cmd/compile/internal/s390x: add initial spill support

This adds some initial support for spilling and reloading registers in
the new ABI for s390x

Update #40724

Change-Id: Icc46a9375454765dea7d03fc4c8f2dbcc87f5f50
Reviewed-on: https://go-review.googlesource.com/c/go/+/719463
Reviewed-by: Vishwanatha HD <vishwanatha.hd@ibm.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@golang.org>

diff --git a/src/cmd/compile/internal/s390x/galign.go b/src/cmd/compile/internal/s390x/galign.go
index d880834c220d91c763667614a46b241fb23484bb..1fb371a52c6ac2f13f7d5821aa1ce43bcc520dbb 100644 (file)
--- a/src/cmd/compile/internal/s390x/galign.go
+++ b/src/cmd/compile/internal/s390x/galign.go
@@ -20,4 +20,6 @@ func Init(arch *ssagen.ArchInfo) {
        arch.SSAMarkMoves = ssaMarkMoves
        arch.SSAGenValue = ssaGenValue
        arch.SSAGenBlock = ssaGenBlock
+       arch.LoadRegResult = loadRegResult
+       arch.SpillArgReg = spillArgReg
 }

diff --git a/src/cmd/compile/internal/s390x/ssa.go b/src/cmd/compile/internal/s390x/ssa.go
index 03af5bdd9e783e0809a0b3d6d6183bfdbdcf2526..ce060597d9a4c4c6dfab673c5242be48b3adbf33 100644 (file)
--- a/src/cmd/compile/internal/s390x/ssa.go
+++ b/src/cmd/compile/internal/s390x/ssa.go
@@ -10,6 +10,7 @@ import (
        "cmd/compile/internal/base"
        "cmd/compile/internal/ir"
        "cmd/compile/internal/logopt"
+       "cmd/compile/internal/objw"
        "cmd/compile/internal/ssa"
        "cmd/compile/internal/ssagen"
        "cmd/compile/internal/types"
@@ -541,6 +542,17 @@ 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:
+               // 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, s390x.REGSP, base.Ctxt.Arch.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.OpS390XLoweredGetClosurePtr:
                // Closure pointer is R12 (already)
@@ -1031,3 +1043,22 @@ func ssaGenBlock(s *ssagen.State, b, next *ssa.Block) {
                s.Br(s390x.ABR, succs[1])
        }
 }
+
+func loadRegResult(s *ssagen.State, f *ssa.Func, t *types.Type, reg int16, n *ir.Name, off int64) *obj.Prog {
+       p := s.Prog(loadByType(t))
+       p.From.Type = obj.TYPE_MEM
+       p.From.Name = obj.NAME_AUTO
+       p.From.Sym = n.Linksym()
+       p.From.Offset = n.FrameOffset() + off
+       p.To.Type = obj.TYPE_REG
+       p.To.Reg = reg
+       return p
+}
+
+func spillArgReg(pp *objw.Progs, p *obj.Prog, f *ssa.Func, t *types.Type, reg int16, n *ir.Name, off int64) *obj.Prog {
+       p = pp.Append(p, storeByType(t), obj.TYPE_REG, reg, 0, obj.TYPE_MEM, 0, n.FrameOffset()+off)
+       p.To.Name = obj.NAME_PARAM
+       p.To.Sym = n.Linksym()
+       p.Pos = p.Pos.WithNotStmt()
+       return p
+}