// copysub substitute s for v in a.
// copysub returns true on failure to substitute.
// TODO(dfc) reverse this logic to return false on sunstitution failure.
func copysub(a *obj.Addr, v *obj.Addr, s *obj.Addr, f bool) bool {
if copyas(a, v) {
if s.Reg >= x86.REG_AX && s.Reg <= x86.REG_DI || s.Reg >= x86.REG_X0 && s.Reg <= x86.REG_X7 {
if f {
a.Reg = s.Reg
}
}
return false
}
if regtyp(v) {
if (a.Type == obj.TYPE_MEM || a.Type == obj.TYPE_ADDR) && a.Reg == v.Reg {
if (s.Reg == x86.REG_BP) && a.Index != x86.REG_NONE {
return true /* can't use BP-base with index */
}
if f {
a.Reg = s.Reg
}
}
if a.Index == v.Reg {
if f {
a.Index = s.Reg
}
}
}
return false
}
func nacladdr(ctxt *obj.Link, p *obj.Prog, a *obj.Addr) {
if p.As == ALEAL || p.As == ALEAQ {
return
}
if a.Reg == REG_BP {
ctxt.Diag("invalid address: %v", p)
return
}
if a.Reg == REG_TLS {
a.Reg = REG_BP
}
if a.Type == obj.TYPE_MEM && a.Name == obj.NAME_NONE {
switch a.Reg {
// all ok
case REG_BP, REG_SP, REG_R15:
break
default:
if a.Index != REG_NONE {
ctxt.Diag("invalid address %v", p)
}
a.Index = a.Reg
if a.Index != REG_NONE {
a.Scale = 1
}
a.Reg = REG_R15
}
}
}
/*
* generate code to compute address of n,
* a reference to a (perhaps nested) field inside
* an array or struct.
* return 0 on failure, 1 on success.
* on success, leaves usable address in a.
*
* caller is responsible for calling sudoclean
* after successful sudoaddable,
* to release the register used for a.
*/
func sudoaddable(as obj.As, n *gc.Node, a *obj.Addr) bool {
if n.Type == nil {
return false
}
*a = obj.Addr{}
switch n.Op {
case gc.OLITERAL:
if !gc.Isconst(n, gc.CTINT) {
break
}
v := n.Int64()
if v >= 32000 || v <= -32000 {
break
}
switch as {
default:
return false
case x86.AADDB,
x86.AADDW,
x86.AADDL,
x86.AADDQ,
x86.ASUBB,
x86.ASUBW,
x86.ASUBL,
x86.ASUBQ,
x86.AANDB,
x86.AANDW,
x86.AANDL,
x86.AANDQ,
x86.AORB,
x86.AORW,
x86.AORL,
x86.AORQ,
x86.AXORB,
x86.AXORW,
x86.AXORL,
x86.AXORQ,
x86.AINCB,
x86.AINCW,
x86.AINCL,
x86.AINCQ,
x86.ADECB,
x86.ADECW,
x86.ADECL,
x86.ADECQ,
x86.AMOVB,
x86.AMOVW,
x86.AMOVL,
x86.AMOVQ:
break
}
cleani += 2
reg := &clean[cleani-1]
reg1 := &clean[cleani-2]
reg.Op = gc.OEMPTY
reg1.Op = gc.OEMPTY
gc.Naddr(a, n)
return true
case gc.ODOT,
gc.ODOTPTR:
cleani += 2
reg := &clean[cleani-1]
reg1 := &clean[cleani-2]
reg.Op = gc.OEMPTY
reg1.Op = gc.OEMPTY
var nn *gc.Node
var oary [10]int64
o := gc.Dotoffset(n, oary[:], &nn)
if nn == nil {
sudoclean()
return false
}
if nn.Addable && o == 1 && oary[0] >= 0 {
// directly addressable set of DOTs
n1 := *nn
n1.Type = n.Type
n1.Xoffset += oary[0]
gc.Naddr(a, &n1)
return true
}
gc.Regalloc(reg, gc.Types[gc.Tptr], nil)
n1 := *reg
n1.Op = gc.OINDREG
if oary[0] >= 0 {
gc.Agen(nn, reg)
n1.Xoffset = oary[0]
} else {
gc.Cgen(nn, reg)
gc.Cgen_checknil(reg)
n1.Xoffset = -(oary[0] + 1)
}
for i := 1; i < o; i++ {
if oary[i] >= 0 {
gc.Fatalf("can't happen")
}
gins(movptr, &n1, reg)
gc.Cgen_checknil(reg)
n1.Xoffset = -(oary[i] + 1)
}
a.Type = obj.TYPE_NONE
a.Index = x86.REG_NONE
gc.Fixlargeoffset(&n1)
gc.Naddr(a, &n1)
return true
case gc.OINDEX:
return false
}
return false
}
/*
* generate code to compute address of n,
* a reference to a (perhaps nested) field inside
* an array or struct.
* return 0 on failure, 1 on success.
* on success, leaves usable address in a.
*
* caller is responsible for calling sudoclean
* after successful sudoaddable,
* to release the register used for a.
*/
func sudoaddable(as obj.As, n *gc.Node, a *obj.Addr) bool {
if n.Type == nil {
return false
}
*a = obj.Addr{}
switch n.Op {
case gc.OLITERAL:
if !gc.Isconst(n, gc.CTINT) {
return false
}
v := n.Int64()
switch as {
default:
return false
// operations that can cope with a 32-bit immediate
// TODO(mundaym): logical operations can work on high bits
case s390x.AADD,
s390x.AADDC,
s390x.ASUB,
s390x.AMULLW,
s390x.AAND,
s390x.AOR,
s390x.AXOR,
s390x.ASLD,
s390x.ASLW,
s390x.ASRAW,
s390x.ASRAD,
s390x.ASRW,
s390x.ASRD,
s390x.AMOVB,
s390x.AMOVBZ,
s390x.AMOVH,
s390x.AMOVHZ,
s390x.AMOVW,
s390x.AMOVWZ,
s390x.AMOVD:
if int64(int32(v)) != v {
return false
}
// for comparisons avoid immediates unless they can
// fit into a int8/uint8
// this favours combined compare and branch instructions
case s390x.ACMP:
if int64(int8(v)) != v {
return false
}
case s390x.ACMPU:
if int64(uint8(v)) != v {
return false
}
}
cleani += 2
reg := &clean[cleani-1]
reg1 := &clean[cleani-2]
reg.Op = gc.OEMPTY
reg1.Op = gc.OEMPTY
gc.Naddr(a, n)
return true
case gc.ODOT,
gc.ODOTPTR:
cleani += 2
reg := &clean[cleani-1]
reg1 := &clean[cleani-2]
reg.Op = gc.OEMPTY
reg1.Op = gc.OEMPTY
var nn *gc.Node
var oary [10]int64
o := gc.Dotoffset(n, oary[:], &nn)
if nn == nil {
sudoclean()
return false
}
if nn.Addable && o == 1 && oary[0] >= 0 {
// directly addressable set of DOTs
n1 := *nn
n1.Type = n.Type
n1.Xoffset += oary[0]
// check that the offset fits into a 12-bit displacement
if n1.Xoffset < 0 || n1.Xoffset >= (1<<12)-8 {
sudoclean()
return false
}
gc.Naddr(a, &n1)
return true
}
gc.Regalloc(reg, gc.Types[gc.Tptr], nil)
n1 := *reg
n1.Op = gc.OINDREG
if oary[0] >= 0 {
gc.Agen(nn, reg)
n1.Xoffset = oary[0]
} else {
gc.Cgen(nn, reg)
gc.Cgen_checknil(reg)
n1.Xoffset = -(oary[0] + 1)
}
for i := 1; i < o; i++ {
if oary[i] >= 0 {
gc.Fatalf("can't happen")
}
gins(s390x.AMOVD, &n1, reg)
gc.Cgen_checknil(reg)
n1.Xoffset = -(oary[i] + 1)
}
a.Type = obj.TYPE_NONE
a.Index = 0
// check that the offset fits into a 12-bit displacement
if n1.Xoffset < 0 || n1.Xoffset >= (1<<12)-8 {
tmp := n1
tmp.Op = gc.OREGISTER
tmp.Type = gc.Types[gc.Tptr]
tmp.Xoffset = 0
gc.Cgen_checknil(&tmp)
ginscon(s390x.AADD, n1.Xoffset, &tmp)
n1.Xoffset = 0
}
gc.Naddr(a, &n1)
return true
}
return false
}