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path: root/js/src/jit/arm/disasm/Constants-arm.cpp
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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * vim: set ts=8 sts=4 et sw=4 tw=99:
 */
// Copyright 2009 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 "jit/arm/disasm/Constants-arm.h"

#ifdef JS_DISASM_ARM

namespace js {
namespace jit {
namespace disasm {

double
Instruction::DoubleImmedVmov() const
{
    // Reconstruct a double from the immediate encoded in the vmov instruction.
    //
    //   instruction: [xxxxxxxx,xxxxabcd,xxxxxxxx,xxxxefgh]
    //   double: [aBbbbbbb,bbcdefgh,00000000,00000000,
    //            00000000,00000000,00000000,00000000]
    //
    // where B = ~b. Only the high 16 bits are affected.
    uint64_t high16;
    high16  = (Bits(17, 16) << 4) | Bits(3, 0);   // xxxxxxxx,xxcdefgh.
    high16 |= (0xff * Bit(18)) << 6;              // xxbbbbbb,bbxxxxxx.
    high16 |= (Bit(18) ^ 1) << 14;                // xBxxxxxx,xxxxxxxx.
    high16 |= Bit(19) << 15;                      // axxxxxxx,xxxxxxxx.

    uint64_t imm = high16 << 48;
    double d;
    memcpy(&d, &imm, 8);
    return d;
}


// These register names are defined in a way to match the native disassembler
// formatting. See for example the command "objdump -d <binary file>".
const char* Registers::names_[kNumRegisters] = {
    "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
    "r8", "r9", "r10", "fp", "ip", "sp", "lr", "pc",
};


// List of alias names which can be used when referring to ARM registers.
const Registers::RegisterAlias Registers::aliases_[] = {
    {10, "sl"},
    {11, "r11"},
    {12, "r12"},
    {13, "r13"},
    {14, "r14"},
    {15, "r15"},
    {kNoRegister, NULL}
};


const char*
Registers::Name(int reg)
{
    const char* result;
    if ((0 <= reg) && (reg < kNumRegisters)) {
        result = names_[reg];
    } else {
        result = "noreg";
    }
    return result;
}


// Support for VFP registers s0 to s31 (d0 to d15) and d16-d31.
// Note that "sN:sM" is the same as "dN/2" up to d15.
// These register names are defined in a way to match the native disassembler
// formatting. See for example the command "objdump -d <binary file>".
const char* VFPRegisters::names_[kNumVFPRegisters] = {
    "s0", "s1", "s2", "s3", "s4", "s5", "s6", "s7",
    "s8", "s9", "s10", "s11", "s12", "s13", "s14", "s15",
    "s16", "s17", "s18", "s19", "s20", "s21", "s22", "s23",
    "s24", "s25", "s26", "s27", "s28", "s29", "s30", "s31",
    "d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7",
    "d8", "d9", "d10", "d11", "d12", "d13", "d14", "d15",
    "d16", "d17", "d18", "d19", "d20", "d21", "d22", "d23",
    "d24", "d25", "d26", "d27", "d28", "d29", "d30", "d31"
};


const char*
VFPRegisters::Name(int reg, bool is_double)
{
    MOZ_ASSERT((0 <= reg) && (reg < kNumVFPRegisters));
    return names_[reg + (is_double ? kNumVFPSingleRegisters : 0)];
}


int
VFPRegisters::Number(const char* name, bool* is_double)
{
    for (int i = 0; i < kNumVFPRegisters; i++) {
        if (strcmp(names_[i], name) == 0) {
            if (i < kNumVFPSingleRegisters) {
                *is_double = false;
                return i;
            } else {
                *is_double = true;
                return i - kNumVFPSingleRegisters;
            }
        }
    }

    // No register with the requested name found.
    return kNoRegister;
}


int
Registers::Number(const char* name)
{
    // Look through the canonical names.
    for (int i = 0; i < kNumRegisters; i++) {
        if (strcmp(names_[i], name) == 0) {
            return i;
        }
    }

    // Look through the alias names.
    int i = 0;
    while (aliases_[i].reg != kNoRegister) {
        if (strcmp(aliases_[i].name, name) == 0) {
            return aliases_[i].reg;
        }
        i++;
    }

    // No register with the requested name found.
    return kNoRegister;
}


}  // namespace disasm
}  // namespace jit
}  // namespace js

#endif // JS_DISASM_ARM