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cmd/compile: reorganize SSA register numbering

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Teach SSA about the cmd/internal/obj/$ARCH register numbering.
It can then return that numbering when requested.  Each architecture
now does not need to know anything about the internal SSA numbering
of registers.

Change-Id: I34472a2736227c15482e60994eebcdd2723fa52d
Reviewed-on: https://go-review.googlesource.com/29249
Reviewed-by: David Chase <drchase@google.com>
This commit is contained in:
Keith Randall 2016-09-16 09:36:00 -07:00
parent b87d7a5cf6
commit 833ed7c431
22 changed files with 913 additions and 1300 deletions
Download patch file Download diff file Expand all files Collapse all files

194
src/cmd/compile/internal/x86/ssa.go
View file

@ -14,30 +14,6 @@ import (
"cmd/internal/obj/x86"
)
// Smallest possible faulting page at address zero.
const minZeroPage = 4096
// ssaRegToReg maps ssa register numbers to obj register numbers.
var ssaRegToReg = []int16{
x86.REG_AX,
x86.REG_CX,
x86.REG_DX,
x86.REG_BX,
x86.REG_SP,
x86.REG_BP,
x86.REG_SI,
x86.REG_DI,
x86.REG_X0,
x86.REG_X1,
x86.REG_X2,
x86.REG_X3,
x86.REG_X4,
x86.REG_X5,
x86.REG_X6,
x86.REG_X7,
0, // SB isn't a real register. We fill an Addr.Reg field with 0 in this case.
}
// markMoves marks any MOVXconst ops that need to avoid clobbering flags.
func ssaMarkMoves(s *gc.SSAGenState, b *ssa.Block) {
flive := b.FlagsLiveAtEnd
@ -148,9 +124,9 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
switch v.Op {
case ssa.Op386ADDL:
r := gc.SSARegNum(v)
r1 := gc.SSARegNum(v.Args[0])
r2 := gc.SSARegNum(v.Args[1])
r := v.Reg()
r1 := v.Args[0].Reg()
r2 := v.Args[1].Reg()
switch {
case r == r1:
p := gc.Prog(v.Op.Asm())
@ -188,24 +164,24 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
ssa.Op386PXOR,
ssa.Op386ADCL,
ssa.Op386SBBL:
r := gc.SSARegNum(v)
if r != gc.SSARegNum(v.Args[0]) {
r := v.Reg()
if r != v.Args[0].Reg() {
v.Fatalf("input[0] and output not in same register %s", v.LongString())
}
opregreg(v.Op.Asm(), r, gc.SSARegNum(v.Args[1]))
opregreg(v.Op.Asm(), r, v.Args[1].Reg())
case ssa.Op386ADDLcarry, ssa.Op386SUBLcarry:
// output 0 is carry/borrow, output 1 is the low 32 bits.
r := gc.SSARegNum0(v)
if r != gc.SSARegNum(v.Args[0]) {
r := v.Reg0()
if r != v.Args[0].Reg() {
v.Fatalf("input[0] and output[0] not in same register %s", v.LongString())
}
opregreg(v.Op.Asm(), r, gc.SSARegNum(v.Args[1]))
opregreg(v.Op.Asm(), r, v.Args[1].Reg())
case ssa.Op386ADDLconstcarry, ssa.Op386SUBLconstcarry:
// output 0 is carry/borrow, output 1 is the low 32 bits.
r := gc.SSARegNum0(v)
if r != gc.SSARegNum(v.Args[0]) {
r := v.Reg0()
if r != v.Args[0].Reg() {
v.Fatalf("input[0] and output[0] not in same register %s", v.LongString())
}
p := gc.Prog(v.Op.Asm())
@ -221,7 +197,7 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
// Arg[0] is already in AX as it's the only register we allow
// and AX is the only output
x := gc.SSARegNum(v.Args[1])
x := v.Args[1].Reg()
// CPU faults upon signed overflow, which occurs when most
// negative int is divided by -1.
@ -298,7 +274,7 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
// and DX is the only output we care about (the high bits)
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[1])
p.From.Reg = v.Args[1].Reg()
// IMULB puts the high portion in AH instead of DL,
// so move it to DL for consistency
@ -314,11 +290,11 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
// AX * args[1], high 32 bits in DX (result[0]), low 32 bits in AX (result[1]).
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[1])
p.From.Reg = v.Args[1].Reg()
case ssa.Op386ADDLconst:
r := gc.SSARegNum(v)
a := gc.SSARegNum(v.Args[0])
r := v.Reg()
a := v.Args[0].Reg()
if r == a {
if v.AuxInt == 1 {
p := gc.Prog(x86.AINCL)
@ -347,8 +323,8 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
p.To.Reg = r
case ssa.Op386MULLconst:
r := gc.SSARegNum(v)
if r != gc.SSARegNum(v.Args[0]) {
r := v.Reg()
if r != v.Args[0].Reg() {
v.Fatalf("input[0] and output not in same register %s", v.LongString())
}
p := gc.Prog(v.Op.Asm())
@ -360,7 +336,7 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
// then we don't need to use resultInArg0 for these ops.
//p.From3 = new(obj.Addr)
//p.From3.Type = obj.TYPE_REG
//p.From3.Reg = gc.SSARegNum(v.Args[0])
//p.From3.Reg = v.Args[0].Reg()
case ssa.Op386SUBLconst,
ssa.Op386ADCLconst,
@ -372,8 +348,8 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
ssa.Op386SHRLconst, ssa.Op386SHRWconst, ssa.Op386SHRBconst,
ssa.Op386SARLconst, ssa.Op386SARWconst, ssa.Op386SARBconst,
ssa.Op386ROLLconst, ssa.Op386ROLWconst, ssa.Op386ROLBconst:
r := gc.SSARegNum(v)
if r != gc.SSARegNum(v.Args[0]) {
r := v.Reg()
if r != v.Args[0].Reg() {
v.Fatalf("input[0] and output not in same register %s", v.LongString())
}
p := gc.Prog(v.Op.Asm())
@ -382,15 +358,15 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
p.To.Type = obj.TYPE_REG
p.To.Reg = r
case ssa.Op386SBBLcarrymask:
r := gc.SSARegNum(v)
r := v.Reg()
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = r
p.To.Type = obj.TYPE_REG
p.To.Reg = r
case ssa.Op386LEAL1, ssa.Op386LEAL2, ssa.Op386LEAL4, ssa.Op386LEAL8:
r := gc.SSARegNum(v.Args[0])
i := gc.SSARegNum(v.Args[1])
r := v.Args[0].Reg()
i := v.Args[1].Reg()
p := gc.Prog(x86.ALEAL)
switch v.Op {
case ssa.Op386LEAL1:
@ -410,25 +386,25 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
p.From.Index = i
gc.AddAux(&p.From, v)
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
p.To.Reg = v.Reg()
case ssa.Op386LEAL:
p := gc.Prog(x86.ALEAL)
p.From.Type = obj.TYPE_MEM
p.From.Reg = gc.SSARegNum(v.Args[0])
p.From.Reg = v.Args[0].Reg()
gc.AddAux(&p.From, v)
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
p.To.Reg = v.Reg()
case ssa.Op386CMPL, ssa.Op386CMPW, ssa.Op386CMPB,
ssa.Op386TESTL, ssa.Op386TESTW, ssa.Op386TESTB:
opregreg(v.Op.Asm(), gc.SSARegNum(v.Args[1]), gc.SSARegNum(v.Args[0]))
opregreg(v.Op.Asm(), v.Args[1].Reg(), v.Args[0].Reg())
case ssa.Op386UCOMISS, ssa.Op386UCOMISD:
// Go assembler has swapped operands for UCOMISx relative to CMP,
// must account for that right here.
opregreg(v.Op.Asm(), gc.SSARegNum(v.Args[0]), gc.SSARegNum(v.Args[1]))
opregreg(v.Op.Asm(), v.Args[0].Reg(), v.Args[1].Reg())
case ssa.Op386CMPLconst, ssa.Op386CMPWconst, ssa.Op386CMPBconst:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[0])
p.From.Reg = v.Args[0].Reg()
p.To.Type = obj.TYPE_CONST
p.To.Offset = v.AuxInt
case ssa.Op386TESTLconst, ssa.Op386TESTWconst, ssa.Op386TESTBconst:
@ -436,9 +412,9 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
p.From.Type = obj.TYPE_CONST
p.From.Offset = v.AuxInt
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v.Args[0])
p.To.Reg = v.Args[0].Reg()
case ssa.Op386MOVLconst:
x := gc.SSARegNum(v)
x := v.Reg()
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_CONST
p.From.Offset = v.AuxInt
@ -450,7 +426,7 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
p.Mark |= x86.PRESERVEFLAGS
}
case ssa.Op386MOVSSconst, ssa.Op386MOVSDconst:
x := gc.SSARegNum(v)
x := v.Reg()
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_FCONST
p.From.Val = math.Float64frombits(uint64(v.AuxInt))
@ -469,51 +445,51 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
p.From.Sym = obj.Linklookup(gc.Ctxt, literal, 0)
p.From.Sym.Local = true
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
p.To.Reg = v.Reg()
case ssa.Op386MOVSSconst2, ssa.Op386MOVSDconst2:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_MEM
p.From.Reg = gc.SSARegNum(v.Args[0])
p.From.Reg = v.Args[0].Reg()
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
p.To.Reg = v.Reg()
case ssa.Op386MOVSSload, ssa.Op386MOVSDload, ssa.Op386MOVLload, ssa.Op386MOVWload, ssa.Op386MOVBload, ssa.Op386MOVBLSXload, ssa.Op386MOVWLSXload:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_MEM
p.From.Reg = gc.SSARegNum(v.Args[0])
p.From.Reg = v.Args[0].Reg()
gc.AddAux(&p.From, v)
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
p.To.Reg = v.Reg()
case ssa.Op386MOVSDloadidx8:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_MEM
p.From.Reg = gc.SSARegNum(v.Args[0])
p.From.Reg = v.Args[0].Reg()
gc.AddAux(&p.From, v)
p.From.Scale = 8
p.From.Index = gc.SSARegNum(v.Args[1])
p.From.Index = v.Args[1].Reg()
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
p.To.Reg = v.Reg()
case ssa.Op386MOVLloadidx4, ssa.Op386MOVSSloadidx4:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_MEM
p.From.Reg = gc.SSARegNum(v.Args[0])
p.From.Reg = v.Args[0].Reg()
gc.AddAux(&p.From, v)
p.From.Scale = 4
p.From.Index = gc.SSARegNum(v.Args[1])
p.From.Index = v.Args[1].Reg()
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
p.To.Reg = v.Reg()
case ssa.Op386MOVWloadidx2:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_MEM
p.From.Reg = gc.SSARegNum(v.Args[0])
p.From.Reg = v.Args[0].Reg()
gc.AddAux(&p.From, v)
p.From.Scale = 2
p.From.Index = gc.SSARegNum(v.Args[1])
p.From.Index = v.Args[1].Reg()
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
p.To.Reg = v.Reg()
case ssa.Op386MOVBloadidx1, ssa.Op386MOVWloadidx1, ssa.Op386MOVLloadidx1, ssa.Op386MOVSSloadidx1, ssa.Op386MOVSDloadidx1:
r := gc.SSARegNum(v.Args[0])
i := gc.SSARegNum(v.Args[1])
r := v.Args[0].Reg()
i := v.Args[1].Reg()
if i == x86.REG_SP {
r, i = i, r
}
@ -524,50 +500,50 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
p.From.Index = i
gc.AddAux(&p.From, v)
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
p.To.Reg = v.Reg()
case ssa.Op386MOVSSstore, ssa.Op386MOVSDstore, ssa.Op386MOVLstore, ssa.Op386MOVWstore, ssa.Op386MOVBstore:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[1])
p.From.Reg = v.Args[1].Reg()
p.To.Type = obj.TYPE_MEM
p.To.Reg = gc.SSARegNum(v.Args[0])
p.To.Reg = v.Args[0].Reg()
gc.AddAux(&p.To, v)
case ssa.Op386MOVSDstoreidx8:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[2])
p.From.Reg = v.Args[2].Reg()
p.To.Type = obj.TYPE_MEM
p.To.Reg = gc.SSARegNum(v.Args[0])
p.To.Reg = v.Args[0].Reg()
p.To.Scale = 8
p.To.Index = gc.SSARegNum(v.Args[1])
p.To.Index = v.Args[1].Reg()
gc.AddAux(&p.To, v)
case ssa.Op386MOVSSstoreidx4, ssa.Op386MOVLstoreidx4:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[2])
p.From.Reg = v.Args[2].Reg()
p.To.Type = obj.TYPE_MEM
p.To.Reg = gc.SSARegNum(v.Args[0])
p.To.Reg = v.Args[0].Reg()
p.To.Scale = 4
p.To.Index = gc.SSARegNum(v.Args[1])
p.To.Index = v.Args[1].Reg()
gc.AddAux(&p.To, v)
case ssa.Op386MOVWstoreidx2:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[2])
p.From.Reg = v.Args[2].Reg()
p.To.Type = obj.TYPE_MEM
p.To.Reg = gc.SSARegNum(v.Args[0])
p.To.Reg = v.Args[0].Reg()
p.To.Scale = 2
p.To.Index = gc.SSARegNum(v.Args[1])
p.To.Index = v.Args[1].Reg()
gc.AddAux(&p.To, v)
case ssa.Op386MOVBstoreidx1, ssa.Op386MOVWstoreidx1, ssa.Op386MOVLstoreidx1, ssa.Op386MOVSSstoreidx1, ssa.Op386MOVSDstoreidx1:
r := gc.SSARegNum(v.Args[0])
i := gc.SSARegNum(v.Args[1])
r := v.Args[0].Reg()
i := v.Args[1].Reg()
if i == x86.REG_SP {
r, i = i, r
}
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[2])
p.From.Reg = v.Args[2].Reg()
p.To.Type = obj.TYPE_MEM
p.To.Reg = r
p.To.Scale = 1
@ -579,15 +555,15 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
sc := v.AuxValAndOff()
p.From.Offset = sc.Val()
p.To.Type = obj.TYPE_MEM
p.To.Reg = gc.SSARegNum(v.Args[0])
p.To.Reg = v.Args[0].Reg()
gc.AddAux2(&p.To, v, sc.Off())
case ssa.Op386MOVLstoreconstidx1, ssa.Op386MOVLstoreconstidx4, ssa.Op386MOVWstoreconstidx1, ssa.Op386MOVWstoreconstidx2, ssa.Op386MOVBstoreconstidx1:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_CONST
sc := v.AuxValAndOff()
p.From.Offset = sc.Val()
r := gc.SSARegNum(v.Args[0])
i := gc.SSARegNum(v.Args[1])
r := v.Args[0].Reg()
i := v.Args[1].Reg()
switch v.Op {
case ssa.Op386MOVBstoreconstidx1, ssa.Op386MOVWstoreconstidx1, ssa.Op386MOVLstoreconstidx1:
p.To.Scale = 1
@ -607,7 +583,7 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
ssa.Op386CVTSL2SS, ssa.Op386CVTSL2SD,
ssa.Op386CVTTSS2SL, ssa.Op386CVTTSD2SL,
ssa.Op386CVTSS2SD, ssa.Op386CVTSD2SS:
opregreg(v.Op.Asm(), gc.SSARegNum(v), gc.SSARegNum(v.Args[0]))
opregreg(v.Op.Asm(), v.Reg(), v.Args[0].Reg())
case ssa.Op386DUFFZERO:
p := gc.Prog(obj.ADUFFZERO)
p.To.Type = obj.TYPE_ADDR
@ -623,8 +599,8 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
if v.Type.IsMemory() {
return
}
x := gc.SSARegNum(v.Args[0])
y := gc.SSARegNum(v)
x := v.Args[0].Reg()
y := v.Reg()
if x != y {
opregreg(moveByType(v.Type), y, x)
}
@ -646,7 +622,7 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
p.From.Name = obj.NAME_AUTO
}
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
p.To.Reg = v.Reg()
case ssa.OpStoreReg:
if v.Type.IsFlags() {
@ -655,7 +631,7 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
}
p := gc.Prog(storeByType(v.Type))
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[0])
p.From.Reg = v.Args[0].Reg()
n, off := gc.AutoVar(v)
p.To.Type = obj.TYPE_MEM
p.To.Node = n
@ -677,7 +653,7 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
// Closure pointer is DX.
gc.CheckLoweredGetClosurePtr(v)
case ssa.Op386LoweredGetG:
r := gc.SSARegNum(v)
r := v.Reg()
// See the comments in cmd/internal/obj/x86/obj6.go
// near CanUse1InsnTLS for a detailed explanation of these instructions.
if x86.CanUse1InsnTLS(gc.Ctxt) {
@ -725,7 +701,7 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
case ssa.Op386CALLclosure:
p := gc.Prog(obj.ACALL)
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v.Args[0])
p.To.Reg = v.Args[0].Reg()
if gc.Maxarg < v.AuxInt {
gc.Maxarg = v.AuxInt
}
@ -748,15 +724,15 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
case ssa.Op386CALLinter:
p := gc.Prog(obj.ACALL)
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v.Args[0])
p.To.Reg = v.Args[0].Reg()
if gc.Maxarg < v.AuxInt {
gc.Maxarg = v.AuxInt
}
case ssa.Op386NEGL,
ssa.Op386BSWAPL,
ssa.Op386NOTL:
r := gc.SSARegNum(v)
if r != gc.SSARegNum(v.Args[0]) {
r := v.Reg()
if r != v.Args[0].Reg() {
v.Fatalf("input[0] and output not in same register %s", v.LongString())
}
p := gc.Prog(v.Op.Asm())
@ -767,9 +743,9 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
ssa.Op386SQRTSD:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_REG
p.From.Reg = gc.SSARegNum(v.Args[0])
p.From.Reg = v.Args[0].Reg()
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
p.To.Reg = v.Reg()
case ssa.OpSP, ssa.OpSB, ssa.OpSelect0, ssa.OpSelect1:
// nothing to do
case ssa.Op386SETEQ, ssa.Op386SETNE,
@ -781,25 +757,25 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
ssa.Op386SETA, ssa.Op386SETAE:
p := gc.Prog(v.Op.Asm())
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
p.To.Reg = v.Reg()
case ssa.Op386SETNEF:
p := gc.Prog(v.Op.Asm())
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
p.To.Reg = v.Reg()
q := gc.Prog(x86.ASETPS)
q.To.Type = obj.TYPE_REG
q.To.Reg = x86.REG_AX
opregreg(x86.AORL, gc.SSARegNum(v), x86.REG_AX)
opregreg(x86.AORL, v.Reg(), x86.REG_AX)
case ssa.Op386SETEQF:
p := gc.Prog(v.Op.Asm())
p.To.Type = obj.TYPE_REG
p.To.Reg = gc.SSARegNum(v)
p.To.Reg = v.Reg()
q := gc.Prog(x86.ASETPC)
q.To.Type = obj.TYPE_REG
q.To.Reg = x86.REG_AX
opregreg(x86.AANDL, gc.SSARegNum(v), x86.REG_AX)
opregreg(x86.AANDL, v.Reg(), x86.REG_AX)
case ssa.Op386InvertFlags:
v.Fatalf("InvertFlags should never make it to codegen %v", v.LongString())
@ -830,7 +806,7 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
p.From.Type = obj.TYPE_REG
p.From.Reg = x86.REG_AX
p.To.Type = obj.TYPE_MEM
p.To.Reg = gc.SSARegNum(v.Args[0])
p.To.Reg = v.Args[0].Reg()
gc.AddAux(&p.To, v)
if gc.Debug_checknil != 0 && v.Line > 1 { // v.Line==1 in generated wrappers
gc.Warnl(v.Line, "generated nil check")