// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build ignore
package main
import "strings"
// Notes:
// - Integer types live in the low portion of registers. Upper portions are junk.
// - Boolean types use the low-order byte of a register. 0=false, 1=true.
// Upper bytes are junk.
// - Unused portions of AuxInt are filled by sign-extending the used portion.
// - *const instructions may use a constant larger than the instruction can encode.
// In this case the assembler expands to multiple instructions and uses tmp
// register (R23).
// Suffixes encode the bit width of various instructions.
// W (word) = 32 bit
// H (half word) = 16 bit
// HU = 16 bit unsigned
// B (byte) = 8 bit
// BU = 8 bit unsigned
// F (float) = 32 bit float
// D (double) = 64 bit float
// Note: registers not used in regalloc are not included in this list,
// so that regmask stays within int64
// Be careful when hand coding regmasks.
var regNamesMIPS = []string{
"R0", // constant 0
"R1",
"R2",
"R3",
"R4",
"R5",
"R6",
"R7",
"R8",
"R9",
"R10",
"R11",
"R12",
"R13",
"R14",
"R15",
"R16",
"R17",
"R18",
"R19",
"R20",
"R21",
"R22",
//REGTMP
"R24",
"R25",
// R26 reserved by kernel
// R27 reserved by kernel
"R28",
"SP", // aka R29
"g", // aka R30
"R31", // REGLINK
// odd FP registers contain high parts of 64-bit FP values
"F0",
"F2",
"F4",
"F6",
"F8",
"F10",
"F12",
"F14",
"F16",
"F18",
"F20",
"F22",
"F24",
"F26",
"F28",
"F30",
"HI", // high bits of multiplication
"LO", // low bits of multiplication
// pseudo-registers
"SB",
}
func init() {
// Make map from reg names to reg integers.
if len(regNamesMIPS) > 64 {
panic("too many registers")
}
num := map[string]int{}
for i, name := range regNamesMIPS {
num[name] = i
}
buildReg := func(s string) regMask {
m := regMask(0)
for _, r := range strings.Split(s, " ") {
if n, ok := num[r]; ok {
m |= regMask(1) << uint(n)
continue
}
panic("register " + r + " not found")
}
return m
}
// Common individual register masks
var (
gp = buildReg("R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15 R16 R17 R18 R19 R20 R21 R22 R24 R25 R28 R31")
gpg = gp | buildReg("g")
gpsp = gp | buildReg("SP")
gpspg = gpg | buildReg("SP")
gpspsbg = gpspg | buildReg("SB")
fp = buildReg("F0 F2 F4 F6 F8 F10 F12 F14 F16 F18 F20 F22 F24 F26 F28 F30")
lo = buildReg("LO")
hi = buildReg("HI")
callerSave = gp | fp | lo | hi | buildReg("g") // runtime.setg (and anything calling it) may clobber g
)
// Common regInfo
var (
gp01 = regInfo{inputs: nil, outputs: []regMask{gp}}
gp11 = regInfo{inputs: []regMask{gpg}, outputs: []regMask{gp}}
gp11sp = regInfo{inputs: []regMask{gpspg}, outputs: []regMask{gp}}
gp21 = regInfo{inputs: []regMask{gpg, gpg}, outputs: []regMask{gp}}
gp31 = regInfo{inputs: []regMask{gp, gp, gp}, outputs: []regMask{gp}}
gp2hilo = regInfo{inputs: []regMask{gpg, gpg}, outputs: []regMask{hi, lo}}
gpload = regInfo{inputs: []regMask{gpspsbg}, outputs: []regMask{gp}}
gpstore = regInfo{inputs: []regMask{gpspsbg, gpg}}
gpxchg = regInfo{inputs: []regMask{gpspsbg, gpg}, outputs: []regMask{gp}}
gpcas = regInfo{inputs: []regMask{gpspsbg, gpg, gpg}, outputs: []regMask{gp}}
gpstore0 = regInfo{inputs: []regMask{gpspsbg}}
fp01 = regInfo{inputs: nil, outputs: []regMask{fp}}
fp11 = regInfo{inputs: []regMask{fp}, outputs: []regMask{fp}}
fp21 = regInfo{inputs: []regMask{fp, fp}, outputs: []regMask{fp}}
fp2flags = regInfo{inputs: []regMask{fp, fp}}
fpload = regInfo{inputs: []regMask{gpspsbg}, outputs: []regMask{fp}}
fpstore = regInfo{inputs: []regMask{gpspsbg, fp}}
readflags = regInfo{inputs: nil, outputs: []regMask{gp}}
)
ops := []opData{
{name: "ADD", argLength: 2, reg: gp21, asm: "ADDU", commutative: true}, // arg0 + arg1
{name: "ADDconst", argLength: 1, reg: gp11sp, asm: "ADDU", aux: "Int32"}, // arg0 + auxInt
{name: "SUB", argLength: 2, reg: gp21, asm: "SUBU"}, // arg0 - arg1
{name: "SUBconst", argLength: 1, reg: gp11, asm: "SUBU", aux: "Int32"}, // arg0 - auxInt
{name: "MUL", argLength: 2, reg: regInfo{inputs: []regMask{gpg, gpg}, outputs: []regMask{gp}, clobbers: hi | lo}, asm: "MUL", commutative: true}, // arg0 * arg1
{name: "MULT", argLength: 2, reg: gp2hilo, asm: "MUL", commutative: true, typ: "(Int32,Int32)"}, // arg0 * arg1, signed, results hi,lo
{name: "MULTU", argLength: 2, reg: gp2hilo, asm: "MULU", commutative: true, typ: "(UInt32,UInt32)"}, // arg0 * arg1, unsigned, results hi,lo
{name: "DIV", argLength: 2, reg: gp2hilo, asm: "DIV", typ: "(Int32,Int32)"}, // arg0 / arg1, signed, results hi=arg0%arg1,lo=arg0/arg1
{name: "DIVU", argLength: 2, reg: gp2hilo, asm: "DIVU", typ: "(UInt32,UInt32)"}, // arg0 / arg1, signed, results hi=arg0%arg1,lo=arg0/arg1
{name: "ADDF", argLength: 2, reg: fp21, asm: "ADDF", commutative: true}, // arg0 + arg1
{name: "ADDD", argLength: 2, reg: fp21, asm: "ADDD", commutative: true}, // arg0 + arg1
{name: "SUBF", argLength: 2, reg: fp21, asm: "SUBF"}, // arg0 - arg1
{name: "SUBD", argLength: 2, reg: fp21, asm: "SUBD"}, // arg0 - arg1
{name: "MULF", argLength: 2, reg: fp21, asm: "MULF", commutative: true}, // arg0 * arg1
{name: "MULD", argLength: 2, reg: fp21, asm: "MULD", commutative: true}, // arg0 * arg1
{name: "DIVF", argLength: 2, reg: fp21, asm: "DIVF"}, // arg0 / arg1
{name: "DIVD", argLength: 2, reg: fp21, asm: "DIVD"}, // arg0 / arg1
{name: "AND", argLength: 2, reg: gp21, asm: "AND", commutative: true}, // arg0 & arg1
{name: "ANDconst", argLength: 1, reg: gp11, asm: "AND", aux: "Int32"}, // arg0 & auxInt
{name: "OR", argLength: 2, reg: gp21, asm: "OR", commutative: true}, // arg0 | arg1
{name: "ORconst", argLength: 1, reg: gp11, asm: "OR", aux: "Int32"}, // arg0 | auxInt
{name: "XOR", argLength: 2, reg: gp21, asm: "XOR", commutative: true, typ: "UInt32"}, // arg0 ^ arg1
{name: "XORconst", argLength: 1, reg: gp11, asm: "XOR", aux: "Int32", typ: "UInt32"}, // arg0 ^ auxInt
{name: "NOR", argLength: 2, reg: gp21, asm: "NOR", commutative: true}, // ^(arg0 | arg1)
{name: "NORconst", argLength: 1, reg: gp11, asm: "NOR", aux: "Int32"}, // ^(arg0 | auxInt)
{name: "NEG", argLength: 1, reg: gp11}, // -arg0
{name: "NEGF", argLength: 1, reg: fp11, asm: "NEGF"}, // -arg0, float32
{name: "NEGD", argLength: 1, reg: fp11, asm: "NEGD"}, // -arg0, float64
{name: "SQRTD", argLength: 1, reg: fp11, asm: "SQRTD"}, // sqrt(arg0), float64
// shifts
{name: "SLL", argLength: 2, reg: gp21, asm: "SLL"}, // arg0 << arg1, shift amount is mod 32
{name: "SLLconst", argLength: 1, reg: gp11, asm: "SLL", aux: "Int32"}, // arg0 << auxInt
{name: "SRL", argLength: 2, reg: gp21, asm: "SRL"}, // arg0 >> arg1, unsigned, shift amount is mod 32
{name: "SRLconst", argLength: 1, reg: gp11, asm: "SRL", aux: "Int32"}, // arg0 >> auxInt, unsigned
{name: "SRA", argLength: 2, reg: gp21, asm: "SRA"}, // arg0 >> arg1, signed, shift amount is mod 32
{name: "SRAconst", argLength: 1, reg: gp11, asm: "SRA", aux: "Int32"}, // arg0 >> auxInt, signed
{name: "CLZ", argLength: 1, reg: gp11, asm: "CLZ"},
// comparisons
{name: "SGT", argLength: 2, reg: gp21, asm: "SGT", typ: "Bool"}, // 1 if arg0 > arg1 (signed), 0 otherwise
{name: "SGTconst", argLength: 1, reg: gp11, asm: "SGT", aux: "Int32", typ: "Bool"}, // 1 if auxInt > arg0 (signed), 0 otherwise
{name: "SGTzero", argLength: 1, reg: gp11, asm: "SGT", typ: "Bool"}, // 1 if arg0 > 0 (signed), 0 otherwise
{name: "SGTU", argLength: 2, reg: gp21, asm: "SGTU", typ: "Bool"}, // 1 if arg0 > arg1 (unsigned), 0 otherwise
{name: "SGTUconst", argLength: 1, reg: gp11, asm: "SGTU", aux: "Int32", typ: "Bool"}, // 1 if auxInt > arg0 (unsigned), 0 otherwise
{name: "SGTUzero", argLength: 1, reg: gp11, asm: "SGTU", typ: "Bool"}, // 1 if arg0 > 0 (unsigned), 0 otherwise
{name: "CMPEQF", argLength: 2, reg: fp2flags, asm: "CMPEQF", typ: "Flags"}, // flags=true if arg0 = arg1, float32
{name: "CMPEQD", argLength: 2, reg: fp2flags, asm: "CMPEQD", typ: "Flags"}, // flags=true if arg0 = arg1, float64
{name: "CMPGEF", argLength: 2, reg: fp2flags, asm: "CMPGEF", typ: "Flags"}, // flags=true if arg0 >= arg1, float32
{name: "CMPGED", argLength: 2, reg: fp2flags, asm: "CMPGED", typ: "Flags"}, // flags=true if arg0 >= arg1, float64
{name: "CMPGTF", argLength: 2, reg: fp2flags, asm: "CMPGTF", typ: "Flags"}, // flags=true if arg0 > arg1, float32
{name: "CMPGTD", argLength: 2, reg: fp2flags, asm: "CMPGTD", typ: "Flags"}, // flags=true if arg0 > arg1, float64
// moves
{name: "MOVWconst", argLength: 0, reg: gp01, aux: "Int32", asm: "MOVW", typ: "UInt32", rematerializeable: true}, // auxint
{name: "MOVFconst", argLength: 0, reg: fp01, aux: "Float32", asm: "MOVF", typ: "Float32", rematerializeable: true}, // auxint as 64-bit float, convert to 32-bit float
{name: "MOVDconst", argLength: 0, reg: fp01, aux: "Float64", asm: "MOVD", typ: "Float64", rematerializeable: true}, // auxint as 64-bit float
{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
{name: "MOVBload", argLength: 2, reg: gpload, aux: "SymOff", asm: "MOVB", typ: "Int8", faultOnNilArg0: true, symEffect: "Read"}, // load from arg0 + auxInt + aux. arg1=mem.
{name: "MOVBUload", argLength: 2, reg: gpload, aux: "SymOff", asm: "MOVBU", typ: "UInt8", faultOnNilArg0: true, symEffect: "Read"}, // load from arg0 + auxInt + aux. arg1=mem.
{name: "MOVHload", argLength: 2, reg: gpload, aux: "SymOff", asm: "MOVH", typ: "Int16", faultOnNilArg0: true, symEffect: "Read"}, // load from arg0 + auxInt + aux. arg1=mem.
{name: "MOVHUload", argLength: 2, reg: gpload, aux: "SymOff", asm: "MOVHU", typ: "UInt16", faultOnNilArg0: true, symEffect: "Read"}, // load from arg0 + auxInt + aux. arg1=mem.
{name: "MOVWload", argLength: 2, reg: gpload, aux: "SymOff", asm: "MOVW", typ: "UInt32", faultOnNilArg0: true, symEffect: "Read"}, // load from arg0 + auxInt + aux. arg1=mem.
{name: "MOVFload", argLength: 2, reg: fpload, aux: "SymOff", asm: "MOVF", typ: "Float32", faultOnNilArg0: true, symEffect: "Read"}, // load from arg0 + auxInt + aux. arg1=mem.
{name: "MOVDload", argLength: 2, reg: fpload, aux: "SymOff", asm: "MOVD", typ: "Float64", faultOnNilArg0: true, symEffect: "Read"}, // load from arg0 + auxInt + aux. arg1=mem.
{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.
{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.
{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.
{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.
{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.
{name: "MOVBstorezero", argLength: 2, reg: gpstore0, aux: "SymOff", asm: "MOVB", typ: "Mem", faultOnNilArg0: true, symEffect: "Write"}, // store 1 byte of zero to arg0 + auxInt + aux. arg1=mem.
{name: "MOVHstorezero", argLength: 2, reg: gpstore0, aux: "SymOff", asm: "MOVH", typ: "Mem", faultOnNilArg0: true, symEffect: "Write"}, // store 2 bytes of zero to arg0 + auxInt + aux. arg1=mem.
{name: "MOVWstorezero", argLength: 2, reg: gpstore0, aux: "SymOff", asm: "MOVW", typ: "Mem", faultOnNilArg0: true, symEffect: "Write"}, // store 4 bytes of zero to arg0 + auxInt + aux. arg1=mem.
// conversions
{name: "MOVBreg", argLength: 1, reg: gp11, asm: "MOVB"}, // move from arg0, sign-extended from byte
{name: "MOVBUreg", argLength: 1, reg: gp11, asm: "MOVBU"}, // move from arg0, unsign-extended from byte
{name: "MOVHreg", argLength: 1, reg: gp11, asm: "MOVH"}, // move from arg0, sign-extended from half
{name: "MOVHUreg", argLength: 1, reg: gp11, asm: "MOVHU"}, // move from arg0, unsign-extended from half
{name: "MOVWreg", argLength: 1, reg: gp11, asm: "MOVW"}, // move from arg0
{name: "MOVWnop", argLength: 1, reg: regInfo{inputs: []regMask{gp}, outputs: []regMask{gp}}, resultInArg0: true}, // nop, return arg0 in same register
// conditional move on zero (returns arg1 if arg2 is 0, otherwise arg0)
// order of parameters is reversed so we can use resultInArg0 (OpCMOVZ result arg1 arg2-> CMOVZ arg2reg, arg1reg, resultReg)
{name: "CMOVZ", argLength: 3, reg: gp31, asm: "CMOVZ", resultInArg0: true},
{name: "CMOVZzero", argLength: 2, reg: regInfo{inputs: []regMask{gp, gpg}, outputs: []regMask{gp}}, asm: "CMOVZ", resultInArg0: true},
{name: "MOVWF", argLength: 1, reg: fp11, asm: "MOVWF"}, // int32 -> float32
{name: "MOVWD", argLength: 1, reg: fp11, asm: "MOVWD"}, // int32 -> float64
{name: "TRUNCFW", argLength: 1, reg: fp11, asm: "TRUNCFW"}, // float32 -> int32
{name: "TRUNCDW", argLength: 1, reg: fp11, asm: "TRUNCDW"}, // float64 -> int32
{name: "MOVFD", argLength: 1, reg: fp11, asm: "MOVFD"}, // float32 -> float64
{name: "MOVDF", argLength: 1, reg: fp11, asm: "MOVDF"}, // float64 -> float32
// function calls
{name: "CALLstatic", argLength: 1, reg: regInfo{clobbers: callerSave}, aux: "SymOff", clobberFlags: true, call: true, symEffect: "None"}, // call static function aux.(*obj.LSym). arg0=mem, auxint=argsize, returns mem
{name: "CALLclosure", argLength: 3, reg: regInfo{inputs: []regMask{gpsp, buildReg("R22"), 0}, clobbers: callerSave}, aux: "Int64", clobberFlags: true, call: true}, // call function via closure. arg0=codeptr, arg1=closure, arg2=mem, auxint=argsize, returns mem
{name: "CALLinter", argLength: 2, reg: regInfo{inputs: []regMask{gp}, clobbers: callerSave}, aux: "Int64", clobberFlags: true, call: true}, // call fn by pointer. arg0=codeptr, arg1=mem, auxint=argsize, returns mem
// atomic ops
// load from arg0. arg1=mem.
// returns <value,memory> so they can be properly ordered with other loads.
// SYNC
// MOVW (Rarg0), Rout
// SYNC
{name: "LoweredAtomicLoad", argLength: 2, reg: gpload, faultOnNilArg0: true},
// store arg1 to arg0. arg2=mem. returns memory.
// SYNC
// MOVW Rarg1, (Rarg0)
// SYNC
{name: "LoweredAtomicStore", argLength: 3, reg: gpstore, faultOnNilArg0: true, hasSideEffects: true},
{name: "LoweredAtomicStorezero", argLength: 2, reg: gpstore0, faultOnNilArg0: true, hasSideEffects: true},
// atomic exchange.
// store arg1 to arg0. arg2=mem. returns <old content of *arg0, memory>.
// SYNC
// LL (Rarg0), Rout
// MOVW Rarg1, Rtmp
// SC Rtmp, (Rarg0)
// BEQ Rtmp, -3(PC)
// SYNC
{name: "LoweredAtomicExchange", argLength: 3, reg: gpxchg, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true},
// atomic add.
// *arg0 += arg1. arg2=mem. returns <new content of *arg0, memory>.
// SYNC
// LL (Rarg0), Rout
// ADDU Rarg1, Rout, Rtmp
// SC Rtmp, (Rarg0)
// BEQ Rtmp, -3(PC)
// SYNC
// ADDU Rarg1, Rout
{name: "LoweredAtomicAdd", argLength: 3, reg: gpxchg, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true},
{name: "LoweredAtomicAddconst", argLength: 2, reg: regInfo{inputs: []regMask{gpspsbg}, outputs: []regMask{gp}}, aux: "Int32", resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true},
// atomic compare and swap.
// arg0 = pointer, arg1 = old value, arg2 = new value, arg3 = memory.
// if *arg0 == arg1 {
// *arg0 = arg2
// return (true, memory)
// } else {
// return (false, memory)
// }
// SYNC
// MOVW $0, Rout
// LL (Rarg0), Rtmp
// BNE Rtmp, Rarg1, 4(PC)
// MOVW Rarg2, Rout
// SC Rout, (Rarg0)
// BEQ Rout, -4(PC)
// SYNC
{name: "LoweredAtomicCas", argLength: 4, reg: gpcas, resultNotInArgs: true, faultOnNilArg0: true, hasSideEffects: true},
// atomic and/or.
// *arg0 &= (|=) arg1. arg2=mem. returns memory.
// SYNC
// LL (Rarg0), Rtmp
// AND Rarg1, Rtmp
// SC Rtmp, (Rarg0)
// BEQ Rtmp, -3(PC)
// SYNC
{name: "LoweredAtomicAnd", argLength: 3, reg: gpstore, asm: "AND", faultOnNilArg0: true, hasSideEffects: true},
{name: "LoweredAtomicOr", argLength: 3, reg: gpstore, asm: "OR", faultOnNilArg0: true, hasSideEffects: true},
// large or unaligned zeroing
// arg0 = address of memory to zero (in R1, changed as side effect)
// arg1 = address of the last element to zero
// arg2 = mem
// auxint = alignment
// returns mem
// SUBU $4, R1
// MOVW R0, 4(R1)
// ADDU $4, R1
// BNE Rarg1, R1, -2(PC)
{
name: "LoweredZero",
aux: "Int32",
argLength: 3,
reg: regInfo{
inputs: []regMask{buildReg("R1"), gp},
clobbers: buildReg("R1"),
},
faultOnNilArg0: true,
},
// large or unaligned move
// arg0 = address of dst memory (in R2, changed as side effect)
// arg1 = address of src memory (in R1, changed as side effect)
// arg2 = address of the last element of src
// arg3 = mem
// auxint = alignment
// returns mem
// SUBU $4, R1
// MOVW 4(R1), Rtmp
// MOVW Rtmp, (R2)
// ADDU $4, R1
// ADDU $4, R2
// BNE Rarg2, R1, -4(PC)
{
name: "LoweredMove",
aux: "Int32",
argLength: 4,
reg: regInfo{
inputs: []regMask{buildReg("R2"), buildReg("R1"), gp},
clobbers: buildReg("R1 R2"),
},
faultOnNilArg0: true,
faultOnNilArg1: true,
},
// pseudo-ops
{name: "LoweredNilCheck", argLength: 2, reg: regInfo{inputs: []regMask{gpg}}, nilCheck: true, faultOnNilArg0: true}, // panic if arg0 is nil. arg1=mem.
{name: "FPFlagTrue", argLength: 1, reg: readflags}, // bool, true if FP flag is true
{name: "FPFlagFalse", argLength: 1, reg: readflags}, // bool, true if FP flag is false
// Scheduler ensures LoweredGetClosurePtr occurs only in entry block,
// and sorts it to the very beginning of the block to prevent other
// use of R22 (mips.REGCTXT, the closure pointer)
{name: "LoweredGetClosurePtr", reg: regInfo{outputs: []regMask{buildReg("R22")}}},
// LoweredGetCallerSP returns the SP of the caller of the current function.
{name: "LoweredGetCallerSP", reg: gp01, rematerializeable: true},
// MOVWconvert converts between pointers and integers.
// We have a special op for this so as to not confuse GC
// (particularly stack maps). It takes a memory arg so it
// gets correctly ordered with respect to GC safepoints.
// arg0=ptr/int arg1=mem, output=int/ptr
{name: "MOVWconvert", argLength: 2, reg: gp11, asm: "MOVW"},
}
blocks := []blockData{
{name: "EQ"},
{name: "NE"},
{name: "LTZ"}, // < 0
{name: "LEZ"}, // <= 0
{name: "GTZ"}, // > 0
{name: "GEZ"}, // >= 0
{name: "FPT"}, // FP flag is true
{name: "FPF"}, // FP flag is false
}
archs = append(archs, arch{
name: "MIPS",
pkg: "cmd/internal/obj/mips",
genfile: "../../mips/ssa.go",
ops: ops,
blocks: blocks,
regnames: regNamesMIPS,
gpregmask: gp,
fpregmask: fp,
specialregmask: hi | lo,
framepointerreg: -1, // not used
linkreg: int8(num["R31"]),
})
}