cmd/compile/internal/ssa: replace Frontend.Auto with Func.NewLocal

Change-Id: I0858568d225daba1c318842dc0c9b5e652dff612
Reviewed-on: https://go-review.googlesource.com/c/go/+/526519
Auto-Submit: Matthew Dempsky <mdempsky@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>

src/cmd/compile/internal/ssa/config.go

@@ -146,10 +146,6 @@ type Frontend interface {
 	// StringData returns a symbol pointing to the given string's contents.
 	StringData(string) *obj.LSym
 
-	// Auto returns a Node for an auto variable of the given type.
-	// The SSA compiler uses this function to allocate space for spills.
-	Auto(src.XPos, *types.Type) *ir.Name
-
 	// Given the name for a compound type, returns the name we should use
 	// for the parts of that compound type.
 	SplitSlot(parent *LocalSlot, suffix string, offset int64, t *types.Type) LocalSlot

src/cmd/compile/internal/ssa/cse_test.go

@@ -6,7 +6,6 @@ package ssa
 
 import (
 	"cmd/compile/internal/types"
-	"cmd/internal/src"
 	"testing"
 )
 
@@ -22,7 +21,7 @@ func TestCSEAuxPartitionBug(t *testing.T) {
 	arg1Aux := &tstAux{"arg1-aux"}
 	arg2Aux := &tstAux{"arg2-aux"}
 	arg3Aux := &tstAux{"arg3-aux"}
-	a := c.Frontend().Auto(src.NoXPos, c.config.Types.Int8.PtrTo())
+	a := c.Temp(c.config.Types.Int8.PtrTo())
 
 	// construct lots of values with args that have aux values and place
 	// them in an order that triggers the bug
@@ -93,7 +92,7 @@ func TestCSEAuxPartitionBug(t *testing.T) {
 // TestZCSE tests the zero arg cse.
 func TestZCSE(t *testing.T) {
 	c := testConfig(t)
-	a := c.Frontend().Auto(src.NoXPos, c.config.Types.Int8.PtrTo())
+	a := c.Temp(c.config.Types.Int8.PtrTo())
 
 	fun := c.Fun("entry",
 		Bloc("entry",

src/cmd/compile/internal/ssa/export_test.go

@@ -70,6 +70,12 @@ func (c *Conf) Frontend() Frontend {
 	return c.fe
 }
 
+func (c *Conf) Temp(typ *types.Type) *ir.Name {
+	n := ir.NewNameAt(src.NoXPos, &types.Sym{Name: "aFakeAuto"}, typ)
+	n.Class = ir.PAUTO
+	return n
+}
+
 // TestFrontend is a test-only frontend.
 // It assumes 64 bit integers and pointers.
 type TestFrontend struct {
@@ -81,11 +87,6 @@ type TestFrontend struct {
 func (TestFrontend) StringData(s string) *obj.LSym {
 	return nil
 }
-func (TestFrontend) Auto(pos src.XPos, t *types.Type) *ir.Name {
-	n := ir.NewNameAt(pos, &types.Sym{Name: "aFakeAuto"}, t)
-	n.Class = ir.PAUTO
-	return n
-}
 func (d TestFrontend) SplitSlot(parent *LocalSlot, suffix string, offset int64, t *types.Type) LocalSlot {
 	return LocalSlot{N: parent.N, Type: t, Off: offset}
 }

src/cmd/compile/internal/ssa/func.go

@@ -7,6 +7,8 @@ package ssa
 import (
 	"cmd/compile/internal/abi"
 	"cmd/compile/internal/base"
+	"cmd/compile/internal/ir"
+	"cmd/compile/internal/typecheck"
 	"cmd/compile/internal/types"
 	"cmd/internal/src"
 	"fmt"
@@ -818,3 +820,8 @@ func (f *Func) useFMA(v *Value) bool {
 	}
 	return base.FmaHash.MatchPos(v.Pos, nil)
 }
+
+// NewLocal returns a new anonymous local variable of the given type.
+func (f *Func) NewLocal(pos src.XPos, typ *types.Type) *ir.Name {
+	return typecheck.TempAt(pos, f.fe.Func(), typ) // Note: adds new auto to fn.Dcl list
+}

src/cmd/compile/internal/ssa/regalloc.go

@@ -2544,7 +2544,7 @@ func (e *edgeState) findRegFor(typ *types.Type) Location {
 					// Allocate a temp location to spill a register to.
 					// The type of the slot is immaterial - it will not be live across
 					// any safepoint. Just use a type big enough to hold any register.
-					t := LocalSlot{N: e.s.f.fe.Auto(c.Pos, types.Int64), Type: types.Int64}
+					t := LocalSlot{N: e.s.f.NewLocal(c.Pos, types.Int64), Type: types.Int64}
 					// TODO: reuse these slots. They'll need to be erased first.
 					e.set(t, vid, x, false, c.Pos)
 					if e.s.f.pass.debug > regDebug {

src/cmd/compile/internal/ssa/regalloc_test.go

@@ -6,7 +6,6 @@ package ssa
 
 import (
 	"cmd/compile/internal/types"
-	"cmd/internal/src"
 	"testing"
 )
 
@@ -53,7 +52,7 @@ func TestNoGetgLoadReg(t *testing.T) {
 	f := c.Fun("b1",
 		Bloc("b1",
 			Valu("v1", OpInitMem, types.TypeMem, 0, nil),
-			Valu("v6", OpArg, c.config.Types.Int64, 0, c.Frontend().Auto(src.NoXPos, c.config.Types.Int64)),
+			Valu("v6", OpArg, c.config.Types.Int64, 0, c.Temp(c.config.Types.Int64)),
 			Valu("v8", OpGetG, c.config.Types.Int64.PtrTo(), 0, nil, "v1"),
 			Valu("v11", OpARM64CMPconst, types.TypeFlags, 0, nil, "v6"),
 			Eq("v11", "b2", "b4"),
@@ -92,8 +91,8 @@ func TestSpillWithLoop(t *testing.T) {
 	f := c.Fun("entry",
 		Bloc("entry",
 			Valu("mem", OpInitMem, types.TypeMem, 0, nil),
-			Valu("ptr", OpArg, c.config.Types.Int64.PtrTo(), 0, c.Frontend().Auto(src.NoXPos, c.config.Types.Int64)),
-			Valu("cond", OpArg, c.config.Types.Bool, 0, c.Frontend().Auto(src.NoXPos, c.config.Types.Bool)),
+			Valu("ptr", OpArg, c.config.Types.Int64.PtrTo(), 0, c.Temp(c.config.Types.Int64)),
+			Valu("cond", OpArg, c.config.Types.Bool, 0, c.Temp(c.config.Types.Bool)),
 			Valu("ld", OpAMD64MOVQload, c.config.Types.Int64, 0, nil, "ptr", "mem"), // this value needs a spill
 			Goto("loop"),
 		),
@@ -125,8 +124,8 @@ func TestSpillMove1(t *testing.T) {
 	f := c.Fun("entry",
 		Bloc("entry",
 			Valu("mem", OpInitMem, types.TypeMem, 0, nil),
-			Valu("x", OpArg, c.config.Types.Int64, 0, c.Frontend().Auto(src.NoXPos, c.config.Types.Int64)),
-			Valu("p", OpArg, c.config.Types.Int64.PtrTo(), 0, c.Frontend().Auto(src.NoXPos, c.config.Types.Int64.PtrTo())),
+			Valu("x", OpArg, c.config.Types.Int64, 0, c.Temp(c.config.Types.Int64)),
+			Valu("p", OpArg, c.config.Types.Int64.PtrTo(), 0, c.Temp(c.config.Types.Int64.PtrTo())),
 			Valu("a", OpAMD64TESTQ, types.TypeFlags, 0, nil, "x", "x"),
 			Goto("loop1"),
 		),
@@ -174,8 +173,8 @@ func TestSpillMove2(t *testing.T) {
 	f := c.Fun("entry",
 		Bloc("entry",
 			Valu("mem", OpInitMem, types.TypeMem, 0, nil),
-			Valu("x", OpArg, c.config.Types.Int64, 0, c.Frontend().Auto(src.NoXPos, c.config.Types.Int64)),
-			Valu("p", OpArg, c.config.Types.Int64.PtrTo(), 0, c.Frontend().Auto(src.NoXPos, c.config.Types.Int64.PtrTo())),
+			Valu("x", OpArg, c.config.Types.Int64, 0, c.Temp(c.config.Types.Int64)),
+			Valu("p", OpArg, c.config.Types.Int64.PtrTo(), 0, c.Temp(c.config.Types.Int64.PtrTo())),
 			Valu("a", OpAMD64TESTQ, types.TypeFlags, 0, nil, "x", "x"),
 			Goto("loop1"),
 		),

src/cmd/compile/internal/ssa/stackalloc.go

@@ -280,7 +280,7 @@ func (s *stackAllocState) stackalloc() {
 			// If there is no unused stack slot, allocate a new one.
 			if i == len(locs) {
 				s.nAuto++
-				locs = append(locs, LocalSlot{N: f.fe.Auto(v.Pos, v.Type), Type: v.Type, Off: 0})
+				locs = append(locs, LocalSlot{N: f.NewLocal(v.Pos, v.Type), Type: v.Type, Off: 0})
 				locations[v.Type] = locs
 			}
 			// Use the stack variable at that index for v.

src/cmd/compile/internal/ssa/writebarrier.go

@@ -319,7 +319,7 @@ func writebarrier(f *Func) {
 						}
 
 						t := val.Type.Elem()
-						tmp := f.fe.Auto(w.Pos, t)
+						tmp := f.NewLocal(w.Pos, t)
 						mem = b.NewValue1A(w.Pos, OpVarDef, types.TypeMem, tmp, mem)
 						tmpaddr := b.NewValue2A(w.Pos, OpLocalAddr, t.PtrTo(), tmp, sp, mem)
 						siz := t.Size()

src/cmd/compile/internal/ssagen/ssa.go

@@ -7918,10 +7918,6 @@ func (e *ssafn) StringData(s string) *obj.LSym {
 	return data
 }
 
-func (e *ssafn) Auto(pos src.XPos, t *types.Type) *ir.Name {
-	return typecheck.TempAt(pos, e.curfn, t) // Note: adds new auto to e.curfn.Func.Dcl list
-}
-
 // SplitSlot returns a slot representing the data of parent starting at offset.
 func (e *ssafn) SplitSlot(parent *ssa.LocalSlot, suffix string, offset int64, t *types.Type) ssa.LocalSlot {
 	node := parent.N