cmd/compile: implement unsafe.Add and unsafe.Slice

Updates #19367.
Updates #40481.

Change-Id: Iabd2afdd0d520e5d68fd9e6dedd013335a4b3886
Reviewed-on: https://go-review.googlesource.com/c/go/+/312214
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Trust: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>

4 files changed, 117 insertions, 109 deletions

diff --git a/src/cmd/compile/internal/ir/expr.go b/src/cmd/compile/internal/ir/expr.go
index 94255116a0..f70645f079 100644
--- a/src/cmd/compile/internal/ir/expr.go
+++ b/src/cmd/compile/internal/ir/expr.go
@@ -136,7 +136,7 @@ func (n *BinaryExpr) SetOp(op Op) {
 		panic(n.no("SetOp " + op.String()))
 	case OADD, OADDSTR, OAND, OANDNOT, ODIV, OEQ, OGE, OGT, OLE,
 		OLSH, OLT, OMOD, OMUL, ONE, OOR, ORSH, OSUB, OXOR,
-		OCOPY, OCOMPLEX,
+		OCOPY, OCOMPLEX, OUNSAFEADD, OUNSAFESLICE,
 		OEFACE:
 		n.op = op
 	}
diff --git a/src/cmd/compile/internal/ir/fmt.go b/src/cmd/compile/internal/ir/fmt.go
index 8eb1cffc59..f2ae0f7606 100644
--- a/src/cmd/compile/internal/ir/fmt.go
+++ b/src/cmd/compile/internal/ir/fmt.go
@@ -25,69 +25,71 @@ import (
 // Op
 
 var OpNames = []string{
-	OADDR:     "&",
-	OADD:      "+",
-	OADDSTR:   "+",
-	OALIGNOF:  "unsafe.Alignof",
-	OANDAND:   "&&",
-	OANDNOT:   "&^",
-	OAND:      "&",
-	OAPPEND:   "append",
-	OAS:       "=",
-	OAS2:      "=",
-	OBREAK:    "break",
-	OCALL:     "function call", // not actual syntax
-	OCAP:      "cap",
-	OCASE:     "case",
-	OCLOSE:    "close",
-	OCOMPLEX:  "complex",
-	OBITNOT:   "^",
-	OCONTINUE: "continue",
-	OCOPY:     "copy",
-	ODELETE:   "delete",
-	ODEFER:    "defer",
-	ODIV:      "/",
-	OEQ:       "==",
-	OFALL:     "fallthrough",
-	OFOR:      "for",
-	OFORUNTIL: "foruntil", // not actual syntax; used to avoid off-end pointer live on backedge.892
-	OGE:       ">=",
-	OGOTO:     "goto",
-	OGT:       ">",
-	OIF:       "if",
-	OIMAG:     "imag",
-	OINLMARK:  "inlmark",
-	ODEREF:    "*",
-	OLEN:      "len",
-	OLE:       "<=",
-	OLSH:      "<<",
-	OLT:       "<",
-	OMAKE:     "make",
-	ONEG:      "-",
-	OMOD:      "%",
-	OMUL:      "*",
-	ONEW:      "new",
-	ONE:       "!=",
-	ONOT:      "!",
-	OOFFSETOF: "unsafe.Offsetof",
-	OOROR:     "||",
-	OOR:       "|",
-	OPANIC:    "panic",
-	OPLUS:     "+",
-	OPRINTN:   "println",
-	OPRINT:    "print",
-	ORANGE:    "range",
-	OREAL:     "real",
-	ORECV:     "<-",
-	ORECOVER:  "recover",
-	ORETURN:   "return",
-	ORSH:      ">>",
-	OSELECT:   "select",
-	OSEND:     "<-",
-	OSIZEOF:   "unsafe.Sizeof",
-	OSUB:      "-",
-	OSWITCH:   "switch",
-	OXOR:      "^",
+	OADDR:        "&",
+	OADD:         "+",
+	OADDSTR:      "+",
+	OALIGNOF:     "unsafe.Alignof",
+	OANDAND:      "&&",
+	OANDNOT:      "&^",
+	OAND:         "&",
+	OAPPEND:      "append",
+	OAS:          "=",
+	OAS2:         "=",
+	OBREAK:       "break",
+	OCALL:        "function call", // not actual syntax
+	OCAP:         "cap",
+	OCASE:        "case",
+	OCLOSE:       "close",
+	OCOMPLEX:     "complex",
+	OBITNOT:      "^",
+	OCONTINUE:    "continue",
+	OCOPY:        "copy",
+	ODELETE:      "delete",
+	ODEFER:       "defer",
+	ODIV:         "/",
+	OEQ:          "==",
+	OFALL:        "fallthrough",
+	OFOR:         "for",
+	OFORUNTIL:    "foruntil", // not actual syntax; used to avoid off-end pointer live on backedge.892
+	OGE:          ">=",
+	OGOTO:        "goto",
+	OGT:          ">",
+	OIF:          "if",
+	OIMAG:        "imag",
+	OINLMARK:     "inlmark",
+	ODEREF:       "*",
+	OLEN:         "len",
+	OLE:          "<=",
+	OLSH:         "<<",
+	OLT:          "<",
+	OMAKE:        "make",
+	ONEG:         "-",
+	OMOD:         "%",
+	OMUL:         "*",
+	ONEW:         "new",
+	ONE:          "!=",
+	ONOT:         "!",
+	OOFFSETOF:    "unsafe.Offsetof",
+	OOROR:        "||",
+	OOR:          "|",
+	OPANIC:       "panic",
+	OPLUS:        "+",
+	OPRINTN:      "println",
+	OPRINT:       "print",
+	ORANGE:       "range",
+	OREAL:        "real",
+	ORECV:        "<-",
+	ORECOVER:     "recover",
+	ORETURN:      "return",
+	ORSH:         ">>",
+	OSELECT:      "select",
+	OSEND:        "<-",
+	OSIZEOF:      "unsafe.Sizeof",
+	OSUB:         "-",
+	OSWITCH:      "switch",
+	OUNSAFEADD:   "unsafe.Add",
+	OUNSAFESLICE: "unsafe.Slice",
+	OXOR:         "^",
 }
 
 // GoString returns the Go syntax for the Op, or else its name.
@@ -218,6 +220,8 @@ var OpPrec = []int{
 	OTMAP:          8,
 	OTSTRUCT:       8,
 	OTYPE:          8,
+	OUNSAFEADD:     8,
+	OUNSAFESLICE:   8,
 	OINDEXMAP:      8,
 	OINDEX:         8,
 	OSLICE:         8,
@@ -794,7 +798,7 @@ func exprFmt(n Node, s fmt.State, prec int) {
 		n := n.(*SliceHeaderExpr)
 		fmt.Fprintf(s, "sliceheader{%v,%v,%v}", n.Ptr, n.Len, n.Cap)
 
-	case OCOMPLEX, OCOPY:
+	case OCOMPLEX, OCOPY, OUNSAFEADD, OUNSAFESLICE:
 		n := n.(*BinaryExpr)
 		fmt.Fprintf(s, "%v(%v, %v)", n.Op(), n.X, n.Y)
 
diff --git a/src/cmd/compile/internal/ir/node.go b/src/cmd/compile/internal/ir/node.go
index a73b81d196..af559cc082 100644
--- a/src/cmd/compile/internal/ir/node.go
+++ b/src/cmd/compile/internal/ir/node.go
@@ -247,6 +247,8 @@ const (
 	OALIGNOF     // unsafe.Alignof(X)
 	OOFFSETOF    // unsafe.Offsetof(X)
 	OSIZEOF      // unsafe.Sizeof(X)
+	OUNSAFEADD   // unsafe.Add(X, Y)
+	OUNSAFESLICE // unsafe.Slice(X, Y)
 	OMETHEXPR    // method expression
 
 	// statements
diff --git a/src/cmd/compile/internal/ir/op_string.go b/src/cmd/compile/internal/ir/op_string.go
index 776a5c1e8d..405a0c6b3c 100644
--- a/src/cmd/compile/internal/ir/op_string.go
+++ b/src/cmd/compile/internal/ir/op_string.go
@@ -119,53 +119,55 @@ func _() {
 	_ = x[OALIGNOF-108]
 	_ = x[OOFFSETOF-109]
 	_ = x[OSIZEOF-110]
-	_ = x[OMETHEXPR-111]
-	_ = x[OBLOCK-112]
-	_ = x[OBREAK-113]
-	_ = x[OCASE-114]
-	_ = x[OCONTINUE-115]
-	_ = x[ODEFER-116]
-	_ = x[OFALL-117]
-	_ = x[OFOR-118]
-	_ = x[OFORUNTIL-119]
-	_ = x[OGOTO-120]
-	_ = x[OIF-121]
-	_ = x[OLABEL-122]
-	_ = x[OGO-123]
-	_ = x[ORANGE-124]
-	_ = x[ORETURN-125]
-	_ = x[OSELECT-126]
-	_ = x[OSWITCH-127]
-	_ = x[OTYPESW-128]
-	_ = x[OFUNCINST-129]
-	_ = x[OTCHAN-130]
-	_ = x[OTMAP-131]
-	_ = x[OTSTRUCT-132]
-	_ = x[OTINTER-133]
-	_ = x[OTFUNC-134]
-	_ = x[OTARRAY-135]
-	_ = x[OTSLICE-136]
-	_ = x[OINLCALL-137]
-	_ = x[OEFACE-138]
-	_ = x[OITAB-139]
-	_ = x[OIDATA-140]
-	_ = x[OSPTR-141]
-	_ = x[OCFUNC-142]
-	_ = x[OCHECKNIL-143]
-	_ = x[OVARDEF-144]
-	_ = x[OVARKILL-145]
-	_ = x[OVARLIVE-146]
-	_ = x[ORESULT-147]
-	_ = x[OINLMARK-148]
-	_ = x[OLINKSYMOFFSET-149]
-	_ = x[OTAILCALL-150]
-	_ = x[OGETG-151]
-	_ = x[OEND-152]
+	_ = x[OUNSAFEADD-111]
+	_ = x[OUNSAFESLICE-112]
+	_ = x[OMETHEXPR-113]
+	_ = x[OBLOCK-114]
+	_ = x[OBREAK-115]
+	_ = x[OCASE-116]
+	_ = x[OCONTINUE-117]
+	_ = x[ODEFER-118]
+	_ = x[OFALL-119]
+	_ = x[OFOR-120]
+	_ = x[OFORUNTIL-121]
+	_ = x[OGOTO-122]
+	_ = x[OIF-123]
+	_ = x[OLABEL-124]
+	_ = x[OGO-125]
+	_ = x[ORANGE-126]
+	_ = x[ORETURN-127]
+	_ = x[OSELECT-128]
+	_ = x[OSWITCH-129]
+	_ = x[OTYPESW-130]
+	_ = x[OFUNCINST-131]
+	_ = x[OTCHAN-132]
+	_ = x[OTMAP-133]
+	_ = x[OTSTRUCT-134]
+	_ = x[OTINTER-135]
+	_ = x[OTFUNC-136]
+	_ = x[OTARRAY-137]
+	_ = x[OTSLICE-138]
+	_ = x[OINLCALL-139]
+	_ = x[OEFACE-140]
+	_ = x[OITAB-141]
+	_ = x[OIDATA-142]
+	_ = x[OSPTR-143]
+	_ = x[OCFUNC-144]
+	_ = x[OCHECKNIL-145]
+	_ = x[OVARDEF-146]
+	_ = x[OVARKILL-147]
+	_ = x[OVARLIVE-148]
+	_ = x[ORESULT-149]
+	_ = x[OINLMARK-150]
+	_ = x[OLINKSYMOFFSET-151]
+	_ = x[OTAILCALL-152]
+	_ = x[OGETG-153]
+	_ = x[OEND-154]
 }
 
-const _Op_name = "XXXNAMENONAMETYPEPACKLITERALNILADDSUBORXORADDSTRADDRANDANDAPPENDBYTES2STRBYTES2STRTMPRUNES2STRSTR2BYTESSTR2BYTESTMPSTR2RUNESSLICE2ARRPTRASAS2AS2DOTTYPEAS2FUNCAS2MAPRAS2RECVASOPCALLCALLFUNCCALLMETHCALLINTERCALLPARTCAPCLOSECLOSURECOMPLITMAPLITSTRUCTLITARRAYLITSLICELITPTRLITCONVCONVIFACECONVNOPCOPYDCLDCLFUNCDCLCONSTDCLTYPEDELETEDOTDOTPTRDOTMETHDOTINTERXDOTDOTTYPEDOTTYPE2EQNELTLEGEGTDEREFINDEXINDEXMAPKEYSTRUCTKEYLENMAKEMAKECHANMAKEMAPMAKESLICEMAKESLICECOPYMULDIVMODLSHRSHANDANDNOTNEWNOTBITNOTPLUSNEGORORPANICPRINTPRINTNPARENSENDSLICESLICEARRSLICESTRSLICE3SLICE3ARRSLICEHEADERRECOVERRECVRUNESTRSELRECV2IOTAREALIMAGCOMPLEXALIGNOFOFFSETOFSIZEOFMETHEXPRBLOCKBREAKCASECONTINUEDEFERFALLFORFORUNTILGOTOIFLABELGORANGERETURNSELECTSWITCHTYPESWFUNCINSTTCHANTMAPTSTRUCTTINTERTFUNCTARRAYTSLICEINLCALLEFACEITABIDATASPTRCFUNCCHECKNILVARDEFVARKILLVARLIVERESULTINLMARKLINKSYMOFFSETTAILCALLGETGEND"
+const _Op_name = "XXXNAMENONAMETYPEPACKLITERALNILADDSUBORXORADDSTRADDRANDANDAPPENDBYTES2STRBYTES2STRTMPRUNES2STRSTR2BYTESSTR2BYTESTMPSTR2RUNESSLICE2ARRPTRASAS2AS2DOTTYPEAS2FUNCAS2MAPRAS2RECVASOPCALLCALLFUNCCALLMETHCALLINTERCALLPARTCAPCLOSECLOSURECOMPLITMAPLITSTRUCTLITARRAYLITSLICELITPTRLITCONVCONVIFACECONVNOPCOPYDCLDCLFUNCDCLCONSTDCLTYPEDELETEDOTDOTPTRDOTMETHDOTINTERXDOTDOTTYPEDOTTYPE2EQNELTLEGEGTDEREFINDEXINDEXMAPKEYSTRUCTKEYLENMAKEMAKECHANMAKEMAPMAKESLICEMAKESLICECOPYMULDIVMODLSHRSHANDANDNOTNEWNOTBITNOTPLUSNEGORORPANICPRINTPRINTNPARENSENDSLICESLICEARRSLICESTRSLICE3SLICE3ARRSLICEHEADERRECOVERRECVRUNESTRSELRECV2IOTAREALIMAGCOMPLEXALIGNOFOFFSETOFSIZEOFUNSAFEADDUNSAFESLICEMETHEXPRBLOCKBREAKCASECONTINUEDEFERFALLFORFORUNTILGOTOIFLABELGORANGERETURNSELECTSWITCHTYPESWFUNCINSTTCHANTMAPTSTRUCTTINTERTFUNCTARRAYTSLICEINLCALLEFACEITABIDATASPTRCFUNCCHECKNILVARDEFVARKILLVARLIVERESULTINLMARKLINKSYMOFFSETTAILCALLGETGEND"
 
-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, 136, 138, 141, 151, 158, 165, 172, 176, 180, 188, 196, 205, 213, 216, 221, 228, 235, 241, 250, 258, 266, 272, 276, 285, 292, 296, 299, 306, 314, 321, 327, 330, 336, 343, 351, 355, 362, 370, 372, 374, 376, 378, 380, 382, 387, 392, 400, 403, 412, 415, 419, 427, 434, 443, 456, 459, 462, 465, 468, 471, 474, 480, 483, 486, 492, 496, 499, 503, 508, 513, 519, 524, 528, 533, 541, 549, 555, 564, 575, 582, 586, 593, 601, 605, 609, 613, 620, 627, 635, 641, 649, 654, 659, 663, 671, 676, 680, 683, 691, 695, 697, 702, 704, 709, 715, 721, 727, 733, 741, 746, 750, 757, 763, 768, 774, 780, 787, 792, 796, 801, 805, 810, 818, 824, 831, 838, 844, 851, 864, 872, 876, 879}
+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, 136, 138, 141, 151, 158, 165, 172, 176, 180, 188, 196, 205, 213, 216, 221, 228, 235, 241, 250, 258, 266, 272, 276, 285, 292, 296, 299, 306, 314, 321, 327, 330, 336, 343, 351, 355, 362, 370, 372, 374, 376, 378, 380, 382, 387, 392, 400, 403, 412, 415, 419, 427, 434, 443, 456, 459, 462, 465, 468, 471, 474, 480, 483, 486, 492, 496, 499, 503, 508, 513, 519, 524, 528, 533, 541, 549, 555, 564, 575, 582, 586, 593, 601, 605, 609, 613, 620, 627, 635, 641, 650, 661, 669, 674, 679, 683, 691, 696, 700, 703, 711, 715, 717, 722, 724, 729, 735, 741, 747, 753, 761, 766, 770, 777, 783, 788, 794, 800, 807, 812, 816, 821, 825, 830, 838, 844, 851, 858, 864, 871, 884, 892, 896, 899}
 
 func (i Op) String() string {
 	if i >= Op(len(_Op_index)-1) {