y);
     43 #endif
     44 }
     45 #endif  // defined(V8_OS_WIN)
     46 
     47 
     48 #define UNARY_MATH_FUNCTION(name, generator)                             \
     49   static UnaryMathFunctionWithIsolate fast_##name##_function = nullptr;  \
     50   double std_##name(double x, Isolate* isolate) { return std::name(x); } \
     51   void init_fast_##name##_function(Isolate* isolate) {                   \
     52     if (FLAG_fast_math) fast_##name##_function = generator(isolate);     \
     53     if (!fast_##name##_function) fast_##name##_function = std_##name;    \
     54   }                                                                      \
     55   void lazily_initialize_fast_##name(Isolate* isolate) {                 \
     56     if (!fast_##name##_function) init_fast_##name##_function(isolate);   \
     57   }                                                                      \
     58   double fast_##name(double x, Isolate* isolate) {                       \
     59     return (*fast_##name##_function)(x, isolate);                        \
     60   }
     61 
     62 UNARY_MATH_FUNCTION(sqrt, CreateSqrtFunction)
     63 
     64 #undef UNARY_MATH_FUNCTION
     65 
     66 
     67 #define __ ACCESS_MASM(masm_)
     68 
     69 #ifdef DEBUG
     70 
     71 Comment::Comment(MacroAssembler* masm, const char* msg)
     72     : masm_(masm), msg_(msg) {
     73   __ RecordComment(msg);
     74 }
     75 
     76 
     77 Comment::~Comment() {
     78   if (msg_[0] == '[') __ RecordComment("]");
     79 }
     80 
     81 #endif  // DEBUG
     82 
     83 #undef __
     84 
     85 
     86 void CodeGenerator::MakeCodePrologue(CompilationInfo* info, const char* kind) {
     87   bool print_source = false;
     88   bool print_ast = false;
     89   const char* ftype;
     90 
     91   if (info->isolate()->bootstrapper()->IsActive()) {
     92     print_source = FLAG_print_builtin_source;
     93     print_ast = FLAG_print_builtin_ast;
     94     ftype = "builtin";
     95   } else {
     96     print_source = FLAG_print_source;
     97     print_ast = FLAG_print_ast;
     98     ftype = "user-defined";
     99   }
    100 
    101   if (FLAG_trace_codegen || print_source || print_ast) {
    102     base::SmartArrayPointer<char> name = info->GetDebugName();
    103     PrintF("[generating %s code for %s function: %s]\n", kind, ftype,
    104            name.get());
    105   }
    106 
    107 #ifdef DEBUG
    108   if (info->parse_info() && print_source) {
    109     PrintF("--- Source from AST ---\n%s\n",
    110            PrettyPrinter(info->isolate()).PrintProgram(info->literal()));
    111   }
    112 
    113   if (info->parse_info() && print_ast) {
    114     PrintF("--- AST ---\n%s\n",
    115            AstPrinter(info->isolate()).PrintProgram(info->literal()));
    116   }
    117 #endif  // DEBUG
    118 }
    119 
    120 
    121 Handle<Code> CodeGenerator::MakeCodeEpilogue(MacroAssembler* masm,
    122                                              CompilationInfo* info) {
    123   Isolate* isolate = info->isolate();
    124 
    125   // Allocate and install the code.
    126   CodeDesc desc;
    127   Code::Flags flags = info->code_flags();
    128   bool is_crankshafted =
    129       Code::ExtractKindFromFlags(flags) == Code::OPTIMIZED_FUNCTION ||
    130       info->IsStub();
    131   masm->GetCode(&desc);
    132   Handle<Code> code =
    133       isolate->factory()->NewCode(desc, flags, masm->CodeObject(),
    134                                   false, is_crankshafted,
    135                                   info->prologue_offset(),
    136                                   info->is_debug() && !is_crankshafted);
    137   isolate->counters()->total_compiled_code_size()->Increment(
    138       code->instruction_size());
    139   isolate->heap()->IncrementCodeGeneratedBytes(is_crankshafted,
    140       code->instruction_size());
    141   return code;
    142 }
    143 
    144 
    145 void CodeGenerator::PrintCode(Handle<Code> code, CompilationInfo* info) {
    146 #ifdef ENABLE_DISASSEMBLER
    147   AllowDeferredHandleDereference allow_deference_for_print_code;
    148   Isolate* isolate = info->isolate();
    149   bool print_code =
    150       isolate->bootstrapper()->IsActive()
    151           ? FLAG_print_builtin_code
    152           : (FLAG_print_code || (info->IsStub() && FLAG_print_code_stubs) ||
    153              (info->IsOptimizing() && FLAG_print_opt_code));
    154   if (print_code) {
    155     base::SmartArrayPointer<char> debug_name = info->GetDebugName();
    156     CodeTracer::Scope tracing_scope(info->isolate()->GetCodeTracer());
    157     OFStream os(tracing_scope.file());
    158 
    159     // Print the source code if available.
    160     bool print_source =
    161         info->parse_info() && (code->kind() == Code::OPTIMIZED_FUNCTION ||
    162                                code->kind() == Code::FUNCTION);
    163     if (print_source) {
    164       Handle<SharedFunctionInfo> shared = info->shared_info();
    165       Handle<Script> script = info->script();
    166       if (!script->IsUndefined(isolate) &&
    167           !script->source()->IsUndefined(isolate)) {
    168         os << "--- Raw source ---\n";
    169         StringCharacterStream stream(String::cast(script->source()),
    170                                      shared->start_position());
    171         // fun->end_position() points to the last character in the stream. We
    172         // need to compensate by adding one to calculate the length.
    173         int source_len = shared->end_position() - shared->start_position() + 1;
    174         for (int i = 0; i < source_len; i++) {
    175           if (stream.HasMore()) {
    176             os << AsReversiblyEscapedUC16(stream.GetNext());
    177           }
    178         }
    179         os << "\n\n";
    180       }
    181     }
    182     if (info->IsOptimizing()) {
    183       if (FLAG_print_unopt_code && info->parse_info()) {
    184         os << "--- Unoptimized code ---\n";
    185         info->closure()->shared()->code()->Disassemble(debug_name.get(), os);
    186       }
    187       os << "--- Optimized code ---\n"
    188          << "optimization_id = " << info->optimization_id() << "\n";
    189     } else {
    190       os << "--- Code ---\n";
    191     }
    192     if (print_source) {
    193       Handle<SharedFunctionInfo> shared = info->shared_info();
    194       os << "source_position = " << shared->start_position() << "\n";
    195     }
    196     code->Disassemble(debug_name.get(), os);
    197     os << "--- End code ---\n";
    198   }
    199 #endif  // ENABLE_DISASSEMBLER
    200 }
    201 
    202 }  // namespace internal
    203 }  // namespace v8
    204