[dev.regabi] cmd/compile: add ir.TailCallStmt

This CL splits out ORETJMP as a new TailCallStmt node, separate from
the other BranchStmt nodes. In doing so, this allows us to change it
from identifying a function by *types.Sym to identifying one by
directly pointing to the *ir.Func.

While here, also rename the operation to OTAILCALL.

Passes toolstash -cmp.

Change-Id: I273e6ea5d92bf3005ae02fb59b3240a190a6cf1b
Reviewed-on: https://go-review.googlesource.com/c/go/+/284227
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>

diff --git a/src/cmd/compile/internal/deadcode/deadcode.go b/src/cmd/compile/internal/deadcode/deadcode.go
index c409320fc4894f5563dd2b4b8515723bcae15553..520203787f02dc97968e4cd71c577f7fc646d24d 100644 (file)
--- a/src/cmd/compile/internal/deadcode/deadcode.go
+++ b/src/cmd/compile/internal/deadcode/deadcode.go
@@ -75,7 +75,7 @@ func stmts(nn *ir.Nodes) {
                                // might be the target of a goto. See issue 28616.
                                if body := body; len(body) != 0 {
                                        switch body[(len(body) - 1)].Op() {
-                                       case ir.ORETURN, ir.ORETJMP, ir.OPANIC:
+                                       case ir.ORETURN, ir.OTAILCALL, ir.OPANIC:
                                                if i > lastLabel {
                                                        cut = true
                                                }

diff --git a/src/cmd/compile/internal/escape/escape.go b/src/cmd/compile/internal/escape/escape.go
index 26420b820a96891f6a3fe780b8af732a1985b918..5ee6d4f498dd41f303f562d8c00e73bad73d1149 100644 (file)
--- a/src/cmd/compile/internal/escape/escape.go
+++ b/src/cmd/compile/internal/escape/escape.go
@@ -534,8 +534,8 @@ func (e *escape) stmt(n ir.Node) {
                e.stmts(n.Call.Init())
                e.call(nil, n.Call, n)
 
-       case ir.ORETJMP:
-               // TODO(mdempsky): What do? esc.go just ignores it.
+       case ir.OTAILCALL:
+               // TODO(mdempsky): Treat like a normal call? esc.go used to just ignore it.
        }
 }
 

diff --git a/src/cmd/compile/internal/inline/inl.go b/src/cmd/compile/internal/inline/inl.go
index 4bb849cdaee81848c663a497a741041fb3665f00..143fbe9efe1b9e68b6d32703987fa383d7821b27 100644 (file)
--- a/src/cmd/compile/internal/inline/inl.go
+++ b/src/cmd/compile/internal/inline/inl.go
@@ -359,7 +359,7 @@ func (v *hairyVisitor) doNode(n ir.Node) error {
                ir.OGO,
                ir.ODEFER,
                ir.ODCLTYPE, // can't print yet
-               ir.ORETJMP:
+               ir.OTAILCALL:
                return errors.New("unhandled op " + n.Op().String())
 
        case ir.OAPPEND:

diff --git a/src/cmd/compile/internal/ir/fmt.go b/src/cmd/compile/internal/ir/fmt.go
index 68e1bc156997fd77dee061138131059548ab0e63..ee6a62625afdabf537be533cd5edba25fb4aadba 100644 (file)
--- a/src/cmd/compile/internal/ir/fmt.go
+++ b/src/cmd/compile/internal/ir/fmt.go
@@ -378,9 +378,9 @@ func stmtFmt(n Node, s fmt.State) {
                n := n.(*ReturnStmt)
                fmt.Fprintf(s, "return %.v", n.Results)
 
-       case ORETJMP:
-               n := n.(*BranchStmt)
-               fmt.Fprintf(s, "retjmp %v", n.Label)
+       case OTAILCALL:
+               n := n.(*TailCallStmt)
+               fmt.Fprintf(s, "tailcall %v", n.Target)
 
        case OINLMARK:
                n := n.(*InlineMarkStmt)

diff --git a/src/cmd/compile/internal/ir/node.go b/src/cmd/compile/internal/ir/node.go
index a725307c2c64eac744a142f3b1a072efe5954c17..291e1286bb8f12017a3dfc9affecdc48d3794fe6 100644 (file)
--- a/src/cmd/compile/internal/ir/node.go
+++ b/src/cmd/compile/internal/ir/node.go
@@ -306,8 +306,8 @@ const (
        OLINKSYMOFFSET // offset within a name
 
        // arch-specific opcodes
-       ORETJMP // return to other function
-       OGETG   // runtime.getg() (read g pointer)
+       OTAILCALL // tail call to another function
+       OGETG     // runtime.getg() (read g pointer)
 
        OEND
 )

diff --git a/src/cmd/compile/internal/ir/node_gen.go b/src/cmd/compile/internal/ir/node_gen.go
index 8f89c6774865851f5d70963296c0264dd44ffd93..af9ee8d86ecd5da710ebea9dbfabe2da60c1ee00 100644 (file)
--- a/src/cmd/compile/internal/ir/node_gen.go
+++ b/src/cmd/compile/internal/ir/node_gen.go
@@ -1227,6 +1227,28 @@ func (n *SwitchStmt) editChildren(edit func(Node) Node) {
        editNodes(n.Compiled, edit)
 }
 
+func (n *TailCallStmt) Format(s fmt.State, verb rune) { fmtNode(n, s, verb) }
+func (n *TailCallStmt) copy() Node {
+       c := *n
+       c.init = copyNodes(c.init)
+       return &c
+}
+func (n *TailCallStmt) doChildren(do func(Node) bool) bool {
+       if doNodes(n.init, do) {
+               return true
+       }
+       if n.Target != nil && do(n.Target) {
+               return true
+       }
+       return false
+}
+func (n *TailCallStmt) editChildren(edit func(Node) Node) {
+       editNodes(n.init, edit)
+       if n.Target != nil {
+               n.Target = edit(n.Target).(*Name)
+       }
+}
+
 func (n *TypeAssertExpr) Format(s fmt.State, verb rune) { fmtNode(n, s, verb) }
 func (n *TypeAssertExpr) copy() Node {
        c := *n

diff --git a/src/cmd/compile/internal/ir/op_string.go b/src/cmd/compile/internal/ir/op_string.go
index 35196b01aee83347e10df901b8b8deacd8fa9021..15c60baf449d906a4db2717cd246cc58ad148f21 100644 (file)
--- a/src/cmd/compile/internal/ir/op_string.go
+++ b/src/cmd/compile/internal/ir/op_string.go
@@ -157,14 +157,14 @@ func _() {
        _ = x[ORESULT-146]
        _ = x[OINLMARK-147]
        _ = x[OLINKSYMOFFSET-148]
-       _ = x[ORETJMP-149]
+       _ = x[OTAILCALL-149]
        _ = x[OGETG-150]
        _ = x[OEND-151]
 }
 
-const _Op_name = "XXXNAMENONAMETYPEPACKLITERALNILADDSUBORXORADDSTRADDRANDANDAPPENDBYTES2STRBYTES2STRTMPRUNES2STRSTR2BYTESSTR2BYTESTMPSTR2RUNESASAS2AS2DOTTYPEAS2FUNCAS2MAPRAS2RECVASOPCALLCALLFUNCCALLMETHCALLINTERCALLPARTCAPCLOSECLOSURECOMPLITMAPLITSTRUCTLITARRAYLITSLICELITPTRLITCONVCONVIFACECONVNOPCOPYDCLDCLFUNCDCLCONSTDCLTYPEDELETEDOTDOTPTRDOTMETHDOTINTERXDOTDOTTYPEDOTTYPE2EQNELTLEGEGTDEREFINDEXINDEXMAPKEYSTRUCTKEYLENMAKEMAKECHANMAKEMAPMAKESLICEMAKESLICECOPYMULDIVMODLSHRSHANDANDNOTNEWNOTBITNOTPLUSNEGORORPANICPRINTPRINTNPARENSENDSLICESLICEARRSLICESTRSLICE3SLICE3ARRSLICEHEADERRECOVERRECVRUNESTRSELRECV2IOTAREALIMAGCOMPLEXALIGNOFOFFSETOFSIZEOFMETHEXPRSTMTEXPRBLOCKBREAKCASECONTINUEDEFERFALLFORFORUNTILGOTOIFLABELGORANGERETURNSELECTSWITCHTYPESWTCHANTMAPTSTRUCTTINTERTFUNCTARRAYTSLICEINLCALLEFACEITABIDATASPTRCFUNCCHECKNILVARDEFVARKILLVARLIVERESULTINLMARKLINKSYMOFFSETRETJMPGETGEND"
+const _Op_name = "XXXNAMENONAMETYPEPACKLITERALNILADDSUBORXORADDSTRADDRANDANDAPPENDBYTES2STRBYTES2STRTMPRUNES2STRSTR2BYTESSTR2BYTESTMPSTR2RUNESASAS2AS2DOTTYPEAS2FUNCAS2MAPRAS2RECVASOPCALLCALLFUNCCALLMETHCALLINTERCALLPARTCAPCLOSECLOSURECOMPLITMAPLITSTRUCTLITARRAYLITSLICELITPTRLITCONVCONVIFACECONVNOPCOPYDCLDCLFUNCDCLCONSTDCLTYPEDELETEDOTDOTPTRDOTMETHDOTINTERXDOTDOTTYPEDOTTYPE2EQNELTLEGEGTDEREFINDEXINDEXMAPKEYSTRUCTKEYLENMAKEMAKECHANMAKEMAPMAKESLICEMAKESLICECOPYMULDIVMODLSHRSHANDANDNOTNEWNOTBITNOTPLUSNEGORORPANICPRINTPRINTNPARENSENDSLICESLICEARRSLICESTRSLICE3SLICE3ARRSLICEHEADERRECOVERRECVRUNESTRSELRECV2IOTAREALIMAGCOMPLEXALIGNOFOFFSETOFSIZEOFMETHEXPRSTMTEXPRBLOCKBREAKCASECONTINUEDEFERFALLFORFORUNTILGOTOIFLABELGORANGERETURNSELECTSWITCHTYPESWTCHANTMAPTSTRUCTTINTERTFUNCTARRAYTSLICEINLCALLEFACEITABIDATASPTRCFUNCCHECKNILVARDEFVARKILLVARLIVERESULTINLMARKLINKSYMOFFSETTAILCALLGETGEND"
 
-var _Op_index = [...]uint16{0, 3, 7, 13, 17, 21, 28, 31, 34, 37, 39, 42, 48, 52, 58, 64, 73, 85, 94, 103, 115, 124, 126, 129, 139, 146, 153, 160, 164, 168, 176, 184, 193, 201, 204, 209, 216, 223, 229, 238, 246, 254, 260, 264, 273, 280, 284, 287, 294, 302, 309, 315, 318, 324, 331, 339, 343, 350, 358, 360, 362, 364, 366, 368, 370, 375, 380, 388, 391, 400, 403, 407, 415, 422, 431, 444, 447, 450, 453, 456, 459, 462, 468, 471, 474, 480, 484, 487, 491, 496, 501, 507, 512, 516, 521, 529, 537, 543, 552, 563, 570, 574, 581, 589, 593, 597, 601, 608, 615, 623, 629, 637, 645, 650, 655, 659, 667, 672, 676, 679, 687, 691, 693, 698, 700, 705, 711, 717, 723, 729, 734, 738, 745, 751, 756, 762, 768, 775, 780, 784, 789, 793, 798, 806, 812, 819, 826, 832, 839, 852, 858, 862, 865}
+var _Op_index = [...]uint16{0, 3, 7, 13, 17, 21, 28, 31, 34, 37, 39, 42, 48, 52, 58, 64, 73, 85, 94, 103, 115, 124, 126, 129, 139, 146, 153, 160, 164, 168, 176, 184, 193, 201, 204, 209, 216, 223, 229, 238, 246, 254, 260, 264, 273, 280, 284, 287, 294, 302, 309, 315, 318, 324, 331, 339, 343, 350, 358, 360, 362, 364, 366, 368, 370, 375, 380, 388, 391, 400, 403, 407, 415, 422, 431, 444, 447, 450, 453, 456, 459, 462, 468, 471, 474, 480, 484, 487, 491, 496, 501, 507, 512, 516, 521, 529, 537, 543, 552, 563, 570, 574, 581, 589, 593, 597, 601, 608, 615, 623, 629, 637, 645, 650, 655, 659, 667, 672, 676, 679, 687, 691, 693, 698, 700, 705, 711, 717, 723, 729, 734, 738, 745, 751, 756, 762, 768, 775, 780, 784, 789, 793, 798, 806, 812, 819, 826, 832, 839, 852, 860, 864, 867}
 
 func (i Op) String() string {
        if i >= Op(len(_Op_index)-1) {

diff --git a/src/cmd/compile/internal/ir/stmt.go b/src/cmd/compile/internal/ir/stmt.go
index 0358569a1f6ee27d405cb894f68e561a5c2d5ea4..c304867e1d9a9dc662c48cb54fb925f8558fcf5a 100644 (file)
--- a/src/cmd/compile/internal/ir/stmt.go
+++ b/src/cmd/compile/internal/ir/stmt.go
@@ -144,9 +144,6 @@ func NewBlockStmt(pos src.XPos, list []Node) *BlockStmt {
 }
 
 // A BranchStmt is a break, continue, fallthrough, or goto statement.
-//
-// For back-end code generation, Op may also be RETJMP (return+jump),
-// in which case the label names another function entirely.
 type BranchStmt struct {
        miniStmt
        Label *types.Sym // label if present
@@ -154,7 +151,7 @@ type BranchStmt struct {
 
 func NewBranchStmt(pos src.XPos, op Op, label *types.Sym) *BranchStmt {
        switch op {
-       case OBREAK, OCONTINUE, OFALL, OGOTO, ORETJMP:
+       case OBREAK, OCONTINUE, OFALL, OGOTO:
                // ok
        default:
                panic("NewBranch " + op.String())
@@ -384,6 +381,23 @@ func NewSwitchStmt(pos src.XPos, tag Node, cases []*CaseClause) *SwitchStmt {
        return n
 }
 
+// A TailCallStmt is a tail call statement, which is used for back-end
+// code generation to jump directly to another function entirely.
+type TailCallStmt struct {
+       miniStmt
+       Target *Name
+}
+
+func NewTailCallStmt(pos src.XPos, target *Name) *TailCallStmt {
+       if target.Op() != ONAME || target.Class != PFUNC {
+               base.FatalfAt(pos, "tail call to non-func %v", target)
+       }
+       n := &TailCallStmt{Target: target}
+       n.pos = pos
+       n.op = OTAILCALL
+       return n
+}
+
 // A TypeSwitchGuard is the [Name :=] X.(type) in a type switch.
 type TypeSwitchGuard struct {
        miniNode

diff --git a/src/cmd/compile/internal/reflectdata/reflect.go b/src/cmd/compile/internal/reflectdata/reflect.go
index efe863cc3fa395289f13c46214995400595d2b40..fd3e6beaa3bca25732ff36f8c980ebc6ea632c21 100644 (file)
--- a/src/cmd/compile/internal/reflectdata/reflect.go
+++ b/src/cmd/compile/internal/reflectdata/reflect.go
@@ -1794,7 +1794,7 @@ func methodWrapper(rcvr *types.Type, method *types.Field) *obj.LSym {
                }
                as := ir.NewAssignStmt(base.Pos, nthis, typecheck.ConvNop(left, rcvr))
                fn.Body.Append(as)
-               fn.Body.Append(ir.NewBranchStmt(base.Pos, ir.ORETJMP, ir.MethodSym(methodrcvr, method.Sym)))
+               fn.Body.Append(ir.NewTailCallStmt(base.Pos, method.Nname.(*ir.Name)))
        } else {
                fn.SetWrapper(true) // ignore frame for panic+recover matching
                call := ir.NewCallExpr(base.Pos, ir.OCALL, dot, nil)

diff --git a/src/cmd/compile/internal/ssagen/abi.go b/src/cmd/compile/internal/ssagen/abi.go
index 274c543ca553ad9ac146b3d06e5abf54800d0235..b5da42087251bae2a28e5e169c673abe369de64e 100644 (file)
--- a/src/cmd/compile/internal/ssagen/abi.go
+++ b/src/cmd/compile/internal/ssagen/abi.go
@@ -303,7 +303,7 @@ func makeABIWrapper(f *ir.Func, wrapperABI obj.ABI) {
        var tail ir.Node
        if tfn.Type().NumResults() == 0 && tfn.Type().NumParams() == 0 && tfn.Type().NumRecvs() == 0 && !(base.Ctxt.Arch.Name == "ppc64le" && base.Ctxt.Flag_dynlink) {
 
-               tail = ir.NewBranchStmt(base.Pos, ir.ORETJMP, f.Nname.Sym())
+               tail = ir.NewTailCallStmt(base.Pos, f.Nname)
        } else {
                call := ir.NewCallExpr(base.Pos, ir.OCALL, f.Nname, nil)
                call.Args = ir.ParamNames(tfn.Type())

diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go
index 1cd49a487ec5ac76d2370b0d4cc94b40709e9f9f..beef0d8234668b14426c2998da08961bc9c14d40 100644 (file)
--- a/src/cmd/compile/internal/ssagen/ssa.go
+++ b/src/cmd/compile/internal/ssagen/ssa.go
@@ -1580,11 +1580,11 @@ func (s *state) stmt(n ir.Node) {
                b := s.exit()
                b.Pos = s.lastPos.WithIsStmt()
 
-       case ir.ORETJMP:
-               n := n.(*ir.BranchStmt)
+       case ir.OTAILCALL:
+               n := n.(*ir.TailCallStmt)
                b := s.exit()
                b.Kind = ssa.BlockRetJmp // override BlockRet
-               b.Aux = callTargetLSym(n.Label, s.curfn.LSym)
+               b.Aux = callTargetLSym(n.Target.Sym(), s.curfn.LSym)
 
        case ir.OCONTINUE, ir.OBREAK:
                n := n.(*ir.BranchStmt)

diff --git a/src/cmd/compile/internal/typecheck/typecheck.go b/src/cmd/compile/internal/typecheck/typecheck.go
index 5b44a5743fc3a18ec0cdb216039dc839e6a0250b..7881ea308dacb5ae8c08b9a359b54fb203915864 100644 (file)
--- a/src/cmd/compile/internal/typecheck/typecheck.go
+++ b/src/cmd/compile/internal/typecheck/typecheck.go
@@ -857,8 +857,8 @@ func typecheck1(n ir.Node, top int) ir.Node {
                n := n.(*ir.ReturnStmt)
                return tcReturn(n)
 
-       case ir.ORETJMP:
-               n := n.(*ir.BranchStmt)
+       case ir.OTAILCALL:
+               n := n.(*ir.TailCallStmt)
                return n
 
        case ir.OSELECT:
@@ -2023,7 +2023,7 @@ func isTermNode(n ir.Node) bool {
                n := n.(*ir.BlockStmt)
                return isTermNodes(n.List)
 
-       case ir.OGOTO, ir.ORETURN, ir.ORETJMP, ir.OPANIC, ir.OFALL:
+       case ir.OGOTO, ir.ORETURN, ir.OTAILCALL, ir.OPANIC, ir.OFALL:
                return true
 
        case ir.OFOR, ir.OFORUNTIL:

diff --git a/src/cmd/compile/internal/walk/order.go b/src/cmd/compile/internal/walk/order.go
index d34c58009acbea2630f58c3bc9d12d6634c727de..e1e9f168bbc4b88fa1f6988a67a2b1ca644e2f3b 100644 (file)
--- a/src/cmd/compile/internal/walk/order.go
+++ b/src/cmd/compile/internal/walk/order.go
@@ -692,7 +692,7 @@ func (o *orderState) stmt(n ir.Node) {
                ir.OFALL,
                ir.OGOTO,
                ir.OLABEL,
-               ir.ORETJMP:
+               ir.OTAILCALL:
                o.out = append(o.out, n)
 
        // Special: handle call arguments.

diff --git a/src/cmd/compile/internal/walk/stmt.go b/src/cmd/compile/internal/walk/stmt.go
index d892b2413f13885342a37f115ab74cf25e9a53b1..46a621c2ba74d9aa6b236e8d1316af82ab87dce0 100644 (file)
--- a/src/cmd/compile/internal/walk/stmt.go
+++ b/src/cmd/compile/internal/walk/stmt.go
@@ -136,8 +136,8 @@ func walkStmt(n ir.Node) ir.Node {
                n := n.(*ir.ReturnStmt)
                return walkReturn(n)
 
-       case ir.ORETJMP:
-               n := n.(*ir.BranchStmt)
+       case ir.OTAILCALL:
+               n := n.(*ir.TailCallStmt)
                return n
 
        case ir.OINLMARK: