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      1 // Copyright 2010 the V8 project authors. All rights reserved.
      2 // Redistribution and use in source and binary forms, with or without
      3 // modification, are permitted provided that the following conditions are
      4 // met:
      5 //
      6 //     * Redistributions of source code must retain the above copyright
      7 //       notice, this list of conditions and the following disclaimer.
      8 //     * Redistributions in binary form must reproduce the above
      9 //       copyright notice, this list of conditions and the following
     10 //       disclaimer in the documentation and/or other materials provided
     11 //       with the distribution.
     12 //     * Neither the name of Google Inc. nor the names of its
     13 //       contributors may be used to endorse or promote products derived
     14 //       from this software without specific prior written permission.
     15 //
     16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27 
     28 #include "v8.h"
     29 
     30 #include "codegen-inl.h"
     31 #include "fast-codegen.h"
     32 
     33 namespace v8 {
     34 namespace internal {
     35 
     36 #define __ ACCESS_MASM(masm())
     37 
     38 Register FastCodeGenerator::accumulator0() { return r0; }
     39 Register FastCodeGenerator::accumulator1() { return r1; }
     40 Register FastCodeGenerator::scratch0() { return r3; }
     41 Register FastCodeGenerator::scratch1() { return r4; }
     42 Register FastCodeGenerator::receiver_reg() { return r2; }
     43 Register FastCodeGenerator::context_reg() { return cp; }
     44 
     45 
     46 void FastCodeGenerator::EmitLoadReceiver() {
     47   // Offset 2 is due to return address and saved frame pointer.
     48   int index = 2 + scope()->num_parameters();
     49   __ ldr(receiver_reg(), MemOperand(sp, index * kPointerSize));
     50 }
     51 
     52 
     53 void FastCodeGenerator::EmitGlobalVariableLoad(Handle<Object> cell) {
     54   ASSERT(!destination().is(no_reg));
     55   ASSERT(cell->IsJSGlobalPropertyCell());
     56 
     57   __ mov(destination(), Operand(cell));
     58   __ ldr(destination(),
     59          FieldMemOperand(destination(), JSGlobalPropertyCell::kValueOffset));
     60   if (FLAG_debug_code) {
     61     __ mov(ip, Operand(Factory::the_hole_value()));
     62     __ cmp(destination(), ip);
     63     __ Check(ne, "DontDelete cells can't contain the hole");
     64   }
     65 
     66   // The loaded value is not known to be a smi.
     67   clear_as_smi(destination());
     68 }
     69 
     70 
     71 void FastCodeGenerator::EmitThisPropertyStore(Handle<String> name) {
     72   LookupResult lookup;
     73   info()->receiver()->Lookup(*name, &lookup);
     74 
     75   ASSERT(lookup.holder() == *info()->receiver());
     76   ASSERT(lookup.type() == FIELD);
     77   Handle<Map> map(Handle<HeapObject>::cast(info()->receiver())->map());
     78   int index = lookup.GetFieldIndex() - map->inobject_properties();
     79   int offset = index * kPointerSize;
     80 
     81   // We will emit the write barrier unless the stored value is statically
     82   // known to be a smi.
     83   bool needs_write_barrier = !is_smi(accumulator0());
     84 
     85   // Negative offsets are inobject properties.
     86   if (offset < 0) {
     87     offset += map->instance_size();
     88     __ str(accumulator0(), FieldMemOperand(receiver_reg(), offset));
     89     if (needs_write_barrier) {
     90       // Preserve receiver from write barrier.
     91       __ mov(scratch0(), receiver_reg());
     92     }
     93   } else {
     94     offset += FixedArray::kHeaderSize;
     95     __ ldr(scratch0(),
     96            FieldMemOperand(receiver_reg(), JSObject::kPropertiesOffset));
     97     __ str(accumulator0(), FieldMemOperand(scratch0(), offset));
     98   }
     99 
    100   if (needs_write_barrier) {
    101     __ mov(scratch1(), Operand(offset));
    102     __ RecordWrite(scratch0(), scratch1(), ip);
    103   }
    104 
    105   if (destination().is(accumulator1())) {
    106     __ mov(accumulator1(), accumulator0());
    107     if (is_smi(accumulator0())) {
    108       set_as_smi(accumulator1());
    109     } else {
    110       clear_as_smi(accumulator1());
    111     }
    112   }
    113 }
    114 
    115 
    116 void FastCodeGenerator::EmitThisPropertyLoad(Handle<String> name) {
    117   ASSERT(!destination().is(no_reg));
    118   LookupResult lookup;
    119   info()->receiver()->Lookup(*name, &lookup);
    120 
    121   ASSERT(lookup.holder() == *info()->receiver());
    122   ASSERT(lookup.type() == FIELD);
    123   Handle<Map> map(Handle<HeapObject>::cast(info()->receiver())->map());
    124   int index = lookup.GetFieldIndex() - map->inobject_properties();
    125   int offset = index * kPointerSize;
    126 
    127   // Perform the load.  Negative offsets are inobject properties.
    128   if (offset < 0) {
    129     offset += map->instance_size();
    130     __ ldr(destination(), FieldMemOperand(receiver_reg(), offset));
    131   } else {
    132     offset += FixedArray::kHeaderSize;
    133     __ ldr(scratch0(),
    134            FieldMemOperand(receiver_reg(), JSObject::kPropertiesOffset));
    135     __ ldr(destination(), FieldMemOperand(scratch0(), offset));
    136   }
    137 
    138   // The loaded value is not known to be a smi.
    139   clear_as_smi(destination());
    140 }
    141 
    142 
    143 void FastCodeGenerator::EmitBitOr() {
    144   if (is_smi(accumulator0()) && is_smi(accumulator1())) {
    145     // If both operands are known to be a smi then there is no need to check
    146     // the operands or result.  There is no need to perform the operation in
    147     // an effect context.
    148     if (!destination().is(no_reg)) {
    149       __ orr(destination(), accumulator1(), Operand(accumulator0()));
    150     }
    151   } else {
    152     // Left is in accumulator1, right in accumulator0.
    153     if (destination().is(accumulator0())) {
    154       __ mov(scratch0(), accumulator0());
    155       __ orr(destination(), accumulator1(), Operand(accumulator1()));
    156       Label* bailout =
    157           info()->AddBailout(accumulator1(), scratch0());  // Left, right.
    158       __ BranchOnNotSmi(destination(), bailout);
    159     } else if (destination().is(accumulator1())) {
    160       __ mov(scratch0(), accumulator1());
    161       __ orr(destination(), accumulator1(), Operand(accumulator0()));
    162       Label* bailout = info()->AddBailout(scratch0(), accumulator0());
    163       __ BranchOnNotSmi(destination(), bailout);
    164     } else {
    165       ASSERT(destination().is(no_reg));
    166       __ orr(scratch0(), accumulator1(), Operand(accumulator0()));
    167       Label* bailout = info()->AddBailout(accumulator1(), accumulator0());
    168       __ BranchOnNotSmi(scratch0(), bailout);
    169     }
    170   }
    171 
    172   // If we didn't bailout, the result (in fact, both inputs too) is known to
    173   // be a smi.
    174   set_as_smi(accumulator0());
    175   set_as_smi(accumulator1());
    176 }
    177 
    178 
    179 void FastCodeGenerator::Generate(CompilationInfo* compilation_info) {
    180   ASSERT(info_ == NULL);
    181   info_ = compilation_info;
    182 
    183   // Save the caller's frame pointer and set up our own.
    184   Comment prologue_cmnt(masm(), ";; Prologue");
    185   __ stm(db_w, sp, r1.bit() | cp.bit() | fp.bit() | lr.bit());
    186   __ add(fp, sp, Operand(2 * kPointerSize));
    187   // Note that we keep a live register reference to cp (context) at
    188   // this point.
    189 
    190   Label* bailout_to_beginning = info()->AddBailout();
    191   // Receiver (this) is allocated to a fixed register.
    192   if (info()->has_this_properties()) {
    193     Comment cmnt(masm(), ";; MapCheck(this)");
    194     if (FLAG_print_ir) {
    195       PrintF("MapCheck(this)\n");
    196     }
    197     ASSERT(info()->has_receiver() && info()->receiver()->IsHeapObject());
    198     Handle<HeapObject> object = Handle<HeapObject>::cast(info()->receiver());
    199     Handle<Map> map(object->map());
    200     EmitLoadReceiver();
    201     __ CheckMap(receiver_reg(), scratch0(), map, bailout_to_beginning, false);
    202   }
    203 
    204   // If there is a global variable access check if the global object is the
    205   // same as at lazy-compilation time.
    206   if (info()->has_globals()) {
    207     Comment cmnt(masm(), ";; MapCheck(GLOBAL)");
    208     if (FLAG_print_ir) {
    209       PrintF("MapCheck(GLOBAL)\n");
    210     }
    211     ASSERT(info()->has_global_object());
    212     Handle<Map> map(info()->global_object()->map());
    213     __ ldr(scratch0(), CodeGenerator::GlobalObject());
    214     __ CheckMap(scratch0(), scratch1(), map, bailout_to_beginning, true);
    215   }
    216 
    217   VisitStatements(function()->body());
    218 
    219   Comment return_cmnt(masm(), ";; Return(<undefined>)");
    220   if (FLAG_print_ir) {
    221     PrintF("Return(<undefined>)\n");
    222   }
    223   __ LoadRoot(r0, Heap::kUndefinedValueRootIndex);
    224   __ mov(sp, fp);
    225   __ ldm(ia_w, sp, fp.bit() | lr.bit());
    226   int32_t sp_delta = (scope()->num_parameters() + 1) * kPointerSize;
    227   __ add(sp, sp, Operand(sp_delta));
    228   __ Jump(lr);
    229 }
    230 
    231 
    232 #undef __
    233 
    234 
    235 } }  // namespace v8::internal
    236