cmd/compile/internal/ssagen: call AllocFrame after ssa.Compile

This indirection is no longer necessary.

Change-Id: Ibb5eb1753febdc17a93ea9c35130e3d2b26c360e
Reviewed-on: https://go-review.googlesource.com/c/go/+/526518
Reviewed-by: Keith Randall <khr@google.com>
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@golang.org>

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

@@ -508,7 +508,6 @@ var passes = [...]pass{
 	{name: "flagalloc", fn: flagalloc, required: true}, // allocate flags register
 	{name: "regalloc", fn: regalloc, required: true},   // allocate int & float registers + stack slots
 	{name: "loop rotate", fn: loopRotate},
-	{name: "stackframe", fn: stackframe, required: true},
 	{name: "trim", fn: trim}, // remove empty blocks
 }
 
@@ -577,8 +576,6 @@ var passOrder = [...]constraint{
 	{"flagalloc", "regalloc"},
 	// loopRotate will confuse regalloc.
 	{"regalloc", "loop rotate"},
-	// stackframe needs to know about spilled registers.
-	{"regalloc", "stackframe"},
 	// trim needs regalloc to be done first.
 	{"regalloc", "trim"},
 	// memcombine works better if fuse happens first, to help merge stores.

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

@@ -154,9 +154,6 @@ type Frontend interface {
 	// for the parts of that compound type.
 	SplitSlot(parent *LocalSlot, suffix string, offset int64, t *types.Type) LocalSlot
 
-	// AllocFrame assigns frame offsets to all live auto variables.
-	AllocFrame(f *Func)
-
 	// Syslook returns a symbol of the runtime function/variable with the
 	// given name.
 	Syslook(string) *obj.LSym

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

@@ -89,8 +89,6 @@ func (TestFrontend) Auto(pos src.XPos, t *types.Type) *ir.Name {
 func (d TestFrontend) SplitSlot(parent *LocalSlot, suffix string, offset int64, t *types.Type) LocalSlot {
 	return LocalSlot{N: parent.N, Type: t, Off: offset}
 }
-func (TestFrontend) AllocFrame(f *Func) {
-}
 func (d TestFrontend) Syslook(s string) *obj.LSym {
 	return d.ctxt.Lookup(s)
 }

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

@@ -1,10 +0,0 @@
-// Copyright 2016 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 ssa
-
-// stackframe calls back into the frontend to assign frame offsets.
-func stackframe(f *Func) {
-	f.fe.AllocFrame(f)
-}

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

@@ -566,6 +566,8 @@ func buildssa(fn *ir.Func, worker int) *ssa.Func {
 	// Main call to ssa package to compile function
 	ssa.Compile(s.f)
 
+	fe.AllocFrame(s.f)
+
 	if len(s.openDefers) != 0 {
 		s.emitOpenDeferInfo()
 	}