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>

20 files changed, 439 insertions, 204 deletions

diff --git a/src/cmd/compile/internal/escape/escape.go b/src/cmd/compile/internal/escape/escape.go
index 05bd44c35d..3ac7ff1ebe 100644
--- a/src/cmd/compile/internal/escape/escape.go
+++ b/src/cmd/compile/internal/escape/escape.go
@@ -677,7 +677,7 @@ func (e *escape) exprSkipInit(k hole, n ir.Node) {
 		n := n.(*ir.UnaryExpr)
 		e.discard(n.X)
 
-	case ir.OCALLMETH, ir.OCALLFUNC, ir.OCALLINTER, ir.OLEN, ir.OCAP, ir.OCOMPLEX, ir.OREAL, ir.OIMAG, ir.OAPPEND, ir.OCOPY:
+	case ir.OCALLMETH, ir.OCALLFUNC, ir.OCALLINTER, ir.OLEN, ir.OCAP, ir.OCOMPLEX, ir.OREAL, ir.OIMAG, ir.OAPPEND, ir.OCOPY, ir.OUNSAFEADD, ir.OUNSAFESLICE:
 		e.call([]hole{k}, n, nil)
 
 	case ir.ONEW:
@@ -1101,6 +1101,11 @@ func (e *escape) call(ks []hole, call, where ir.Node) {
 	case ir.OLEN, ir.OCAP, ir.OREAL, ir.OIMAG, ir.OCLOSE:
 		call := call.(*ir.UnaryExpr)
 		argument(e.discardHole(), call.X)
+
+	case ir.OUNSAFEADD, ir.OUNSAFESLICE:
+		call := call.(*ir.BinaryExpr)
+		argument(ks[0], call.X)
+		argument(e.discardHole(), call.Y)
 	}
 }
 
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) {
diff --git a/src/cmd/compile/internal/noder/expr.go b/src/cmd/compile/internal/noder/expr.go
index b2c2616b35..c7695ed920 100644
--- a/src/cmd/compile/internal/noder/expr.go
+++ b/src/cmd/compile/internal/noder/expr.go
@@ -29,6 +29,14 @@ func (g *irgen) expr(expr syntax.Expr) ir.Node {
 	}
 	switch {
 	case tv.IsBuiltin():
+		// Qualified builtins, such as unsafe.Add and unsafe.Slice.
+		if expr, ok := expr.(*syntax.SelectorExpr); ok {
+			if name, ok := expr.X.(*syntax.Name); ok {
+				if _, ok := g.info.Uses[name].(*types2.PkgName); ok {
+					return g.use(expr.Sel)
+				}
+			}
+		}
 		return g.use(expr.(*syntax.Name))
 	case tv.IsType():
 		return ir.TypeNode(g.typ(tv.Type))
diff --git a/src/cmd/compile/internal/noder/transform.go b/src/cmd/compile/internal/noder/transform.go
index 31f8d1d61b..2859089e69 100644
--- a/src/cmd/compile/internal/noder/transform.go
+++ b/src/cmd/compile/internal/noder/transform.go
@@ -795,11 +795,11 @@ func transformBuiltin(n *ir.CallExpr) ir.Node {
 			return u1
 		}
 
-	case ir.OCOMPLEX, ir.OCOPY:
+	case ir.OCOMPLEX, ir.OCOPY, ir.OUNSAFEADD, ir.OUNSAFESLICE:
 		transformArgs(n)
 		b := ir.NewBinaryExpr(n.Pos(), op, n.Args[0], n.Args[1])
 		n1 := typed(n.Type(), ir.InitExpr(n.Init(), b))
-		if op == ir.OCOPY {
+		if op != ir.OCOMPLEX {
 			// nothing more to do
 			return n1
 		}
diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go
index 5eda8c4b1c..0d4e3264ba 100644
--- a/src/cmd/compile/internal/ssagen/ssa.go
+++ b/src/cmd/compile/internal/ssagen/ssa.go
@@ -3196,6 +3196,12 @@ func (s *state) expr(n ir.Node) *ssa.Value {
 		n := n.(*ir.UnaryExpr)
 		return s.newObject(n.Type().Elem())
 
+	case ir.OUNSAFEADD:
+		n := n.(*ir.BinaryExpr)
+		ptr := s.expr(n.X)
+		len := s.expr(n.Y)
+		return s.newValue2(ssa.OpAddPtr, n.Type(), ptr, len)
+
 	default:
 		s.Fatalf("unhandled expr %v", n.Op())
 		return nil
diff --git a/src/cmd/compile/internal/typecheck/builtin.go b/src/cmd/compile/internal/typecheck/builtin.go
index 0631a67780..67a894c7ed 100644
--- a/src/cmd/compile/internal/typecheck/builtin.go
+++ b/src/cmd/compile/internal/typecheck/builtin.go
@@ -136,69 +136,71 @@ var runtimeDecls = [...]struct {
 	{"makeslice64", funcTag, 113},
 	{"makeslicecopy", funcTag, 114},
 	{"growslice", funcTag, 116},
-	{"memmove", funcTag, 117},
-	{"memclrNoHeapPointers", funcTag, 118},
-	{"memclrHasPointers", funcTag, 118},
-	{"memequal", funcTag, 119},
-	{"memequal0", funcTag, 120},
-	{"memequal8", funcTag, 120},
-	{"memequal16", funcTag, 120},
-	{"memequal32", funcTag, 120},
-	{"memequal64", funcTag, 120},
-	{"memequal128", funcTag, 120},
-	{"f32equal", funcTag, 121},
-	{"f64equal", funcTag, 121},
-	{"c64equal", funcTag, 121},
-	{"c128equal", funcTag, 121},
-	{"strequal", funcTag, 121},
-	{"interequal", funcTag, 121},
-	{"nilinterequal", funcTag, 121},
-	{"memhash", funcTag, 122},
-	{"memhash0", funcTag, 123},
-	{"memhash8", funcTag, 123},
-	{"memhash16", funcTag, 123},
-	{"memhash32", funcTag, 123},
-	{"memhash64", funcTag, 123},
-	{"memhash128", funcTag, 123},
-	{"f32hash", funcTag, 123},
-	{"f64hash", funcTag, 123},
-	{"c64hash", funcTag, 123},
-	{"c128hash", funcTag, 123},
-	{"strhash", funcTag, 123},
-	{"interhash", funcTag, 123},
-	{"nilinterhash", funcTag, 123},
-	{"int64div", funcTag, 124},
-	{"uint64div", funcTag, 125},
-	{"int64mod", funcTag, 124},
-	{"uint64mod", funcTag, 125},
-	{"float64toint64", funcTag, 126},
-	{"float64touint64", funcTag, 127},
-	{"float64touint32", funcTag, 128},
-	{"int64tofloat64", funcTag, 129},
-	{"uint64tofloat64", funcTag, 130},
-	{"uint32tofloat64", funcTag, 131},
-	{"complex128div", funcTag, 132},
-	{"getcallerpc", funcTag, 133},
-	{"getcallersp", funcTag, 133},
+	{"unsafeslice", funcTag, 117},
+	{"unsafeslice64", funcTag, 118},
+	{"memmove", funcTag, 119},
+	{"memclrNoHeapPointers", funcTag, 120},
+	{"memclrHasPointers", funcTag, 120},
+	{"memequal", funcTag, 121},
+	{"memequal0", funcTag, 122},
+	{"memequal8", funcTag, 122},
+	{"memequal16", funcTag, 122},
+	{"memequal32", funcTag, 122},
+	{"memequal64", funcTag, 122},
+	{"memequal128", funcTag, 122},
+	{"f32equal", funcTag, 123},
+	{"f64equal", funcTag, 123},
+	{"c64equal", funcTag, 123},
+	{"c128equal", funcTag, 123},
+	{"strequal", funcTag, 123},
+	{"interequal", funcTag, 123},
+	{"nilinterequal", funcTag, 123},
+	{"memhash", funcTag, 124},
+	{"memhash0", funcTag, 125},
+	{"memhash8", funcTag, 125},
+	{"memhash16", funcTag, 125},
+	{"memhash32", funcTag, 125},
+	{"memhash64", funcTag, 125},
+	{"memhash128", funcTag, 125},
+	{"f32hash", funcTag, 125},
+	{"f64hash", funcTag, 125},
+	{"c64hash", funcTag, 125},
+	{"c128hash", funcTag, 125},
+	{"strhash", funcTag, 125},
+	{"interhash", funcTag, 125},
+	{"nilinterhash", funcTag, 125},
+	{"int64div", funcTag, 126},
+	{"uint64div", funcTag, 127},
+	{"int64mod", funcTag, 126},
+	{"uint64mod", funcTag, 127},
+	{"float64toint64", funcTag, 128},
+	{"float64touint64", funcTag, 129},
+	{"float64touint32", funcTag, 130},
+	{"int64tofloat64", funcTag, 131},
+	{"uint64tofloat64", funcTag, 132},
+	{"uint32tofloat64", funcTag, 133},
+	{"complex128div", funcTag, 134},
+	{"getcallerpc", funcTag, 135},
+	{"getcallersp", funcTag, 135},
 	{"racefuncenter", funcTag, 31},
 	{"racefuncexit", funcTag, 9},
 	{"raceread", funcTag, 31},
 	{"racewrite", funcTag, 31},
-	{"racereadrange", funcTag, 134},
-	{"racewriterange", funcTag, 134},
-	{"msanread", funcTag, 134},
-	{"msanwrite", funcTag, 134},
-	{"msanmove", funcTag, 135},
-	{"checkptrAlignment", funcTag, 136},
-	{"checkptrArithmetic", funcTag, 138},
-	{"libfuzzerTraceCmp1", funcTag, 139},
-	{"libfuzzerTraceCmp2", funcTag, 140},
-	{"libfuzzerTraceCmp4", funcTag, 141},
-	{"libfuzzerTraceCmp8", funcTag, 142},
-	{"libfuzzerTraceConstCmp1", funcTag, 139},
-	{"libfuzzerTraceConstCmp2", funcTag, 140},
-	{"libfuzzerTraceConstCmp4", funcTag, 141},
-	{"libfuzzerTraceConstCmp8", funcTag, 142},
+	{"racereadrange", funcTag, 136},
+	{"racewriterange", funcTag, 136},
+	{"msanread", funcTag, 136},
+	{"msanwrite", funcTag, 136},
+	{"msanmove", funcTag, 137},
+	{"checkptrAlignment", funcTag, 138},
+	{"checkptrArithmetic", funcTag, 140},
+	{"libfuzzerTraceCmp1", funcTag, 141},
+	{"libfuzzerTraceCmp2", funcTag, 142},
+	{"libfuzzerTraceCmp4", funcTag, 143},
+	{"libfuzzerTraceCmp8", funcTag, 144},
+	{"libfuzzerTraceConstCmp1", funcTag, 141},
+	{"libfuzzerTraceConstCmp2", funcTag, 142},
+	{"libfuzzerTraceConstCmp4", funcTag, 143},
+	{"libfuzzerTraceConstCmp8", funcTag, 144},
 	{"x86HasPOPCNT", varTag, 6},
 	{"x86HasSSE41", varTag, 6},
 	{"x86HasFMA", varTag, 6},
@@ -221,7 +223,7 @@ func params(tlist ...*types.Type) []*types.Field {
 }
 
 func runtimeTypes() []*types.Type {
-	var typs [143]*types.Type
+	var typs [145]*types.Type
 	typs[0] = types.ByteType
 	typs[1] = types.NewPtr(typs[0])
 	typs[2] = types.Types[types.TANY]
@@ -339,31 +341,33 @@ func runtimeTypes() []*types.Type {
 	typs[114] = newSig(params(typs[1], typs[15], typs[15], typs[7]), params(typs[7]))
 	typs[115] = types.NewSlice(typs[2])
 	typs[116] = newSig(params(typs[1], typs[115], typs[15]), params(typs[115]))
-	typs[117] = newSig(params(typs[3], typs[3], typs[5]), nil)
-	typs[118] = newSig(params(typs[7], typs[5]), nil)
-	typs[119] = newSig(params(typs[3], typs[3], typs[5]), params(typs[6]))
-	typs[120] = newSig(params(typs[3], typs[3]), params(typs[6]))
-	typs[121] = newSig(params(typs[7], typs[7]), params(typs[6]))
-	typs[122] = newSig(params(typs[7], typs[5], typs[5]), params(typs[5]))
-	typs[123] = newSig(params(typs[7], typs[5]), params(typs[5]))
-	typs[124] = newSig(params(typs[22], typs[22]), params(typs[22]))
-	typs[125] = newSig(params(typs[24], typs[24]), params(typs[24]))
-	typs[126] = newSig(params(typs[20]), params(typs[22]))
-	typs[127] = newSig(params(typs[20]), params(typs[24]))
-	typs[128] = newSig(params(typs[20]), params(typs[60]))
-	typs[129] = newSig(params(typs[22]), params(typs[20]))
-	typs[130] = newSig(params(typs[24]), params(typs[20]))
-	typs[131] = newSig(params(typs[60]), params(typs[20]))
-	typs[132] = newSig(params(typs[26], typs[26]), params(typs[26]))
-	typs[133] = newSig(nil, params(typs[5]))
-	typs[134] = newSig(params(typs[5], typs[5]), nil)
-	typs[135] = newSig(params(typs[5], typs[5], typs[5]), nil)
-	typs[136] = newSig(params(typs[7], typs[1], typs[5]), nil)
-	typs[137] = types.NewSlice(typs[7])
-	typs[138] = newSig(params(typs[7], typs[137]), nil)
-	typs[139] = newSig(params(typs[64], typs[64]), nil)
-	typs[140] = newSig(params(typs[58], typs[58]), nil)
-	typs[141] = newSig(params(typs[60], typs[60]), nil)
-	typs[142] = newSig(params(typs[24], typs[24]), nil)
+	typs[117] = newSig(params(typs[1], typs[15]), nil)
+	typs[118] = newSig(params(typs[1], typs[22]), nil)
+	typs[119] = newSig(params(typs[3], typs[3], typs[5]), nil)
+	typs[120] = newSig(params(typs[7], typs[5]), nil)
+	typs[121] = newSig(params(typs[3], typs[3], typs[5]), params(typs[6]))
+	typs[122] = newSig(params(typs[3], typs[3]), params(typs[6]))
+	typs[123] = newSig(params(typs[7], typs[7]), params(typs[6]))
+	typs[124] = newSig(params(typs[7], typs[5], typs[5]), params(typs[5]))
+	typs[125] = newSig(params(typs[7], typs[5]), params(typs[5]))
+	typs[126] = newSig(params(typs[22], typs[22]), params(typs[22]))
+	typs[127] = newSig(params(typs[24], typs[24]), params(typs[24]))
+	typs[128] = newSig(params(typs[20]), params(typs[22]))
+	typs[129] = newSig(params(typs[20]), params(typs[24]))
+	typs[130] = newSig(params(typs[20]), params(typs[60]))
+	typs[131] = newSig(params(typs[22]), params(typs[20]))
+	typs[132] = newSig(params(typs[24]), params(typs[20]))
+	typs[133] = newSig(params(typs[60]), params(typs[20]))
+	typs[134] = newSig(params(typs[26], typs[26]), params(typs[26]))
+	typs[135] = newSig(nil, params(typs[5]))
+	typs[136] = newSig(params(typs[5], typs[5]), nil)
+	typs[137] = newSig(params(typs[5], typs[5], typs[5]), nil)
+	typs[138] = newSig(params(typs[7], typs[1], typs[5]), nil)
+	typs[139] = types.NewSlice(typs[7])
+	typs[140] = newSig(params(typs[7], typs[139]), nil)
+	typs[141] = newSig(params(typs[64], typs[64]), nil)
+	typs[142] = newSig(params(typs[58], typs[58]), nil)
+	typs[143] = newSig(params(typs[60], typs[60]), nil)
+	typs[144] = newSig(params(typs[24], typs[24]), nil)
 	return typs[:]
 }
diff --git a/src/cmd/compile/internal/typecheck/builtin/runtime.go b/src/cmd/compile/internal/typecheck/builtin/runtime.go
index e736f913b6..ebeaeae79e 100644
--- a/src/cmd/compile/internal/typecheck/builtin/runtime.go
+++ b/src/cmd/compile/internal/typecheck/builtin/runtime.go
@@ -183,6 +183,9 @@ func makeslice(typ *byte, len int, cap int) unsafe.Pointer
 func makeslice64(typ *byte, len int64, cap int64) unsafe.Pointer
 func makeslicecopy(typ *byte, tolen int, fromlen int, from unsafe.Pointer) unsafe.Pointer
 func growslice(typ *byte, old []any, cap int) (ary []any)
+func unsafeslice(typ *byte, len int)
+func unsafeslice64(typ *byte, len int64)
+
 func memmove(to *any, frm *any, length uintptr)
 func memclrNoHeapPointers(ptr unsafe.Pointer, n uintptr)
 func memclrHasPointers(ptr unsafe.Pointer, n uintptr)
diff --git a/src/cmd/compile/internal/typecheck/const.go b/src/cmd/compile/internal/typecheck/const.go
index 9b3a27b2d8..5a35eeade9 100644
--- a/src/cmd/compile/internal/typecheck/const.go
+++ b/src/cmd/compile/internal/typecheck/const.go
@@ -760,7 +760,9 @@ func anyCallOrChan(n ir.Node) bool {
 			ir.OPRINTN,
 			ir.OREAL,
 			ir.ORECOVER,
-			ir.ORECV:
+			ir.ORECV,
+			ir.OUNSAFEADD,
+			ir.OUNSAFESLICE:
 			return true
 		}
 		return false
diff --git a/src/cmd/compile/internal/typecheck/func.go b/src/cmd/compile/internal/typecheck/func.go
index eaae2a81fa..e154c39269 100644
--- a/src/cmd/compile/internal/typecheck/func.go
+++ b/src/cmd/compile/internal/typecheck/func.go
@@ -430,7 +430,7 @@ func tcCall(n *ir.CallExpr, top int) ir.Node {
 			u := ir.NewUnaryExpr(n.Pos(), l.BuiltinOp, arg)
 			return typecheck(ir.InitExpr(n.Init(), u), top) // typecheckargs can add to old.Init
 
-		case ir.OCOMPLEX, ir.OCOPY:
+		case ir.OCOMPLEX, ir.OCOPY, ir.OUNSAFEADD, ir.OUNSAFESLICE:
 			typecheckargs(n)
 			arg1, arg2, ok := needTwoArgs(n)
 			if !ok {
@@ -977,3 +977,39 @@ func tcRecover(n *ir.CallExpr) ir.Node {
 	n.SetType(types.Types[types.TINTER])
 	return n
 }
+
+// tcUnsafeAdd typechecks an OUNSAFEADD node.
+func tcUnsafeAdd(n *ir.BinaryExpr) *ir.BinaryExpr {
+	n.X = AssignConv(Expr(n.X), types.Types[types.TUNSAFEPTR], "argument to unsafe.Add")
+	n.Y = DefaultLit(Expr(n.Y), types.Types[types.TINT])
+	if n.X.Type() == nil || n.Y.Type() == nil {
+		n.SetType(nil)
+		return n
+	}
+	if !n.Y.Type().IsInteger() {
+		n.SetType(nil)
+		return n
+	}
+	n.SetType(n.X.Type())
+	return n
+}
+
+// tcUnsafeSlice typechecks an OUNSAFESLICE node.
+func tcUnsafeSlice(n *ir.BinaryExpr) *ir.BinaryExpr {
+	n.X = Expr(n.X)
+	n.Y = Expr(n.Y)
+	if n.X.Type() == nil || n.Y.Type() == nil {
+		n.SetType(nil)
+		return n
+	}
+	t := n.X.Type()
+	if !t.IsPtr() {
+		base.Errorf("first argument to unsafe.Slice must be pointer; have %L", t)
+	}
+	if !checkunsafeslice(&n.Y) {
+		n.SetType(nil)
+		return n
+	}
+	n.SetType(types.NewSlice(t.Elem()))
+	return n
+}
diff --git a/src/cmd/compile/internal/typecheck/iexport.go b/src/cmd/compile/internal/typecheck/iexport.go
index ad9eaab07a..64d68ef625 100644
--- a/src/cmd/compile/internal/typecheck/iexport.go
+++ b/src/cmd/compile/internal/typecheck/iexport.go
@@ -1664,7 +1664,7 @@ func (w *exportWriter) expr(n ir.Node) {
 			w.typ(n.Type())
 		}
 
-	case ir.OCOPY, ir.OCOMPLEX:
+	case ir.OCOPY, ir.OCOMPLEX, ir.OUNSAFEADD, ir.OUNSAFESLICE:
 		// treated like other builtin calls (see e.g., OREAL)
 		n := n.(*ir.BinaryExpr)
 		w.op(n.Op())
diff --git a/src/cmd/compile/internal/typecheck/iimport.go b/src/cmd/compile/internal/typecheck/iimport.go
index 642abe61ba..00f6a6e483 100644
--- a/src/cmd/compile/internal/typecheck/iimport.go
+++ b/src/cmd/compile/internal/typecheck/iimport.go
@@ -1269,10 +1269,10 @@ func (r *importReader) node() ir.Node {
 		}
 		return ir.NewConvExpr(r.pos(), op, r.typ(), r.expr())
 
-	case ir.OCOPY, ir.OCOMPLEX, ir.OREAL, ir.OIMAG, ir.OAPPEND, ir.OCAP, ir.OCLOSE, ir.ODELETE, ir.OLEN, ir.OMAKE, ir.ONEW, ir.OPANIC, ir.ORECOVER, ir.OPRINT, ir.OPRINTN:
+	case ir.OCOPY, ir.OCOMPLEX, ir.OREAL, ir.OIMAG, ir.OAPPEND, ir.OCAP, ir.OCLOSE, ir.ODELETE, ir.OLEN, ir.OMAKE, ir.ONEW, ir.OPANIC, ir.ORECOVER, ir.OPRINT, ir.OPRINTN, ir.OUNSAFEADD, ir.OUNSAFESLICE:
 		if go117ExportTypes {
 			switch op {
-			case ir.OCOPY, ir.OCOMPLEX:
+			case ir.OCOPY, ir.OCOMPLEX, ir.OUNSAFEADD, ir.OUNSAFESLICE:
 				n := ir.NewBinaryExpr(r.pos(), op, r.expr(), r.expr())
 				n.SetType(r.typ())
 				return n
diff --git a/src/cmd/compile/internal/typecheck/typecheck.go b/src/cmd/compile/internal/typecheck/typecheck.go
index 00dd44b96b..1650144375 100644
--- a/src/cmd/compile/internal/typecheck/typecheck.go
+++ b/src/cmd/compile/internal/typecheck/typecheck.go
@@ -775,6 +775,14 @@ func typecheck1(n ir.Node, top int) ir.Node {
 		n := n.(*ir.CallExpr)
 		return tcRecover(n)
 
+	case ir.OUNSAFEADD:
+		n := n.(*ir.BinaryExpr)
+		return tcUnsafeAdd(n)
+
+	case ir.OUNSAFESLICE:
+		n := n.(*ir.BinaryExpr)
+		return tcUnsafeSlice(n)
+
 	case ir.OCLOSURE:
 		n := n.(*ir.ClosureExpr)
 		tcClosure(n, top)
@@ -1934,6 +1942,35 @@ func checkmake(t *types.Type, arg string, np *ir.Node) bool {
 	return true
 }
 
+// checkunsafeslice is like checkmake but for unsafe.Slice.
+func checkunsafeslice(np *ir.Node) bool {
+	n := *np
+	if !n.Type().IsInteger() && n.Type().Kind() != types.TIDEAL {
+		base.Errorf("non-integer len argument in unsafe.Slice - %v", n.Type())
+		return false
+	}
+
+	// Do range checks for constants before DefaultLit
+	// to avoid redundant "constant NNN overflows int" errors.
+	if n.Op() == ir.OLITERAL {
+		v := toint(n.Val())
+		if constant.Sign(v) < 0 {
+			base.Errorf("negative len argument in unsafe.Slice")
+			return false
+		}
+		if ir.ConstOverflow(v, types.Types[types.TINT]) {
+			base.Errorf("len argument too large in unsafe.Slice")
+			return false
+		}
+	}
+
+	// DefaultLit is necessary for non-constants too: n might be 1.1<<k.
+	n = DefaultLit(n, types.Types[types.TINT])
+	*np = n
+
+	return true
+}
+
 // markBreak marks control statements containing break statements with SetHasBreak(true).
 func markBreak(fn *ir.Func) {
 	var labels map[*types.Sym]ir.Node
diff --git a/src/cmd/compile/internal/typecheck/universe.go b/src/cmd/compile/internal/typecheck/universe.go
index f04dcb671c..de185ab944 100644
--- a/src/cmd/compile/internal/typecheck/universe.go
+++ b/src/cmd/compile/internal/typecheck/universe.go
@@ -85,9 +85,11 @@ var unsafeFuncs = [...]struct {
 	name string
 	op   ir.Op
 }{
+	{"Add", ir.OUNSAFEADD},
 	{"Alignof", ir.OALIGNOF},
 	{"Offsetof", ir.OOFFSETOF},
 	{"Sizeof", ir.OSIZEOF},
+	{"Slice", ir.OUNSAFESLICE},
 }
 
 // InitUniverse initializes the universe block.
diff --git a/src/cmd/compile/internal/walk/builtin.go b/src/cmd/compile/internal/walk/builtin.go
index aacdedcb4d..62eb4298f4 100644
--- a/src/cmd/compile/internal/walk/builtin.go
+++ b/src/cmd/compile/internal/walk/builtin.go
@@ -653,6 +653,45 @@ func walkRecover(nn *ir.CallExpr, init *ir.Nodes) ir.Node {
 	return mkcall("gorecover", nn.Type(), init, fp)
 }
 
+func walkUnsafeSlice(n *ir.BinaryExpr, init *ir.Nodes) ir.Node {
+	len := safeExpr(n.Y, init)
+
+	fnname := "unsafeslice64"
+	argtype := types.Types[types.TINT64]
+
+	// Type checking guarantees that TIDEAL len/cap are positive and fit in an int.
+	// The case of len or cap overflow when converting TUINT or TUINTPTR to TINT
+	// will be handled by the negative range checks in unsafeslice during runtime.
+	if len.Type().IsKind(types.TIDEAL) || len.Type().Size() <= types.Types[types.TUINT].Size() {
+		fnname = "unsafeslice"
+		argtype = types.Types[types.TINT]
+	}
+
+	t := n.Type()
+
+	// Call runtime.unsafeslice[64] to check that the length argument is
+	// non-negative and smaller than the max length allowed for the
+	// element type.
+	fn := typecheck.LookupRuntime(fnname)
+	init.Append(mkcall1(fn, nil, init, reflectdata.TypePtr(t.Elem()), typecheck.Conv(len, argtype)))
+
+	ptr := walkExpr(n.X, init)
+
+	c := ir.NewUnaryExpr(n.Pos(), ir.OCHECKNIL, ptr)
+	c.SetTypecheck(1)
+	init.Append(c)
+
+	// TODO(mdempsky): checkptr instrumentation. Maybe merge into length
+	// check above, along with nil check? Need to be careful about
+	// notinheap pointers though: can't pass them as unsafe.Pointer.
+
+	h := ir.NewSliceHeaderExpr(n.Pos(), t,
+		typecheck.Conv(ptr, types.Types[types.TUNSAFEPTR]),
+		typecheck.Conv(len, types.Types[types.TINT]),
+		typecheck.Conv(len, types.Types[types.TINT]))
+	return walkExpr(typecheck.Expr(h), init)
+}
+
 func badtype(op ir.Op, tl, tr *types.Type) {
 	var s string
 	if tl != nil {
diff --git a/src/cmd/compile/internal/walk/expr.go b/src/cmd/compile/internal/walk/expr.go
index 5a1a2441bf..2fb907710b 100644
--- a/src/cmd/compile/internal/walk/expr.go
+++ b/src/cmd/compile/internal/walk/expr.go
@@ -117,12 +117,17 @@ func walkExpr1(n ir.Node, init *ir.Nodes) ir.Node {
 		n.X = walkExpr(n.X, init)
 		return n
 
-	case ir.OEFACE, ir.OAND, ir.OANDNOT, ir.OSUB, ir.OMUL, ir.OADD, ir.OOR, ir.OXOR, ir.OLSH, ir.ORSH:
+	case ir.OEFACE, ir.OAND, ir.OANDNOT, ir.OSUB, ir.OMUL, ir.OADD, ir.OOR, ir.OXOR, ir.OLSH, ir.ORSH,
+		ir.OUNSAFEADD:
 		n := n.(*ir.BinaryExpr)
 		n.X = walkExpr(n.X, init)
 		n.Y = walkExpr(n.Y, init)
 		return n
 
+	case ir.OUNSAFESLICE:
+		n := n.(*ir.BinaryExpr)
+		return walkUnsafeSlice(n, init)
+
 	case ir.ODOT, ir.ODOTPTR:
 		n := n.(*ir.SelectorExpr)
 		return walkDot(n, init)
diff --git a/src/runtime/slice.go b/src/runtime/slice.go
index c0647d95a0..f9d4154acf 100644
--- a/src/runtime/slice.go
+++ b/src/runtime/slice.go
@@ -112,6 +112,25 @@ func makeslice64(et *_type, len64, cap64 int64) unsafe.Pointer {
 	return makeslice(et, len, cap)
 }
 
+func unsafeslice(et *_type, len int) {
+	mem, overflow := math.MulUintptr(et.size, uintptr(len))
+	if overflow || mem > maxAlloc || len < 0 {
+		panicunsafeslicelen()
+	}
+}
+
+func unsafeslice64(et *_type, len64 int64) {
+	len := int(len64)
+	if int64(len) != len64 {
+		panicunsafeslicelen()
+	}
+	unsafeslice(et, len)
+}
+
+func panicunsafeslicelen() {
+	panic(errorString("unsafe.Slice: len out of range"))
+}
+
 // growslice handles slice growth during append.
 // It is passed the slice element type, the old slice, and the desired new minimum capacity,
 // and it returns a new slice with at least that capacity, with the old data
diff --git a/test/unsafebuiltins.go b/test/unsafebuiltins.go
new file mode 100644
index 0000000000..c10f8084a7
--- /dev/null
+++ b/test/unsafebuiltins.go
@@ -0,0 +1,61 @@
+// run
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"math"
+	"unsafe"
+)
+
+const maxUintptr = 1 << (8 * unsafe.Sizeof(uintptr(0)))
+
+func main() {
+	var p [10]byte
+
+	// unsafe.Add
+	{
+		p1 := unsafe.Pointer(&p[1])
+		assert(unsafe.Add(p1, 1) == unsafe.Pointer(&p[2]))
+		assert(unsafe.Add(p1, -1) == unsafe.Pointer(&p[0]))
+	}
+
+	// unsafe.Slice
+	{
+		s := unsafe.Slice(&p[0], len(p))
+		assert(&s[0] == &p[0])
+		assert(len(s) == len(p))
+		assert(cap(s) == len(p))
+
+		// nil pointer
+		mustPanic(func() { _ = unsafe.Slice((*int)(nil), 0) })
+
+		// negative length
+		var neg int = -1
+		mustPanic(func() { _ = unsafe.Slice(new(byte), neg) })
+
+		// length too large
+		var tooBig uint64 = math.MaxUint64
+		mustPanic(func() { _ = unsafe.Slice(new(byte), tooBig) })
+
+		// size overflows address space
+		mustPanic(func() { _ = unsafe.Slice(new(uint64), maxUintptr/8) })
+		mustPanic(func() { _ = unsafe.Slice(new(uint64), maxUintptr/8+1) })
+	}
+}
+
+func assert(ok bool) {
+	if !ok {
+		panic("FAIL")
+	}
+}
+
+func mustPanic(f func()) {
+	defer func() {
+		assert(recover() != nil)
+	}()
+	f()
+}