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Constants-arm.cpp (3801B)


      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
      2 * vim: set ts=8 sts=2 et sw=2 tw=80:
      3 */
      4 // Copyright 2009 the V8 project authors. All rights reserved.
      5 // Use of this source code is governed by a BSD-style license that can be
      6 // found in the LICENSE file.
      7 
      8 #include "jit/arm/disasm/Constants-arm.h"
      9 
     10 #ifdef JS_DISASM_ARM
     11 
     12 namespace js {
     13 namespace jit {
     14 namespace disasm {
     15 
     16 double Instruction::DoubleImmedVmov() const {
     17  // Reconstruct a double from the immediate encoded in the vmov instruction.
     18  //
     19  //   instruction: [xxxxxxxx,xxxxabcd,xxxxxxxx,xxxxefgh]
     20  //   double: [aBbbbbbb,bbcdefgh,00000000,00000000,
     21  //            00000000,00000000,00000000,00000000]
     22  //
     23  // where B = ~b. Only the high 16 bits are affected.
     24  uint64_t high16;
     25  high16 = (Bits(17, 16) << 4) | Bits(3, 0);  // xxxxxxxx,xxcdefgh.
     26  high16 |= (0xff * Bit(18)) << 6;            // xxbbbbbb,bbxxxxxx.
     27  high16 |= (Bit(18) ^ 1) << 14;              // xBxxxxxx,xxxxxxxx.
     28  high16 |= Bit(19) << 15;                    // axxxxxxx,xxxxxxxx.
     29 
     30  uint64_t imm = high16 << 48;
     31  double d;
     32  memcpy(&d, &imm, 8);
     33  return d;
     34 }
     35 
     36 // These register names are defined in a way to match the native disassembler
     37 // formatting. See for example the command "objdump -d <binary file>".
     38 const char* Registers::names_[kNumRegisters] = {
     39    "r0", "r1", "r2",  "r3", "r4", "r5", "r6", "r7",
     40    "r8", "r9", "r10", "fp", "ip", "sp", "lr", "pc",
     41 };
     42 
     43 // List of alias names which can be used when referring to ARM registers.
     44 const Registers::RegisterAlias Registers::aliases_[] = {
     45    {10, "sl"},  {11, "r11"}, {12, "r12"},        {13, "r13"},
     46    {14, "r14"}, {15, "r15"}, {kNoRegister, NULL}};
     47 
     48 const char* Registers::Name(int reg) {
     49  const char* result;
     50  if ((0 <= reg) && (reg < kNumRegisters)) {
     51    result = names_[reg];
     52  } else {
     53    result = "noreg";
     54  }
     55  return result;
     56 }
     57 
     58 // Support for VFP registers s0 to s31 (d0 to d15) and d16-d31.
     59 // Note that "sN:sM" is the same as "dN/2" up to d15.
     60 // These register names are defined in a way to match the native disassembler
     61 // formatting. See for example the command "objdump -d <binary file>".
     62 const char* VFPRegisters::names_[kNumVFPRegisters] = {
     63    "s0",  "s1",  "s2",  "s3",  "s4",  "s5",  "s6",  "s7",  "s8",  "s9",  "s10",
     64    "s11", "s12", "s13", "s14", "s15", "s16", "s17", "s18", "s19", "s20", "s21",
     65    "s22", "s23", "s24", "s25", "s26", "s27", "s28", "s29", "s30", "s31", "d0",
     66    "d1",  "d2",  "d3",  "d4",  "d5",  "d6",  "d7",  "d8",  "d9",  "d10", "d11",
     67    "d12", "d13", "d14", "d15", "d16", "d17", "d18", "d19", "d20", "d21", "d22",
     68    "d23", "d24", "d25", "d26", "d27", "d28", "d29", "d30", "d31"};
     69 
     70 const char* VFPRegisters::Name(int reg, bool is_double) {
     71  MOZ_ASSERT((0 <= reg) && (reg < kNumVFPRegisters));
     72  return names_[reg + (is_double ? kNumVFPSingleRegisters : 0)];
     73 }
     74 
     75 int VFPRegisters::Number(const char* name, bool* is_double) {
     76  for (int i = 0; i < kNumVFPRegisters; i++) {
     77    if (strcmp(names_[i], name) == 0) {
     78      if (i < kNumVFPSingleRegisters) {
     79        *is_double = false;
     80        return i;
     81      } else {
     82        *is_double = true;
     83        return i - kNumVFPSingleRegisters;
     84      }
     85    }
     86  }
     87 
     88  // No register with the requested name found.
     89  return kNoRegister;
     90 }
     91 
     92 int Registers::Number(const char* name) {
     93  // Look through the canonical names.
     94  for (int i = 0; i < kNumRegisters; i++) {
     95    if (strcmp(names_[i], name) == 0) {
     96      return i;
     97    }
     98  }
     99 
    100  // Look through the alias names.
    101  int i = 0;
    102  while (aliases_[i].reg != kNoRegister) {
    103    if (strcmp(aliases_[i].name, name) == 0) {
    104      return aliases_[i].reg;
    105    }
    106    i++;
    107  }
    108 
    109  // No register with the requested name found.
    110  return kNoRegister;
    111 }
    112 
    113 }  // namespace disasm
    114 }  // namespace jit
    115 }  // namespace js
    116 
    117 #endif  // JS_DISASM_ARM