Golang RegCoder.OpTrapCall方法代码示例

func (mach X86) opCheckDivideByZero(code gen.RegCoder, t types.T, reg regs.R) {
	var end links.L

	Test.opFromReg(code, t, reg, reg)
	Jne.rel8.opStub(code)
	end.AddSite(code.Len())

	code.OpTrapCall(traps.IntegerDivideByZero)

	end.Addr = code.Len()
	mach.updateBranches8(code, &end)
}

//.........这里部分代码省略.........
				checkOverflow = false
			}
		}

		reg, ok := code.TryAllocReg(t)
		if !ok {
			// borrow a register which we don't need in this function
			MovMMX.opFromReg(code, types.I64, regScratchMMX, regTextBase)
			defer MovMMX.opToReg(code, types.I64, regTextBase, regScratchMMX)

			reg = regTextBase
		}

		mach.OpMove(code, reg, b, true)
		b = values.RegOperand(true, t, reg)
	}

	mach.OpMove(code, regResult, a, false)

	remainder := (index & opers.DivmulRem) != 0

	var doNot links.L

	if division {
		if checkZero {
			mach.opCheckDivideByZero(code, t, b.Reg())
		}

		if a.Storage == values.Imm {
			value := a.ImmValue()
			if t.Size() == types.Size32 {
				if value != -0x80000000 {
					checkOverflow = false
				}
			} else {
				if value != -0x8000000000000000 {
					checkOverflow = false
				}
			}
		}

		signed := (index & opers.DivmulSign) != 0

		if signed && checkOverflow {
			var do links.L

			if remainder {
				Xor.opFromReg(code, types.I32, regScratch, regScratch) // moved to result at the end

				Cmp.opImm(code, t, b.Reg(), -1)
				Je.rel8.opStub(code)
				doNot.AddSite(code.Len())
			} else {
				switch t.Size() {
				case types.Size32:
					Cmp.opImm(code, t, regResult, -0x80000000)

				case types.Size64:
					MovImm64.op(code, t, regScratch, -0x8000000000000000)
					Cmp.opFromReg(code, t, regResult, regScratch)

				default:
					panic(a)
				}

				Jne.rel8.opStub(code)
				do.AddSite(code.Len())

				Cmp.opImm(code, t, b.Reg(), -1)
				Jne.rel8.opStub(code)
				do.AddSite(code.Len())

				code.OpTrapCall(traps.IntegerOverflow)
			}

			do.Addr = code.Len()
			mach.updateBranches8(code, &do)
		}

		if signed {
			// sign-extend dividend low bits to high bits
			CdqCqo.op(code, t)
		} else {
			// zero-extend dividend high bits
			Xor.opFromReg(code, types.I32, regScratch, regScratch)
		}
	}

	insn.opReg(code, t, b.Reg())
	code.Consumed(b)

	doNot.Addr = code.Len()
	mach.updateBranches8(code, &doNot)

	if remainder {
		Mov.opFromReg(code, t, regResult, regScratch)
	}

	return values.TempRegOperand(t, regResult, true)
}

// StoreOp makes sure that index gets zero-extended if it's a VarReg operand.
func (mach X86) StoreOp(code gen.RegCoder, oper uint16, index, x values.Operand, offset uint32) {
	size := oper >> 8

	baseReg, indexReg, ownIndexReg, disp := mach.opMemoryAddress(code, size, index, offset)
	if ownIndexReg {
		defer code.FreeReg(types.I64, indexReg)
	}

	store := memoryStores[uint8(oper)]

	insnType := store.insnType
	if insnType == 0 {
		insnType = x.Type
	}

	if x.Storage == values.Imm {
		value := x.ImmValue()
		value32 := int32(value)

		switch {
		case size == 1:
			value32 = int32(int8(value32))

		case size == 2:
			value32 = int32(int16(value32))

		case size == 4 || (value >= -0x80000000 && value < 0x80000000):

		default:
			goto large
		}

		store.insn.opImmToIndirect(code, insnType, 0, indexReg, baseReg, disp, value32)
		return

	large:
	}

	valueReg, _, own := mach.opBorrowMaybeResultReg(code, x, false)
	if own {
		defer code.FreeReg(x.Type, valueReg)
	}

	store.insn.opToIndirect(code, insnType, valueReg, 0, indexReg, baseReg, disp)
}

// opMemoryAddress may return the scratch register as the base.
func (mach X86) opMemoryAddress(code gen.RegCoder, size uint16, index values.Operand, offset uint32) (baseReg, indexReg regs.R, ownIndexReg bool, disp int32) {
	sizeReach := uint64(size - 1)
	reachOffset := uint64(offset) + sizeReach

	if reachOffset >= 0x80000000 {
		code.OpTrapCall(traps.MemoryOutOfBounds)
		return
	}

	alreadyChecked := reachOffset < uint64(index.Bounds.Upper)

	switch index.Storage {
	case values.Imm:
		value := uint64(index.ImmValue())

		if value >= 0x80000000 {
			code.OpTrapCall(traps.MemoryOutOfBounds)
			return
		}

		addr := value + uint64(offset)
		reachAddr := addr + sizeReach

		if reachAddr >= 0x80000000 {
			code.OpTrapCall(traps.MemoryOutOfBounds)
			return
		}

		if reachAddr < uint64(code.MinMemorySize()) || alreadyChecked {
			baseReg = regMemoryBase
			indexReg = NoIndex
			disp = int32(addr)
			return
		}

		Lea.opFromIndirect(code, types.I64, regScratch, 0, NoIndex, regMemoryBase, int32(reachAddr))

	default:
		reg, zeroExt, own := mach.opBorrowMaybeScratchReg(code, index, true)

		if !zeroExt {
			Mov.opFromReg(code, types.I32, reg, reg) // zero-extend index
		}

		if alreadyChecked {
			baseReg = regMemoryBase
			indexReg = reg
			ownIndexReg = own
			disp = int32(offset)
			return
		}

//.........这里部分代码省略.........