diff --git a/src/cmd/compile/internal/gc/op_string.go b/src/cmd/compile/internal/gc/op_string.go
index 41d588309c..f7d31f912c 100644
--- a/src/cmd/compile/internal/gc/op_string.go
+++ b/src/cmd/compile/internal/gc/op_string.go
@@ -14,158 +14,159 @@ func _() {
 	_ = x[OTYPE-3]
 	_ = x[OPACK-4]
 	_ = x[OLITERAL-5]
-	_ = x[OADD-6]
-	_ = x[OSUB-7]
-	_ = x[OOR-8]
-	_ = x[OXOR-9]
-	_ = x[OADDSTR-10]
-	_ = x[OADDR-11]
-	_ = x[OANDAND-12]
-	_ = x[OAPPEND-13]
-	_ = x[OBYTES2STR-14]
-	_ = x[OBYTES2STRTMP-15]
-	_ = x[ORUNES2STR-16]
-	_ = x[OSTR2BYTES-17]
-	_ = x[OSTR2BYTESTMP-18]
-	_ = x[OSTR2RUNES-19]
-	_ = x[OAS-20]
-	_ = x[OAS2-21]
-	_ = x[OAS2DOTTYPE-22]
-	_ = x[OAS2FUNC-23]
-	_ = x[OAS2MAPR-24]
-	_ = x[OAS2RECV-25]
-	_ = x[OASOP-26]
-	_ = x[OCALL-27]
-	_ = x[OCALLFUNC-28]
-	_ = x[OCALLMETH-29]
-	_ = x[OCALLINTER-30]
-	_ = x[OCALLPART-31]
-	_ = x[OCAP-32]
-	_ = x[OCLOSE-33]
-	_ = x[OCLOSURE-34]
-	_ = x[OCOMPLIT-35]
-	_ = x[OMAPLIT-36]
-	_ = x[OSTRUCTLIT-37]
-	_ = x[OARRAYLIT-38]
-	_ = x[OSLICELIT-39]
-	_ = x[OPTRLIT-40]
-	_ = x[OCONV-41]
-	_ = x[OCONVIFACE-42]
-	_ = x[OCONVNOP-43]
-	_ = x[OCOPY-44]
-	_ = x[ODCL-45]
-	_ = x[ODCLFUNC-46]
-	_ = x[ODCLFIELD-47]
-	_ = x[ODCLCONST-48]
-	_ = x[ODCLTYPE-49]
-	_ = x[ODELETE-50]
-	_ = x[ODOT-51]
-	_ = x[ODOTPTR-52]
-	_ = x[ODOTMETH-53]
-	_ = x[ODOTINTER-54]
-	_ = x[OXDOT-55]
-	_ = x[ODOTTYPE-56]
-	_ = x[ODOTTYPE2-57]
-	_ = x[OEQ-58]
-	_ = x[ONE-59]
-	_ = x[OLT-60]
-	_ = x[OLE-61]
-	_ = x[OGE-62]
-	_ = x[OGT-63]
-	_ = x[ODEREF-64]
-	_ = x[OINDEX-65]
-	_ = x[OINDEXMAP-66]
-	_ = x[OKEY-67]
-	_ = x[OSTRUCTKEY-68]
-	_ = x[OLEN-69]
-	_ = x[OMAKE-70]
-	_ = x[OMAKECHAN-71]
-	_ = x[OMAKEMAP-72]
-	_ = x[OMAKESLICE-73]
-	_ = x[OMAKESLICECOPY-74]
-	_ = x[OMUL-75]
-	_ = x[ODIV-76]
-	_ = x[OMOD-77]
-	_ = x[OLSH-78]
-	_ = x[ORSH-79]
-	_ = x[OAND-80]
-	_ = x[OANDNOT-81]
-	_ = x[ONEW-82]
-	_ = x[ONEWOBJ-83]
-	_ = x[ONOT-84]
-	_ = x[OBITNOT-85]
-	_ = x[OPLUS-86]
-	_ = x[ONEG-87]
-	_ = x[OOROR-88]
-	_ = x[OPANIC-89]
-	_ = x[OPRINT-90]
-	_ = x[OPRINTN-91]
-	_ = x[OPAREN-92]
-	_ = x[OSEND-93]
-	_ = x[OSLICE-94]
-	_ = x[OSLICEARR-95]
-	_ = x[OSLICESTR-96]
-	_ = x[OSLICE3-97]
-	_ = x[OSLICE3ARR-98]
-	_ = x[OSLICEHEADER-99]
-	_ = x[ORECOVER-100]
-	_ = x[ORECV-101]
-	_ = x[ORUNESTR-102]
-	_ = x[OSELRECV-103]
-	_ = x[OSELRECV2-104]
-	_ = x[OIOTA-105]
-	_ = x[OREAL-106]
-	_ = x[OIMAG-107]
-	_ = x[OCOMPLEX-108]
-	_ = x[OALIGNOF-109]
-	_ = x[OOFFSETOF-110]
-	_ = x[OSIZEOF-111]
-	_ = x[OBLOCK-112]
-	_ = x[OBREAK-113]
-	_ = x[OCASE-114]
-	_ = x[OCONTINUE-115]
-	_ = x[ODEFER-116]
-	_ = x[OEMPTY-117]
-	_ = x[OFALL-118]
-	_ = x[OFOR-119]
-	_ = x[OFORUNTIL-120]
-	_ = x[OGOTO-121]
-	_ = x[OIF-122]
-	_ = x[OLABEL-123]
-	_ = x[OGO-124]
-	_ = x[ORANGE-125]
-	_ = x[ORETURN-126]
-	_ = x[OSELECT-127]
-	_ = x[OSWITCH-128]
-	_ = x[OTYPESW-129]
-	_ = x[OTCHAN-130]
-	_ = x[OTMAP-131]
-	_ = x[OTSTRUCT-132]
-	_ = x[OTINTER-133]
-	_ = x[OTFUNC-134]
-	_ = x[OTARRAY-135]
-	_ = x[ODDD-136]
-	_ = x[OINLCALL-137]
-	_ = x[OEFACE-138]
-	_ = x[OITAB-139]
-	_ = x[OIDATA-140]
-	_ = x[OSPTR-141]
-	_ = x[OCLOSUREVAR-142]
-	_ = x[OCFUNC-143]
-	_ = x[OCHECKNIL-144]
-	_ = x[OVARDEF-145]
-	_ = x[OVARKILL-146]
-	_ = x[OVARLIVE-147]
-	_ = x[ORESULT-148]
-	_ = x[OINLMARK-149]
-	_ = x[ORETJMP-150]
-	_ = x[OGETG-151]
-	_ = x[OEND-152]
+	_ = x[ONIL-6]
+	_ = x[OADD-7]
+	_ = x[OSUB-8]
+	_ = x[OOR-9]
+	_ = x[OXOR-10]
+	_ = x[OADDSTR-11]
+	_ = x[OADDR-12]
+	_ = x[OANDAND-13]
+	_ = x[OAPPEND-14]
+	_ = x[OBYTES2STR-15]
+	_ = x[OBYTES2STRTMP-16]
+	_ = x[ORUNES2STR-17]
+	_ = x[OSTR2BYTES-18]
+	_ = x[OSTR2BYTESTMP-19]
+	_ = x[OSTR2RUNES-20]
+	_ = x[OAS-21]
+	_ = x[OAS2-22]
+	_ = x[OAS2DOTTYPE-23]
+	_ = x[OAS2FUNC-24]
+	_ = x[OAS2MAPR-25]
+	_ = x[OAS2RECV-26]
+	_ = x[OASOP-27]
+	_ = x[OCALL-28]
+	_ = x[OCALLFUNC-29]
+	_ = x[OCALLMETH-30]
+	_ = x[OCALLINTER-31]
+	_ = x[OCALLPART-32]
+	_ = x[OCAP-33]
+	_ = x[OCLOSE-34]
+	_ = x[OCLOSURE-35]
+	_ = x[OCOMPLIT-36]
+	_ = x[OMAPLIT-37]
+	_ = x[OSTRUCTLIT-38]
+	_ = x[OARRAYLIT-39]
+	_ = x[OSLICELIT-40]
+	_ = x[OPTRLIT-41]
+	_ = x[OCONV-42]
+	_ = x[OCONVIFACE-43]
+	_ = x[OCONVNOP-44]
+	_ = x[OCOPY-45]
+	_ = x[ODCL-46]
+	_ = x[ODCLFUNC-47]
+	_ = x[ODCLFIELD-48]
+	_ = x[ODCLCONST-49]
+	_ = x[ODCLTYPE-50]
+	_ = x[ODELETE-51]
+	_ = x[ODOT-52]
+	_ = x[ODOTPTR-53]
+	_ = x[ODOTMETH-54]
+	_ = x[ODOTINTER-55]
+	_ = x[OXDOT-56]
+	_ = x[ODOTTYPE-57]
+	_ = x[ODOTTYPE2-58]
+	_ = x[OEQ-59]
+	_ = x[ONE-60]
+	_ = x[OLT-61]
+	_ = x[OLE-62]
+	_ = x[OGE-63]
+	_ = x[OGT-64]
+	_ = x[ODEREF-65]
+	_ = x[OINDEX-66]
+	_ = x[OINDEXMAP-67]
+	_ = x[OKEY-68]
+	_ = x[OSTRUCTKEY-69]
+	_ = x[OLEN-70]
+	_ = x[OMAKE-71]
+	_ = x[OMAKECHAN-72]
+	_ = x[OMAKEMAP-73]
+	_ = x[OMAKESLICE-74]
+	_ = x[OMAKESLICECOPY-75]
+	_ = x[OMUL-76]
+	_ = x[ODIV-77]
+	_ = x[OMOD-78]
+	_ = x[OLSH-79]
+	_ = x[ORSH-80]
+	_ = x[OAND-81]
+	_ = x[OANDNOT-82]
+	_ = x[ONEW-83]
+	_ = x[ONEWOBJ-84]
+	_ = x[ONOT-85]
+	_ = x[OBITNOT-86]
+	_ = x[OPLUS-87]
+	_ = x[ONEG-88]
+	_ = x[OOROR-89]
+	_ = x[OPANIC-90]
+	_ = x[OPRINT-91]
+	_ = x[OPRINTN-92]
+	_ = x[OPAREN-93]
+	_ = x[OSEND-94]
+	_ = x[OSLICE-95]
+	_ = x[OSLICEARR-96]
+	_ = x[OSLICESTR-97]
+	_ = x[OSLICE3-98]
+	_ = x[OSLICE3ARR-99]
+	_ = x[OSLICEHEADER-100]
+	_ = x[ORECOVER-101]
+	_ = x[ORECV-102]
+	_ = x[ORUNESTR-103]
+	_ = x[OSELRECV-104]
+	_ = x[OSELRECV2-105]
+	_ = x[OIOTA-106]
+	_ = x[OREAL-107]
+	_ = x[OIMAG-108]
+	_ = x[OCOMPLEX-109]
+	_ = x[OALIGNOF-110]
+	_ = x[OOFFSETOF-111]
+	_ = x[OSIZEOF-112]
+	_ = x[OBLOCK-113]
+	_ = x[OBREAK-114]
+	_ = x[OCASE-115]
+	_ = x[OCONTINUE-116]
+	_ = x[ODEFER-117]
+	_ = x[OEMPTY-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[OTCHAN-131]
+	_ = x[OTMAP-132]
+	_ = x[OTSTRUCT-133]
+	_ = x[OTINTER-134]
+	_ = x[OTFUNC-135]
+	_ = x[OTARRAY-136]
+	_ = x[ODDD-137]
+	_ = x[OINLCALL-138]
+	_ = x[OEFACE-139]
+	_ = x[OITAB-140]
+	_ = x[OIDATA-141]
+	_ = x[OSPTR-142]
+	_ = x[OCLOSUREVAR-143]
+	_ = x[OCFUNC-144]
+	_ = x[OCHECKNIL-145]
+	_ = x[OVARDEF-146]
+	_ = x[OVARKILL-147]
+	_ = x[OVARLIVE-148]
+	_ = x[ORESULT-149]
+	_ = x[OINLMARK-150]
+	_ = x[ORETJMP-151]
+	_ = x[OGETG-152]
+	_ = x[OEND-153]
 }
 
-const _Op_name = "XXXNAMENONAMETYPEPACKLITERALADDSUBORXORADDSTRADDRANDANDAPPENDBYTES2STRBYTES2STRTMPRUNES2STRSTR2BYTESSTR2BYTESTMPSTR2RUNESASAS2AS2DOTTYPEAS2FUNCAS2MAPRAS2RECVASOPCALLCALLFUNCCALLMETHCALLINTERCALLPARTCAPCLOSECLOSURECOMPLITMAPLITSTRUCTLITARRAYLITSLICELITPTRLITCONVCONVIFACECONVNOPCOPYDCLDCLFUNCDCLFIELDDCLCONSTDCLTYPEDELETEDOTDOTPTRDOTMETHDOTINTERXDOTDOTTYPEDOTTYPE2EQNELTLEGEGTDEREFINDEXINDEXMAPKEYSTRUCTKEYLENMAKEMAKECHANMAKEMAPMAKESLICEMAKESLICECOPYMULDIVMODLSHRSHANDANDNOTNEWNEWOBJNOTBITNOTPLUSNEGORORPANICPRINTPRINTNPARENSENDSLICESLICEARRSLICESTRSLICE3SLICE3ARRSLICEHEADERRECOVERRECVRUNESTRSELRECVSELRECV2IOTAREALIMAGCOMPLEXALIGNOFOFFSETOFSIZEOFBLOCKBREAKCASECONTINUEDEFEREMPTYFALLFORFORUNTILGOTOIFLABELGORANGERETURNSELECTSWITCHTYPESWTCHANTMAPTSTRUCTTINTERTFUNCTARRAYDDDINLCALLEFACEITABIDATASPTRCLOSUREVARCFUNCCHECKNILVARDEFVARKILLVARLIVERESULTINLMARKRETJMPGETGEND"
+const _Op_name = "XXXNAMENONAMETYPEPACKLITERALNILADDSUBORXORADDSTRADDRANDANDAPPENDBYTES2STRBYTES2STRTMPRUNES2STRSTR2BYTESSTR2BYTESTMPSTR2RUNESASAS2AS2DOTTYPEAS2FUNCAS2MAPRAS2RECVASOPCALLCALLFUNCCALLMETHCALLINTERCALLPARTCAPCLOSECLOSURECOMPLITMAPLITSTRUCTLITARRAYLITSLICELITPTRLITCONVCONVIFACECONVNOPCOPYDCLDCLFUNCDCLFIELDDCLCONSTDCLTYPEDELETEDOTDOTPTRDOTMETHDOTINTERXDOTDOTTYPEDOTTYPE2EQNELTLEGEGTDEREFINDEXINDEXMAPKEYSTRUCTKEYLENMAKEMAKECHANMAKEMAPMAKESLICEMAKESLICECOPYMULDIVMODLSHRSHANDANDNOTNEWNEWOBJNOTBITNOTPLUSNEGORORPANICPRINTPRINTNPARENSENDSLICESLICEARRSLICESTRSLICE3SLICE3ARRSLICEHEADERRECOVERRECVRUNESTRSELRECVSELRECV2IOTAREALIMAGCOMPLEXALIGNOFOFFSETOFSIZEOFBLOCKBREAKCASECONTINUEDEFEREMPTYFALLFORFORUNTILGOTOIFLABELGORANGERETURNSELECTSWITCHTYPESWTCHANTMAPTSTRUCTTINTERTFUNCTARRAYDDDINLCALLEFACEITABIDATASPTRCLOSUREVARCFUNCCHECKNILVARDEFVARKILLVARLIVERESULTINLMARKRETJMPGETGEND"
 
-var _Op_index = [...]uint16{0, 3, 7, 13, 17, 21, 28, 31, 34, 36, 39, 45, 49, 55, 61, 70, 82, 91, 100, 112, 121, 123, 126, 136, 143, 150, 157, 161, 165, 173, 181, 190, 198, 201, 206, 213, 220, 226, 235, 243, 251, 257, 261, 270, 277, 281, 284, 291, 299, 307, 314, 320, 323, 329, 336, 344, 348, 355, 363, 365, 367, 369, 371, 373, 375, 380, 385, 393, 396, 405, 408, 412, 420, 427, 436, 449, 452, 455, 458, 461, 464, 467, 473, 476, 482, 485, 491, 495, 498, 502, 507, 512, 518, 523, 527, 532, 540, 548, 554, 563, 574, 581, 585, 592, 599, 607, 611, 615, 619, 626, 633, 641, 647, 652, 657, 661, 669, 674, 679, 683, 686, 694, 698, 700, 705, 707, 712, 718, 724, 730, 736, 741, 745, 752, 758, 763, 769, 772, 779, 784, 788, 793, 797, 807, 812, 820, 826, 833, 840, 846, 853, 859, 863, 866}
+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, 310, 317, 323, 326, 332, 339, 347, 351, 358, 366, 368, 370, 372, 374, 376, 378, 383, 388, 396, 399, 408, 411, 415, 423, 430, 439, 452, 455, 458, 461, 464, 467, 470, 476, 479, 485, 488, 494, 498, 501, 505, 510, 515, 521, 526, 530, 535, 543, 551, 557, 566, 577, 584, 588, 595, 602, 610, 614, 618, 622, 629, 636, 644, 650, 655, 660, 664, 672, 677, 682, 686, 689, 697, 701, 703, 708, 710, 715, 721, 727, 733, 739, 744, 748, 755, 761, 766, 772, 775, 782, 787, 791, 796, 800, 810, 815, 823, 829, 836, 843, 849, 856, 862, 866, 869}
 
 func (i Op) String() string {
 	if i >= Op(len(_Op_index)-1) {
diff --git a/src/cmd/compile/internal/gc/syntax.go b/src/cmd/compile/internal/gc/syntax.go
index e46a0dadf3..b86510a294 100644
--- a/src/cmd/compile/internal/gc/syntax.go
+++ b/src/cmd/compile/internal/gc/syntax.go
@@ -758,6 +758,7 @@ const (
 	OTYPE    // type name
 	OPACK    // import
 	OLITERAL // literal
+	ONIL     // nil
 
 	// expressions
 	OADD          // Left + Right