// lookupVarOutgoing finds the variable's value at the end of block b.
func (s *simplePhiState) lookupVarOutgoing(b *ssa.Block, t ssa.Type, var_ *Node, line int32) *ssa.Value {
for {
if v := s.defvars[b.ID][var_]; v != nil {
return v
}
// The variable is not defined by b and we haven't looked it up yet.
// If b has exactly one predecessor, loop to look it up there.
// Otherwise, give up and insert a new FwdRef and resolve it later.
if len(b.Preds) != 1 {
break
}
b = b.Preds[0].Block()
}
// Generate a FwdRef for the variable and return that.
v := b.NewValue0A(line, ssa.OpFwdRef, t, var_)
s.defvars[b.ID][var_] = v
s.s.addNamedValue(var_, v)
s.fwdrefs = append(s.fwdrefs, v)
return v
}
func ssaGenBlock(s *gc.SSAGenState, b, next *ssa.Block) {
s.SetLineno(b.Line)
switch b.Kind {
case ssa.BlockPlain, ssa.BlockCall, ssa.BlockCheck:
if b.Succs[0] != next {
p := gc.Prog(obj.AJMP)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{p, b.Succs[0]})
}
case ssa.BlockDefer:
// defer returns in rax:
// 0 if we should continue executing
// 1 if we should jump to deferreturn call
p := gc.Prog(x86.ATESTL)
p.From.Type = obj.TYPE_REG
p.From.Reg = x86.REG_AX
p.To.Type = obj.TYPE_REG
p.To.Reg = x86.REG_AX
p = gc.Prog(x86.AJNE)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{p, b.Succs[1]})
if b.Succs[0] != next {
p := gc.Prog(obj.AJMP)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{p, b.Succs[0]})
}
case ssa.BlockExit:
gc.Prog(obj.AUNDEF) // tell plive.go that we never reach here
case ssa.BlockRet:
gc.Prog(obj.ARET)
case ssa.BlockRetJmp:
p := gc.Prog(obj.AJMP)
p.To.Type = obj.TYPE_MEM
p.To.Name = obj.NAME_EXTERN
p.To.Sym = gc.Linksym(b.Aux.(*gc.Sym))
case ssa.BlockAMD64EQF:
gc.SSAGenFPJump(s, b, next, &eqfJumps)
case ssa.BlockAMD64NEF:
gc.SSAGenFPJump(s, b, next, &nefJumps)
case ssa.BlockAMD64EQ, ssa.BlockAMD64NE,
ssa.BlockAMD64LT, ssa.BlockAMD64GE,
ssa.BlockAMD64LE, ssa.BlockAMD64GT,
ssa.BlockAMD64ULT, ssa.BlockAMD64UGT,
ssa.BlockAMD64ULE, ssa.BlockAMD64UGE:
jmp := blockJump[b.Kind]
likely := b.Likely
var p *obj.Prog
switch next {
case b.Succs[0]:
p = gc.Prog(jmp.invasm)
likely *= -1
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{p, b.Succs[1]})
case b.Succs[1]:
p = gc.Prog(jmp.asm)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{p, b.Succs[0]})
default:
p = gc.Prog(jmp.asm)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{p, b.Succs[0]})
q := gc.Prog(obj.AJMP)
q.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{q, b.Succs[1]})
}
// liblink reorders the instruction stream as it sees fit.
// Pass along what we know so liblink can make use of it.
// TODO: Once we've fully switched to SSA,
// make liblink leave our output alone.
switch likely {
case ssa.BranchUnlikely:
p.From.Type = obj.TYPE_CONST
p.From.Offset = 0
case ssa.BranchLikely:
p.From.Type = obj.TYPE_CONST
p.From.Offset = 1
}
default:
b.Unimplementedf("branch not implemented: %s. Control: %s", b.LongString(), b.Control.LongString())
}
}
func ssaGenBlock(s *gc.SSAGenState, b, next *ssa.Block) {
s.SetLineno(b.Line)
switch b.Kind {
case ssa.BlockPlain:
if b.Succs[0].Block() != next {
p := gc.Prog(obj.AJMP)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
}
case ssa.BlockDefer:
// defer returns in R0:
// 0 if we should continue executing
// 1 if we should jump to deferreturn call
p := gc.Prog(arm.ACMP)
p.From.Type = obj.TYPE_CONST
p.From.Offset = 0
p.Reg = arm.REG_R0
p = gc.Prog(arm.ABNE)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[1].Block()})
if b.Succs[0].Block() != next {
p := gc.Prog(obj.AJMP)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
}
case ssa.BlockExit:
gc.Prog(obj.AUNDEF) // tell plive.go that we never reach here
case ssa.BlockRet:
gc.Prog(obj.ARET)
case ssa.BlockRetJmp:
p := gc.Prog(obj.ARET)
p.To.Type = obj.TYPE_MEM
p.To.Name = obj.NAME_EXTERN
p.To.Sym = gc.Linksym(b.Aux.(*gc.Sym))
case ssa.BlockARMEQ, ssa.BlockARMNE,
ssa.BlockARMLT, ssa.BlockARMGE,
ssa.BlockARMLE, ssa.BlockARMGT,
ssa.BlockARMULT, ssa.BlockARMUGT,
ssa.BlockARMULE, ssa.BlockARMUGE:
jmp := blockJump[b.Kind]
var p *obj.Prog
switch next {
case b.Succs[0].Block():
p = gc.Prog(jmp.invasm)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[1].Block()})
case b.Succs[1].Block():
p = gc.Prog(jmp.asm)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
default:
p = gc.Prog(jmp.asm)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
q := gc.Prog(obj.AJMP)
q.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: q, B: b.Succs[1].Block()})
}
default:
b.Fatalf("branch not implemented: %s. Control: %s", b.LongString(), b.Control.LongString())
}
}
func ssaGenBlock(s *gc.SSAGenState, b, next *ssa.Block) {
s.SetLineno(b.Line)
switch b.Kind {
case ssa.BlockPlain:
if b.Succs[0].Block() != next {
p := gc.Prog(obj.AJMP)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
}
case ssa.BlockDefer:
// defer returns in R1:
// 0 if we should continue executing
// 1 if we should jump to deferreturn call
p := gc.Prog(mips.ABNE)
p.From.Type = obj.TYPE_REG
p.From.Reg = mips.REGZERO
p.Reg = mips.REG_R1
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[1].Block()})
if b.Succs[0].Block() != next {
p := gc.Prog(obj.AJMP)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
}
case ssa.BlockExit:
gc.Prog(obj.AUNDEF) // tell plive.go that we never reach here
case ssa.BlockRet:
gc.Prog(obj.ARET)
case ssa.BlockRetJmp:
p := gc.Prog(obj.ARET)
p.To.Type = obj.TYPE_MEM
p.To.Name = obj.NAME_EXTERN
p.To.Sym = gc.Linksym(b.Aux.(*gc.Sym))
case ssa.BlockMIPSEQ, ssa.BlockMIPSNE,
ssa.BlockMIPSLTZ, ssa.BlockMIPSGEZ,
ssa.BlockMIPSLEZ, ssa.BlockMIPSGTZ,
ssa.BlockMIPSFPT, ssa.BlockMIPSFPF:
jmp := blockJump[b.Kind]
var p *obj.Prog
switch next {
case b.Succs[0].Block():
p = gc.Prog(jmp.invasm)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[1].Block()})
case b.Succs[1].Block():
p = gc.Prog(jmp.asm)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
default:
p = gc.Prog(jmp.asm)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
q := gc.Prog(obj.AJMP)
q.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: q, B: b.Succs[1].Block()})
}
if !b.Control.Type.IsFlags() {
p.From.Type = obj.TYPE_REG
p.From.Reg = b.Control.Reg()
}
default:
b.Fatalf("branch not implemented: %s. Control: %s", b.LongString(), b.Control.LongString())
}
}
func ssaGenBlock(s *gc.SSAGenState, b, next *ssa.Block) {
s.SetLineno(b.Line)
switch b.Kind {
case ssa.BlockDefer:
// defer returns in R3:
// 0 if we should continue executing
// 1 if we should jump to deferreturn call
p := gc.Prog(ppc64.ACMP)
p.From.Type = obj.TYPE_REG
p.From.Reg = ppc64.REG_R3
p.To.Type = obj.TYPE_REG
p.To.Reg = ppc64.REG_R0
p = gc.Prog(ppc64.ABNE)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[1].Block()})
if b.Succs[0].Block() != next {
p := gc.Prog(obj.AJMP)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
}
case ssa.BlockPlain, ssa.BlockCall, ssa.BlockCheck:
if b.Succs[0].Block() != next {
p := gc.Prog(obj.AJMP)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
}
case ssa.BlockExit:
gc.Prog(obj.AUNDEF) // tell plive.go that we never reach here
case ssa.BlockRet:
gc.Prog(obj.ARET)
case ssa.BlockRetJmp:
p := gc.Prog(obj.AJMP)
p.To.Type = obj.TYPE_MEM
p.To.Name = obj.NAME_EXTERN
p.To.Sym = gc.Linksym(b.Aux.(*gc.Sym))
case ssa.BlockPPC64EQ, ssa.BlockPPC64NE,
ssa.BlockPPC64LT, ssa.BlockPPC64GE,
ssa.BlockPPC64LE, ssa.BlockPPC64GT,
ssa.BlockPPC64FLT, ssa.BlockPPC64FGE,
ssa.BlockPPC64FLE, ssa.BlockPPC64FGT:
jmp := blockJump[b.Kind]
likely := b.Likely
var p *obj.Prog
switch next {
case b.Succs[0].Block():
p = gc.Prog(jmp.invasm)
likely *= -1
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[1].Block()})
if jmp.invasmun {
// TODO: The second branch is probably predict-not-taken since it is for FP unordered
q := gc.Prog(ppc64.ABVS)
q.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: q, B: b.Succs[1].Block()})
}
case b.Succs[1].Block():
p = gc.Prog(jmp.asm)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
if jmp.asmeq {
q := gc.Prog(ppc64.ABEQ)
q.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: q, B: b.Succs[0].Block()})
}
default:
p = gc.Prog(jmp.asm)
p.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: p, B: b.Succs[0].Block()})
if jmp.asmeq {
q := gc.Prog(ppc64.ABEQ)
q.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: q, B: b.Succs[0].Block()})
}
q := gc.Prog(obj.AJMP)
q.To.Type = obj.TYPE_BRANCH
s.Branches = append(s.Branches, gc.Branch{P: q, B: b.Succs[1].Block()})
}
// liblink reorders the instruction stream as it sees fit.
// Pass along what we know so liblink can make use of it.
// TODO: Once we've fully switched to SSA,
// make liblink leave our output alone.
//switch likely {
//case ssa.BranchUnlikely:
// p.From.Type = obj.TYPE_CONST
// p.From.Offset = 0
//case ssa.BranchLikely:
// p.From.Type = obj.TYPE_CONST
// p.From.Offset = 1
//}
default:
b.Unimplementedf("branch not implemented: %s. Control: %s", b.LongString(), b.Control.LongString())
}
}