xref: /gem5/src/arch/arm/isa/decoder/arm.isa

// -*- mode:c++ -*-

// Copyright (c) 2010 ARM Limited
// All rights reserved
//
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// property including but not limited to intellectual property relating
// to a hardware implementation of the functionality of the software
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// terms below provided that you ensure that this notice is replicated
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// modified or unmodified, in source code or in binary form.
//
// Copyright (c) 2007-2008 The Florida State University
// All rights reserved.
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// modification, are permitted provided that the following conditions are
// met: redistributions of source code must retain the above copyright
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// Authors: Stephen Hines

////////////////////////////////////////////////////////////////////
//
// The actual ARM ISA decoder
// --------------------------
// The following instructions are specified in the ARM ISA
// Specification. Decoding closely follows the style specified
// in the ARM ISA specification document starting with Table B.1 or 3-1
//
//

0: decode ENCODING {
format DataOp {
    0x0: decode SEVEN_AND_FOUR {
        1: decode MISC_OPCODE {
            0x9: decode PREPOST {
                0: ArmMultAndMultAcc::armMultAndMultAcc();
                1: decode PUBWL {
                    0x10: WarnUnimpl::swp();
                    0x14: WarnUnimpl::swpb();
                    0x18: WarnUnimpl::strex();
                    0x19: WarnUnimpl::ldrex();
                }
            }
            0xb, 0xd, 0xf: AddrMode3::addrMode3();
        }
        0: decode IS_MISC {
            0: ArmDataProcReg::armDataProcReg();
            1: decode OPCODE_7 {
                0x0: decode MISC_OPCODE {
                    0x0: decode OPCODE {
                        0x8: PredOp::mrs_cpsr({{
                            Rd = (Cpsr | CondCodes) & 0xF8FF03DF;
                        }});
                        0x9: decode USEIMM {
                            // The mask field is the same as the RN index.
                            0: PredOp::msr_cpsr_reg({{
                                uint32_t newCpsr =
                                    cpsrWriteByInstr(Cpsr | CondCodes,
                                                     Rm, RN, false);
                                Cpsr = ~CondCodesMask & newCpsr;
                                CondCodes = CondCodesMask & newCpsr;
                            }});
                            1: PredImmOp::msr_cpsr_imm({{
                                uint32_t newCpsr =
                                    cpsrWriteByInstr(Cpsr | CondCodes,
                                                     rotated_imm, RN, false);
                                Cpsr = ~CondCodesMask & newCpsr;
                                CondCodes = CondCodesMask & newCpsr;
                            }});
                        }
                        0xa: PredOp::mrs_spsr({{ Rd = Spsr; }});
                        0xb: decode USEIMM {
                            // The mask field is the same as the RN index.
                            0: PredOp::msr_spsr_reg({{
                                Spsr = spsrWriteByInstr(Spsr, Rm, RN, false);
                            }});
                            1: PredImmOp::msr_spsr_imm({{
                                Spsr = spsrWriteByInstr(Spsr, rotated_imm,
                                                        RN, false);
                            }});
                        }
                    }
                    0x1: decode OPCODE {
                        0x9: ArmBx::armBx();
                        0xb: PredOp::clz({{
                            Rd = ((Rm == 0) ? 32 : (31 - findMsbSet(Rm)));
                        }});
                    }
                    0x2: decode OPCODE {
                        0x9: WarnUnimpl::bxj();
                    }
                    0x3: decode OPCODE {
                        0x9: ArmBlxReg::armBlxReg();
                    }
                    0x5: decode OPCODE {
                        0x8: WarnUnimpl::qadd();
                        0x9: WarnUnimpl::qsub();
                        0xa: WarnUnimpl::qdadd();
                        0xb: WarnUnimpl::qdsub();
                    }
                }
                0x1: ArmHalfWordMultAndMultAcc::armHalfWordMultAndMultAcc();
            }
        }
    }
    0x1: decode IS_MISC {
        0: ArmDataProcImm::armDataProcImm();
        1: decode OPCODE {
            // The following two instructions aren't supposed to be defined
            0x8: DataOp::movw({{ Rd = IMMED_11_0 | (RN << 12) ; }});
            0x9: decode RN {
                0: decode IMM {
                    0: PredImmOp::nop({{ ; }});
                    1: WarnUnimpl::yield();
                    2: WarnUnimpl::wfe();
                    3: WarnUnimpl::wfi();
                    4: WarnUnimpl::sev();
                }
                default: PredImmOp::msr_i_cpsr({{
                            uint32_t newCpsr =
                                cpsrWriteByInstr(Cpsr | CondCodes,
                                                 rotated_imm, RN, false);
                            Cpsr = ~CondCodesMask & newCpsr;
                            CondCodes = CondCodesMask & newCpsr;
                }});
            }
            0xa: PredOp::movt({{ Rd = IMMED_11_0 << 16 | RN << 28 | Rd<15:0>; }});
            0xb: PredImmOp::msr_i_spsr({{
                       Spsr = spsrWriteByInstr(Spsr, rotated_imm, RN, false);
            }});
        }
    }
    0x2: AddrMode2::addrMode2(True);
    0x3: decode OPCODE_4 {
        0: AddrMode2::addrMode2(False);
        1: decode OPCODE_24_23 {
            0x0: WarnUnimpl::parallel_add_subtract_instructions();
            0x1: decode MEDIA_OPCODE {
                0x8: decode MISC_OPCODE {
                    0x1, 0x9: WarnUnimpl::pkhbt();
                    0x7: WarnUnimpl::sxtab16();
                    0xb: WarnUnimpl::sel();
                    0x5, 0xd: WarnUnimpl::pkhtb();
                    0x3: WarnUnimpl::sign_zero_extend_add();
                }
                0xa, 0xb: decode SHIFT {
                    0x0, 0x2: WarnUnimpl::ssat();
                    0x1: WarnUnimpl::ssat16();
                }
                0xe, 0xf: decode SHIFT {
                    0x0, 0x2: WarnUnimpl::usat();
                    0x1: WarnUnimpl::usat16();
                }
            }
            0x2: ArmSignedMultiplies::armSignedMultiplies();
            0x3: decode MEDIA_OPCODE {
                0x18: decode RN {
                    0xf: WarnUnimpl::usada8();
                    default: WarnUnimpl::usad8();
                }
            }
        }
    }
    0x4: ArmMacroMem::armMacroMem();
    0x5: decode OPCODE_24 {
        0: ArmBBlxImm::armBBlxImm();
        1: ArmBlBlxImm::armBlBlxImm();
    }
    0x6: decode CPNUM {
        0xb: decode LOADOP {
            0x0: WarnUnimpl::fstmx();
            0x1: WarnUnimpl::fldmx();
        }
    }
    0x7: decode OPCODE_24 {
        0: decode OPCODE_4 {
            0: decode CPNUM {
                0xa, 0xb: decode OPCODE_23_20 {
##include "vfp.isa"
                }
            } // CPNUM
            1: decode CPNUM { // 27-24=1110,4 ==1
                1: decode OPCODE_15_12 {
                    format FloatOp {
                        0xf: decode OPCODE_23_21 {
                            format FloatCmp {
                                0x4: cmf({{ Fn.df }}, {{ Fm.df }});
                                0x5: cnf({{ Fn.df }}, {{ -Fm.df }});
                                0x6: cmfe({{ Fn.df }}, {{ Fm.df}});
                                0x7: cnfe({{ Fn.df }}, {{ -Fm.df}});
                            }
                        }
                        default: decode OPCODE_23_20 {
                            0x0: decode OPCODE_7 {
                                0: flts({{ Fn.sf = (float) Rd.sw; }});
                                1: fltd({{ Fn.df = (double) Rd.sw; }});
                            }
                            0x1: decode OPCODE_7 {
                                0: fixs({{ Rd = (uint32_t) Fm.sf; }});
                                1: fixd({{ Rd = (uint32_t) Fm.df; }});
                            }
                            0x2: wfs({{ Fpsr = Rd; }});
                            0x3: rfs({{ Rd = Fpsr; }});
                            0x4: FailUnimpl::wfc();
                            0x5: FailUnimpl::rfc();
                        }
                    } // format FloatOp
                }
                0xa: decode MISC_OPCODE {
                    0x1: decode MEDIA_OPCODE {
                        0xf: decode RN {
                            0x0: FloatOp::fmrx_fpsid({{ Rd = Fpsid; }});
                            0x1: FloatOp::fmrx_fpscr({{ Rd = Fpscr; }});
                            0x8: FloatOp::fmrx_fpexc({{ Rd = Fpexc; }});
                        }
                        0xe: decode RN {
                            0x0: FloatOp::fmxr_fpsid({{ Fpsid = Rd; }});
                            0x1: FloatOp::fmxr_fpscr({{ Fpscr = Rd; }});
                            0x8: FloatOp::fmxr_fpexc({{ Fpexc = Rd; }});
                        }
                    } // MEDIA_OPCODE (MISC_OPCODE 0x1)
                } // MISC_OPCODE (CPNUM 0xA)
                0xf: decode RN {
                    // Barrriers, Cache Maintence, NOPS
                    7: decode OPCODE_23_21 {
                        0: decode RM {
                            0: decode OPC2 {
                                4: decode OPCODE_20 {
                                    0: PredOp::mcr_cp15_nop1({{ }}); // was wfi
                                }
                            }
                            1: WarnUnimpl::cp15_cache_maint();
                            4: WarnUnimpl::cp15_par();
                            5: decode OPC2 {
                                0,1: WarnUnimpl::cp15_cache_maint2();
                                4: PredOp::cp15_isb({{ ; }}, IsMemBarrier, IsSerializeBefore);
                                6,7: WarnUnimpl::cp15_bp_maint();
                            }
                            6: WarnUnimpl::cp15_cache_maint3();
                            8: WarnUnimpl::cp15_va_to_pa();
                            10: decode OPC2 {
                                1,2: WarnUnimpl::cp15_cache_maint3();
                                4: PredOp::cp15_dsb({{ ; }}, IsMemBarrier, IsSerializeBefore);
                                5: PredOp::cp15_dmb({{ ; }}, IsMemBarrier, IsSerializeBefore);
                            }
                            11: WarnUnimpl::cp15_cache_maint4();
                            13: decode OPC2 {
                                1: decode OPCODE_20 {
                                    0: PredOp::mcr_cp15_nop2({{ }}); // was prefetch
                                }
                            }
                            14: WarnUnimpl::cp15_cache_maint5();
                        } // RM
                    } // OPCODE_23_21 CR

                    // Thread ID and context ID registers
                    // Thread ID register needs cheaper access than miscreg
                    13: WarnUnimpl::mcr_mrc_cp15_c7();

                    // All the rest
                    default: decode OPCODE_20 {
                        0: PredOp::mcr_cp15({{
                               fault = setCp15Register(Rd, RN, OPCODE_23_21, RM, OPC2);
                        }});
                        1: PredOp::mrc_cp15({{
                               fault = readCp15Register(Rd, RN, OPCODE_23_21, RM, OPC2);
                        }});
                    }
                }  // RN
            } // CPNUM  (OP4 == 1)
        } //OPCODE_4

#if FULL_SYSTEM
        1: PredOp::swi({{ fault = new SupervisorCall; }}, IsSerializeAfter, IsNonSpeculative, IsSyscall);
#else
        1: PredOp::swi({{ if (testPredicate(CondCodes, condCode))
            {
                if (IMMED_23_0)
                    xc->syscall(IMMED_23_0);
                else
                    xc->syscall(R7);
            }
        }});
#endif // FULL_SYSTEM
    } // OPCODE_24

}
}