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

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

// Copyright (c) 2010 ARM Limited
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// Copyright (c) 2007-2008 The Florida State University
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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 COND_CODE {
0xF: ArmUnconditional::armUnconditional();
default: decode ENCODING {
format DataOp {
    0x0: decode SEVEN_AND_FOUR {
        1: decode MISC_OPCODE {
            0x9: decode PREPOST {
                0: ArmMultAndMultAcc::armMultAndMultAcc();
                1: ArmSyncMem::armSyncMem();
            }
            0xb, 0xd, 0xf: AddrMode3::addrMode3();
        }
        0: decode IS_MISC {
            0: ArmDataProcReg::armDataProcReg();
            1: decode OPCODE_7 {
                0x0: decode MISC_OPCODE {
                    0x0: ArmMsrMrs::armMsrMrs();
                    // bxj unimplemented, treated as bx
                    0x1,0x2: ArmBxClz::armBxClz();
                    0x3: decode OPCODE {
                        0x9: ArmBlxReg::armBlxReg();
                    }
                    0x5: ArmSatAddSub::armSatAddSub();
                }
                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({{ ; }});
#if FULL_SYSTEM
                    1: PredImmOp::yield({{ ; }});
                    2: PredImmOp::wfe({{
                        if (SevMailbox)
                            SevMailbox = 0;
                        else
                            PseudoInst::quiesce(xc->tcBase());
                    }}, IsNonSpeculative, IsQuiesce);
                    3: PredImmOp::wfi({{
                            PseudoInst::quiesce(xc->tcBase());
                    }}, IsNonSpeculative, IsQuiesce);
                    4: PredImmOp::sev({{
                        // Need a way for O3 to not scoreboard these
                        // accesses as pipeflushs
                        System *sys = xc->tcBase()->getSystemPtr();
                        for (int x = 0; x < sys->numContexts(); x++) {
                            ThreadContext *oc = sys->getThreadContext(x);
                            oc->setMiscReg(MISCREG_SEV_MAILBOX, 1);
                        }
                    }});
#endif
                }
                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: ArmParallelAddSubtract::armParallelAddSubtract();
            0x1: ArmPackUnpackSatReverse::armPackUnpackSatReverse();
            0x2: ArmSignedMultiplies::armSignedMultiplies();
            0x3: ArmMiscMedia::armMiscMedia();
        }
    }
    0x4: ArmMacroMem::armMacroMem();
    0x5: decode OPCODE_24 {
        0: ArmBBlxImm::armBBlxImm();
        1: ArmBlBlxImm::armBlBlxImm();
    }
    0x6: decode CPNUM {
        0xa, 0xb: ExtensionRegLoadStore::extensionRegLoadStore();
    }
    0x7: decode OPCODE_24 {
        0: decode OPCODE_4 {
            0: decode CPNUM {
                0xa, 0xb: VfpData::vfpData();
            } // 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, 0xb: ShortFpTransfer::shortFpTransfer();
                0xf: McrMrc15::mcrMrc15();
            } // CPNUM  (OP4 == 1)
        } //OPCODE_4

        1: Svc::svc();
    } // OPCODE_24

}
}
}