dfg/DFGNonSpeculativeJIT.h

   1 /*
   2  * Copyright (C) 2011 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
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   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
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  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef DFGNonSpeculativeJIT_h
  27 #define DFGNonSpeculativeJIT_h
  28
  29 #if ENABLE(DFG_JIT)
  30
  31 #include <dfg/DFGJITCodeGenerator.h>
  32
  33 namespace JSC { namespace DFG {
  34
  35 class SpeculationCheckIndexIterator;
  36
  37 // === EntryLocation ===
  38 //
  39 // This structure describes an entry point into the non-speculative
  40 // code path. This is used in linking bail-outs from the speculative path.
  41 struct EntryLocation {
  42     EntryLocation(MacroAssembler::Label, NonSpeculativeJIT*);
  43
  44     // The node this entry point corresponds to, and the label
  45     // marking the start of code for the given node.
  46     MacroAssembler::Label m_entry;
  47     NodeIndex m_nodeIndex;
  48
  49     // For every entry point we record a map recording for every
  50     // machine register which, if any, values it contains. For
  51     // GPR registers we must also record the format of the value.
  52     struct RegisterInfo {
  53         NodeIndex nodeIndex;
  54         DataFormat format;
  55     };
  56     RegisterInfo m_gprInfo[GPRInfo::numberOfRegisters];
  57     NodeIndex m_fprInfo[FPRInfo::numberOfRegisters];
  58 };
  59
  60 // === NonSpeculativeJIT ===
  61 //
  62 // This class is used to generate code for the non-speculative path.
  63 // Code generation will take advantage of static information available
  64 // in the dataflow to perform safe optimizations - for example, avoiding
  65 // boxing numeric values between arithmetic operations, but will not
  66 // perform any unsafe optimizations that would render the code unable
  67 // to produce the correct results for any possible input.
  68 class NonSpeculativeJIT : public JITCodeGenerator {
  69     friend struct EntryLocation;
  70 public:
  71     NonSpeculativeJIT(JITCompiler& jit)
  72         : JITCodeGenerator(jit, false)
  73     {
  74     }
  75
  76     void compile(SpeculationCheckIndexIterator&);
  77
  78     typedef SegmentedVector<EntryLocation, 16> EntryLocationVector;
  79     EntryLocationVector& entryLocations() { return m_entryLocations; }
  80
  81 private:
  82     void compile(SpeculationCheckIndexIterator&, Node&);
  83     void compile(SpeculationCheckIndexIterator&, BasicBlock&);
  84
  85     bool isKnownInteger(NodeIndex);
  86     bool isKnownNumeric(NodeIndex);
  87
  88     // These methods are used when generating 'unexpected'
  89     // calls out from JIT code to C++ helper routines -
  90     // they spill all live values to the appropriate
  91     // slots in the RegisterFile without changing any state
  92     // in the GenerationInfo.
  93     void silentSpillGPR(VirtualRegister spillMe, GPRReg exclude = InvalidGPRReg)
  94     {
  95         GenerationInfo& info = m_generationInfo[spillMe];
  96         ASSERT(info.registerFormat() != DataFormatNone && info.registerFormat() != DataFormatDouble);
  97
  98         if (!info.needsSpill() || (info.gpr() == exclude))
  99             return;
 100
 101         DataFormat registerFormat = info.registerFormat();
 102
 103         if (registerFormat == DataFormatInteger) {
 104             m_jit.orPtr(GPRInfo::tagTypeNumberRegister, info.gpr());
 105             m_jit.storePtr(info.gpr(), JITCompiler::addressFor(spillMe));
 106         } else {
 107             ASSERT(registerFormat & DataFormatJS || registerFormat == DataFormatCell);
 108             m_jit.storePtr(info.gpr(), JITCompiler::addressFor(spillMe));
 109         }
 110     }
 111     void silentSpillFPR(VirtualRegister spillMe, GPRReg canTrample, FPRReg exclude = InvalidFPRReg)
 112     {
 113         GenerationInfo& info = m_generationInfo[spillMe];
 114         ASSERT(info.registerFormat() == DataFormatDouble);
 115
 116         if (!info.needsSpill() || (info.fpr() == exclude))
 117             return;
 118
 119         boxDouble(info.fpr(), canTrample);
 120         m_jit.storePtr(canTrample, JITCompiler::addressFor(spillMe));
 121     }
 122
 123     void silentFillGPR(VirtualRegister spillMe, GPRReg exclude = InvalidGPRReg)
 124     {
 125         GenerationInfo& info = m_generationInfo[spillMe];
 126         if (info.gpr() == exclude)
 127             return;
 128
 129         NodeIndex nodeIndex = info.nodeIndex();
 130         Node& node = m_jit.graph()[nodeIndex];
 131         ASSERT(info.registerFormat() != DataFormatNone && info.registerFormat() != DataFormatDouble);
 132         DataFormat registerFormat = info.registerFormat();
 133
 134         if (registerFormat == DataFormatInteger) {
 135             if (node.isConstant()) {
 136                 ASSERT(isInt32Constant(nodeIndex));
 137                 m_jit.move(Imm32(valueOfInt32Constant(nodeIndex)), info.gpr());
 138             } else
 139                 m_jit.load32(JITCompiler::addressFor(spillMe), info.gpr());
 140             return;
 141         }
 142
 143         if (node.isConstant())
 144             m_jit.move(constantAsJSValueAsImmPtr(nodeIndex), info.gpr());
 145         else {
 146             ASSERT(registerFormat & DataFormatJS || registerFormat == DataFormatCell);
 147             m_jit.loadPtr(JITCompiler::addressFor(spillMe), info.gpr());
 148         }
 149     }
 150     void silentFillFPR(VirtualRegister spillMe, GPRReg canTrample, FPRReg exclude = InvalidFPRReg)
 151     {
 152         GenerationInfo& info = m_generationInfo[spillMe];
 153         if (info.fpr() == exclude)
 154             return;
 155
 156         NodeIndex nodeIndex = info.nodeIndex();
 157         Node& node = m_jit.graph()[nodeIndex];
 158         ASSERT(info.registerFormat() == DataFormatDouble);
 159
 160         if (node.isConstant())
 161             m_jit.move(constantAsJSValueAsImmPtr(nodeIndex), info.gpr());
 162         else {
 163             m_jit.loadPtr(JITCompiler::addressFor(spillMe), canTrample);
 164             unboxDouble(canTrample, info.fpr());
 165         }
 166     }
 167
 168     void silentSpillAllRegisters(GPRReg exclude, GPRReg preserve = InvalidGPRReg)
 169     {
 170         GPRReg canTrample = GPRInfo::regT0;
 171         if (preserve == GPRInfo::regT0)
 172             canTrample = GPRInfo::regT1;
 173
 174         for (gpr_iterator iter = m_gprs.begin(); iter != m_gprs.end(); ++iter) {
 175             if (iter.name() != InvalidVirtualRegister)
 176                 silentSpillGPR(iter.name(), exclude);
 177         }
 178         for (fpr_iterator iter = m_fprs.begin(); iter != m_fprs.end(); ++iter) {
 179             if (iter.name() != InvalidVirtualRegister)
 180                 silentSpillFPR(iter.name(), canTrample);
 181         }
 182     }
 183     void silentSpillAllRegisters(FPRReg exclude, GPRReg preserve = InvalidGPRReg)
 184     {
 185         GPRReg canTrample = GPRInfo::regT0;
 186         if (preserve == GPRInfo::regT0)
 187             canTrample = GPRInfo::regT1;
 188
 189         for (gpr_iterator iter = m_gprs.begin(); iter != m_gprs.end(); ++iter) {
 190             if (iter.name() != InvalidVirtualRegister)
 191                 silentSpillGPR(iter.name());
 192         }
 193         for (fpr_iterator iter = m_fprs.begin(); iter != m_fprs.end(); ++iter) {
 194             if (iter.name() != InvalidVirtualRegister)
 195                 silentSpillFPR(iter.name(), canTrample, exclude);
 196         }
 197     }
 198     void silentFillAllRegisters(GPRReg exclude)
 199     {
 200         GPRReg canTrample = GPRInfo::regT0;
 201         if (exclude == GPRInfo::regT0)
 202             canTrample = GPRInfo::regT1;
 203
 204         for (fpr_iterator iter = m_fprs.begin(); iter != m_fprs.end(); ++iter) {
 205             if (iter.name() != InvalidVirtualRegister)
 206                 silentFillFPR(iter.name(), canTrample);
 207         }
 208         for (gpr_iterator iter = m_gprs.begin(); iter != m_gprs.end(); ++iter) {
 209             if (iter.name() != InvalidVirtualRegister)
 210                 silentFillGPR(iter.name(), exclude);
 211         }
 212     }
 213     void silentFillAllRegisters(FPRReg exclude)
 214     {
 215         GPRReg canTrample = GPRInfo::regT0;
 216
 217         for (fpr_iterator iter = m_fprs.begin(); iter != m_fprs.end(); ++iter) {
 218             if (iter.name() != InvalidVirtualRegister) {
 219                 ASSERT_UNUSED(exclude, iter.regID() != exclude);
 220                 silentFillFPR(iter.name(), canTrample, exclude);
 221             }
 222         }
 223         for (gpr_iterator iter = m_gprs.begin(); iter != m_gprs.end(); ++iter) {
 224             if (iter.name() != InvalidVirtualRegister)
 225                 silentFillGPR(iter.name());
 226         }
 227     }
 228
 229     // These methods are used to plant calls out to C++
 230     // helper routines to convert between types.
 231     void valueToNumber(JSValueOperand&, FPRReg result);
 232     void valueToInt32(JSValueOperand&, GPRReg result);
 233     void numberToInt32(FPRReg, GPRReg result);
 234
 235     // Record an entry location into the non-speculative code path;
 236     // for every bail-out on the speculative path we record information
 237     // to be able to re-enter into the non-speculative one.
 238     void trackEntry(MacroAssembler::Label entry)
 239     {
 240         m_entryLocations.append(EntryLocation(entry, this));
 241     }
 242
 243     EntryLocationVector m_entryLocations;
 244 };
 245
 246 } } // namespace JSC::DFG
 247
 248 #endif
 249 #endif
 250