func (f *Function) UnOp(instr *ssa.UnOp) (string, *Error) {
var err *Error
asm := ""
switch instr.Op {
default:
ice(fmt.Sprintf("unknown Op token (%v): \"%v\"", instr.Op, instr))
case token.NOT: // logical negation
asm, err = f.UnOpXor(instr, 1)
case token.XOR: //bitwise negation
asm, err = f.UnOpXor(instr, -1)
case token.SUB: // arithmetic negation e.g. x=>-x
asm, err = f.UnOpSub(instr)
case token.MUL: //pointer indirection
asm, err = f.UnOpPointer(instr)
}
asm = fmt.Sprintf("// BEGIN ssa.UnOp: %v = %v\n", instr.Name(), instr) + asm
asm += fmt.Sprintf("// END ssa.UnOp: %v = %v\n", instr.Name(), instr)
return asm, err
}
// arithmetic negation
func (f *Function) UnOpSub(instr *ssa.UnOp) (string, *Error) {
ctx := context{f, instr}
if ident := f.Ident(instr); ident == nil {
return ErrorMsg(fmt.Sprintf("Cannot alloc value: %v", instr))
}
var regSubX, regX, regVal *register
var a1, a2 string
a1, regVal = f.allocReg(instr, regType(instr.Type()), f.sizeof(instr))
a2, regSubX = f.allocReg(instr, regType(instr.X.Type()), f.sizeof(instr.X))
addr, ok := f.identifiers[instr.Name()]
if !ok {
msg := fmt.Sprintf("unknown name (%v), instr (%v)\n", instr.Name(), instr)
ice(msg)
}
a3, regX, err := f.LoadValueSimple(instr, instr.X)
asm := a1 + a2 + a3
if err != nil {
return asm, err
}
asm += ZeroReg(ctx, regSubX)
optypes := GetOpDataType(instr.Type())
asm += ArithOp(ctx, optypes, token.SUB, regSubX, regX, regVal)
f.freeReg(regX)
f.freeReg(regSubX)
a, err := f.StoreValue(instr, addr, regVal)
if err != nil {
return asm, err
} else {
asm += a
}
f.freeReg(regVal)
asm = fmt.Sprintf("// BEGIN ssa.UnOpSub, %v = %v\n", instr.Name(), instr) + asm
asm += fmt.Sprintf("// END ssa.UnOpSub, %v = %v\n", instr.Name(), instr)
return asm, nil
}
// bitwise negation
func (f *Function) UnOpXor(instr *ssa.UnOp, xorVal int32) (string, *Error) {
ctx := context{f, instr}
if ident := f.Ident(instr); ident == nil {
return ErrorMsg(fmt.Sprintf("Cannot alloc value: %v", instr))
}
addr, ok := f.identifiers[instr.Name()]
if !ok {
msg := fmt.Sprintf("unknown name (%v), instr (%v)\n", instr.Name(), instr)
ice(msg)
}
asm, reg, err := f.LoadValueSimple(instr, instr.X)
if err != nil {
return asm, err
}
if reg.size() < 8 {
asm += XorImm32Reg(ctx, xorVal, reg, reg.size(), true)
} else {
asm += XorImm64Reg(ctx, int64(xorVal), reg, reg.size(), true)
}
a, err := f.StoreValue(instr, addr, reg)
f.freeReg(reg)
if err != nil {
return asm, err
} else {
asm += a
}
asm = fmt.Sprintf("// BEGIN ssa.UnOpNot, %v = %v\n", instr.Name(), instr) + asm
asm += fmt.Sprintf("// END ssa.UnOpNot, %v = %v\n", instr.Name(), instr)
return asm, nil
}
//pointer indirection, in assignment such as "z = *x"
func (f *Function) UnOpPointer(instr *ssa.UnOp) (string, *Error) {
asm := ""
assignment := f.Ident(instr)
if assignment == nil {
return ErrorMsg(fmt.Sprintf("Cannot alloc value: %v", instr))
}
xName := instr.X.Name()
xInfo, okX := f.identifiers[xName]
if !xInfo.isSsaLocal() && xInfo.param == nil && xInfo.ptr == nil {
panic("unexpected nil ptr")
} else if !xInfo.isSsaLocal() && xInfo.param == nil {
asm += xInfo.ptr.spillAllRegisters(instr)
}
// TODO add complex64/128 support
if isComplex(instr.Type()) || isComplex(instr.X.Type()) {
return ErrorMsg("complex64/complex128 unimplemented")
}
if !okX {
msgstr := "Unknown name for UnOp X (%v), instr \"(%v)\""
ice(fmt.Sprintf(msgstr, instr.X, instr))
}
if xInfo.local == nil && xInfo.param == nil && !xInfo.isPointer() {
fmtstr := "in UnOp, X (%v) isn't a pointer, X.type (%v), instr \"(%v)\""
msg := fmt.Sprintf(fmtstr, instr.X, instr.X.Type(), instr)
ice(msg)
}
_, _, size := assignment.Addr()
if xInfo.isSsaLocal() {
ctx := context{f, instr}
a, reg := xInfo.load(ctx)
asm += a
asm += assignment.newValue(ctx, reg, 0, xInfo.size())
f.freeReg(reg)
} else {
var tmpData *register
var a1 string
if isXmm(instr.Type()) {
a1, tmpData = f.allocReg(instr, XMM_REG, XmmRegSize)
} else {
a1, tmpData = f.allocReg(instr, regType(instr.Type()), DataRegSize)
}
asm += a1
var a2 string
var tmpAddr *register
a2, tmpAddr = f.allocReg(instr, DATA_REG, DataRegSize)
asm += a2
src, ok := xInfo.storage.(*memory)
if !ok {
ice("cannot dereference pointer to constant")
}
dst, ok := assignment.storage.(*memory)
if !ok {
ice("cannot modify constant")
}
dst.removeAliases()
ctx := context{f, instr}
a, srcReg := src.load(ctx, src.ownerRegion())
asm += a
aReg, aOffset, _ := assignment.Addr()
asm += MovRegIndirectMem(ctx, dst.optype(), srcReg, assignment.name, aOffset, &aReg, size, tmpAddr, tmpData)
dst.setInitialized(region{0, size})
f.freeReg(srcReg)
f.freeReg(tmpAddr)
f.freeReg(tmpData)
}
asm = fmt.Sprintf("// BEGIN ssa.UnOpPointer, %v = %v\n", instr.Name(), instr) + asm
asm += fmt.Sprintf("// END ssa.UnOpPointer, %v = %v\n", instr.Name(), instr)
return asm, nil
}