[dev.typeparams] cmd/compile: add morestack arg spilling code on ARM64

Spill arg registers before calling morestack, and reload after.

Change-Id: I09404def321b8f935d5e8836a46ccae8256d0d55
Reviewed-on: https://go-review.googlesource.com/c/go/+/322853
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>

diff --git a/src/cmd/compile/internal/arm64/ssa.go b/src/cmd/compile/internal/arm64/ssa.go
index ca76b18497e768d8bcae6729512986fe1dd845c2..d82788218d9aae0c6df40e3261c55c109a355afc 100644 (file)
--- a/src/cmd/compile/internal/arm64/ssa.go
+++ b/src/cmd/compile/internal/arm64/ssa.go
@@ -162,7 +162,16 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
                p.From.Reg = v.Args[0].Reg()
                ssagen.AddrAuto(&p.To, v)
        case ssa.OpArgIntReg, ssa.OpArgFloatReg:
-               // TODO: generate morestack spill code
+               // The assembler needs to wrap the entry safepoint/stack growth code with spill/unspill
+               // The loop only runs once.
+               for _, a := range v.Block.Func.RegArgs {
+                       // Pass the spill/unspill information along to the assembler, offset by size of
+                       // the saved LR slot.
+                       addr := ssagen.SpillSlotAddr(a, arm64.REGSP, base.Ctxt.FixedFrameSize())
+                       s.FuncInfo().AddSpill(
+                               obj.RegSpill{Reg: a.Reg, Addr: addr, Unspill: loadByType(a.Type), Spill: storeByType(a.Type)})
+               }
+               v.Block.Func.RegArgs = nil
                ssagen.CheckArgReg(v)
        case ssa.OpARM64ADD,
                ssa.OpARM64SUB,

diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go
index 004e084f72848946c34288c025dec508cf3beca3..91b0c79cd3e8cbe779aeed8f984f9deb5a93ee75 100644 (file)
--- a/src/cmd/compile/internal/ssagen/ssa.go
+++ b/src/cmd/compile/internal/ssagen/ssa.go
@@ -650,7 +650,6 @@ func buildssa(fn *ir.Func, worker int) *ssa.Func {
        // it mimics the behavior of the former ABI (everything stored) and because it's not 100%
        // clear if naming conventions are respected in autogenerated code.
        // TODO figure out exactly what's unused, don't spill it. Make liveness fine-grained, also.
-       // TODO non-amd64 architectures have link registers etc that may require adjustment here.
        for _, p := range params.InParams() {
                typs, offs := p.RegisterTypesAndOffsets()
                for i, t := range typs {

diff --git a/src/cmd/internal/obj/arm64/obj7.go b/src/cmd/internal/obj/arm64/obj7.go
index 13966f7b867d04c1520c9b1179060c2f5bc4636d..c94a0b67ee2bc743e7ad6cd93697625702be3956 100644 (file)
--- a/src/cmd/internal/obj/arm64/obj7.go
+++ b/src/cmd/internal/obj/arm64/obj7.go
@@ -161,17 +161,20 @@ func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
        pcdata := c.ctxt.EmitEntryStackMap(c.cursym, spfix, c.newprog)
        pcdata = c.ctxt.StartUnsafePoint(pcdata, c.newprog)
 
+       if q != nil {
+               q.To.SetTarget(pcdata)
+       }
+       bls.To.SetTarget(pcdata)
+
+       spill := c.cursym.Func().SpillRegisterArgs(pcdata, c.newprog)
+
        // MOV  LR, R3
-       movlr := obj.Appendp(pcdata, c.newprog)
+       movlr := obj.Appendp(spill, c.newprog)
        movlr.As = AMOVD
        movlr.From.Type = obj.TYPE_REG
        movlr.From.Reg = REGLINK
        movlr.To.Type = obj.TYPE_REG
        movlr.To.Reg = REG_R3
-       if q != nil {
-               q.To.SetTarget(movlr)
-       }
-       bls.To.SetTarget(movlr)
 
        debug := movlr
        if false {
@@ -196,7 +199,8 @@ func (c *ctxt7) stacksplit(p *obj.Prog, framesize int32) *obj.Prog {
        }
        call.To.Sym = c.ctxt.Lookup(morestack)
 
-       pcdata = c.ctxt.EndUnsafePoint(call, c.newprog, -1)
+       unspill := c.cursym.Func().UnspillRegisterArgs(call, c.newprog)
+       pcdata = c.ctxt.EndUnsafePoint(unspill, c.newprog, -1)
 
        // B    start
        jmp := obj.Appendp(pcdata, c.newprog)