cmd/compile: do more type conversion inline

The code to do the conversion is smaller than the
call to the runtime.
The 1-result asserts need to call panic if they fail, but that
code is out of line.

The only conversions left in the runtime are those which
might allocate and those which might need to generate an itab.

Given the following types:
  type E interface{}
  type I interface { foo() }
  type I2 iterface { foo(); bar() }
  type Big [10]int
  func (b Big) foo() { ... }

This CL inlines the following conversions:

was assertE2T
  var e E = ...
  b := i.(Big)
was assertE2T2
  var e E = ...
  b, ok := i.(Big)
was assertI2T
  var i I = ...
  b := i.(Big)
was assertI2T2
  var i I = ...
  b, ok := i.(Big)
was assertI2E
  var i I = ...
  e := i.(E)
was assertI2E2
  var i I = ...
  e, ok := i.(E)

These are the remaining runtime calls:

convT2E:
  var b Big = ...
  var e E = b
convT2I:
  var b Big = ...
  var i I = b
convI2I:
  var i2 I2 = ...
  var i I = i2
assertE2I:
  var e E = ...
  i := e.(I)
assertE2I2:
  var e E = ...
  i, ok := e.(I)
assertI2I:
  var i I = ...
  i2 := i.(I2)
assertI2I2:
  var i I = ...
  i2, ok := i.(I2)

Fixes #17405
Fixes #8422

Change-Id: Ida2367bf8ce3cd2c6bb599a1814f1d275afabe21
Reviewed-on: https://go-review.googlesource.com/32313
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>

src/cmd/compile/internal/gc/builtin.go

@@ -49,19 +49,12 @@ var runtimeDecls = [...]struct {
 	{"convI2I", funcTag, 53},
 	{"convT2E", funcTag, 54},
 	{"convT2I", funcTag, 54},
-	{"assertE2E", funcTag, 55},
-	{"assertE2E2", funcTag, 56},
-	{"assertE2I", funcTag, 55},
-	{"assertE2I2", funcTag, 56},
-	{"assertE2T", funcTag, 55},
-	{"assertE2T2", funcTag, 56},
-	{"assertI2E", funcTag, 55},
-	{"assertI2E2", funcTag, 56},
-	{"assertI2I", funcTag, 55},
-	{"assertI2I2", funcTag, 56},
-	{"assertI2T", funcTag, 55},
-	{"assertI2T2", funcTag, 56},
-	{"panicdottype", funcTag, 57},
+	{"assertE2I", funcTag, 53},
+	{"assertE2I2", funcTag, 55},
+	{"assertI2I", funcTag, 53},
+	{"assertI2I2", funcTag, 55},
+	{"panicdottype", funcTag, 56},
+	{"panicnildottype", funcTag, 57},
 	{"ifaceeq", funcTag, 58},
 	{"efaceeq", funcTag, 58},
 	{"makemap", funcTag, 60},
@@ -97,43 +90,43 @@ var runtimeDecls = [...]struct {
 	{"selectrecv", funcTag, 73},
 	{"selectrecv2", funcTag, 86},
 	{"selectdefault", funcTag, 87},
-	{"selectgo", funcTag, 88},
+	{"selectgo", funcTag, 57},
 	{"block", funcTag, 5},
-	{"makeslice", funcTag, 90},
-	{"makeslice64", funcTag, 91},
-	{"growslice", funcTag, 92},
-	{"memmove", funcTag, 93},
-	{"memclrNoHeapPointers", funcTag, 94},
-	{"memclrHasPointers", funcTag, 94},
-	{"memequal", funcTag, 95},
-	{"memequal8", funcTag, 96},
-	{"memequal16", funcTag, 96},
-	{"memequal32", funcTag, 96},
-	{"memequal64", funcTag, 96},
-	{"memequal128", funcTag, 96},
-	{"int64div", funcTag, 97},
-	{"uint64div", funcTag, 98},
-	{"int64mod", funcTag, 97},
-	{"uint64mod", funcTag, 98},
-	{"float64toint64", funcTag, 99},
-	{"float64touint64", funcTag, 100},
-	{"float64touint32", funcTag, 102},
-	{"int64tofloat64", funcTag, 103},
-	{"uint64tofloat64", funcTag, 104},
-	{"uint32tofloat64", funcTag, 105},
-	{"complex128div", funcTag, 106},
-	{"racefuncenter", funcTag, 107},
+	{"makeslice", funcTag, 89},
+	{"makeslice64", funcTag, 90},
+	{"growslice", funcTag, 91},
+	{"memmove", funcTag, 92},
+	{"memclrNoHeapPointers", funcTag, 93},
+	{"memclrHasPointers", funcTag, 93},
+	{"memequal", funcTag, 94},
+	{"memequal8", funcTag, 95},
+	{"memequal16", funcTag, 95},
+	{"memequal32", funcTag, 95},
+	{"memequal64", funcTag, 95},
+	{"memequal128", funcTag, 95},
+	{"int64div", funcTag, 96},
+	{"uint64div", funcTag, 97},
+	{"int64mod", funcTag, 96},
+	{"uint64mod", funcTag, 97},
+	{"float64toint64", funcTag, 98},
+	{"float64touint64", funcTag, 99},
+	{"float64touint32", funcTag, 101},
+	{"int64tofloat64", funcTag, 102},
+	{"uint64tofloat64", funcTag, 103},
+	{"uint32tofloat64", funcTag, 104},
+	{"complex128div", funcTag, 105},
+	{"racefuncenter", funcTag, 106},
 	{"racefuncexit", funcTag, 5},
-	{"raceread", funcTag, 107},
-	{"racewrite", funcTag, 107},
-	{"racereadrange", funcTag, 108},
-	{"racewriterange", funcTag, 108},
-	{"msanread", funcTag, 108},
-	{"msanwrite", funcTag, 108},
+	{"raceread", funcTag, 106},
+	{"racewrite", funcTag, 106},
+	{"racereadrange", funcTag, 107},
+	{"racewriterange", funcTag, 107},
+	{"msanread", funcTag, 107},
+	{"msanwrite", funcTag, 107},
 }
 
 func runtimeTypes() []*Type {
-	var typs [109]*Type
+	var typs [108]*Type
 	typs[0] = bytetype
 	typs[1] = typPtr(typs[0])
 	typs[2] = Types[TANY]
@@ -189,9 +182,9 @@ func runtimeTypes() []*Type {
 	typs[52] = functype(nil, []*Node{anonfield(typs[2]), anonfield(typs[2])}, []*Node{anonfield(typs[33])})
 	typs[53] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[2])}, []*Node{anonfield(typs[2])})
 	typs[54] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[3])}, []*Node{anonfield(typs[2])})
-	typs[55] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[2]), anonfield(typs[3])}, nil)
-	typs[56] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[2]), anonfield(typs[3])}, []*Node{anonfield(typs[13])})
-	typs[57] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[1]), anonfield(typs[1])}, nil)
+	typs[55] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[2])}, []*Node{anonfield(typs[2]), anonfield(typs[13])})
+	typs[56] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[1]), anonfield(typs[1])}, nil)
+	typs[57] = functype(nil, []*Node{anonfield(typs[1])}, nil)
 	typs[58] = functype(nil, []*Node{anonfield(typs[2]), anonfield(typs[2])}, []*Node{anonfield(typs[13])})
 	typs[59] = typMap(typs[2], typs[2])
 	typs[60] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[17]), anonfield(typs[3]), anonfield(typs[3])}, []*Node{anonfield(typs[59])})
@@ -222,26 +215,25 @@ func runtimeTypes() []*Type {
 	typs[85] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[17]), anonfield(typs[10])}, nil)
 	typs[86] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[71]), anonfield(typs[3]), anonfield(typs[83])}, []*Node{anonfield(typs[13])})
 	typs[87] = functype(nil, []*Node{anonfield(typs[1])}, []*Node{anonfield(typs[13])})
-	typs[88] = functype(nil, []*Node{anonfield(typs[1])}, nil)
-	typs[89] = typSlice(typs[2])
-	typs[90] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[33]), anonfield(typs[33])}, []*Node{anonfield(typs[89])})
-	typs[91] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[17]), anonfield(typs[17])}, []*Node{anonfield(typs[89])})
-	typs[92] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[89]), anonfield(typs[33])}, []*Node{anonfield(typs[89])})
-	typs[93] = functype(nil, []*Node{anonfield(typs[3]), anonfield(typs[3]), anonfield(typs[50])}, nil)
-	typs[94] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[50])}, nil)
-	typs[95] = functype(nil, []*Node{anonfield(typs[3]), anonfield(typs[3]), anonfield(typs[50])}, []*Node{anonfield(typs[13])})
-	typs[96] = functype(nil, []*Node{anonfield(typs[3]), anonfield(typs[3])}, []*Node{anonfield(typs[13])})
-	typs[97] = functype(nil, []*Node{anonfield(typs[17]), anonfield(typs[17])}, []*Node{anonfield(typs[17])})
-	typs[98] = functype(nil, []*Node{anonfield(typs[19]), anonfield(typs[19])}, []*Node{anonfield(typs[19])})
-	typs[99] = functype(nil, []*Node{anonfield(typs[15])}, []*Node{anonfield(typs[17])})
-	typs[100] = functype(nil, []*Node{anonfield(typs[15])}, []*Node{anonfield(typs[19])})
-	typs[101] = Types[TUINT32]
-	typs[102] = functype(nil, []*Node{anonfield(typs[15])}, []*Node{anonfield(typs[101])})
-	typs[103] = functype(nil, []*Node{anonfield(typs[17])}, []*Node{anonfield(typs[15])})
-	typs[104] = functype(nil, []*Node{anonfield(typs[19])}, []*Node{anonfield(typs[15])})
-	typs[105] = functype(nil, []*Node{anonfield(typs[101])}, []*Node{anonfield(typs[15])})
-	typs[106] = functype(nil, []*Node{anonfield(typs[21]), anonfield(typs[21])}, []*Node{anonfield(typs[21])})
-	typs[107] = functype(nil, []*Node{anonfield(typs[50])}, nil)
-	typs[108] = functype(nil, []*Node{anonfield(typs[50]), anonfield(typs[50])}, nil)
+	typs[88] = typSlice(typs[2])
+	typs[89] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[33]), anonfield(typs[33])}, []*Node{anonfield(typs[88])})
+	typs[90] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[17]), anonfield(typs[17])}, []*Node{anonfield(typs[88])})
+	typs[91] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[88]), anonfield(typs[33])}, []*Node{anonfield(typs[88])})
+	typs[92] = functype(nil, []*Node{anonfield(typs[3]), anonfield(typs[3]), anonfield(typs[50])}, nil)
+	typs[93] = functype(nil, []*Node{anonfield(typs[1]), anonfield(typs[50])}, nil)
+	typs[94] = functype(nil, []*Node{anonfield(typs[3]), anonfield(typs[3]), anonfield(typs[50])}, []*Node{anonfield(typs[13])})
+	typs[95] = functype(nil, []*Node{anonfield(typs[3]), anonfield(typs[3])}, []*Node{anonfield(typs[13])})
+	typs[96] = functype(nil, []*Node{anonfield(typs[17]), anonfield(typs[17])}, []*Node{anonfield(typs[17])})
+	typs[97] = functype(nil, []*Node{anonfield(typs[19]), anonfield(typs[19])}, []*Node{anonfield(typs[19])})
+	typs[98] = functype(nil, []*Node{anonfield(typs[15])}, []*Node{anonfield(typs[17])})
+	typs[99] = functype(nil, []*Node{anonfield(typs[15])}, []*Node{anonfield(typs[19])})
+	typs[100] = Types[TUINT32]
+	typs[101] = functype(nil, []*Node{anonfield(typs[15])}, []*Node{anonfield(typs[100])})
+	typs[102] = functype(nil, []*Node{anonfield(typs[17])}, []*Node{anonfield(typs[15])})
+	typs[103] = functype(nil, []*Node{anonfield(typs[19])}, []*Node{anonfield(typs[15])})
+	typs[104] = functype(nil, []*Node{anonfield(typs[100])}, []*Node{anonfield(typs[15])})
+	typs[105] = functype(nil, []*Node{anonfield(typs[21]), anonfield(typs[21])}, []*Node{anonfield(typs[21])})
+	typs[106] = functype(nil, []*Node{anonfield(typs[50])}, nil)
+	typs[107] = functype(nil, []*Node{anonfield(typs[50]), anonfield(typs[50])}, nil)
 	return typs[:]
 }

src/cmd/compile/internal/gc/builtin/runtime.go

@@ -62,19 +62,12 @@ func convT2E(typ *byte, elem *any) (ret any)
 func convT2I(tab *byte, elem *any) (ret any)
 
 // interface type assertions  x.(T)
-func assertE2E(typ *byte, iface any, ret *any)
-func assertE2E2(typ *byte, iface any, ret *any) bool
-func assertE2I(typ *byte, iface any, ret *any)
-func assertE2I2(typ *byte, iface any, ret *any) bool
-func assertE2T(typ *byte, iface any, ret *any)
-func assertE2T2(typ *byte, iface any, ret *any) bool
-func assertI2E(typ *byte, iface any, ret *any)
-func assertI2E2(typ *byte, iface any, ret *any) bool
-func assertI2I(typ *byte, iface any, ret *any)
-func assertI2I2(typ *byte, iface any, ret *any) bool
-func assertI2T(typ *byte, iface any, ret *any)
-func assertI2T2(typ *byte, iface any, ret *any) bool
+func assertE2I(typ *byte, iface any) (ret any)
+func assertE2I2(typ *byte, iface any) (ret any, b bool)
+func assertI2I(typ *byte, iface any) (ret any)
+func assertI2I2(typ *byte, iface any) (ret any, b bool)
 func panicdottype(have, want, iface *byte)
+func panicnildottype(want *byte)
 
 func ifaceeq(i1 any, i2 any) (ret bool)
 func efaceeq(i1 any, i2 any) (ret bool)

src/cmd/compile/internal/gc/go.go

@@ -363,18 +363,18 @@ var pcloc int32
 
 var Thearch Arch
 
-var Newproc *Node
-
-var Deferproc *Node
-
-var Deferreturn *Node
-
-var panicindex *Node
-
-var panicslice *Node
-
-var panicdivide *Node
-
-var growslice *Node
-
-var panicdottype *Node
+var (
+	Newproc,
+	Deferproc,
+	Deferreturn,
+	panicindex,
+	panicslice,
+	panicdivide,
+	growslice,
+	panicdottype,
+	panicnildottype,
+	assertE2I,
+	assertE2I2,
+	assertI2I,
+	assertI2I2 *Node
+)

src/cmd/compile/internal/gc/pgen.go

@@ -304,6 +304,11 @@ func compile(fn *Node) {
 		panicdivide = Sysfunc("panicdivide")
 		growslice = Sysfunc("growslice")
 		panicdottype = Sysfunc("panicdottype")
+		panicnildottype = Sysfunc("panicnildottype")
+		assertE2I = Sysfunc("assertE2I")
+		assertE2I2 = Sysfunc("assertE2I2")
+		assertI2I = Sysfunc("assertI2I")
+		assertI2I2 = Sysfunc("assertI2I2")
 	}
 
 	defer func(lno int32) {

src/cmd/compile/internal/gc/racewalk.go

@@ -318,6 +318,15 @@ func instrumentnode(np **Node, init *Nodes, wr int, skip int) {
 		instrumentnode(&n.Left, init, 0, 0)
 		goto ret
 
+	case OAS2DOTTYPE:
+		instrumentnode(&n.Left, init, 1, 0)
+		instrumentnode(&n.Right, init, 0, 0)
+		goto ret
+
+	case ODOTTYPE, ODOTTYPE2:
+		instrumentnode(&n.Left, init, 0, 0)
+		goto ret
+
 		// should not appear in AST by now
 	case OSEND,
 		ORECV,
@@ -345,9 +354,6 @@ func instrumentnode(np **Node, init *Nodes, wr int, skip int) {
 		// lowered to call
 		OCMPSTR,
 		OADDSTR,
-		ODOTTYPE,
-		ODOTTYPE2,
-		OAS2DOTTYPE,
 		OCALLPART,
 		// lowered to PTRLIT
 		OCLOSURE,  // lowered to PTRLIT