cmd/compile: rip out support for OVARKILL from compiler frontend

Change-Id: I2c5b1064084bade68aaa065cf74dca6886fb752f
Reviewed-on: https://go-review.googlesource.com/c/go/+/419236
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>

diff --git a/src/cmd/compile/internal/ir/expr.go b/src/cmd/compile/internal/ir/expr.go
index 83105de253d650e462cfd24e5b9644bfd9f9d0c9..c7bf296bf7ad5b24df3b8a01c41cb5914ed6551f 100644 (file)
--- a/src/cmd/compile/internal/ir/expr.go
+++ b/src/cmd/compile/internal/ir/expr.go
@@ -734,7 +734,7 @@ func (n *UnaryExpr) SetOp(op Op) {
        case OBITNOT, ONEG, ONOT, OPLUS, ORECV,
                OALIGNOF, OCAP, OCLOSE, OIMAG, OLEN, ONEW,
                OOFFSETOF, OPANIC, OREAL, OSIZEOF,
-               OCHECKNIL, OCFUNC, OIDATA, OITAB, OSPTR, OVARDEF, OVARKILL, OVARLIVE:
+               OCHECKNIL, OCFUNC, OIDATA, OITAB, OSPTR, OVARDEF, OVARLIVE:
                n.op = op
        }
 }

diff --git a/src/cmd/compile/internal/ir/node.go b/src/cmd/compile/internal/ir/node.go
index 0ce5339c12d01499103b59ecb6d7100019cd56ae..4f2b66497c18294a8779b25723731ebe37c288dd 100644 (file)
--- a/src/cmd/compile/internal/ir/node.go
+++ b/src/cmd/compile/internal/ir/node.go
@@ -289,7 +289,6 @@ const (
        OCFUNC         // reference to c function pointer (not go func value)
        OCHECKNIL      // emit code to ensure pointer/interface not nil
        OVARDEF        // variable is about to be fully initialized
-       OVARKILL       // variable is dead
        OVARLIVE       // variable is alive
        ORESULT        // result of a function call; Xoffset is stack offset
        OINLMARK       // start of an inlined body, with file/line of caller. Xoffset is an index into the inline tree.

diff --git a/src/cmd/compile/internal/ir/op_string.go b/src/cmd/compile/internal/ir/op_string.go
index d2a933f9ec4cb977477ed82abed7d2afac1e1ab8..7304cb96b66bd8d53b299bf603a41ab088292081 100644 (file)
--- a/src/cmd/compile/internal/ir/op_string.go
+++ b/src/cmd/compile/internal/ir/op_string.go
@@ -147,25 +147,24 @@ func _() {
        _ = x[OCFUNC-136]
        _ = x[OCHECKNIL-137]
        _ = x[OVARDEF-138]
-       _ = x[OVARKILL-139]
-       _ = x[OVARLIVE-140]
-       _ = x[ORESULT-141]
-       _ = x[OINLMARK-142]
-       _ = x[OLINKSYMOFFSET-143]
-       _ = x[OJUMPTABLE-144]
-       _ = x[ODYNAMICDOTTYPE-145]
-       _ = x[ODYNAMICDOTTYPE2-146]
-       _ = x[ODYNAMICTYPE-147]
-       _ = x[OTAILCALL-148]
-       _ = x[OGETG-149]
-       _ = x[OGETCALLERPC-150]
-       _ = x[OGETCALLERSP-151]
-       _ = x[OEND-152]
+       _ = x[OVARLIVE-139]
+       _ = x[ORESULT-140]
+       _ = x[OINLMARK-141]
+       _ = x[OLINKSYMOFFSET-142]
+       _ = x[OJUMPTABLE-143]
+       _ = x[ODYNAMICDOTTYPE-144]
+       _ = x[ODYNAMICDOTTYPE2-145]
+       _ = x[ODYNAMICTYPE-146]
+       _ = x[OTAILCALL-147]
+       _ = x[OGETG-148]
+       _ = x[OGETCALLERPC-149]
+       _ = x[OGETCALLERSP-150]
+       _ = x[OEND-151]
 }
 
-const _Op_name = "XXXNAMENONAMETYPELITERALNILADDSUBORXORADDSTRADDRANDANDAPPENDBYTES2STRBYTES2STRTMPRUNES2STRSTR2BYTESSTR2BYTESTMPSTR2RUNESSLICE2ARRPTRASAS2AS2DOTTYPEAS2FUNCAS2MAPRAS2RECVASOPCALLCALLFUNCCALLMETHCALLINTERCAPCLOSECLOSURECOMPLITMAPLITSTRUCTLITARRAYLITSLICELITPTRLITCONVCONVIFACECONVIDATACONVNOPCOPYDCLDCLFUNCDCLCONSTDCLTYPEDELETEDOTDOTPTRDOTMETHDOTINTERXDOTDOTTYPEDOTTYPE2EQNELTLEGEGTDEREFINDEXINDEXMAPKEYSTRUCTKEYLENMAKEMAKECHANMAKEMAPMAKESLICEMAKESLICECOPYMULDIVMODLSHRSHANDANDNOTNEWNOTBITNOTPLUSNEGORORPANICPRINTPRINTNPARENSENDSLICESLICEARRSLICESTRSLICE3SLICE3ARRSLICEHEADERRECOVERRECOVERFPRECVRUNESTRSELRECV2REALIMAGCOMPLEXALIGNOFOFFSETOFSIZEOFUNSAFEADDUNSAFESLICEMETHEXPRMETHVALUEBLOCKBREAKCASECONTINUEDEFERFALLFORGOTOIFLABELGORANGERETURNSELECTSWITCHTYPESWFUNCINSTINLCALLEFACEITABIDATASPTRCFUNCCHECKNILVARDEFVARKILLVARLIVERESULTINLMARKLINKSYMOFFSETJUMPTABLEDYNAMICDOTTYPEDYNAMICDOTTYPE2DYNAMICTYPETAILCALLGETGGETCALLERPCGETCALLERSPEND"
+const _Op_name = "XXXNAMENONAMETYPELITERALNILADDSUBORXORADDSTRADDRANDANDAPPENDBYTES2STRBYTES2STRTMPRUNES2STRSTR2BYTESSTR2BYTESTMPSTR2RUNESSLICE2ARRPTRASAS2AS2DOTTYPEAS2FUNCAS2MAPRAS2RECVASOPCALLCALLFUNCCALLMETHCALLINTERCAPCLOSECLOSURECOMPLITMAPLITSTRUCTLITARRAYLITSLICELITPTRLITCONVCONVIFACECONVIDATACONVNOPCOPYDCLDCLFUNCDCLCONSTDCLTYPEDELETEDOTDOTPTRDOTMETHDOTINTERXDOTDOTTYPEDOTTYPE2EQNELTLEGEGTDEREFINDEXINDEXMAPKEYSTRUCTKEYLENMAKEMAKECHANMAKEMAPMAKESLICEMAKESLICECOPYMULDIVMODLSHRSHANDANDNOTNEWNOTBITNOTPLUSNEGORORPANICPRINTPRINTNPARENSENDSLICESLICEARRSLICESTRSLICE3SLICE3ARRSLICEHEADERRECOVERRECOVERFPRECVRUNESTRSELRECV2REALIMAGCOMPLEXALIGNOFOFFSETOFSIZEOFUNSAFEADDUNSAFESLICEMETHEXPRMETHVALUEBLOCKBREAKCASECONTINUEDEFERFALLFORGOTOIFLABELGORANGERETURNSELECTSWITCHTYPESWFUNCINSTINLCALLEFACEITABIDATASPTRCFUNCCHECKNILVARDEFVARLIVERESULTINLMARKLINKSYMOFFSETJUMPTABLEDYNAMICDOTTYPEDYNAMICDOTTYPE2DYNAMICTYPETAILCALLGETGGETCALLERPCGETCALLERSPEND"
 
-var _Op_index = [...]uint16{0, 3, 7, 13, 17, 24, 27, 30, 33, 35, 38, 44, 48, 54, 60, 69, 81, 90, 99, 111, 120, 132, 134, 137, 147, 154, 161, 168, 172, 176, 184, 192, 201, 204, 209, 216, 223, 229, 238, 246, 254, 260, 264, 273, 282, 289, 293, 296, 303, 311, 318, 324, 327, 333, 340, 348, 352, 359, 367, 369, 371, 373, 375, 377, 379, 384, 389, 397, 400, 409, 412, 416, 424, 431, 440, 453, 456, 459, 462, 465, 468, 471, 477, 480, 483, 489, 493, 496, 500, 505, 510, 516, 521, 525, 530, 538, 546, 552, 561, 572, 579, 588, 592, 599, 607, 611, 615, 622, 629, 637, 643, 652, 663, 671, 680, 685, 690, 694, 702, 707, 711, 714, 718, 720, 725, 727, 732, 738, 744, 750, 756, 764, 771, 776, 780, 785, 789, 794, 802, 808, 815, 822, 828, 835, 848, 857, 871, 886, 897, 905, 909, 920, 931, 934}
+var _Op_index = [...]uint16{0, 3, 7, 13, 17, 24, 27, 30, 33, 35, 38, 44, 48, 54, 60, 69, 81, 90, 99, 111, 120, 132, 134, 137, 147, 154, 161, 168, 172, 176, 184, 192, 201, 204, 209, 216, 223, 229, 238, 246, 254, 260, 264, 273, 282, 289, 293, 296, 303, 311, 318, 324, 327, 333, 340, 348, 352, 359, 367, 369, 371, 373, 375, 377, 379, 384, 389, 397, 400, 409, 412, 416, 424, 431, 440, 453, 456, 459, 462, 465, 468, 471, 477, 480, 483, 489, 493, 496, 500, 505, 510, 516, 521, 525, 530, 538, 546, 552, 561, 572, 579, 588, 592, 599, 607, 611, 615, 622, 629, 637, 643, 652, 663, 671, 680, 685, 690, 694, 702, 707, 711, 714, 718, 720, 725, 727, 732, 738, 744, 750, 756, 764, 771, 776, 780, 785, 789, 794, 802, 808, 815, 821, 828, 841, 850, 864, 879, 890, 898, 902, 913, 924, 927}
 
 func (i Op) String() string {
        if i >= Op(len(_Op_index)-1) {

diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go
index 7cb1da32058de7a3da139cdc44e541825718428b..3e7adeb2ab5ad123ea01a116cc022885a0623cbd 100644 (file)
--- a/src/cmd/compile/internal/ssagen/ssa.go
+++ b/src/cmd/compile/internal/ssagen/ssa.go
@@ -1384,8 +1384,8 @@ func (s *state) stmtList(l ir.Nodes) {
 
 // stmt converts the statement n to SSA and adds it to s.
 func (s *state) stmt(n ir.Node) {
-       if !(n.Op() == ir.OVARKILL || n.Op() == ir.OVARLIVE || n.Op() == ir.OVARDEF) {
-               // OVARKILL, OVARLIVE, and OVARDEF are invisible to the programmer, so we don't use their line numbers to avoid confusion in debugging.
+       if !(n.Op() == ir.OVARLIVE || n.Op() == ir.OVARDEF) {
+               // OVARLIVE and OVARDEF are invisible to the programmer, so we don't use their line numbers to avoid confusion in debugging.
                s.pushLine(n.Pos())
                defer s.popLine()
        }

diff --git a/src/cmd/compile/internal/typecheck/typecheck.go b/src/cmd/compile/internal/typecheck/typecheck.go
index 44e1b3ef78e6e7bd40f8963aa3de904fdd55af59..26b26182ce7035cd3e889a9fc8f250520137b2ff 100644 (file)
--- a/src/cmd/compile/internal/typecheck/typecheck.go
+++ b/src/cmd/compile/internal/typecheck/typecheck.go
@@ -359,7 +359,7 @@ func typecheck(n ir.Node, top int) (res ir.Node) {
        case ir.OAPPEND:
                // Must be used (and not BinaryExpr/UnaryExpr).
                isStmt = false
-       case ir.OCLOSE, ir.ODELETE, ir.OPANIC, ir.OPRINT, ir.OPRINTN, ir.OVARKILL, ir.OVARLIVE:
+       case ir.OCLOSE, ir.ODELETE, ir.OPANIC, ir.OPRINT, ir.OPRINTN, ir.OVARLIVE:
                // Must not be used.
                isExpr = false
                isStmt = true
@@ -750,7 +750,6 @@ func typecheck1(n ir.Node, top int) ir.Node {
                ir.ODCL,
                ir.OGOTO,
                ir.OFALL,
-               ir.OVARKILL,
                ir.OVARLIVE:
                return n
 

diff --git a/src/cmd/compile/internal/walk/order.go b/src/cmd/compile/internal/walk/order.go
index 774bcc2316317d3c311c1e4fb9b1eeeb5813c7b1..0300985a29f854d70f7fff18744d8cab6a15ee75 100644 (file)
--- a/src/cmd/compile/internal/walk/order.go
+++ b/src/cmd/compile/internal/walk/order.go
@@ -597,7 +597,7 @@ func (o *orderState) stmt(n ir.Node) {
        default:
                base.Fatalf("order.stmt %v", n.Op())
 
-       case ir.OVARKILL, ir.OVARLIVE, ir.OINLMARK:
+       case ir.OVARLIVE, ir.OINLMARK:
                o.out = append(o.out, n)
 
        case ir.OAS:

diff --git a/src/cmd/compile/internal/walk/stmt.go b/src/cmd/compile/internal/walk/stmt.go
index 9ddc82336cd59fbee18fc095dd420f1200daa4ac..f0000fc08167bf06465999efa46c53f3cae4d65c 100644 (file)
--- a/src/cmd/compile/internal/walk/stmt.go
+++ b/src/cmd/compile/internal/walk/stmt.go
@@ -91,7 +91,6 @@ func walkStmt(n ir.Node) ir.Node {
                ir.ODCLTYPE,
                ir.OCHECKNIL,
                ir.OVARDEF,
-               ir.OVARKILL,
                ir.OVARLIVE:
                return n
 

diff --git a/src/cmd/compile/internal/walk/switch.go b/src/cmd/compile/internal/walk/switch.go
index 257903c0b3ceff7d0fbc0ff1aa6f3a90bbd0410a..82da1562c0b39c246cfa6b31663dfb2944af1bd5 100644 (file)
--- a/src/cmd/compile/internal/walk/switch.go
+++ b/src/cmd/compile/internal/walk/switch.go
@@ -372,19 +372,10 @@ func allCaseExprsAreSideEffectFree(sw *ir.SwitchStmt) bool {
 
 // endsInFallthrough reports whether stmts ends with a "fallthrough" statement.
 func endsInFallthrough(stmts []ir.Node) (bool, src.XPos) {
-       // Search backwards for the index of the fallthrough
-       // statement. Do not assume it'll be in the last
-       // position, since in some cases (e.g. when the statement
-       // list contains autotmp_ variables), one or more OVARKILL
-       // nodes will be at the end of the list.
-
-       i := len(stmts) - 1
-       for i >= 0 && stmts[i].Op() == ir.OVARKILL {
-               i--
-       }
-       if i < 0 {
+       if len(stmts) == 0 {
                return false, src.NoXPos
        }
+       i := len(stmts) - 1
        return stmts[i].Op() == ir.OFALL, stmts[i].Pos()
 }