github.com/go-asm/go@v1.21.1-0.20240213172139-40c5ead50c48/cmd/compile/ssa/_gen/ARMOps.go (about)

     1  // Copyright 2016 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package main
     6  
     7  import "strings"
     8  
     9  // Notes:
    10  //  - Integer types live in the low portion of registers. Upper portions are junk.
    11  //  - Boolean types use the low-order byte of a register. 0=false, 1=true.
    12  //    Upper bytes are junk.
    13  //  - *const instructions may use a constant larger than the instruction can encode.
    14  //    In this case the assembler expands to multiple instructions and uses tmp
    15  //    register (R11).
    16  
    17  // Suffixes encode the bit width of various instructions.
    18  // W (word)      = 32 bit
    19  // H (half word) = 16 bit
    20  // HU            = 16 bit unsigned
    21  // B (byte)      = 8 bit
    22  // BU            = 8 bit unsigned
    23  // F (float)     = 32 bit float
    24  // D (double)    = 64 bit float
    25  
    26  var regNamesARM = []string{
    27  	"R0",
    28  	"R1",
    29  	"R2",
    30  	"R3",
    31  	"R4",
    32  	"R5",
    33  	"R6",
    34  	"R7",
    35  	"R8",
    36  	"R9",
    37  	"g",   // aka R10
    38  	"R11", // tmp
    39  	"R12",
    40  	"SP",  // aka R13
    41  	"R14", // link
    42  	"R15", // pc
    43  
    44  	"F0",
    45  	"F1",
    46  	"F2",
    47  	"F3",
    48  	"F4",
    49  	"F5",
    50  	"F6",
    51  	"F7",
    52  	"F8",
    53  	"F9",
    54  	"F10",
    55  	"F11",
    56  	"F12",
    57  	"F13",
    58  	"F14",
    59  	"F15", // tmp
    60  
    61  	// If you add registers, update asyncPreempt in runtime.
    62  
    63  	// pseudo-registers
    64  	"SB",
    65  }
    66  
    67  func init() {
    68  	// Make map from reg names to reg integers.
    69  	if len(regNamesARM) > 64 {
    70  		panic("too many registers")
    71  	}
    72  	num := map[string]int{}
    73  	for i, name := range regNamesARM {
    74  		num[name] = i
    75  	}
    76  	buildReg := func(s string) regMask {
    77  		m := regMask(0)
    78  		for _, r := range strings.Split(s, " ") {
    79  			if n, ok := num[r]; ok {
    80  				m |= regMask(1) << uint(n)
    81  				continue
    82  			}
    83  			panic("register " + r + " not found")
    84  		}
    85  		return m
    86  	}
    87  
    88  	// Common individual register masks
    89  	var (
    90  		gp         = buildReg("R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R12 R14")
    91  		gpg        = gp | buildReg("g")
    92  		gpsp       = gp | buildReg("SP")
    93  		gpspg      = gpg | buildReg("SP")
    94  		gpspsbg    = gpspg | buildReg("SB")
    95  		fp         = buildReg("F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 F14 F15")
    96  		callerSave = gp | fp | buildReg("g") // runtime.setg (and anything calling it) may clobber g
    97  		r0         = buildReg("R0")
    98  		r1         = buildReg("R1")
    99  		r2         = buildReg("R2")
   100  		r3         = buildReg("R3")
   101  		r4         = buildReg("R4")
   102  	)
   103  	// Common regInfo
   104  	var (
   105  		gp01      = regInfo{inputs: nil, outputs: []regMask{gp}}
   106  		gp11      = regInfo{inputs: []regMask{gpg}, outputs: []regMask{gp}}
   107  		gp11carry = regInfo{inputs: []regMask{gpg}, outputs: []regMask{gp, 0}}
   108  		gp11sp    = regInfo{inputs: []regMask{gpspg}, outputs: []regMask{gp}}
   109  		gp1flags  = regInfo{inputs: []regMask{gpg}}
   110  		gp1flags1 = regInfo{inputs: []regMask{gp}, outputs: []regMask{gp}}
   111  		gp21      = regInfo{inputs: []regMask{gpg, gpg}, outputs: []regMask{gp}}
   112  		gp21carry = regInfo{inputs: []regMask{gpg, gpg}, outputs: []regMask{gp, 0}}
   113  		gp2flags  = regInfo{inputs: []regMask{gpg, gpg}}
   114  		gp2flags1 = regInfo{inputs: []regMask{gp, gp}, outputs: []regMask{gp}}
   115  		gp22      = regInfo{inputs: []regMask{gpg, gpg}, outputs: []regMask{gp, gp}}
   116  		gp31      = regInfo{inputs: []regMask{gp, gp, gp}, outputs: []regMask{gp}}
   117  		gp31carry = regInfo{inputs: []regMask{gp, gp, gp}, outputs: []regMask{gp, 0}}
   118  		gp3flags  = regInfo{inputs: []regMask{gp, gp, gp}}
   119  		gp3flags1 = regInfo{inputs: []regMask{gp, gp, gp}, outputs: []regMask{gp}}
   120  		gpload    = regInfo{inputs: []regMask{gpspsbg}, outputs: []regMask{gp}}
   121  		gpstore   = regInfo{inputs: []regMask{gpspsbg, gpg}}
   122  		gp2load   = regInfo{inputs: []regMask{gpspsbg, gpg}, outputs: []regMask{gp}}
   123  		gp2store  = regInfo{inputs: []regMask{gpspsbg, gpg, gpg}}
   124  		fp01      = regInfo{inputs: nil, outputs: []regMask{fp}}
   125  		fp11      = regInfo{inputs: []regMask{fp}, outputs: []regMask{fp}}
   126  		fp1flags  = regInfo{inputs: []regMask{fp}}
   127  		fpgp      = regInfo{inputs: []regMask{fp}, outputs: []regMask{gp}, clobbers: buildReg("F15")} // int-float conversion uses F15 as tmp
   128  		gpfp      = regInfo{inputs: []regMask{gp}, outputs: []regMask{fp}, clobbers: buildReg("F15")}
   129  		fp21      = regInfo{inputs: []regMask{fp, fp}, outputs: []regMask{fp}}
   130  		fp31      = regInfo{inputs: []regMask{fp, fp, fp}, outputs: []regMask{fp}}
   131  		fp2flags  = regInfo{inputs: []regMask{fp, fp}}
   132  		fpload    = regInfo{inputs: []regMask{gpspsbg}, outputs: []regMask{fp}}
   133  		fpstore   = regInfo{inputs: []regMask{gpspsbg, fp}}
   134  		readflags = regInfo{inputs: nil, outputs: []regMask{gp}}
   135  	)
   136  	ops := []opData{
   137  		// binary ops
   138  		{name: "ADD", argLength: 2, reg: gp21, asm: "ADD", commutative: true},     // arg0 + arg1
   139  		{name: "ADDconst", argLength: 1, reg: gp11sp, asm: "ADD", aux: "Int32"},   // arg0 + auxInt
   140  		{name: "SUB", argLength: 2, reg: gp21, asm: "SUB"},                        // arg0 - arg1
   141  		{name: "SUBconst", argLength: 1, reg: gp11, asm: "SUB", aux: "Int32"},     // arg0 - auxInt
   142  		{name: "RSB", argLength: 2, reg: gp21, asm: "RSB"},                        // arg1 - arg0
   143  		{name: "RSBconst", argLength: 1, reg: gp11, asm: "RSB", aux: "Int32"},     // auxInt - arg0
   144  		{name: "MUL", argLength: 2, reg: gp21, asm: "MUL", commutative: true},     // arg0 * arg1
   145  		{name: "HMUL", argLength: 2, reg: gp21, asm: "MULL", commutative: true},   // (arg0 * arg1) >> 32, signed
   146  		{name: "HMULU", argLength: 2, reg: gp21, asm: "MULLU", commutative: true}, // (arg0 * arg1) >> 32, unsigned
   147  
   148  		// udiv runtime call for soft division
   149  		// output0 = arg0/arg1, output1 = arg0%arg1
   150  		// see ../../../../../runtime/vlop_arm.s
   151  		{
   152  			name:      "CALLudiv",
   153  			argLength: 2,
   154  			reg: regInfo{
   155  				inputs:   []regMask{buildReg("R1"), buildReg("R0")},
   156  				outputs:  []regMask{buildReg("R0"), buildReg("R1")},
   157  				clobbers: buildReg("R2 R3 R12 R14"), // R14 is LR, R12 is linker trampoline scratch register
   158  			},
   159  			clobberFlags: true,
   160  			typ:          "(UInt32,UInt32)",
   161  			call:         false, // TODO(mdempsky): Should this be true?
   162  		},
   163  
   164  		{name: "ADDS", argLength: 2, reg: gp21carry, asm: "ADD", commutative: true}, // arg0 + arg1, set carry flag
   165  		{name: "ADDSconst", argLength: 1, reg: gp11carry, asm: "ADD", aux: "Int32"}, // arg0 + auxInt, set carry flag
   166  		{name: "ADC", argLength: 3, reg: gp2flags1, asm: "ADC", commutative: true},  // arg0 + arg1 + carry, arg2=flags
   167  		{name: "ADCconst", argLength: 2, reg: gp1flags1, asm: "ADC", aux: "Int32"},  // arg0 + auxInt + carry, arg1=flags
   168  		{name: "SUBS", argLength: 2, reg: gp21carry, asm: "SUB"},                    // arg0 - arg1, set carry flag
   169  		{name: "SUBSconst", argLength: 1, reg: gp11carry, asm: "SUB", aux: "Int32"}, // arg0 - auxInt, set carry flag
   170  		{name: "RSBSconst", argLength: 1, reg: gp11carry, asm: "RSB", aux: "Int32"}, // auxInt - arg0, set carry flag
   171  		{name: "SBC", argLength: 3, reg: gp2flags1, asm: "SBC"},                     // arg0 - arg1 - carry, arg2=flags
   172  		{name: "SBCconst", argLength: 2, reg: gp1flags1, asm: "SBC", aux: "Int32"},  // arg0 - auxInt - carry, arg1=flags
   173  		{name: "RSCconst", argLength: 2, reg: gp1flags1, asm: "RSC", aux: "Int32"},  // auxInt - arg0 - carry, arg1=flags
   174  
   175  		{name: "MULLU", argLength: 2, reg: gp22, asm: "MULLU", commutative: true}, // arg0 * arg1, high 32 bits in out0, low 32 bits in out1
   176  		{name: "MULA", argLength: 3, reg: gp31, asm: "MULA"},                      // arg0 * arg1 + arg2
   177  		{name: "MULS", argLength: 3, reg: gp31, asm: "MULS"},                      // arg2 - arg0 * arg1
   178  
   179  		{name: "ADDF", argLength: 2, reg: fp21, asm: "ADDF", commutative: true},   // arg0 + arg1
   180  		{name: "ADDD", argLength: 2, reg: fp21, asm: "ADDD", commutative: true},   // arg0 + arg1
   181  		{name: "SUBF", argLength: 2, reg: fp21, asm: "SUBF"},                      // arg0 - arg1
   182  		{name: "SUBD", argLength: 2, reg: fp21, asm: "SUBD"},                      // arg0 - arg1
   183  		{name: "MULF", argLength: 2, reg: fp21, asm: "MULF", commutative: true},   // arg0 * arg1
   184  		{name: "MULD", argLength: 2, reg: fp21, asm: "MULD", commutative: true},   // arg0 * arg1
   185  		{name: "NMULF", argLength: 2, reg: fp21, asm: "NMULF", commutative: true}, // -(arg0 * arg1)
   186  		{name: "NMULD", argLength: 2, reg: fp21, asm: "NMULD", commutative: true}, // -(arg0 * arg1)
   187  		{name: "DIVF", argLength: 2, reg: fp21, asm: "DIVF"},                      // arg0 / arg1
   188  		{name: "DIVD", argLength: 2, reg: fp21, asm: "DIVD"},                      // arg0 / arg1
   189  
   190  		{name: "MULAF", argLength: 3, reg: fp31, asm: "MULAF", resultInArg0: true}, // arg0 + (arg1 * arg2)
   191  		{name: "MULAD", argLength: 3, reg: fp31, asm: "MULAD", resultInArg0: true}, // arg0 + (arg1 * arg2)
   192  		{name: "MULSF", argLength: 3, reg: fp31, asm: "MULSF", resultInArg0: true}, // arg0 - (arg1 * arg2)
   193  		{name: "MULSD", argLength: 3, reg: fp31, asm: "MULSD", resultInArg0: true}, // arg0 - (arg1 * arg2)
   194  
   195  		// FMULAD only exists on platforms with the VFPv4 instruction set.
   196  		// Any use must be preceded by a successful check of runtime.arm_support_vfpv4.
   197  		{name: "FMULAD", argLength: 3, reg: fp31, asm: "FMULAD", resultInArg0: true}, // arg0 + (arg1 * arg2)
   198  
   199  		{name: "AND", argLength: 2, reg: gp21, asm: "AND", commutative: true}, // arg0 & arg1
   200  		{name: "ANDconst", argLength: 1, reg: gp11, asm: "AND", aux: "Int32"}, // arg0 & auxInt
   201  		{name: "OR", argLength: 2, reg: gp21, asm: "ORR", commutative: true},  // arg0 | arg1
   202  		{name: "ORconst", argLength: 1, reg: gp11, asm: "ORR", aux: "Int32"},  // arg0 | auxInt
   203  		{name: "XOR", argLength: 2, reg: gp21, asm: "EOR", commutative: true}, // arg0 ^ arg1
   204  		{name: "XORconst", argLength: 1, reg: gp11, asm: "EOR", aux: "Int32"}, // arg0 ^ auxInt
   205  		{name: "BIC", argLength: 2, reg: gp21, asm: "BIC"},                    // arg0 &^ arg1
   206  		{name: "BICconst", argLength: 1, reg: gp11, asm: "BIC", aux: "Int32"}, // arg0 &^ auxInt
   207  
   208  		// bit extraction, AuxInt = Width<<8 | LSB
   209  		{name: "BFX", argLength: 1, reg: gp11, asm: "BFX", aux: "Int32"},   // extract W bits from bit L in arg0, then signed extend
   210  		{name: "BFXU", argLength: 1, reg: gp11, asm: "BFXU", aux: "Int32"}, // extract W bits from bit L in arg0, then unsigned extend
   211  
   212  		// unary ops
   213  		{name: "MVN", argLength: 1, reg: gp11, asm: "MVN"}, // ^arg0
   214  
   215  		{name: "NEGF", argLength: 1, reg: fp11, asm: "NEGF"},   // -arg0, float32
   216  		{name: "NEGD", argLength: 1, reg: fp11, asm: "NEGD"},   // -arg0, float64
   217  		{name: "SQRTD", argLength: 1, reg: fp11, asm: "SQRTD"}, // sqrt(arg0), float64
   218  		{name: "SQRTF", argLength: 1, reg: fp11, asm: "SQRTF"}, // sqrt(arg0), float32
   219  		{name: "ABSD", argLength: 1, reg: fp11, asm: "ABSD"},   // abs(arg0), float64
   220  
   221  		{name: "CLZ", argLength: 1, reg: gp11, asm: "CLZ"},     // count leading zero
   222  		{name: "REV", argLength: 1, reg: gp11, asm: "REV"},     // reverse byte order
   223  		{name: "REV16", argLength: 1, reg: gp11, asm: "REV16"}, // reverse byte order in 16-bit halfwords
   224  		{name: "RBIT", argLength: 1, reg: gp11, asm: "RBIT"},   // reverse bit order
   225  
   226  		// shifts
   227  		{name: "SLL", argLength: 2, reg: gp21, asm: "SLL"},                    // arg0 << arg1, shift amount is mod 256
   228  		{name: "SLLconst", argLength: 1, reg: gp11, asm: "SLL", aux: "Int32"}, // arg0 << auxInt, 0 <= auxInt < 32
   229  		{name: "SRL", argLength: 2, reg: gp21, asm: "SRL"},                    // arg0 >> arg1, unsigned, shift amount is mod 256
   230  		{name: "SRLconst", argLength: 1, reg: gp11, asm: "SRL", aux: "Int32"}, // arg0 >> auxInt, unsigned, 0 <= auxInt < 32
   231  		{name: "SRA", argLength: 2, reg: gp21, asm: "SRA"},                    // arg0 >> arg1, signed, shift amount is mod 256
   232  		{name: "SRAconst", argLength: 1, reg: gp11, asm: "SRA", aux: "Int32"}, // arg0 >> auxInt, signed, 0 <= auxInt < 32
   233  		{name: "SRR", argLength: 2, reg: gp21},                                // arg0 right rotate by arg1 bits
   234  		{name: "SRRconst", argLength: 1, reg: gp11, aux: "Int32"},             // arg0 right rotate by auxInt bits, 0 <= auxInt < 32
   235  
   236  		// auxInt for all of these satisfy 0 <= auxInt < 32
   237  		{name: "ADDshiftLL", argLength: 2, reg: gp21, asm: "ADD", aux: "Int32"}, // arg0 + arg1<<auxInt
   238  		{name: "ADDshiftRL", argLength: 2, reg: gp21, asm: "ADD", aux: "Int32"}, // arg0 + arg1>>auxInt, unsigned shift
   239  		{name: "ADDshiftRA", argLength: 2, reg: gp21, asm: "ADD", aux: "Int32"}, // arg0 + arg1>>auxInt, signed shift
   240  		{name: "SUBshiftLL", argLength: 2, reg: gp21, asm: "SUB", aux: "Int32"}, // arg0 - arg1<<auxInt
   241  		{name: "SUBshiftRL", argLength: 2, reg: gp21, asm: "SUB", aux: "Int32"}, // arg0 - arg1>>auxInt, unsigned shift
   242  		{name: "SUBshiftRA", argLength: 2, reg: gp21, asm: "SUB", aux: "Int32"}, // arg0 - arg1>>auxInt, signed shift
   243  		{name: "RSBshiftLL", argLength: 2, reg: gp21, asm: "RSB", aux: "Int32"}, // arg1<<auxInt - arg0
   244  		{name: "RSBshiftRL", argLength: 2, reg: gp21, asm: "RSB", aux: "Int32"}, // arg1>>auxInt - arg0, unsigned shift
   245  		{name: "RSBshiftRA", argLength: 2, reg: gp21, asm: "RSB", aux: "Int32"}, // arg1>>auxInt - arg0, signed shift
   246  		{name: "ANDshiftLL", argLength: 2, reg: gp21, asm: "AND", aux: "Int32"}, // arg0 & (arg1<<auxInt)
   247  		{name: "ANDshiftRL", argLength: 2, reg: gp21, asm: "AND", aux: "Int32"}, // arg0 & (arg1>>auxInt), unsigned shift
   248  		{name: "ANDshiftRA", argLength: 2, reg: gp21, asm: "AND", aux: "Int32"}, // arg0 & (arg1>>auxInt), signed shift
   249  		{name: "ORshiftLL", argLength: 2, reg: gp21, asm: "ORR", aux: "Int32"},  // arg0 | arg1<<auxInt
   250  		{name: "ORshiftRL", argLength: 2, reg: gp21, asm: "ORR", aux: "Int32"},  // arg0 | arg1>>auxInt, unsigned shift
   251  		{name: "ORshiftRA", argLength: 2, reg: gp21, asm: "ORR", aux: "Int32"},  // arg0 | arg1>>auxInt, signed shift
   252  		{name: "XORshiftLL", argLength: 2, reg: gp21, asm: "EOR", aux: "Int32"}, // arg0 ^ arg1<<auxInt
   253  		{name: "XORshiftRL", argLength: 2, reg: gp21, asm: "EOR", aux: "Int32"}, // arg0 ^ arg1>>auxInt, unsigned shift
   254  		{name: "XORshiftRA", argLength: 2, reg: gp21, asm: "EOR", aux: "Int32"}, // arg0 ^ arg1>>auxInt, signed shift
   255  		{name: "XORshiftRR", argLength: 2, reg: gp21, asm: "EOR", aux: "Int32"}, // arg0 ^ (arg1 right rotate by auxInt)
   256  		{name: "BICshiftLL", argLength: 2, reg: gp21, asm: "BIC", aux: "Int32"}, // arg0 &^ (arg1<<auxInt)
   257  		{name: "BICshiftRL", argLength: 2, reg: gp21, asm: "BIC", aux: "Int32"}, // arg0 &^ (arg1>>auxInt), unsigned shift
   258  		{name: "BICshiftRA", argLength: 2, reg: gp21, asm: "BIC", aux: "Int32"}, // arg0 &^ (arg1>>auxInt), signed shift
   259  		{name: "MVNshiftLL", argLength: 1, reg: gp11, asm: "MVN", aux: "Int32"}, // ^(arg0<<auxInt)
   260  		{name: "MVNshiftRL", argLength: 1, reg: gp11, asm: "MVN", aux: "Int32"}, // ^(arg0>>auxInt), unsigned shift
   261  		{name: "MVNshiftRA", argLength: 1, reg: gp11, asm: "MVN", aux: "Int32"}, // ^(arg0>>auxInt), signed shift
   262  
   263  		{name: "ADCshiftLL", argLength: 3, reg: gp2flags1, asm: "ADC", aux: "Int32"}, // arg0 + arg1<<auxInt + carry, arg2=flags
   264  		{name: "ADCshiftRL", argLength: 3, reg: gp2flags1, asm: "ADC", aux: "Int32"}, // arg0 + arg1>>auxInt + carry, unsigned shift, arg2=flags
   265  		{name: "ADCshiftRA", argLength: 3, reg: gp2flags1, asm: "ADC", aux: "Int32"}, // arg0 + arg1>>auxInt + carry, signed shift, arg2=flags
   266  		{name: "SBCshiftLL", argLength: 3, reg: gp2flags1, asm: "SBC", aux: "Int32"}, // arg0 - arg1<<auxInt - carry, arg2=flags
   267  		{name: "SBCshiftRL", argLength: 3, reg: gp2flags1, asm: "SBC", aux: "Int32"}, // arg0 - arg1>>auxInt - carry, unsigned shift, arg2=flags
   268  		{name: "SBCshiftRA", argLength: 3, reg: gp2flags1, asm: "SBC", aux: "Int32"}, // arg0 - arg1>>auxInt - carry, signed shift, arg2=flags
   269  		{name: "RSCshiftLL", argLength: 3, reg: gp2flags1, asm: "RSC", aux: "Int32"}, // arg1<<auxInt - arg0 - carry, arg2=flags
   270  		{name: "RSCshiftRL", argLength: 3, reg: gp2flags1, asm: "RSC", aux: "Int32"}, // arg1>>auxInt - arg0 - carry, unsigned shift, arg2=flags
   271  		{name: "RSCshiftRA", argLength: 3, reg: gp2flags1, asm: "RSC", aux: "Int32"}, // arg1>>auxInt - arg0 - carry, signed shift, arg2=flags
   272  
   273  		{name: "ADDSshiftLL", argLength: 2, reg: gp21carry, asm: "ADD", aux: "Int32"}, // arg0 + arg1<<auxInt, set carry flag
   274  		{name: "ADDSshiftRL", argLength: 2, reg: gp21carry, asm: "ADD", aux: "Int32"}, // arg0 + arg1>>auxInt, unsigned shift, set carry flag
   275  		{name: "ADDSshiftRA", argLength: 2, reg: gp21carry, asm: "ADD", aux: "Int32"}, // arg0 + arg1>>auxInt, signed shift, set carry flag
   276  		{name: "SUBSshiftLL", argLength: 2, reg: gp21carry, asm: "SUB", aux: "Int32"}, // arg0 - arg1<<auxInt, set carry flag
   277  		{name: "SUBSshiftRL", argLength: 2, reg: gp21carry, asm: "SUB", aux: "Int32"}, // arg0 - arg1>>auxInt, unsigned shift, set carry flag
   278  		{name: "SUBSshiftRA", argLength: 2, reg: gp21carry, asm: "SUB", aux: "Int32"}, // arg0 - arg1>>auxInt, signed shift, set carry flag
   279  		{name: "RSBSshiftLL", argLength: 2, reg: gp21carry, asm: "RSB", aux: "Int32"}, // arg1<<auxInt - arg0, set carry flag
   280  		{name: "RSBSshiftRL", argLength: 2, reg: gp21carry, asm: "RSB", aux: "Int32"}, // arg1>>auxInt - arg0, unsigned shift, set carry flag
   281  		{name: "RSBSshiftRA", argLength: 2, reg: gp21carry, asm: "RSB", aux: "Int32"}, // arg1>>auxInt - arg0, signed shift, set carry flag
   282  
   283  		{name: "ADDshiftLLreg", argLength: 3, reg: gp31, asm: "ADD"}, // arg0 + arg1<<arg2
   284  		{name: "ADDshiftRLreg", argLength: 3, reg: gp31, asm: "ADD"}, // arg0 + arg1>>arg2, unsigned shift
   285  		{name: "ADDshiftRAreg", argLength: 3, reg: gp31, asm: "ADD"}, // arg0 + arg1>>arg2, signed shift
   286  		{name: "SUBshiftLLreg", argLength: 3, reg: gp31, asm: "SUB"}, // arg0 - arg1<<arg2
   287  		{name: "SUBshiftRLreg", argLength: 3, reg: gp31, asm: "SUB"}, // arg0 - arg1>>arg2, unsigned shift
   288  		{name: "SUBshiftRAreg", argLength: 3, reg: gp31, asm: "SUB"}, // arg0 - arg1>>arg2, signed shift
   289  		{name: "RSBshiftLLreg", argLength: 3, reg: gp31, asm: "RSB"}, // arg1<<arg2 - arg0
   290  		{name: "RSBshiftRLreg", argLength: 3, reg: gp31, asm: "RSB"}, // arg1>>arg2 - arg0, unsigned shift
   291  		{name: "RSBshiftRAreg", argLength: 3, reg: gp31, asm: "RSB"}, // arg1>>arg2 - arg0, signed shift
   292  		{name: "ANDshiftLLreg", argLength: 3, reg: gp31, asm: "AND"}, // arg0 & (arg1<<arg2)
   293  		{name: "ANDshiftRLreg", argLength: 3, reg: gp31, asm: "AND"}, // arg0 & (arg1>>arg2), unsigned shift
   294  		{name: "ANDshiftRAreg", argLength: 3, reg: gp31, asm: "AND"}, // arg0 & (arg1>>arg2), signed shift
   295  		{name: "ORshiftLLreg", argLength: 3, reg: gp31, asm: "ORR"},  // arg0 | arg1<<arg2
   296  		{name: "ORshiftRLreg", argLength: 3, reg: gp31, asm: "ORR"},  // arg0 | arg1>>arg2, unsigned shift
   297  		{name: "ORshiftRAreg", argLength: 3, reg: gp31, asm: "ORR"},  // arg0 | arg1>>arg2, signed shift
   298  		{name: "XORshiftLLreg", argLength: 3, reg: gp31, asm: "EOR"}, // arg0 ^ arg1<<arg2
   299  		{name: "XORshiftRLreg", argLength: 3, reg: gp31, asm: "EOR"}, // arg0 ^ arg1>>arg2, unsigned shift
   300  		{name: "XORshiftRAreg", argLength: 3, reg: gp31, asm: "EOR"}, // arg0 ^ arg1>>arg2, signed shift
   301  		{name: "BICshiftLLreg", argLength: 3, reg: gp31, asm: "BIC"}, // arg0 &^ (arg1<<arg2)
   302  		{name: "BICshiftRLreg", argLength: 3, reg: gp31, asm: "BIC"}, // arg0 &^ (arg1>>arg2), unsigned shift
   303  		{name: "BICshiftRAreg", argLength: 3, reg: gp31, asm: "BIC"}, // arg0 &^ (arg1>>arg2), signed shift
   304  		{name: "MVNshiftLLreg", argLength: 2, reg: gp21, asm: "MVN"}, // ^(arg0<<arg1)
   305  		{name: "MVNshiftRLreg", argLength: 2, reg: gp21, asm: "MVN"}, // ^(arg0>>arg1), unsigned shift
   306  		{name: "MVNshiftRAreg", argLength: 2, reg: gp21, asm: "MVN"}, // ^(arg0>>arg1), signed shift
   307  
   308  		{name: "ADCshiftLLreg", argLength: 4, reg: gp3flags1, asm: "ADC"}, // arg0 + arg1<<arg2 + carry, arg3=flags
   309  		{name: "ADCshiftRLreg", argLength: 4, reg: gp3flags1, asm: "ADC"}, // arg0 + arg1>>arg2 + carry, unsigned shift, arg3=flags
   310  		{name: "ADCshiftRAreg", argLength: 4, reg: gp3flags1, asm: "ADC"}, // arg0 + arg1>>arg2 + carry, signed shift, arg3=flags
   311  		{name: "SBCshiftLLreg", argLength: 4, reg: gp3flags1, asm: "SBC"}, // arg0 - arg1<<arg2 - carry, arg3=flags
   312  		{name: "SBCshiftRLreg", argLength: 4, reg: gp3flags1, asm: "SBC"}, // arg0 - arg1>>arg2 - carry, unsigned shift, arg3=flags
   313  		{name: "SBCshiftRAreg", argLength: 4, reg: gp3flags1, asm: "SBC"}, // arg0 - arg1>>arg2 - carry, signed shift, arg3=flags
   314  		{name: "RSCshiftLLreg", argLength: 4, reg: gp3flags1, asm: "RSC"}, // arg1<<arg2 - arg0 - carry, arg3=flags
   315  		{name: "RSCshiftRLreg", argLength: 4, reg: gp3flags1, asm: "RSC"}, // arg1>>arg2 - arg0 - carry, unsigned shift, arg3=flags
   316  		{name: "RSCshiftRAreg", argLength: 4, reg: gp3flags1, asm: "RSC"}, // arg1>>arg2 - arg0 - carry, signed shift, arg3=flags
   317  
   318  		{name: "ADDSshiftLLreg", argLength: 3, reg: gp31carry, asm: "ADD"}, // arg0 + arg1<<arg2, set carry flag
   319  		{name: "ADDSshiftRLreg", argLength: 3, reg: gp31carry, asm: "ADD"}, // arg0 + arg1>>arg2, unsigned shift, set carry flag
   320  		{name: "ADDSshiftRAreg", argLength: 3, reg: gp31carry, asm: "ADD"}, // arg0 + arg1>>arg2, signed shift, set carry flag
   321  		{name: "SUBSshiftLLreg", argLength: 3, reg: gp31carry, asm: "SUB"}, // arg0 - arg1<<arg2, set carry flag
   322  		{name: "SUBSshiftRLreg", argLength: 3, reg: gp31carry, asm: "SUB"}, // arg0 - arg1>>arg2, unsigned shift, set carry flag
   323  		{name: "SUBSshiftRAreg", argLength: 3, reg: gp31carry, asm: "SUB"}, // arg0 - arg1>>arg2, signed shift, set carry flag
   324  		{name: "RSBSshiftLLreg", argLength: 3, reg: gp31carry, asm: "RSB"}, // arg1<<arg2 - arg0, set carry flag
   325  		{name: "RSBSshiftRLreg", argLength: 3, reg: gp31carry, asm: "RSB"}, // arg1>>arg2 - arg0, unsigned shift, set carry flag
   326  		{name: "RSBSshiftRAreg", argLength: 3, reg: gp31carry, asm: "RSB"}, // arg1>>arg2 - arg0, signed shift, set carry flag
   327  
   328  		// comparisons
   329  		{name: "CMP", argLength: 2, reg: gp2flags, asm: "CMP", typ: "Flags"},                    // arg0 compare to arg1
   330  		{name: "CMPconst", argLength: 1, reg: gp1flags, asm: "CMP", aux: "Int32", typ: "Flags"}, // arg0 compare to auxInt
   331  		{name: "CMN", argLength: 2, reg: gp2flags, asm: "CMN", typ: "Flags", commutative: true}, // arg0 compare to -arg1, provided arg1 is not 1<<63
   332  		{name: "CMNconst", argLength: 1, reg: gp1flags, asm: "CMN", aux: "Int32", typ: "Flags"}, // arg0 compare to -auxInt
   333  		{name: "TST", argLength: 2, reg: gp2flags, asm: "TST", typ: "Flags", commutative: true}, // arg0 & arg1 compare to 0
   334  		{name: "TSTconst", argLength: 1, reg: gp1flags, asm: "TST", aux: "Int32", typ: "Flags"}, // arg0 & auxInt compare to 0
   335  		{name: "TEQ", argLength: 2, reg: gp2flags, asm: "TEQ", typ: "Flags", commutative: true}, // arg0 ^ arg1 compare to 0
   336  		{name: "TEQconst", argLength: 1, reg: gp1flags, asm: "TEQ", aux: "Int32", typ: "Flags"}, // arg0 ^ auxInt compare to 0
   337  		{name: "CMPF", argLength: 2, reg: fp2flags, asm: "CMPF", typ: "Flags"},                  // arg0 compare to arg1, float32
   338  		{name: "CMPD", argLength: 2, reg: fp2flags, asm: "CMPD", typ: "Flags"},                  // arg0 compare to arg1, float64
   339  
   340  		{name: "CMPshiftLL", argLength: 2, reg: gp2flags, asm: "CMP", aux: "Int32", typ: "Flags"}, // arg0 compare to arg1<<auxInt
   341  		{name: "CMPshiftRL", argLength: 2, reg: gp2flags, asm: "CMP", aux: "Int32", typ: "Flags"}, // arg0 compare to arg1>>auxInt, unsigned shift
   342  		{name: "CMPshiftRA", argLength: 2, reg: gp2flags, asm: "CMP", aux: "Int32", typ: "Flags"}, // arg0 compare to arg1>>auxInt, signed shift
   343  		{name: "CMNshiftLL", argLength: 2, reg: gp2flags, asm: "CMN", aux: "Int32", typ: "Flags"}, // arg0 compare to -(arg1<<auxInt)
   344  		{name: "CMNshiftRL", argLength: 2, reg: gp2flags, asm: "CMN", aux: "Int32", typ: "Flags"}, // arg0 compare to -(arg1>>auxInt), unsigned shift
   345  		{name: "CMNshiftRA", argLength: 2, reg: gp2flags, asm: "CMN", aux: "Int32", typ: "Flags"}, // arg0 compare to -(arg1>>auxInt), signed shift
   346  		{name: "TSTshiftLL", argLength: 2, reg: gp2flags, asm: "TST", aux: "Int32", typ: "Flags"}, // arg0 & (arg1<<auxInt) compare to 0
   347  		{name: "TSTshiftRL", argLength: 2, reg: gp2flags, asm: "TST", aux: "Int32", typ: "Flags"}, // arg0 & (arg1>>auxInt) compare to 0, unsigned shift
   348  		{name: "TSTshiftRA", argLength: 2, reg: gp2flags, asm: "TST", aux: "Int32", typ: "Flags"}, // arg0 & (arg1>>auxInt) compare to 0, signed shift
   349  		{name: "TEQshiftLL", argLength: 2, reg: gp2flags, asm: "TEQ", aux: "Int32", typ: "Flags"}, // arg0 ^ (arg1<<auxInt) compare to 0
   350  		{name: "TEQshiftRL", argLength: 2, reg: gp2flags, asm: "TEQ", aux: "Int32", typ: "Flags"}, // arg0 ^ (arg1>>auxInt) compare to 0, unsigned shift
   351  		{name: "TEQshiftRA", argLength: 2, reg: gp2flags, asm: "TEQ", aux: "Int32", typ: "Flags"}, // arg0 ^ (arg1>>auxInt) compare to 0, signed shift
   352  
   353  		{name: "CMPshiftLLreg", argLength: 3, reg: gp3flags, asm: "CMP", typ: "Flags"}, // arg0 compare to arg1<<arg2
   354  		{name: "CMPshiftRLreg", argLength: 3, reg: gp3flags, asm: "CMP", typ: "Flags"}, // arg0 compare to arg1>>arg2, unsigned shift
   355  		{name: "CMPshiftRAreg", argLength: 3, reg: gp3flags, asm: "CMP", typ: "Flags"}, // arg0 compare to arg1>>arg2, signed shift
   356  		{name: "CMNshiftLLreg", argLength: 3, reg: gp3flags, asm: "CMN", typ: "Flags"}, // arg0 + (arg1<<arg2) compare to 0
   357  		{name: "CMNshiftRLreg", argLength: 3, reg: gp3flags, asm: "CMN", typ: "Flags"}, // arg0 + (arg1>>arg2) compare to 0, unsigned shift
   358  		{name: "CMNshiftRAreg", argLength: 3, reg: gp3flags, asm: "CMN", typ: "Flags"}, // arg0 + (arg1>>arg2) compare to 0, signed shift
   359  		{name: "TSTshiftLLreg", argLength: 3, reg: gp3flags, asm: "TST", typ: "Flags"}, // arg0 & (arg1<<arg2) compare to 0
   360  		{name: "TSTshiftRLreg", argLength: 3, reg: gp3flags, asm: "TST", typ: "Flags"}, // arg0 & (arg1>>arg2) compare to 0, unsigned shift
   361  		{name: "TSTshiftRAreg", argLength: 3, reg: gp3flags, asm: "TST", typ: "Flags"}, // arg0 & (arg1>>arg2) compare to 0, signed shift
   362  		{name: "TEQshiftLLreg", argLength: 3, reg: gp3flags, asm: "TEQ", typ: "Flags"}, // arg0 ^ (arg1<<arg2) compare to 0
   363  		{name: "TEQshiftRLreg", argLength: 3, reg: gp3flags, asm: "TEQ", typ: "Flags"}, // arg0 ^ (arg1>>arg2) compare to 0, unsigned shift
   364  		{name: "TEQshiftRAreg", argLength: 3, reg: gp3flags, asm: "TEQ", typ: "Flags"}, // arg0 ^ (arg1>>arg2) compare to 0, signed shift
   365  
   366  		{name: "CMPF0", argLength: 1, reg: fp1flags, asm: "CMPF", typ: "Flags"}, // arg0 compare to 0, float32
   367  		{name: "CMPD0", argLength: 1, reg: fp1flags, asm: "CMPD", typ: "Flags"}, // arg0 compare to 0, float64
   368  
   369  		// moves
   370  		{name: "MOVWconst", argLength: 0, reg: gp01, aux: "Int32", asm: "MOVW", typ: "UInt32", rematerializeable: true},    // 32 low bits of auxint
   371  		{name: "MOVFconst", argLength: 0, reg: fp01, aux: "Float64", asm: "MOVF", typ: "Float32", rematerializeable: true}, // auxint as 64-bit float, convert to 32-bit float
   372  		{name: "MOVDconst", argLength: 0, reg: fp01, aux: "Float64", asm: "MOVD", typ: "Float64", rematerializeable: true}, // auxint as 64-bit float
   373  
   374  		{name: "MOVWaddr", argLength: 1, reg: regInfo{inputs: []regMask{buildReg("SP") | buildReg("SB")}, outputs: []regMask{gp}}, aux: "SymOff", asm: "MOVW", rematerializeable: true, symEffect: "Addr"}, // arg0 + auxInt + aux.(*gc.Sym), arg0=SP/SB
   375  
   376  		{name: "MOVBload", argLength: 2, reg: gpload, aux: "SymOff", asm: "MOVB", typ: "Int8", faultOnNilArg0: true, symEffect: "Read"},     // load from arg0 + auxInt + aux.  arg1=mem.
   377  		{name: "MOVBUload", argLength: 2, reg: gpload, aux: "SymOff", asm: "MOVBU", typ: "UInt8", faultOnNilArg0: true, symEffect: "Read"},  // load from arg0 + auxInt + aux.  arg1=mem.
   378  		{name: "MOVHload", argLength: 2, reg: gpload, aux: "SymOff", asm: "MOVH", typ: "Int16", faultOnNilArg0: true, symEffect: "Read"},    // load from arg0 + auxInt + aux.  arg1=mem.
   379  		{name: "MOVHUload", argLength: 2, reg: gpload, aux: "SymOff", asm: "MOVHU", typ: "UInt16", faultOnNilArg0: true, symEffect: "Read"}, // load from arg0 + auxInt + aux.  arg1=mem.
   380  		{name: "MOVWload", argLength: 2, reg: gpload, aux: "SymOff", asm: "MOVW", typ: "UInt32", faultOnNilArg0: true, symEffect: "Read"},   // load from arg0 + auxInt + aux.  arg1=mem.
   381  		{name: "MOVFload", argLength: 2, reg: fpload, aux: "SymOff", asm: "MOVF", typ: "Float32", faultOnNilArg0: true, symEffect: "Read"},  // load from arg0 + auxInt + aux.  arg1=mem.
   382  		{name: "MOVDload", argLength: 2, reg: fpload, aux: "SymOff", asm: "MOVD", typ: "Float64", faultOnNilArg0: true, symEffect: "Read"},  // load from arg0 + auxInt + aux.  arg1=mem.
   383  
   384  		{name: "MOVBstore", argLength: 3, reg: gpstore, aux: "SymOff", asm: "MOVB", typ: "Mem", faultOnNilArg0: true, symEffect: "Write"}, // store 1 byte of arg1 to arg0 + auxInt + aux.  arg2=mem.
   385  		{name: "MOVHstore", argLength: 3, reg: gpstore, aux: "SymOff", asm: "MOVH", typ: "Mem", faultOnNilArg0: true, symEffect: "Write"}, // store 2 bytes of arg1 to arg0 + auxInt + aux.  arg2=mem.
   386  		{name: "MOVWstore", argLength: 3, reg: gpstore, aux: "SymOff", asm: "MOVW", typ: "Mem", faultOnNilArg0: true, symEffect: "Write"}, // store 4 bytes of arg1 to arg0 + auxInt + aux.  arg2=mem.
   387  		{name: "MOVFstore", argLength: 3, reg: fpstore, aux: "SymOff", asm: "MOVF", typ: "Mem", faultOnNilArg0: true, symEffect: "Write"}, // store 4 bytes of arg1 to arg0 + auxInt + aux.  arg2=mem.
   388  		{name: "MOVDstore", argLength: 3, reg: fpstore, aux: "SymOff", asm: "MOVD", typ: "Mem", faultOnNilArg0: true, symEffect: "Write"}, // store 8 bytes of arg1 to arg0 + auxInt + aux.  arg2=mem.
   389  
   390  		{name: "MOVWloadidx", argLength: 3, reg: gp2load, asm: "MOVW", typ: "UInt32"},                   // load from arg0 + arg1. arg2=mem
   391  		{name: "MOVWloadshiftLL", argLength: 3, reg: gp2load, asm: "MOVW", aux: "Int32", typ: "UInt32"}, // load from arg0 + arg1<<auxInt. arg2=mem
   392  		{name: "MOVWloadshiftRL", argLength: 3, reg: gp2load, asm: "MOVW", aux: "Int32", typ: "UInt32"}, // load from arg0 + arg1>>auxInt, unsigned shift. arg2=mem
   393  		{name: "MOVWloadshiftRA", argLength: 3, reg: gp2load, asm: "MOVW", aux: "Int32", typ: "UInt32"}, // load from arg0 + arg1>>auxInt, signed shift. arg2=mem
   394  		{name: "MOVBUloadidx", argLength: 3, reg: gp2load, asm: "MOVBU", typ: "UInt8"},                  // load from arg0 + arg1. arg2=mem
   395  		{name: "MOVBloadidx", argLength: 3, reg: gp2load, asm: "MOVB", typ: "Int8"},                     // load from arg0 + arg1. arg2=mem
   396  		{name: "MOVHUloadidx", argLength: 3, reg: gp2load, asm: "MOVHU", typ: "UInt16"},                 // load from arg0 + arg1. arg2=mem
   397  		{name: "MOVHloadidx", argLength: 3, reg: gp2load, asm: "MOVH", typ: "Int16"},                    // load from arg0 + arg1. arg2=mem
   398  
   399  		{name: "MOVWstoreidx", argLength: 4, reg: gp2store, asm: "MOVW", typ: "Mem"},                   // store arg2 to arg0 + arg1. arg3=mem
   400  		{name: "MOVWstoreshiftLL", argLength: 4, reg: gp2store, asm: "MOVW", aux: "Int32", typ: "Mem"}, // store arg2 to arg0 + arg1<<auxInt. arg3=mem
   401  		{name: "MOVWstoreshiftRL", argLength: 4, reg: gp2store, asm: "MOVW", aux: "Int32", typ: "Mem"}, // store arg2 to arg0 + arg1>>auxInt, unsigned shift. arg3=mem
   402  		{name: "MOVWstoreshiftRA", argLength: 4, reg: gp2store, asm: "MOVW", aux: "Int32", typ: "Mem"}, // store arg2 to arg0 + arg1>>auxInt, signed shift. arg3=mem
   403  		{name: "MOVBstoreidx", argLength: 4, reg: gp2store, asm: "MOVB", typ: "Mem"},                   // store arg2 to arg0 + arg1. arg3=mem
   404  		{name: "MOVHstoreidx", argLength: 4, reg: gp2store, asm: "MOVH", typ: "Mem"},                   // store arg2 to arg0 + arg1. arg3=mem
   405  
   406  		{name: "MOVBreg", argLength: 1, reg: gp11, asm: "MOVBS"},  // move from arg0, sign-extended from byte
   407  		{name: "MOVBUreg", argLength: 1, reg: gp11, asm: "MOVBU"}, // move from arg0, unsign-extended from byte
   408  		{name: "MOVHreg", argLength: 1, reg: gp11, asm: "MOVHS"},  // move from arg0, sign-extended from half
   409  		{name: "MOVHUreg", argLength: 1, reg: gp11, asm: "MOVHU"}, // move from arg0, unsign-extended from half
   410  		{name: "MOVWreg", argLength: 1, reg: gp11, asm: "MOVW"},   // move from arg0
   411  
   412  		{name: "MOVWnop", argLength: 1, reg: regInfo{inputs: []regMask{gp}, outputs: []regMask{gp}}, resultInArg0: true}, // nop, return arg0 in same register
   413  
   414  		{name: "MOVWF", argLength: 1, reg: gpfp, asm: "MOVWF"},  // int32 -> float32
   415  		{name: "MOVWD", argLength: 1, reg: gpfp, asm: "MOVWD"},  // int32 -> float64
   416  		{name: "MOVWUF", argLength: 1, reg: gpfp, asm: "MOVWF"}, // uint32 -> float32, set U bit in the instruction
   417  		{name: "MOVWUD", argLength: 1, reg: gpfp, asm: "MOVWD"}, // uint32 -> float64, set U bit in the instruction
   418  		{name: "MOVFW", argLength: 1, reg: fpgp, asm: "MOVFW"},  // float32 -> int32
   419  		{name: "MOVDW", argLength: 1, reg: fpgp, asm: "MOVDW"},  // float64 -> int32
   420  		{name: "MOVFWU", argLength: 1, reg: fpgp, asm: "MOVFW"}, // float32 -> uint32, set U bit in the instruction
   421  		{name: "MOVDWU", argLength: 1, reg: fpgp, asm: "MOVDW"}, // float64 -> uint32, set U bit in the instruction
   422  		{name: "MOVFD", argLength: 1, reg: fp11, asm: "MOVFD"},  // float32 -> float64
   423  		{name: "MOVDF", argLength: 1, reg: fp11, asm: "MOVDF"},  // float64 -> float32
   424  
   425  		// conditional instructions, for lowering shifts
   426  		{name: "CMOVWHSconst", argLength: 2, reg: gp1flags1, asm: "MOVW", aux: "Int32", resultInArg0: true}, // replace arg0 w/ const if flags indicates HS, arg1=flags
   427  		{name: "CMOVWLSconst", argLength: 2, reg: gp1flags1, asm: "MOVW", aux: "Int32", resultInArg0: true}, // replace arg0 w/ const if flags indicates LS, arg1=flags
   428  		{name: "SRAcond", argLength: 3, reg: gp2flags1, asm: "SRA"},                                         // arg0 >> 31 if flags indicates HS, arg0 >> arg1 otherwise, signed shift, arg2=flags
   429  
   430  		// function calls
   431  		{name: "CALLstatic", argLength: 1, reg: regInfo{clobbers: callerSave}, aux: "CallOff", clobberFlags: true, call: true},                                              // call static function aux.(*obj.LSym).  arg0=mem, auxint=argsize, returns mem
   432  		{name: "CALLtail", argLength: 1, reg: regInfo{clobbers: callerSave}, aux: "CallOff", clobberFlags: true, call: true, tailCall: true},                                // tail call static function aux.(*obj.LSym).  arg0=mem, auxint=argsize, returns mem
   433  		{name: "CALLclosure", argLength: 3, reg: regInfo{inputs: []regMask{gpsp, buildReg("R7"), 0}, clobbers: callerSave}, aux: "CallOff", clobberFlags: true, call: true}, // call function via closure.  arg0=codeptr, arg1=closure, arg2=mem, auxint=argsize, returns mem
   434  		{name: "CALLinter", argLength: 2, reg: regInfo{inputs: []regMask{gp}, clobbers: callerSave}, aux: "CallOff", clobberFlags: true, call: true},                        // call fn by pointer.  arg0=codeptr, arg1=mem, auxint=argsize, returns mem
   435  
   436  		// pseudo-ops
   437  		{name: "LoweredNilCheck", argLength: 2, reg: regInfo{inputs: []regMask{gpg}}, nilCheck: true, faultOnNilArg0: true}, // panic if arg0 is nil.  arg1=mem.
   438  
   439  		{name: "Equal", argLength: 1, reg: readflags},         // bool, true flags encode x==y false otherwise.
   440  		{name: "NotEqual", argLength: 1, reg: readflags},      // bool, true flags encode x!=y false otherwise.
   441  		{name: "LessThan", argLength: 1, reg: readflags},      // bool, true flags encode signed x<y false otherwise.
   442  		{name: "LessEqual", argLength: 1, reg: readflags},     // bool, true flags encode signed x<=y false otherwise.
   443  		{name: "GreaterThan", argLength: 1, reg: readflags},   // bool, true flags encode signed x>y false otherwise.
   444  		{name: "GreaterEqual", argLength: 1, reg: readflags},  // bool, true flags encode signed x>=y false otherwise.
   445  		{name: "LessThanU", argLength: 1, reg: readflags},     // bool, true flags encode unsigned x<y false otherwise.
   446  		{name: "LessEqualU", argLength: 1, reg: readflags},    // bool, true flags encode unsigned x<=y false otherwise.
   447  		{name: "GreaterThanU", argLength: 1, reg: readflags},  // bool, true flags encode unsigned x>y false otherwise.
   448  		{name: "GreaterEqualU", argLength: 1, reg: readflags}, // bool, true flags encode unsigned x>=y false otherwise.
   449  
   450  		// duffzero (must be 4-byte aligned)
   451  		// arg0 = address of memory to zero (in R1, changed as side effect)
   452  		// arg1 = value to store (always zero)
   453  		// arg2 = mem
   454  		// auxint = offset into duffzero code to start executing
   455  		// returns mem
   456  		{
   457  			name:      "DUFFZERO",
   458  			aux:       "Int64",
   459  			argLength: 3,
   460  			reg: regInfo{
   461  				inputs:   []regMask{buildReg("R1"), buildReg("R0")},
   462  				clobbers: buildReg("R1 R12 R14"), // R14 is LR, R12 is linker trampoline scratch register
   463  			},
   464  			faultOnNilArg0: true,
   465  		},
   466  
   467  		// duffcopy (must be 4-byte aligned)
   468  		// arg0 = address of dst memory (in R2, changed as side effect)
   469  		// arg1 = address of src memory (in R1, changed as side effect)
   470  		// arg2 = mem
   471  		// auxint = offset into duffcopy code to start executing
   472  		// returns mem
   473  		{
   474  			name:      "DUFFCOPY",
   475  			aux:       "Int64",
   476  			argLength: 3,
   477  			reg: regInfo{
   478  				inputs:   []regMask{buildReg("R2"), buildReg("R1")},
   479  				clobbers: buildReg("R0 R1 R2 R12 R14"), // R14 is LR, R12 is linker trampoline scratch register
   480  			},
   481  			faultOnNilArg0: true,
   482  			faultOnNilArg1: true,
   483  		},
   484  
   485  		// large or unaligned zeroing
   486  		// arg0 = address of memory to zero (in R1, changed as side effect)
   487  		// arg1 = address of the last element to zero
   488  		// arg2 = value to store (always zero)
   489  		// arg3 = mem
   490  		// returns mem
   491  		//	MOVW.P	Rarg2, 4(R1)
   492  		//	CMP	R1, Rarg1
   493  		//	BLE	-2(PC)
   494  		{
   495  			name:      "LoweredZero",
   496  			aux:       "Int64",
   497  			argLength: 4,
   498  			reg: regInfo{
   499  				inputs:   []regMask{buildReg("R1"), gp, gp},
   500  				clobbers: buildReg("R1"),
   501  			},
   502  			clobberFlags:   true,
   503  			faultOnNilArg0: true,
   504  		},
   505  
   506  		// large or unaligned move
   507  		// arg0 = address of dst memory (in R2, changed as side effect)
   508  		// arg1 = address of src memory (in R1, changed as side effect)
   509  		// arg2 = address of the last element of src
   510  		// arg3 = mem
   511  		// returns mem
   512  		//	MOVW.P	4(R1), Rtmp
   513  		//	MOVW.P	Rtmp, 4(R2)
   514  		//	CMP	R1, Rarg2
   515  		//	BLE	-3(PC)
   516  		{
   517  			name:      "LoweredMove",
   518  			aux:       "Int64",
   519  			argLength: 4,
   520  			reg: regInfo{
   521  				inputs:   []regMask{buildReg("R2"), buildReg("R1"), gp},
   522  				clobbers: buildReg("R1 R2"),
   523  			},
   524  			clobberFlags:   true,
   525  			faultOnNilArg0: true,
   526  			faultOnNilArg1: true,
   527  		},
   528  
   529  		// Scheduler ensures LoweredGetClosurePtr occurs only in entry block,
   530  		// and sorts it to the very beginning of the block to prevent other
   531  		// use of R7 (arm.REGCTXT, the closure pointer)
   532  		{name: "LoweredGetClosurePtr", reg: regInfo{outputs: []regMask{buildReg("R7")}}, zeroWidth: true},
   533  
   534  		// LoweredGetCallerSP returns the SP of the caller of the current function. arg0=mem.
   535  		{name: "LoweredGetCallerSP", argLength: 1, reg: gp01, rematerializeable: true},
   536  
   537  		// LoweredGetCallerPC evaluates to the PC to which its "caller" will return.
   538  		// I.e., if f calls g "calls" getcallerpc,
   539  		// the result should be the PC within f that g will return to.
   540  		// See runtime/stubs.go for a more detailed discussion.
   541  		{name: "LoweredGetCallerPC", reg: gp01, rematerializeable: true},
   542  
   543  		// There are three of these functions so that they can have three different register inputs.
   544  		// When we check 0 <= c <= cap (A), then 0 <= b <= c (B), then 0 <= a <= b (C), we want the
   545  		// default registers to match so we don't need to copy registers around unnecessarily.
   546  		{name: "LoweredPanicBoundsA", argLength: 3, aux: "Int64", reg: regInfo{inputs: []regMask{r2, r3}}, typ: "Mem", call: true}, // arg0=idx, arg1=len, arg2=mem, returns memory. AuxInt contains report code (see PanicBounds in genericOps.go).
   547  		{name: "LoweredPanicBoundsB", argLength: 3, aux: "Int64", reg: regInfo{inputs: []regMask{r1, r2}}, typ: "Mem", call: true}, // arg0=idx, arg1=len, arg2=mem, returns memory. AuxInt contains report code (see PanicBounds in genericOps.go).
   548  		{name: "LoweredPanicBoundsC", argLength: 3, aux: "Int64", reg: regInfo{inputs: []regMask{r0, r1}}, typ: "Mem", call: true}, // arg0=idx, arg1=len, arg2=mem, returns memory. AuxInt contains report code (see PanicBounds in genericOps.go).
   549  		// Extend ops are the same as Bounds ops except the indexes are 64-bit.
   550  		{name: "LoweredPanicExtendA", argLength: 4, aux: "Int64", reg: regInfo{inputs: []regMask{r4, r2, r3}}, typ: "Mem", call: true}, // arg0=idxHi, arg1=idxLo, arg2=len, arg3=mem, returns memory. AuxInt contains report code (see PanicExtend in genericOps.go).
   551  		{name: "LoweredPanicExtendB", argLength: 4, aux: "Int64", reg: regInfo{inputs: []regMask{r4, r1, r2}}, typ: "Mem", call: true}, // arg0=idxHi, arg1=idxLo, arg2=len, arg3=mem, returns memory. AuxInt contains report code (see PanicExtend in genericOps.go).
   552  		{name: "LoweredPanicExtendC", argLength: 4, aux: "Int64", reg: regInfo{inputs: []regMask{r4, r0, r1}}, typ: "Mem", call: true}, // arg0=idxHi, arg1=idxLo, arg2=len, arg3=mem, returns memory. AuxInt contains report code (see PanicExtend in genericOps.go).
   553  
   554  		// Constant flag value.
   555  		// Note: there's an "unordered" outcome for floating-point
   556  		// comparisons, but we don't use such a beast yet.
   557  		// This op is for temporary use by rewrite rules. It
   558  		// cannot appear in the generated assembly.
   559  		{name: "FlagConstant", aux: "FlagConstant"},
   560  
   561  		// (InvertFlags (CMP a b)) == (CMP b a)
   562  		// InvertFlags is a pseudo-op which can't appear in assembly output.
   563  		{name: "InvertFlags", argLength: 1}, // reverse direction of arg0
   564  
   565  		// LoweredWB invokes runtime.gcWriteBarrier. arg0=mem, auxint=# of buffer entries needed
   566  		// It saves all GP registers if necessary,
   567  		// but clobbers R14 (LR) because it's a call, and R12 which is linker trampoline scratch register.
   568  		// Returns a pointer to a write barrier buffer in R8.
   569  		{name: "LoweredWB", argLength: 1, reg: regInfo{clobbers: (callerSave &^ gpg) | buildReg("R12 R14"), outputs: []regMask{buildReg("R8")}}, clobberFlags: true, aux: "Int64"}}
   570  
   571  	blocks := []blockData{
   572  		{name: "EQ", controls: 1},
   573  		{name: "NE", controls: 1},
   574  		{name: "LT", controls: 1},
   575  		{name: "LE", controls: 1},
   576  		{name: "GT", controls: 1},
   577  		{name: "GE", controls: 1},
   578  		{name: "ULT", controls: 1},
   579  		{name: "ULE", controls: 1},
   580  		{name: "UGT", controls: 1},
   581  		{name: "UGE", controls: 1},
   582  		{name: "LTnoov", controls: 1}, // 'LT' but without honoring overflow
   583  		{name: "LEnoov", controls: 1}, // 'LE' but without honoring overflow
   584  		{name: "GTnoov", controls: 1}, // 'GT' but without honoring overflow
   585  		{name: "GEnoov", controls: 1}, // 'GE' but without honoring overflow
   586  	}
   587  
   588  	archs = append(archs, arch{
   589  		name:            "ARM",
   590  		pkg:             "github.com/go-asm/go/cmd/obj/arm",
   591  		genfile:         "../../arm/ssa.go",
   592  		ops:             ops,
   593  		blocks:          blocks,
   594  		regnames:        regNamesARM,
   595  		gpregmask:       gp,
   596  		fpregmask:       fp,
   597  		framepointerreg: -1, // not used
   598  		linkreg:         int8(num["R14"]),
   599  	})
   600  }